Podcasts about igfbp

ReferencesChitnis MM, Yuen JS, Protheroe AS, et al. The type 1 insulin-like growth factor receptor pathway.Clin Cancer Res 2008,14:6364-6370.Werner H, Bruchim I. The insulin-like growth factor-I receptor as an oncogene.Arch Physiol Biochem 2009, 115:58-71.Davies M, Gupta S, Goldspink G, Winslet M. The insulin-like growth factor system and colorectal cancer: clinical and experimental evidence.Int J Colorectal Dis 2006, 21:201-208.Sandhu MS, Dunger DB, Giovannucci EL. Insulin, insulin-like growth factor-I (IGF-I), IGF binding proteins, their biologic interactions, and colorectal cancer.J Natl Cancer Inst 2002, 94:972-980.Kaaks R. Nutrition, insulin, IGF-1 metabolism and cancer risk: a summary of epidemiological evidence.Novartis Found Symp 2004, 262:247-260; discussion 260-268.Lamberts SW, van den Beld AW, van der Lely AJ. The endocrinology of aging.Science 1997, 278:419-424.Doi T, Shimada H, Makizako H, et al. Association of insulin-like growth factor-1 with mild cognitive impairment and slow gait speed.Neurobiol Aging 2015, 36:942-947.Calvo D, Gunstad J, Miller LA, et al. Higher serum insulin-like growth factor-1 is associated with better cognitive performance in persons with mild cognitive impairment.Psychogeriatrics 2013, 13:170-174.Thissen JP, Ketelslegers JM, Underwood LE. Nutritional regulation of the insulin-like growth factors.Endocr Rev 1994,15:80-101.Clemmons DR, Seek MM, Underwood LE. Supplemental essential amino acids augment the somatomedin-C/insulin-like growth factor I response to refeeding after fasting.Metabolism 1985, 34:391-395.Runchey SS, Pollak MN, Valsta LM, et al. Glycemic load effect on fasting and post-prandial serum glucose, insulin, IGF-1 and IGFBP-3 in a randomized, controlled feeding study.Eur J Clin Nutr 2012, 66:1146-1152.Brand-Miller JC, Liu V, Petocz P, Baxter RC. The glycemic index of foods influences postprandial insulin-like growth factor-binding protein responses in lean young subjects.Am J Clin Nutr 2005, 82:350-354.Biddinger SB, Ludwig DS. The insulin-like growth factor axis: a potential link between glycemic index and cancer.Am J Clin Nutr 2005, 82:277-278.Burgers AM, Biermasz NR, Schoones JW, et al. Meta-analysis and dose-response metaregression: circulating insulin-like growth factor I (IGF-I) and mortality.J Clin Endocrinol Metab 2011, 96:2912-2920.Ranke MB, Osterziel KJ, Schweizer R, et al. Reference levels of insulin-like growth factor I in the serum of healthy adults: comparison of four immunoassays.Clin Chem Lab Med 2003, 41:1329-1334.Bidlingmaier M, Friedrich N, Emeny RT, et al. Reference intervals for insulin-like growth factor-1 (igf-i) from birth to senescence: results from a multicenter study using a new automated chemiluminescence IGF-I immunoassay conforming to recent international recommendations.J Clin Endocrinol Metab 2014, 99:1712-1721.Brabant G, von zur Muhlen A, Wuster C, et al. Serum insulin-like growth factor I reference values for an automated chemiluminescence immunoassay system: results from a multicenter study.Horm Res 2003, 60:53-60.Crowe FL, Key TJ, Allen NE, et al. The association between diet and serum concentrations of IGF-I, IGFBP-1, IGFBP-2, and IGFBP-3 in the European Prospective Investigation into Cancer and Nutrition.Cancer Epidemiol Biomarkers Prev 2009,18:1333-1340.Fontana L, Klein S, Holloszy JO. Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk.Am J Clin Nutr 2006, 84:1456-1462.Fontana L, Weiss EP, Villareal DT, et al. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans.Aging Cell 2008, 7:681-687.Friedrich N, Haring R, Nauck M, et al. Mortality and serum insulin-like growth factor (IGF)-I and IGF binding protein 3 concentrations.J Clin Endocrinol Metab 2009, 94:1732-1739.Carlzon D, Svensson J, Petzold M, et al. Both low and high serum IGF-1 levels associate with increased risk of cardiovascular events in elderly men.J Clin Endocrinol Metab 2014, 99:E2308-2316.Svensson J, Carlzon D, Petzold M, et al. Both low and high serum IGF-I levels associate with cancer mortality in older men.J Clin Endocrinol Metab 2012, 97:4623-4630. .van Bunderen CC, van Nieuwpoort IC, van Schoor NM, et al. The Association of Serum Insulin-Like Growth Factor-I with Mortality, Cardiovascular Disease, and Cancer in the Elderly: A Population-Based Study.J Clin Endocrinol Metab 2010.Arai Y, Takayama M, Gondo Y, et al. Adipose endocrine function, insulin-like growth factor-1 axis, and exceptional survival beyond 100 years of age.J Gerontol A Biol Sci Med Sci 2008, 63:1209-1218.Johnsen SP, Hundborg HH, Sorensen HT, et al. Insulin-like growth factor (IGF) I, -II, and IGF binding protein-3 and risk of ischemic stroke.J Clin Endocrinol Metab 2005, 90:5937-5941.Hankinson SE, Willett WC, Colditz GA, et al. Circulating concentrations of insulin-like growth factor-I and risk of breast cancer.Lancet 1998, 351:1393-1396.Chan JM, Stampfer MJ, 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Discover all of the podcasts in our network, search for specific episodes, get the Optimal Living Daily workbook, and learn more at: OLDPodcast.com. Episode 2631: Jill Coleman reveals the surprising link between diet and acne, highlighting how the traditional American diet can exacerbate skin issues. Discover how hormonal imbalances and certain foods contribute to acne, and learn dietary changes to promote clearer skin. Read along with the original article(s) here: https://jillfit.com/2011/07/12/acne-nutrition/ Quotes to ponder: "Acne development starts in the gut, not solely on the skin." "Insulin decreases IGFBP-3's availability to the cells; an undesirable outcome since apoptosis is needed to maintain normal rates of sloughing off." "A low glycemic load diet significantly reduced biochemical markers for acne development in as little as 7 days." Episode references: Journal of the American Academy of Dermatology: https://www.jaad.org/article/S0190-9622(07)00795-5/abstract The Dietary Cure for Acne: https://www.amazon.com/Dietary-Cure-Acne-Loren-Cordain/dp/0978510917 Learn more about your ad choices. Visit megaphone.fm/adchoices

Discover all of the podcasts in our network, search for specific episodes, get the Optimal Living Daily workbook, and learn more at: OLDPodcast.com. Episode 2631: Jill Coleman reveals the surprising link between diet and acne, highlighting how the traditional American diet can exacerbate skin issues. Discover how hormonal imbalances and certain foods contribute to acne, and learn dietary changes to promote clearer skin. Read along with the original article(s) here: https://jillfit.com/2011/07/12/acne-nutrition/ Quotes to ponder: "Acne development starts in the gut, not solely on the skin." "Insulin decreases IGFBP-3's availability to the cells; an undesirable outcome since apoptosis is needed to maintain normal rates of sloughing off." "A low glycemic load diet significantly reduced biochemical markers for acne development in as little as 7 days." Episode references: Journal of the American Academy of Dermatology: https://www.jaad.org/article/S0190-9622(07)00795-5/abstract The Dietary Cure for Acne: https://www.amazon.com/Dietary-Cure-Acne-Loren-Cordain/dp/0978510917 Learn more about your ad choices. Visit megaphone.fm/adchoices

BUFFALO, NY- September 25, 2023 – A new research paper was published in Oncotarget's Volume 14 on September 22, 2023, entitled, “Transcriptomic analysis identifies four novel receptors potentially linking endometrial cancer with polycystic ovary syndrome and generates a transcriptomic atlas.” Polycystic Ovary Syndrome (PCOS) is associated with a 3 to 4-fold increased risk of endometrial cancer (EC), but molecular mechanisms are unclear. Upregulation of the IGF1 gene in PCOS endometrium may increase EC risk, but this is uncertain. In this new study, researchers Fatma Alqutami, Mahmood Hachim, Charlie Hodgman, and William Atiomo from the Mohammed Bin Rashid University of Medicine and Health Sciences and the University of Nottingham aimed to investigate links between EC and PCOS, by analyzing publicly available transcriptomic data. “The original aim of this study was to investigate the links between EC and PCOS, by analysing publicly available transcriptomic data and investigate IGF-1 and IGFBP gene expression in the endometrium of women with PCOS and EC compared with normal endometrium.” The NCBI Gene Expression Omnibus was used to identify relevant studies. Differentially expressed genes (DEGs) were identified and analyzed using Metascape to identify pathways of interest. PCOS DEGs that encode proteins secreted into blood were identified using the Human Protein Atlas blood protein database. EC DEGs that are cellular receptors were identified using EcoTyper. These were intersected to identify which EC receptors interact with PCOS secreted proteins. Seven receptors were identified in EC but only PTPRF, ITGA2, ITGA3, and ITGB4 genes were expressed on epithelial cells. Pathway enrichment of these genes showed that the major and common pathway involved was that of the PI3K-AKT signaling pathway which was consistent with a link between PCOS and EC. However, IGF1 was down regulated in PCOS and EC. “Our conclusions at this stage do not support a link between IGF-1 and IGFBP genes in PCOS and EC. However, we have identified four novel receptors which may underpin the risk of EC in PCOS, and we believe our findings provide sufficient evidence to form the basis for a transcriptomic atlas to underpin future research into the links between PCOS and EC and the molecular mechanisms underpinning both diseases.” DOI - https://doi.org/10.18632/oncotarget.28513 Correspondence to - William Atiomo - william.atiomo@mbru.ac.ae Sign up for free Altmetric alerts about this article - https://oncotarget.altmetric.com/details/email_updates?id=10.18632%2Foncotarget.28513 Subscribe for free publication alerts from Oncotarget - https://www.oncotarget.com/subscribe/ Keywords - cancer, polycystic ovary syndrome, endometrial cancer, transcriptomics, IGF1, in-silico About Oncotarget Oncotarget (a primarily oncology-focused, peer-reviewed, open access journal) aims to maximize research impact through insightful peer-review; eliminate borders between specialties by linking different fields of oncology, cancer research and biomedical sciences; and foster application of basic and clinical science. To learn more about Oncotarget, please visit https://www.oncotarget.com and connect with us: SoundCloud - https://soundcloud.com/oncotarget Facebook - https://www.facebook.com/Oncotarget/ Twitter - https://twitter.com/oncotarget Instagram - https://www.instagram.com/oncotargetjrnl/ YouTube - https://www.youtube.com/@OncotargetJournal LinkedIn - https://www.linkedin.com/company/oncotarget Pinterest - https://www.pinterest.com/oncotarget/ Reddit - https://www.reddit.com/user/Oncotarget/ Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957

It's In the News, a look at the top stories and headlines from the diabetes community happening now. Top stories this week: Dexcom G7 is now available in the United States, Insulet buys assets from Bigfoot and another California company, new studies about cannabis and type 1 and COVID and diabetes, different predictors of type 2 in women and men, plus scholarships for T1D students. Please visit our Sponsors & Partners - they help make the show possible! Take Control with Afrezza  Omnipod - Simplify Life Learn about Dexcom  Check out VIVI Cap to protect your insulin from extreme temperatures Learn more about AG1 from Athletic Greens  Drive research that matters through the T1D Exchange The best way to keep up with Stacey and the show is by signing up for our weekly newsletter: Sign up for our newsletter here Here's where to find us: Facebook (Group) Facebook (Page) Instagram Twitter Check out Stacey's books! Learn more about everything at our home page www.diabetes-connections.com  Reach out with questions or comments: info@diabetes-connections.com Episode Transcription:  Hello and welcome to Diabetes Connections In the News! I'm Stacey Simms and these are the top diabetes stories and headlines happening now XX In the news is brought to you by T1D Exchange dedicated to improving outcomes for the entire T1D population XX Our top story. Today's the day. February 17th is the day Dexcom's G7 becomes available in the United States. Now.. whether you can get it still depends on your insurance, your doctor – a new prescription is needed – and the availability at your pharmacy. Whether you want to get it may depend on if you use a compatible pump system – the G7 will NOT work with Tandem's CIQ or Omnipod 5 for several more months. The G7 will be accessible to all Medicare patients with diabetes who meet the eligibility criteria as of today.. so no wait there. Much more to come on the launch I'm sure.. https://investors.dexcom.com/news/news-details/2023/Dexcom-G7-Continuous-Glucose-Monitoring-System-Will-Be-Available-to-Medicare-Beneficiaries-at-Launch/default.aspx?fbclid=IwAR0cKhAv5C8TMZ8v8f98rlhnvBQ0JkFj3SLRyc7RdMeOAO3_Tpl95cKNX20 XX People who've had Covid-19 have a higher risk of developing diabetes, and that link seems to have persisted into the Omicron era, a new study finds. Mounting evidence suggests Covid-19 infections are tied to a new diagnosis of diabetes, though it's not clear whether this relationship is a coincidence or cause-and-effect. Big study here, 23,000 adults who'd had Covid-19 at least once. The raw data showed that people who'd had Covid-19 had higher risks of being diagnosed with diabetes, high cholesterol and high blood pressure after their infections. But when the researchers adjusted those numbers to account for the benchmark diagnosis, only the risk of diabetes remained significantly elevated. Covid-19 increased the odds of a new diabetes diagnosis by an average of about 58%. The new study is notable because it adds recent data, said Wander, who was not involved in the research. It also used strategies to try to address shifts in health care during the pandemic. Another strength of the study was that it included people who were diagnosed between March 2020 and June 2022, so it was able to estimate the risk even after the Omicron variant swept through the US. https://www.cnn.com/2023/02/14/health/covid-diabetes-risk-study/index.html XX Insulet making a couple of interesting acquisitions.. $25 million in assets from Automated Glucose Control LLC in California. And the same amount $25 million of assets from Bigfoot Biomedical. AGC and Insulet have had a partnership since 2016 which mostly involved the algorithm that led to Omnipod 5. Bigfoot has also claimed patents regarding more hands-off insulin delivery, The acquisition effectively doubles Insulet's IP portfolio, Eric Benjamin, the company's executive VP of innovation, strategy and digital products, said in a press release. XX Dr. Halis Akturk and colleagues began noticing patterns among people with T1D in Colorado hospital emergency departments (ED) after cannabis was legalized in the state. They have since conducted several nationwide retrospective studies on those living with T1D that also use cannabis, including hospitalization records and T1D Exchange Registry participant surveys. They found that T1D participants had repeated return visits to the ED in the following weeks, and DKA was frequently misdiagnosed. Based on that research, Dr. Akturk's team has recently developed a key to differentiating between DKA and a new syndrome that mimics DKA, one they've named HK-CHS: Hyperglycemic Ketosis-Cannabis Hyperemesis Syndrome. To treat HK-CHS, your care team will typically increase fluids, treat the high blood glucose with insulin, and balance your electrolytes, or anion gap. You will be advised to stop using cannabis until the symptoms resolve. These treatments will bring your blood glucose levels back into target range and get your gut moving again, which will ease the nausea and vomiting. Depending on your dose, frequency, and duration of use, symptoms may take several days to several weeks to resolve. https://t1dexchange.org/cannabis-t1d-risks/ XX About two thirds of people with type 1 diabetes in the United States have overweight or obesity, nearly the same proportion as Americans without diabetes, new nationwide survey data suggest. What's more, among people with overweight or obesity, those with type 1 diabetes are less likely to receive lifestyle recommendations from healthcare professionals than those with type 2 diabetes, and are less likely to actually engage in lifestyle weight management activities than others with overweight or obesity, with or without type 2 diabetes. "the lack of evidence for safe, effective methods of diet- and exercise-based weight control in people with type 1 diabetes may be keeping doctors from recommending such methods," these researchers say. "Large clinical trials have been done in type 2 diabetes patients to establish guidelines for diet- and exercise-based weight management, and we now need something similar for type 1 diabetes patients." https://www.medscape.com/viewarticle/988199 XX New research showing men and women have different risk factors when it comes to type 2 diabetes. In healthy women, low serum level of the adipose tissue protein adiponectin was an independent strong predictor of type 2 diabetes and prediabetes in the future. In healthy men, instead, low serum level of the liver protein IGFBP-1, was an independent strong predictor of type 2 diabetes and prediabetes This means that these proteins, which are measures of insulin sensitivity in adipose tissue (adiponectin) and liver and muscle (IGFBP-1), can predict whether one has a high risk of getting type 2 diabetes in 10 years. A previous study performed in Shanghai in 2016 showed gender differences in the same direction. In men with prediabetes the risk of future type 2 diabetes was significantly reduced if they increased their physical activity and muscle mass . In contrast, the same study showed that women with prediabetes must avoid increasing waist circumference and abdominal obesity or reducing large waist circumference to prevent type 2 diabetes. https://medicalxpress.com/news/2023-02-women-men-shown-factors-diabetes.html XX Tempramed/ VIVI Cap XX XX 2023 Diabetes Scholars applications are now open! If you're a high school senior living with type 1 diabetes in the US, you can apply to get money for college. https://diabetesscholars.org/apply-now/?fbclid=IwAR2txFmkmxp9qoMf5ZkKX0f83oxj3aOr69rCXeqozRDxq7Dt94e9QdBQrjg XX On the podcast next week.. Diatech Diabetes is a medical device company based out of Memphis, TN committed to changing the way infusion set failure detection is done with our infusion set failure detection system, SmartFusion. The last episode is with Dr Phyllisa Deroze all about explaining to your child when you, the parent, have diabetes. That's In the News for this week.. if you like it, please share it! Thanks for joining me! See you back here soon. ---- The T1D Exchange Registry is a research study conducted online over time, designed to foster innovation and improve the lives of people with T1D. The platform is open to both adults and children with T1D living in the U.S. Personal information remains confidential and participation is fully voluntary. Once enrolled, participants will complete annual surveys and have the opportunity to sign up for other studies on specific topics related to T1D. The registry aims to improve knowledge of T1D, accelerate the discovery and development of new treatments and technologies, and generate evidence to support policy or insurance changes that help the T1D community. By sharing opinions, experiences and data, patients can help advance meaningful T1D treatment, care and policy.

Tune in to this podcast episode on acute kidney biomarker testing and how pharmacists may apply acute kidney injury biomarkers in their clinical practice. From the 2020 Midyear Clinical Meeting, content matter experts explore the use of NGAL and TIMP-2*IGFBP-7 in clinical practice. The information presented during the podcast reflects solely the opinions of the presenter. The information and materials are not, and are not intended as, a comprehensive source of drug information on this topic. The contents of the podcast have not been reviewed by ASHP, and should neither be interpreted as the official policies of ASHP, nor an endorsement of any product(s), nor should they be considered as a substitute for the professional judgment of the pharmacist or physician.

This week’s episode features author Emma Birks and Associate Editor Hesham Sadek as they discuss the article " Prospective Multicentre Study of Myocardial Recovery Using Left Ventricular Assist Devices (REmission from Stage D Heart Failure: RESTAGE-HF): Medium Term and Primary Endpoint Results." TRANSCRIPT BELOW: Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast, summary and backstage pass to the journal and its editors. I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, associate editor, director of the Pauley Heart Center of VCU Health in Richmond, Virginia. Carolyn, our feature article this week, we're going to examine myocardial recovery using left ventricular assist devices, getting some early results from the RESTAGE-HF study. But before we jump to the feature discussion, how about we discuss some of the papers in the issue? Would you like to go first? Dr. Carolyn Lam: Yes I would. Have you thought about what's the benefit of emergent coronary angiography after resuscitation from out of hospital cardiac arrest for patients without ST elevation? It's an important question. Well, the portal study was reported by Dr. Kern from University of Arizona and colleagues, and this was designed to evaluate the efficacy and safety of early coronary angiography and to determine the prevalence of acute coronary occlusion in resuscitated out of hospital cardiac arrest in patients without ST elevation. So adult comatose survivors without ST elevation after resuscitation, were prospectively randomized to early coronary angiography versus no early coronary angiography, where early was defined as less than 120 minutes from arrival at the PCI capable facility. The primary endpoint was a composite of efficacy and safety measures, including efficacy parameters of survival to discharge favorable neurological status at discharge echo measures of left ventricular ejection fraction, more than 50% and a normal regional wall motion score within 24 hours of admission. Dr. Greg Hundley: So, lots of data here. What did they find? Dr. Carolyn Lam: So, unfortunately the study was prematurely terminated before enrolling the target numbers of patients. A total of 99 patients were enrolled from 2015 to 2018 and 49 were randomized to early coronary angiography. The primary endpoint of efficacy and safety was not different between the two groups. Early coronary angiography was not associated with any significant increase in survival or adverse events. And early coronary angiography revealed a culprit vessel in 47% with a total of 14% of patients undergoing early coronary angiography, having an acutely occluded culprit coronary artery. So while this was an underpowered study, when considered together with previous clinical trials, it does not support early coronary angiography, comatose survivors of cardiac arrest without ST elevation, whether early detection of occluded potential culprit arteries leads to interventions that improve outcomes does require additional study. And this is discussed in an editorial by Dr. Lemkes from Amsterdam university medical center. Dr. Greg Hundley: Very nice Carolyn. So at least the study that points us toward the next study that has to be performed and also does with other studies provide a little more clarity. Well, my next paper is from Professor Sanjiv Shah and--oh, wait a minute! And also from you as a co-author. Well, Carolyn, how about we have a little mini feature discussion where I can ask you some questions and then you can tell us all about your paper. Dr. Carolyn Lam: Happy to. Dr. Greg Hundley: Great. So Carolyn, what hypotheses were you testing and what was your study design and who was included in your study population? Dr. Carolyn Lam: Okay. So the question was we wanted to answer was thus a systemic pro-inflammatory state as indicated by proteomic profiling. Does that mediate the association between comorbidities and normal cardiac structure and function in HFpEF. To answer that we studied 228 patients with HFpEF from our multicenter promis HFpEF study. And these patients had 248 unique circulating proteins quantified using the old link multiplex immunoassay. Now I'm going to describe a complex analysis, but we basically had to first perform principal component analysis. And we did this to summarize 47 proteins known a priori to be involved in inflammation, and then used unbiased network analysis of all the 248 proteins to identify clusters of proteins that over-represented inflammatory pathways. We then used a mediation analysis to determine whether and to what extent inflammation mediates the association of comorbidity burdens with abnormal cardiac structure and function. And finally, we externally validated our findings in an independent cohort of 117 HFpEF cases and 30 comorbidity controls without HFpEF. Dr. Greg Hundley: Wow Carolyn, such a great design and an app machine learning mediation analyses, and then validation in an independent cohort. So tell us, what did you find? Dr. Carolyn Lam: So first, comorbidity burden was associated with abnormal cardiac function and structure and with these principle components of clusters of inflammation proteins. Second, systemic inflammation was associated with echo indicators of worse hemodynamics, like higher EDE' ratio and worse, right ventricular function. And third, inflammation indeed mediated the association between comorbidity burden and many of these echo parameters with, and I'm going to name a couple of routines. So TNF-R1, uPAR, IGFBP-7 and GDF-15 being the top individual mediating proteins. In the validation cohort inflammation was up-regulated in HFpEF compared to controls and the most prominent inflammation protein cluster identified was also the same one as in PROMIS-HFpEF. Dr. Greg Hundley: Beautiful Carolyn. So with these new proteins identified, what's the take home message here? Dr. Carolyn Lam: Here it is. Proteins involved in inflammation form a conserved network in HFpEF. And this was found across two independent cohorts. This may mediate the association between comorbidity burden and echo indicators of worst hemodynamics and right ventricular dysfunction. In totality, these findings support the comorbidity inflammation paradigm in HFpEF. Dr. Greg Hundley: Great job Carolyn, I liked the mini feature. That was so nice having one of the authors of the study here to explain kind of a two for one here, because we're going to get a feature and a mini feature. Have you got another paper you want to tell us about? Dr. Carolyn Lam: Thanks Greg and that works both ways. This next paper provides insights into the identity origin and function of many cells that make up late stage atherosclerotic lesions. It also identifies the mechanisms by which these control plucks stability. So corresponding author, Dr. Owens from Virginia School of Medicine and colleagues conducted a comprehensive single cell RNA sequencing of advanced human carotid endarterectomy samples, and compared these with murine micro dissected advanced atherosclerotic lesions with smooth muscle cell and endothelial lineage tracing to survey all plaque cell types and to rigorously determine their origins. Dr. Greg Hundley: Carolyn you know, this is another great study where we have both human subjects research and small animals. What were their results? Dr. Carolyn Lam: They provided evidence that smooth muscle cell specific knockout of transcription factors, KLF4 versus Oct-4 showed virtually opposite genomic signatures and their putative target genes played an important role, regulating smooth muscle cells phenotypic changes. They also provided evidence that smooth muscle cell derived cells within advanced mouse and human atherosclerotic lesions exhibited far greater phenotypic plasticity than generally believed, with KLF4 regulating the transition to multiple phenotypes, including LGALS 3 plus osteogenic cells likely to be detrimental for late stage atherosclerosis plaque pathogenesis. So in summary, smooth cell phenotypic switching produces cells that can be beneficial or detrimental to lesion stability and may be an important mechanism controlling the risk of unstable atherosclerotic plaque and myocardial infarction or stroke. Dr. Greg Hundley: Oh, great job, Carolyn. Well, the next paper I have is from Professor Muredach Reilly from Columbia University. And Carolyn smooth muscle cells play significant roles in atherosclerosis via phenotypic switching, a pathological process and with smooth muscle cell D differentiation, migration and trans differentiation into other cell types yet how smooth muscle cells contribute completely to the pathophysiology of atherosclerosis remain somewhat illicit. So the authors sought to reveal the trajectories of smooth muscle cell trans differentiation during atherosclerosis, and to identify molecular targets for disease therapy by combining smooth muscle cell fate mapping and single cell RNA sequencing of both mouse and human atherosclerotic plaques. Dr. Carolyn Lam: Echoing what you said earlier, Greg, both animal and human data. Terrific. So what were the results? Dr. Greg Hundley: The authors found that smooth muscle cells transitioned to an intermediate cell state during atherosclerosis, which was also found in human atherosclerotic plaques of carotid and coronary arteries. Smooth muscle cell derived intermediate cells termed stem cells were multiphoton and could differentiate into macrophage like and fibro chondrocyte like cells as well as returned towards the smooth muscle cell phenotype. Retinoic acid signaling was identified as a regulator of the transition of smooth muscle cells to stem cells and RA signaling was dysregulated in symptomatic human atherosclerosis. Finally Carolyn, human genomics revealed enrichment of genome-wide association study signals for coronary artery disease in RA signaling target gene low PSI and correlated between coronary artery disease risk levels and repressed expression of these genes. Now, activation of RA signaling by all trans retinoic acid and the anticancer drug for acute promyelocytic leukemia blocked the smooth muscle cell transition to stem cells, and that also reduced atherosclerotic burden and then promoted fibrous cap stability. So a lot of clarification of the role of smooth muscle cells, trans differentiation and the development of atherosclerotic disease Dr. Carolyn Lam: Indeed and translational implications. Interesting. Now let's review some of the other papers in this issue. Shall we? First as an, on my mind paper by Dr. Kullo on familial hypercholesterolemia, a reportable disorder. There's an exchange of letters between doctors Lazzerini and Li regarding the article autoantibody signature in cardiac arrest. Dr. Greg Hundley: Thanks Carolyn. Well, I've got a couple other papers to tell you about really a series of research letters from the mailbag. So first Daniel Modin has a Research Letter entitled “Acute COVID-19 and the Incidents of Ischemic Stroke and Acute Myocardial Infarction.” Dr. Christian Mueller has a Research Letter entitled “Effect of a Proposed Modification of the Type 1 and Type 2 Myocardial Infarction Definitions on Incidents and Prognosis.” And finally Carolyn a Research letter from Dr. Jizheng Wang involving an East Asian-specific common variant in TNNI3 that appears to predispose to hypertrophic cardiomyopathy. Well, Carolyn, what a great issue and thank you for that many feature, but how about we proceed on next to our feature discussion? Dr. Carolyn Lam: Let's go, Greg. Today's feature paper is one of those that I think is going to change clinical practice. So please listen up. It's about the RESTAGE-HF study. So pleased to have with us the first and corresponding author, Dr. Emma Birks from University of Kentucky Gill Heart and Vascular Institute, as well as our associate editor, Dr. Hesham Sadek from UT Southwestern to discuss this very important paper. Emma, could you please describe the RESTAGE heart failure study? Dr. Emma Birks: Let's say prospective study of patients getting left ventricular assist devices. So patients with very advanced heart failure are receiving left ventricular assist devices as either a bridge to transplant or as destination therapy. And they're seeing them for chronic heart failure because really all other medical therapy has failed and we use the pump to try and recover their own heart. So when the pump's implanted, we optimize the LVAD unloading, the maximum loading, and we give them a very aggressive medical therapy regime, unless they may not have tolerated these medications before because of poor blood pressure and renal dysfunction, we find they do tolerate them. So we give them in very aggressive doses and then we monitor their underlying function at regular intervals and try and promote recovery. So with that, we had done this in England in the past, in a single center study, but it had not yet been reproduced, which was obviously essential to have a bigger impact. Dr. Emma Birks: So we did a prospective study of six big US centers. We found that we've created a primary endpoint that was statistically powered in advance. And the primary endpoint was the number of patients that recovered within an 18 month period, that were explanted and remained off the pump and alive without transplant over for one year. So overall we found that of the 40 patients we recruited in the centers with chronic heart failure, we were able to explore 19. Of those that satisfied the primary endpoint, that was actually 40% of patients, with 52.3% being explanted overall. And importantly, patients were explanted in all six centers, so we found that the protocol was reproducible under the how much higher rate of recovery that you would otherwise see. Normally there is a database in the US that tracks outcomes from bad patients. And generally only 1-2% seemed to recover enough to be explanted generally. So this was a much bigger percentage. Dr. Carolyn Lam: Emma, first of all, congratulations, what an important trial and what stunning results. More than half of patients receiving that protocol were explanted. That's just remarkable. Now, could I just ask, what is it that you did that was different? I noticed you spent a lot of time saying this was an aggressive pharmacological protocol that was along with the LVAD unloading. Could you maybe elaborate on that a little bit more? Dr. Emma Birks: Yeah, I think that was a very important part of it. So generally I think when the LVAD goes in most centers, the patients are very sick, so most of those patients wouldn't then try and recover them or look at underlying functions. I think that was the first thing that was different was to try very hard. And then we had centers, the experience, I had done this before, it was also very helpful, all agreeing to do the same thing. We use a very aggressive regime of ACE inhibitors, Beta blockers, auto serotonin antagonists and ARBs. And that was also an unusual thing. We use the fact that they're supported with the pump to use both an ACE and an ARB together, but the idea that they have better blood flow in the cranial is way more tolerant and we give very high doses. So we use Lisinopril with the target dose of 40 milligrams, Coreg with a target dose of 50 BID, Aldactone 25 milligrams daily. Dr. Emma Birks: And then we add in losartan if they tolerate it and actually aim for 150 milligrams daily, so those doses are very high. And I think not normally given to people on LVADs. So you must've had the LVAD that don't tolerate the medical therapy and stop it. They might just have blood pressure control, etc. There is now also another INTERMACS trial, a sort of big study that's come out that actually shows benefit of neurohormonal antagonists in general. So that goes together with our study to show that they should already be given and then the regular testing. So we had quite thorough testing. So first of all, we do echos on the pump and then we do echos with the LVAD turned down to a speed at which is not contributing. So we do that and we do an echo at five minutes with it down 15 minutes, and then we walk the patient, distress them. Once we show that the hearts come down in size and improved function, then we do an exercise test, right heart cath on an off pump to look at the hemodynamics. Dr. Carolyn Lam: Wow. So tremendous effort and really the protocol is unique in and of itself, not just the pharmacological therapy, also the way this is monitored and decisions are made really, really amazing. Just one last question for me, because it's a humbling reminder of the importance of neurohormonal blockade in these patients. Do you continue that after they're explanted? Dr. Emma Birks: Yes, we do. And we continue aggressively and that's slightly different as well in that normally you wouldn't give a patient a nascent an up of course, but given that they've already tolerated it on the pump in that same patient. So we restart the same drug regime afterwards, and we actually like to get them to quite along that dosage before we discharge them from the XPLAN, we don't want to do that slowly. We get them back on it quite quickly. And then we follow them very carefully because we don't really know the long-term durability. Dr. Carolyn Lam: Wow, thank you. Hesham. I would love your thoughts on this paper. I mean, it really, really is remarkable results. Dr. Hesham Sadek: Yeah. I mean, I was very happy that we received this paper to review, frankly I've been following that work for a long time since the first new England paper that came out and I'd like to congratulate you for an amazing work. I think this will change the field. First, how was this trial different from the first trial, other than the fact that it's multicenter, what would you say are the major changes that you made to the protocol and what you've learned since the first trial? Dr. Emma Birks: Yes, you're absolutely right. We did make some changes. So first of all, it was six sites instead of one site. I think it was very important to reproduce it in the US but we changed the protocol itself as well. The first trial had optimization of the LVAD speed, really just by echo looking at the reduction in the ventricle size. It had the aggressive medical regime was very similar except this time we increased the Losartan dose from 100 to 150 after the Hill's trial came out. The testing was very frequent in the original English Sheffield study, probably a little bit too frequent to be able to be adopted on a wide scale. So we tried to reduce it down a little bit. So we decrease the frequency of the low-speed echos. I think we had them at six weeks, four months, six months, nine months in a year. Dr. Emma Birks: And after that, we saw if they were already improving and started and only did them at a year to 18 months, if they were improving. And then we also cut down the number of exercise tests. So we didn't do the exercise test until the echo was already showing significant improvement. For two reasons, one, we didn't find it very reliable and two, it was just too much testing for the patient. So it was more of a confirmatory test. In fact, it wasn't a requisite for a pump explantation. We didn't do a left heart catheter, which we did before. Previously we tried to measure LVEDP, this time we decided which was enough. So we just did a right heart cath on and off pump. And we did that once the echo was improved as well. So we rationalized that a little bit. And then the other important thing was before in hayfield study, once we saw the ventricular size come down and injection fraction start to improve, we actually added in Clenbuterol, which was a Beta-2 agonist. Dr. Emma Birks: And the idea with that was to cause a kind of physiological hypertrophy so that when you took the pump out, the heart didn't just dilate. We were worried about atrophy at the heart on the pump long-term. So we did that to try and improve the durability of recovery. So the reason we left off this time was really the previous protocol was very good, but was very complicated. So we wanted to see what rate of recovery we could get just with the aggressive reverse remodeling, neurohormonal drugs, plus the aggressive testing and the optimum loading with the idea that later on, we could add on either Clenbuterol or something later to improve the durability of recovery, if the ability of recovery is not good enough, but actually so far it's proven to be pretty good because the study itself takes quite a long time. It was sort of to recruit them. We had an 18 month period than the follow-ups. It was already a multi-year study. So we wanted to establish a regime that many centers could use to try and promote recovery. Dr. Hesham Sadek: I want to follow up on that last point, because as you know, I've looked at some of these Heights as well in our center, and we looked at the results with you and Stavros and others. So the myocytes size is expected to change, decrease with unloading, right with sufficient unloading. So how would you prepare the Myocardium to take on the normal afterload if you are not going to induce by a beta agonist, for example, Dr. Emma Birks: What I would like to do in the future is try using the pump itself actually. Sometimes there's heart recovers, the heart shrinks and actually start opening their own valve and working in the heart. Of course, when you have the HeartMate one, actually, sometimes wasn't synchronous with the heart. So sometimes the heart will beat against the pump anyway. Once you go to the continuous flow pumps, you've got continuous unloading. So I think it'd be very interesting to intermittently turn down the pump speed and load the heart to work it before you take the pump out. So I would really like to do that. I think that might be the next interesting phase of the study to improve your ability to.. So I guess once you've got maximum reverse remodeling and improvement in function, you could just turn the pump speed down to let the valve open. Dr. Hesham Sadek: Do you think perhaps if you do that, you will increase the percentage of patients that can be explanted? Do you think that could be a factor in the percentage of patient that can be explained? Dr. Emma Birks: I think it might be, it might more improve the, to your ability to make sure we have for a long, good echo function afterwards. Dr. Hesham Sadek: That's great. So another question this was limited to not ischemic cardiomyopathy patients. Can you elaborate a bit on why not include, for example, revascularized ischemic cardiomyopathy patients. Dr. Emma Birks: Yeah, so we did that really just because we didn't want to change too much from the original protocol. We also stuck with one device because we thought if you have multiple pumps, multiple diagnosis, it does get hard to analyze in a multicenter trial. So we did that on purpose and we were always trying to simulate the bridge to transplant population in the age group too. But actually interestingly, most of the patients recruited in the trial were destination therapy patients in the end. Dr. Emma Birks: I think this could be done with ischemic cardiomyopathy. I think we don't have enough data on ischemic cardiomyopathy to know whether it does or it doesn't recover. So I don't think our results say that it's only known as ischemics. I think it just means we haven't studied ischemics sufficiently. Logically they might have more scarred. It might be harder to get such a good percentage to recover. I think all of us in our individual centers have seen a few and we've sort of seen the on pump echo improved, and we've tested them and then taken some out. But most of these cases are anecdotal. So I think that is another important study that needs to be done, obviously a large group of patients. Dr. Hesham Sadek: I agree. So given that they're not ischemic cardiomyopathy, do you know how many of them had genetic testing or what is the percentage of monogenic cardiomyopathys or how do you think these patients would respond to this protocol? Dr. Emma Birks: But if you had a familiar history and actually found it didn't make any difference, whether they recovered or not. I think some of us have personally seen actually those were the familial cardiomyopathy tend to recover more actually again, anecdotally. We published a people before looking at the Titin gene saying that that did recover. I think actually only five of these patients, 12% of them had a family history, but some of them recovered Dr. Hesham Sadek: One final question, as you know, I'm a basic scientist. So ultimately the question I'm going to ask, what do you think the mechanism is? Is it that these hearts are just in a vicious cycle of remodeling and validation, increased pressure, and you were sort of giving it a chance for actual structural reverse remodeling where you changed the geometry of the myocardium and perhaps rest of myocardium, allow for improvement of calcium cycling dynamics, or do you think, is something more exciting? Like three-generation for example. Dr. Emma Birks: Yeah, that's very interesting because I think the LVAD doesn't unload, so it shrinks the ventricles. I think it does improve the geometry and the dynamics. And then you use the drugs where they may have felt before you almost put them from class four, heart failure into class three with the bad to give that chance to work again. And then I think various cellular and fibrotic factors have been looked at and it's hard because there was so many factors have been looked at that. You were going to find some that go up and some that go down and what's important. But the impression I get overall is that you do get improvement, the matrix limits, the recovery on the fibrosis and the matrix. Whereas you do get improvements of myocardial function and cellular function. The cells will tend to reverse the dysfunction and it's really whether that happens or not. It's probably limited a lot by the matrix Dr. Carolyn Lam: That is amazing here. Hesham, I'm going to put you on the spot. Do you have your own hypothesis about this Dr. Hesham Sadek: Based on the work that they did initially in the new England paper, we did actually a small pathology study looking at cell cycle of cardiomyocytes from the core samples and from the explanted hearts post-transplant and we saw evidence of increased cardiomyocytes cell cycle in these patients along with decreased DNA damage and some metabolic remodeling as well with mitochondria. So, you can't really tell much from tissue whether you regenerated it or not, but as you know myocytes don't divide and this is the basis for the lack of spontaneous regeneration of the myocardium. So if this in fact removes the block to cardiomyocyte cell cycle, then this might be a regenerative therapy mechanism. Dr. Carolyn Lam: Well, this is amazing. I wish we had all day to discuss this more. I mean, this is the only place you can get a discussion that goes from clinical to basic signs and back to clinical. Thank you so much, Emma and Hesham for sharing today. Thank you audience for joining us today. You've been listening to circulation on the run on behalf of Greg as well. Don't forget to tune in again next week. Speaker 1: Program is copyright the American heart association, 2020.  

"Evaluation of IGF1/IGFBP3 Ratio as an Effective Tool for Assessing the Safety of Growth Hormone Therapy in Small for Gestational age, Hormone Deficient and Prader Willi Children"- Journal of Clinical Research in Pediatric Endocrinology (doi: 10.4274/jcrpe.galenos.2019.2018.0277)] Link artigo adicional: "Age- and Sex-Specific Reference Intervals Across Life Span for Insulin-Like Growth Factor Binding Protein 3 (IGFBP-3) and the IGF-I to IGFBP-3 Ratio Measured by New Automated Chemiluminescence Assays"- The Journal of Clinical Endocrinology & Metabolism, Volume 99, Issue 5, 1 May 2014, Pages 1675–1686 (https://doi.org/10.1210/jc.2013-3060)

Jane Ferguson:                Hi everybody. Welcome to Episode 25. I'm Jane Ferguson. This is Getting Personal: Omics of the Heart, the podcast from Circulation: Genomic and Precision Medicine, and it is February 2019. Let's get started.                                            The first paper this issue is a concurrent publication and comes to us from 29 different editors-in-chief of 27 major cardiovascular journals, led by Joseph Hill, editor-in-chief of Circulation. This editorial, entitled Medical Misinformation: Vet the Message! gives a pointed reminder of the real life risks of misinformation that spreads rapidly through social media and influences people who are making crucial decisions about healthcare for themselves and their families. Quoting directly from the paper they say, "We, the editors-in-chief of the major cardiovascular scientific journals around the globe, sound the alarm that human lives are at stake. People who decline to use a statin when recommended by their doctor, or parents who withhold vaccines from their children, put lives in harm’s way."                                            In this editorial they call on those in the media to do a better job of taking responsibility for the information they disseminate. In particular, in evaluating content before disseminating it, and avoiding false equivalencies where overwhelming scientific evidence favors one side of the so called "debate." I'll add to that that those of us who are medical or scientific professionals need to do our best to take the time to explain our science to those around us. The science underlying most of medicine is complex and hard to explain and sometimes incomplete, but we do a disservice to people if we don't at least try. Let's all join the editors in calling everyone to vet information and hold those with power in the media accountable for the spread of misinformation they enable.                                            Next up this issue, a paper from Jody Ingles, Birgit Funke, and co-authors from the University of Sydney, Harvard Medical School and others, entitled Evaluating the Clinical Validity of Hypertrophic Cardiomyopathy Genes. As panels for clinical genetic testing expands to include more genes, there are more and more variants that are detected and reported to patients, but do not necessarily have underlying evidence to support or disprove pathogenicity. This group aimed to systematically assess the validity of potential gene disease associations with hypertrophic cardiomyopathy and left ventricular hypertrophy by curating variants based on multiple lines of genetic and experimental evidence.                                            They categorized genes based on the strength of evidence of disease causation and reviewed HCM variant classification in the ClinVar variant and phenotype repository. They selected 57 genes to study based on those which were frequently included on test panels or had previous reports of association with HCM. Of HCM genes, only 24% were characterized as having definitive evidence for disease causation, 10% of the genes had moderate evidence, while 66% had limited or no evidence for disease causation. Of syndromic genes, 50% were definitively associated with left ventricular hypertrophy. Of over 4,000 HCM variants in ClinVar, 31% were in genes that, on review, had limited or no evidence for association with disease.                                            What this study shows is that many genes that are included on panels for diagnostic testing for HCM actually have little evidence for any relationship to disease. Systematic curation is required to improve the accuracy of information being acquired and reported to patients and families with HCM.                                            Moving on to the next paper. This manuscript describes the international Triadin Knockout Syndrome Registry: The Clinical Phenotype and Treatment Outcomes of Patients with Triadin Knockout Syndrome. It comes from Daniel Clemens, Michael Ackerman and colleagues from the Mayo Clinic. So, Triadin Knockout Syndrome is a rare inherited arrhythmia syndrome and it is caused by recessive null mutations in the cardiac triadin gene. To improve the ability to study this rare syndrome, this group established the International Triadin Knockout Syndrome Registry, with the goal of including patients across the world with homozygous or compound heterozygous triadin null mutations. The registry currently includes 21 patients from 16 families who have been carefully phenotyped and many of whom exhibit T wave inversions and have transient QTC prolongation.                                            The average age for first presentation with cardiac arrest or syncope was three years of age. Despite a variety of treatments, the majority still have recurrent breakthrough cardiac events. These data highlight the importance of conducting testing for triadin mutations in patients, particularly young children presenting with cardiac arrest, and as this registry grows it will enable a better understanding of the disease and hopefully pave the way for future triadin gene therapy trials.                                            The next paper comes from Daiane Hemerich, Folkert Asselbergs and colleagues from Utrecht University, and is entitled Integrative Functional Annotation of 52 Genetic Loci Influencing Myocardial Mass Identifies Candidate Regulatory Variants and Target Genes. They were interested in whether variants that have been associated with myocardial mass may exert their influence through regulatory elements. They analyze the hearts of hypertrophic cardiomyopathy patients and non-disease controls and ran ChIP-seq in 14 patients and 4 controls and RNA-seq in 11 patients and 11 controls.                                            They selected 52 loci that have been associated with electric cardiogram defined abnormalities in amplitude and duration of the QRS complex and looked specifically at these gene regions. They found differential expression of over 2,700 different genes between HCM and control. They further found differential acetylation over 7,000 regions. They identified over 1000 super enhancers that were unique to the HCM samples. They found significant enrichment for differential regulation between disease and control hearts within the loci previously associated with HCM, compared with loci not associated with HCM. They analyzed regions where putative causal SNPs overlapped regulatory regions, and identified 74 co-localized variants within 20 loci, with particular enrichment for SNPs in differentially expressed promoters. They confirmed associations with 18 previously implicated genes, as well as identifying 14 new genes. Overall, what this study demonstrates is that by looking at regulatory features that differ in affected tissues between disease and healthy individuals, we can learn more about the underlying mechanisms of disease.                                            Moving on, we have a paper entitled Interleukin-6 Receptor Signalling and Abdominal Aortic Aneurysm Growth Rates from Ellie Paige, Marc Clément, Daniel Freitag, Dirk Paul, Ziad Mallatt and colleagues from the University of Cambridge. They aimed to investigate a specific SNP in the Interleukin-6 receptor rs2228145, which has been associated with abdominal aortic aneurysms. Inflammation is thought to be a contributor to aneurism progression. The authors hypothesized that the IL-6 receptor's SNP may affect aneurysm growth. They use data from over 2,800 subjects from nine different prospective cohorts and examine the effect of genotype on annual change in aneurysm diameter. Although there was a significant association between genotype and baseline aneurysm size, there was no statistically significant association with growth over time. It appeared that growth was less in minor allele carriers, but the effect if true, was small and the analyses were not powered for small effect sizes.                                            Sample sizes are limited for cohorts with abdominal aortic aneurysms and the authors already used all available worldwide data. In complimentary experiments in mice, they examined the effect of blocking the IL-6 receptor pathway. They found that selective blockage of the IL-6 trans-signaling pathway mediated by soluble IL-6 receptor was associated with improved survival in two different mouse models. However, blocking the classical membrane-bound IL-6 signaling pathway in addition to the trans-signaling pathway did not lead to improved survival. Although the severe lack of enough subjects for well powered genetic analyses is a major limitation for the study of abdominal aortic aneurism and humans, this paper demonstrates the potential relevance of the IL-6 trans-signaling pathway and aneurysm growth, and suggests that further interrogation of this pathway may be informative in figuring out new ways to prevent aneurysm progression and rupture.                                            Next, we have the first of two research letters this issue. The letter on Common Genetic Variation in Relation to Brachial Vascular Dimensions and Flow-Mediated Vasodilation comes to us from Marcus Dorr, Renate Schnabel and co-authors from several institutions including University Heart Center in Hamburg. They were interested in gaining a better understanding of the genetics underlying vascular function. They ran a meta-analysis of brachial artery diameter, maximum brachial artery diameter adjusted for baseline diameter, and flow-mediated dilation in over 17,000 individuals of European ancestry from six different GWA studies. They sought to replicate findings in over 9,500 newly genotyped individuals. They identified two novel SNPs for baseline brachial artery diameter, but no SNPs reached significance or replication from maximum brachial artery diameter or flow-mediated dilation. One of the significant SNPs was located in the insulin-like growth factor binding protein 3, or IGFBP-3 gene. They analyzed plasma IGFBP-3 protein levels in 1,400 individuals and found a significant association with brachial artery diameter.                                            The second SNP they identified is located within the AS3MT gene for arsenite methyltransferase, and this SNP appears to be an eQTL for AS3MT expression in monocytes and arterial tissue. Along with identifying these two genes with potential involvement in baseline brachial artery diameter, this study also supports a low genetic component to flow-mediated dilation, indicating that environmental factors may be or more influential in FMD.                                            The final research letter comes from Alexis Williams, Craig Lee and colleagues from the University of North Carolina and is entitled CYP2C19 Genotype-Guided Antiplatelet Therapy and 30-Day Outcomes After Percutaneous Coronary Intervention. It is known that loss of function variants in CYP2C19 effect bioactivation of clopidogrel, and CYP2C19 genotyping is increasingly used to guide antiplatelet therapies. The authors were interested in whether genotype-guided therapy is effective in reducing major adverse cardiovascular events in the short term, specifically in the 30 days following percutaneous coronary intervention, when most MACE occurs. They followed over a thousand individuals undergoing PCI and CYP2C19 testing and looked at atherothrombotic and bleeding outcomes. Consistent with implementation of genotype-guided therapy, individuals carrying loss of function alleles were less likely to be prescribed clopidogrel.                                            However, out of loss of function carriers, those who did take clopidogrel had significantly higher risk of MACE with no difference in bleeding risk. There was no difference by therapy in individuals without a loss of function allele. What this study shows us is that even in the 30 days following PCI, genotype-guided therapy can be effective in protecting individuals carrying loss of function CYP2C19 variants.                                            And that's it from us for February. Go online to ahajournals.org/journal/circgen to read the full papers, access videos and more, and of course to delve into the podcast archives. Thank you for listening and I look forward to bringing you more next month. This podcast was brought to you by Circulation: Genomic and Precision Medicine and the American Heart Association Council on Genomic and Precision Medicine. This program is copyright American Heart Association 2019.  

Jane Ferguson:                Hello everyone, and happy new year. Welcome to episode 24 of Getting Personal: Omics of the Heart. It's January 2019, I am Jane Ferguson, an assistant professor at Vanderbilt University Medical Center and an associate editor at Circulation Genomic and Precision Medicine. We have a great line-up of papers this month in the journal, so let's jump right into the articles.                                            First up, a paper from Christopher Nelson, Nilesh Samani, and colleagues from the University of Lester entitled, "Genetic Assessment of Potential Long-Term On-Target Side Effects of PCSK9 Inhibitors."                                            I think most listeners are well aware of the efficacy of PCSK9 inhibition in reducing cardiovascular risk. However, as a relatively new treatment option, we do not yet have data on potential long-term side effects of PCSK9 inhibition. In this study, they utilized genetics as a proxy to understand potential long-term consequences of lower PCSK9 activity. They examined a PCSK9 variant that associates with lower LDL, as well as examining two LDL-lowering variants in HMGCR, the target of statins, which served as a positive control of sorts. They used data from over 479,000 individuals in the UK Biobank and looked for associations between the three LDL-lowering variants and 80 different phenotypes.                                            For the PCSK9 variant, the allele which is associated with lower LDL was significantly associated with the higher risk of type 2 diabetes, higher BMI, higher waist circumference, higher waist-hip ratio, higher diastolic blood pressure, as well as increased risk of type 2 diabetes and insulin use. The HMGCR variants were similarly associated with type 2 diabetes as expected.                                            Mediation analysis suggested that the effect of the PCSK9 variant on type 2 diabetes is independent of its effect on obesity. There were nominal associations between the PCSK9 variant and other diseases, including depression, asthma, chronic kidney disease, venous thromboembolism, and peptic ulcer.                                            While genetics cannot fully recapitulate the information that would be gained from long-term clinical follow up, these data suggest that like statins, PCSK9 inhibition may increase the risk of diabetes and potentially other disease. Overall, the cardiovascular efficacy of PCSK9 inhibition may outweigh these other risks, however, future studies should carefully examine these potential side effects.                                            Next up, we have a paper from Xiao Cui, Fang Qin, Xinping Tian, Jun Cai, and colleagues from Peking Uni and Medical College, on "Novel Biomarkers for the Precise Diagnoses and Activity Classification of Takayasu's Arteritis."                                            They were interested in identifying protein biomarkers of Takayasu arteritis, to improve diagnosis and understanding of disease activity in this chronic vascular disease. They ran a proteomic panel including 440 cytokines on 90 individuals, including individuals with active disease, inactive disease, and healthy controls. They found a number of candidates and validated one protein, TIMP-1, as a specific diagnostic biomarker for Takayasu arteritis. For assessing disease activity, there was no single biomarker that could be used for classification, however, the combination of eight different cytokines identified through random forest-based recursive feature elimination and [inaudible] regression, including CA 125, FLRG, IGFBP-2, CA15-3, GROa, LYVE-1, ULBP-2, and CD 99, were able to accurately discriminate disease activity versus inactivity.                                            Overall, this study was able to identify novel biomarkers that could be used for improved diagnosis and assessment of Takayasu arteritis, and may give some clues as to the mechanisms of pathogenesis.                                            Our next paper is entitled, "Familial Sinus Node Disease Caused By Gain of GIRK Channel Function," and comes from Johanna Kuß, Birgit Stallmeyer, Marie-Cécile Kienitz, and Eric Schulze-Bahr, from University Hospital Münster. They were interested in understanding novel genetic underpinnings of inherited sinus node dysfunction.                                            A recent study identified a gain of function mutation in GNB2 associated with sinus node disease. This mutation led to enhanced activation of the G-protein activated inwardly rectifying potassium channel, or GIRK, prompting the researchers to focus their interest on the genes encoding the GIRK subunits, KCNJ3 and KCNJ5. They sequenced both genes in 52 patients with idiopathic sinus node disease, and then carried out whole exome sequencing in family members of patients with potential disease variants in either gene. They identified a non-synonymous variant in KCNJ5, which was not present in the EVS or ExAC databases, and which segregated with disease in the affected family. This variant was associated with increased GIRK currents in a cell system, and in silico models, predicted the variant altered or spermine binding site within the GIRK channel. Thus, this study demonstrated that a gain of function mutation in a GIRK channel subunit associates with sinus node disease, and suggests that modulation of GIRK channels may be a viable therapeutic target for cardiac pacemaking.                                            Our next paper, "Key Value of RNA Analysis of MYBPC3 Splice-Site Variants in Hypertrophic Cardiomyopathy," comes from Emma Singer, Richard Bagnall, and colleagues from the Centenary Institute and the University of Sydney.                                            They wanted to understand the impact of variants in MYBCP3, a known hypertrophic cardiomyopathy gene, on splicing. They recruited individuals with a clinical diagnosis of hypertrophic cardiomyopathy and genetic testing of cardiomyopathy-related genes. They further examined individuals with a variant in MYBCP3 which had an in silico prediction to affect splicing. They sequenced RNA from blood or from fixed myocardial tissue and assessed the relationship between each DNA variant and gene splicing variation.                                            Of 557 subjects, 10% carried rare splice site variants. Of 29 potential variants identified, they examined 9 which were predicted to affect splicing, and found that 7 of these were indeed associated with splicing errors.                                            Going back to the families, they were able to reclassify four variants in four families from uncertain clinical significance to likely pathogenic, demonstrating the utility of using RNA analysis to understand pathogenicity in genetic testing.                                            The next paper this issue comes from Catriona Syme, Jean Shin, Zdenka Pausova, and colleagues from the University of Toronto, and is entitled, "Epigenetic Loci of Blood Pressure: Underlying Hemodynamics in Adolescents and Adults."                                            A recent large meta epigenome-wide association study identified methylation loci that associate with blood pressure. In this study, they wanted to understand more about how these loci related to blood pressure and hemodynamics. They recruited adolescents and middle-aged adults and assessed 13 CPG loci for associations with hemodynamic markers, including systolic and diastolic blood pressure, heart rate, stroke volume, and total peripheral resistance, measured over almost an hour during normal activities. Several of the loci replicated associations with blood pressure, and two of these also showed age-specific associations with hemodynamic variables. One site in PHGDH was particularly associated with blood pressure and stroke volume in adolescents, as well as with body weight and BMI, where lower methylation resulting in higher gene expression associated with higher blood pressure. A second site in SLC7A11 associated with blood pressure in adults but not adolescents, with lower methylation and consequent higher gene expression associated with increased blood pressure.                                            Overall, this study indicates that methylation mediated changes in gene expression may modulate blood pressure and hemodynamic responses in an age-dependent manner.                                            Next up is a research letter from Ben Brumpton, Cristen Willer, George Davey Smith, Bjørn Olav Åsvold, and colleagues from the Norwegian University of Science and Technology, entitled, "Variation in Serum PCSK9, Cardiovascular Disease Risk, and an Investigation of Potential Unanticipated Effects of PCSK9 Inhibition: A GWAS and Mendelian Randomization Study in the Nord-Trøndelag Health Study, Norway."                                            As we heard about from the first study this issue, the long-term side effects of PCSK9 inhibition remain unknown. In this study, they also applied a genetic approach to understand potential unanticipated consequences of PCSK9 inhibition. They analyzed phenotypes from over 69,000 participants in the Nord-Trøndelag Health Study and measured serum PCSK9 in a subset.                                            In PCSK9 GWAS of over 3,600 people, with replication in over 5,000 individuals from the twin gene study. They defined a genetic risk score for serum PCSK9 and assessed the relationship between genetically predicted PCSK9 and outcomes. They saw the expected associations between lower PCSK9 and lower LDL and coronary heart disease risk. However, there was minimal evidence for associations with other outcomes.                                            While our first study in this issue, from Nelson, et al, found that lower PCSK9 from a single genetic variant was associated with higher diabetes risk, this risk was not found here using the genetic risk score. Differences in the genetic definitions and in the populations used can perhaps explain these differences between the two studies, but overall, the studies are consistent in suggesting that long-term PCSK9 inhibition is unlikely to be associated with major adverse outcomes.                                            Our second research letter comes from Young-Chang Kwon, Bo Kyung Sim, Jong-Keuk Lee, and colleagues from Asan Medical Center in Seoul, on behalf of the Korean Kawasaki Disease Genetics Consortium. The title is, "HLA-B54:01 is Associated with Susceptibility to Kawasaki Disease," and reports on novel Kawasaki disease variants.                                            HLA genes have been previously associated with disease, and in this report, the authors sequenced selected axons in HLA-DRB1, HLA-DQB1, HLA-A, HLA-B, HLA-C, and HLA-DBP1 in 160 Kawasaki disease patients and 278 controls. They find a significant association with HLA-B, and replicated this in a sample of 618 Kawasaki disease patients, compared with over 14,000 in-house controls. They identified specific amino acid residues conferring disease susceptibility, highlighting HLA-B as a potential modulator of Kawasaki disease.                                            Our third and final research letter concerns "Serum Magnesium and Calcium Levels and Risk of Atrial Fibrillation: a Mendelian Randomization Study," and comes to us from Susanna Larsson, Nikola Drca, and Karl Michaëlsson, from the Karolinska Institute.                                            Because magnesium and calcium are known to influence atrial fibrillation, this group was interested in whether genetic predictors of serum methyls associated with disease. They constructed genetic predictors from GWAS of calcium in over 61,000 individuals, and GWAS of magnesium in over 23,000 individuals. They applied these predictors to an AF GWAS including over 65,000 cases and over 522,000 controls. Genetically predicted magnesium was inversely associated with atrial fibrillation, while there was no association with genetically predicted calcium.                                            While this study does not definitively prove causality, future studies aimed at assessing whether dietary or other strategies to raise serum magnesium are protective against AF may yield novel strategies for disease prevention.                                            And that's it from us for this month. Thank you for listening, and come back next month for more from Circulation Genomic and Precision Medicine.                                            This podcast was brought to you by Circulation Genomic and Precision Medicine and the American Heart Association Council on Genomic and Precision Medicine. This program is copyright American Heart Association, 2019.  

On this episode, I discuss my recent 5-day fast: how it went, what I learned, and whether I'll be doing it again. In the News & Views segment, we discuss a CNN article about fasting and longevity as well as a NY Times article that indicates intermittent fasting is becoming more widely accepted. You'll learn about a 450-lb man who did not eat food for over a year and reduced his body to a normal size. In the Moment of Paleo, I offer some ideas about when less is more. And After the Bell features a Dr. Jason Fung presentation about fasting as an important health tool. Enjoy the show! Links for this episode:This Episode's HomepageLatest in Paleo on Facebook - News hunters and gatherers post your links here.Full List of Recommended Books & AudiobooksEat, Fast & Live Longer HD - Video DailymotionOccasional fasting could help you live longer - CNN.comPeriodic fasting may lead to longer, healthier lives - AOLFasting Diets Are Gaining Acceptance - The New York TimesDietary restriction improves repopulation but impairs lymphoid differentiation capacity of hematopoietic stem cells in early agingHere's how occasional fasting could actually be good for you - ScienceAlertThe up- and downside of caloric restriction for aging and healthAGINGADVICE.ORGFasting - Wikipedia, the free encyclopediaDaniel Fast - Wikipedia, the free encyclopediaFasting Chart - Beliefnet.comUsing Fasting for Natural Healing | AllAboutFastingFasting: health benefits and risks - Medical News TodayA Periodic Diet that Mimics Fasting Promotes Multi-System Regeneration, Enhanced Cognitive Performance, and Healthspan: Cell MetabolismA History of Modern Research into Fasting, Starvation, and Inanition - SpringerMedically Supervised Water-only Fasting in the Treatment of HypertensionThe Fasting AdvantageHarpersMagazine Fasting - CloudupFasting: health risks - Live Well - NHS ChoicesWhat no one talks about when they extol the benefits of fasting - VoxFive day 'fasting' diet slows down ageing and may add years to life - TelegraphThe three-day fast: Day Four | Josh MitteldorfLifeboat Foundation Bios: Dr. Joshua MitteldorfBursts of fasting may be key to longevity and health - The Columbia Chronicle: Health & TechCould a 5-Day Fasting Diet Prolong Your Life?Effect of diet and exercise on serum insulin, IGF-I, and IGFBP-1 levels and growth of LNCaP cells in vitro (United States) - SpringerA year without food › Dr Karl's Great Moments In Science (ABC Science)The Ancient Secret of Weight LossIs Fasting an Effective Therapy for Weight Loss? - Weight LossThe Aetiology of Obesity Part 4 of 6: The Fast Solution - YouTubeVisit PuraKai to shop for eco-friendly clothing and stand-up paddle boards. Be sure to use coupon code "latest in paleo" for 15% off all clothing purchases.

Die biochemische Analyse von Hormonen wird durch drei Variablen beeinflusst – die präanalytischen, analytischen und postanalytischen Variabilität. Bezüglich der analytischen und biologischen Variabilität wurden für Nager schon zahlreiche Arbeiten veröffentlicht, jedoch ist die Präanalytik in der Untersuchung von Blutproben von Ratten, in Bezug auf die Hormonanalytik, bislang kaum beachtet worden. Deswegen wurden in dieser Arbeit einige Aspekte der Präanalytik bei der Hormonmessung in Ratten genauer untersucht; auch um Anhaltspunkte zu geben, in wie weit vorbehandelte Blutproben von Ratten zur Messung unterschiedlicher Hormone genutzt werden können und wie sich die Verwendung unterschiedlicher Probenmaterialien, als auch Einfrier-Auftau-Zyklen, auf die Messergebnisse verschiedener Stoffwechselhormone auswirken können. In Bezug auf die biologische Variabilität wurde der Einfluss von Alter und Fasten auf ausgewählte Stoffwechselhormone bei der Ratte genauer untersucht. Ziel dieser Arbeit war es, in Analyseprozessen insbesondere auf den Faktor „Präanalytik“ einzugehen und aufzuzeigen, in welchem Ausmaß Ergebnisse in der Messung von Hormonen mittels Immunassays beeinflusst werden können. Im Vergleich zu reinem Serum waren die gemessenen Konzentrationen von IGF-I (+9,2%, p

Ziel der Arbeit war es aus einem Kollektiv kleinwüchsiger, entwicklungsverzögerter, präpubertärer und sonst gesunder, nicht hGH defizienter Kinder, IGF-I und IGFBP-3 Werte zu sammeln, diese auf das chronologische Alter zu beziehen und mit bereits vorhandenen Normwerten zu vergleichen, auf das Knochenalter zu beziehen und daraus Normwertperzentilen zu erstellen, diese mit altersbezogenen Werten zu vergleichen und die Wertigkeit dieser IGF-I und IGFBP-3 Werte in der Diagnostik der Entwicklungsverzögerung zu ermitteln. Es wurde die Daten von 86 Jungen aus der endokrinologisch -pädiatrischen Ambulanz des Dr. von Hauner Kinderspitals, welche die obengenannten Kriterien erfüllten, analysiert. Aus dem Datenpool wurden mit Hilfe deskriptiver Statistiken Normwertperzentilen erstellt. Es wurden erstmals IGF-I und IGFBP-3 Werte auf das Knochenalter bezogen. Es konnte erstmals gezeigt werden, dass trotz relativ großer Schwankungen eine lineare Beziehung zwischen IGF-I und IGFBP-3 einerseits und dem Knochenalter in diesem Patientenkollektiv besteht. IGF-I und IGFBP-3 sollten statt auf das chronologische Alter auf das Skelettalter der Patienten mit einer konstitutionellen Entwicklungsverzögerung bezogen werden.

Fri, 8 Feb 2008 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/8394/ https://edoc.ub.uni-muenchen.de/8394/1/Breitsameter_Hannelore.pdf Breitsameter, Hannelore ddc:500, ddc:590, Tierärztliche F

Die IGFBP-2-Serumkonzentrationen sind beim menschlichen Kolonkarzinom mit dem Tumorstadium signifikant positiv korreliert und sogar als prognostischer Marker für eine Wiedererkrankung nach Tumorresektion informativ. Dennoch ist die spezifische Rolle von IGFBP-2 für die Entstehung und Progression des Kolonkarzinoms völlig unklar. In vitro wurden für IGFBP-2 sowohl positive als auch negative Effekte auf das Wachstum normaler und maligner Zellen nachgewiesen. Für die zweifelsfreie Zuordnung spezifischer Effekte in vivo wurde in der vorliegenden Arbeit das IGFBP-2-transgene Mausmodell verwendet. In diesem Modell wurde die Kolonkarzinogenese chemisch induziert. Um herauszufinden, in welchem Stadium der mehrstufigen Kolonkarzinogenese IGFBP-2 von Bedeutung ist, wurden die Analysen 10 und 34 Wochen nach Beginn der Behandlung mit dem Karzinogen durchgeführt. Zum früheren Analysezeitpunkt wurde festgestellt, dass IGFBP-2 zunächst die Entstehung von kleinen hyperplastischen aberranten Krypten Foci (ACF) förderte, sich diese ACF aber in der späteren Phase zurückentwickelten und keinen Einfluss auf die Tumorprävalenz hatten. Im Vergleich zum Wildtyp entwickelten die IGFBP-2-transgenen Mäuse jedoch weniger dysplastische ACF. Dysplastische ACF in IGFBP-2-transgenen Mäusen bildeten kleinere Foci und wiesen einen deutlich geringeren Dysplasiegrad auf. Größere ACF des transgenen Genotyps stellten den hyperplastischen ACF-Typ dar. Interessanterweise war die Expression von β-Catenin in den ACF transgener Tiere gegenüber dem Wildtyp deutlich reduziert. Diese Ergebnisse deuten darauf hin, dass IGFBP-2 einen hemmenden Effekt bereits im frühen Stadium der Kolonkarzinogenese ausübt. Zum späteren Untersuchungszeitpunkt unterschied sich die Tumorprävalenz zwischen den beiden Genotypen nicht voneinander. Jedoch war das Volumen der Adenome der IGFBP-2-transgenen Gruppe um das 2,3-fache kleiner als beim Wildtyp, was durch einen geringeren Anteil an proliferierenden Tumorzellen bedingt war und sich bereits bei den ACF der frühen Phase abzeichnete. Zudem wurde, in Übereinstimmung mit den Ergebnissen der früheren Phase, eine deutlich geringere nukleäre Akkumulation von β-Catenin in den Adenomen IGFBP-2-transgener Tiere beobachtet. Diese Ergebnisse zeigen, dass IGFBP-2 sowohl in der frühen als auch in der späteren Phase der Kolonkarzinogenese einen hemmenden Effekt auf das Wachstum von dsyplastischen ACF und Tumoren hat, indem es die Tumorlast reduziert und die Akkumulation von nukleärem β-Catenin inhibiert. Um Effekte von IGFBP-2 auch auf Ebene der Genexpression zu berücksichtigen, wurde eine Expressionsanalyse von Kandidatengenen, die aus der Literatur im Zusammenhang mit einer Überexpression von IGFBP-2 bekannt waren, durchgeführt. Interessanterweise ergab die Real-Time PCR Analyse eine erhöhte MMP2-, TIMP1- und NFκB-mRNA Expression in Tumoren, nicht aber im normalen Kolongewebe von IGFBP-2-transgenen Mäusen. Aus der konditionalen Überexpression von Invasions- und Migrations-assoziierten Genen im Tumor von IGFBP-2-transgenen Mäusen könnte auf einen möglichen Effekt von IGFBP-2 auf die Metastasierung geschlossen werden. Die Relevanz dieser veränderten Genexpression sollte in einem Metastase-Modell weiterführend untersucht werden.

Background: The loss of alveolar walls is a hallmark of emphysema. As fibroblasts play an important role in the maintenance of alveolar structure, a change in fibroblast phenotype could be involved in the pathogenesis of this disease. In a previous study we found a reduced in vitro proliferation rate and number of population doublings of parenchymal lung fibroblasts from patients with emphysema and we hypothesized that these findings could be related to a premature cellular aging of these cells. In this study, we therefore compared cellular senescence markers and expression of respective genes between lung fibroblasts from patients with emphysema and control patients without COPD. Methods: Primary lung fibroblasts were obtained from 13 patients with moderate to severe lung emphysema ( E) and 15 controls ( C) undergoing surgery for lung tumor resection or volume reduction ( n = 2). Fibroblasts (8E/9C) were stained for senescence- associated beta-galactosidase (SA-beta-Gal). In independent cultures, DNA from lung fibroblasts (7E/8C) was assessed for mean telomere length. Two exploratory 12 k cDNA microarrays were used to assess gene expression in pooled fibroblasts (3E/ 3C). Subsequently, expression of selected genes was evaluated by quantitative PCR (qPCR) in fibroblasts of individual patients (10E/9C) and protein concentration was analyzed in the cell culture supernatant. Results: The median ( quartiles) percentage of fibroblasts positive for SA-beta-Gal was 4.4 (3.2; 4.7) % in controls and 16.0 (10.0; 24.8) % in emphysema ( p = 0.001), while telomere length was not different. Among the candidates for differentially expressed genes in the array ( factor = 3), 15 were upregulated and 121 downregulated in emphysema. qPCR confirmed the upregulation of insulin-like growth factor-binding protein ( IGFBP)-3 and IGFBP-rP1 ( p = 0.029, p = 0.0002), while expression of IGFBP-5, - rP2 ( CTGF), - rP4 (Cyr61), FOSL1, LOXL2, OAZ1 and CDK4 was not different between groups. In line with the gene expression we found increased cell culture supernatant concentrations of IGFBP-3 ( p = 0.006) in emphysema. Conclusion: These data support the hypothesis that premature aging of lung fibroblasts occurs in emphysema, via a telomere-independent mechanism. The upregulation of the senescence- associated IGFBP-3 and - rP1 in emphysema suggests that inhibition of the action of insulin and insulin-like growth factors could be involved in the reduced in vitro-proliferation rate.

Ziel der vorliegenden Arbeit war die Untersuchung der Auswirkung von Wachstumshormon (Versuch 1) sowie Insulin-ähnliches-Bindungsprotein-2 (Versuch 2) auf den Knochenstoffwechsel. Hierzu wurden im transgenen Mausmodell die Knochenresorptionsmarker Pyridinolin und Desoxypyridinolin im Urin bestimmt. Im Versuch 1 wurde die Ausscheidung der Resorptionsmarker von Mt-bGH-transgenen Mäusen während der ersten neun Lebensmonate in regelmäßigen Abständen bestimmt, um so Rückschlüsse auf den Knochenstoffwechsel während der unterschiedlichen Entwicklungsstadien machen zu können. Im Versuch 2 wurde die Auswirkung einer IGFBP-2-Überexpression auf die Knochenresorption in Ab- und Anwesenheit einer GH-Überexpression im PEPCK-bGH-transgenen Mausmodell untersucht.

Insulin-like growth factor I (IGF-I) and -II (IGF-II) are single chain peptides produced by many tissues, functioning in an endocrine, autocrine or paracrine fashion to regulate cellular proliferation, survival and differentiation. IGF actions are initiated upon binding to the insulin-like growth factor I receptor (IGF-IR) and are modulated through interactions with a family of six secreted IGF-binding proteins (IGFBP-1 to -6). IGF-I is necessary for normal growth and differentiation during both, embryonic and postnatal development. IGF-II is a stimulator of fetal growth but its functions in the postnatal period are still unclear. Notably, expression of IGF-II is shut down shortly after birth in rodents (but not in humans). Previous studies in phosphoenolpyruvate-carboxykinase (PEPCK)-IGF-II transgenic mice demonstrated that overexpression of IGF-II resulted in disproportionate growth of specific organs but a significant increase in body size was not observed. Homozygous IGF-I deficient mice were shown to be severely retarded in growth. The aim of this study was to test whether elevated levels of circulating IGF-II can rescue the dwarfism in IGF-I deficient mice and thereby function as a stimulator of postnatal growth in the absence of IGF-I. For this purpose, we crossed heterozygous IGF-I deficient mice [I+/- IIwt] with heterozygous IGF-I deficient mice carrying PEPCK-IGF-II transgenes [I+/- IItg]. The resulting offspring comprised six different groups: homozygous IGF-I knockout and PEPCK-IGF-II wildtype mice [I-/- IIwt], homozygous IGF-I knockout and PEPCK-IGF-II transgenic mice [I-/- IItg], animals lacking one IGF-I allele and wildtype for the PEPCK-IGF-II transgene [I+/- IIwt], lacking one IGF-I allele and harbouring the PEPCK-IGF-II transgene [I+/- IItg], wildtype for the IGF-I mutation and carrying the PEPCK-IGF-II transgene [I+/+ IItg], and completely wildtype [I+/+ IIwt]. The genotype of all mice was determined by PCR. Body weight of mice was recorded daily until the age of 8 weeks. The nose-rump length (NRL) and the weights of individual organs and of the carcass were recorded and the femurs and lumbar vertebras prepared for further investigations. At an age of 8 weeks, mean serum concentrations of IGF-I were beyond detection level in [I-/- IIwt] and [I-/- IItg] mice, intermediate in [I+/- IIwt] and [I+/- IItg] animals and highest in [I+/+ IIwt] and [I+/+ IItg] mice. IGF-II levels were significantly increased in animals harbouring the PEPCK-IGF-II transgene ([I-/- IItg], [I+/- IItg], and [I+/+ IItg]) when compared to their wildtype counterparts ([I-/- IIwt], [I+/- IIwt], and [I+/+ IIwt]). This reflected the genotype, demonstrating the appropriateness of our experimental model. Analysis of body weight data from day 3-4 after birth until day 60 revealed that in the absence of IGF-I, elevated levels of IGF-II have no effect on body weight gain. The same was found for the nose-rump length and the carcass. The weight of specific organs, however, was altered. Compared to the wildtype counterparts ([I-/- IIwt]), the relative kidney weight in [I-/- IItg] mice was significantly increased. IGF-I is known to play an important role in bone growth and in cancellous bone homeostasis. Investigations of geometric and structural bone parameters showed that in the presence or absence of IGF-I, an increase in the circulating levels of IGF-II was without effect on the skeleton and could not substitute for the skeletal functions of IGF-I in IGF-I-ablated mice. Homozygous IGF-I deficient mice are known to have elevated levels of growth hormone (GH). To demonstrate that the lack of effect on growth in our [I-/- IItg] animals was not due to a loss of these elevated GH-levels, a GH-Western immunoblot was performed, revealing that, despite elevated levels of IGF-II, increased levels of GH were still present in [I-/- IItg] animals. Evaluation of the serum levels of IGFBPs by Western ligand blot analysis demonstrated that IGFBP-1 and IGFBP-4 levels were similar in all groups, whereas the levels of IGFBP-2 and IGFBP-3 were strongly reduced in [I-/- IIwt] animals. In the presence of IGF-II ([I-/- IItg]), they were partially restored but the amounts were still smaller than in the IGF-I wildtype animals ([I+/+ IIwt] and [I+/+ IItg]). In summary, these results show that under our experimental conditions, IGF-II is not able to rescue the postnatal growth deficit of IGF-I knockout mice and apparently does not exert a negative feedback on the secretion of growth hormone. However, it could be demonstrated, that the IGFs have differentiated effects on the regulation of the expression/stability of individual IGFBPs.

Wachstum und Differenzierung sind zentrale Prozesse bei der Entstehung und Entwicklung des Lebens. Die Größe eines Zellverbandes wird vor allem durch die Balance zwischen Zellwachstum, Proliferation und die Apoptoserate definiert (Lupu et al. 2001). Unterschiedliche Größen von Organen können durch unterschiedliche Zellzahlen und/oder durch unterschiedliche Zellgrößen bedingt sein. So ist der Mensch beispielsweise größer als eine Maus, vor allem weil er mehr Zellen hat (Raff 1996). Im Vergleich dazu wurden bei verschiedenen Drosophila-Unterarten unterschiedliche Flügelgrößen aufgrund einer Änderung der Zellgröße entdeckt (Prout & Barker 1989). Allerdings ist bis heute nur unzureichend geklärt, wie das Wachstum durch Zellgröße und -zahl koordiniert ist und wie dadurch Struktur und Funktion von Organen bzw. Organismen entstehen. Ein zentrales regulatorisches System für die Kontrolle des Wachstums ist das GH/IGF (Wachstumshormon/Insulin-Like Growth Factor)-System. Ohne die endo- und parakrin wirksamen Komponenten GH und IGF-I ist in der Maus postnatal nahezu kein Wachstum möglich. Mäuse, die weder funktionelles GH noch IGF-I besitzen, erreichen nur 17 % der Größe und des Gewichts einer vergleichbaren adulten Maus. Damit stoßen sie an die kleinste gerade noch für ein Säugetier tolerierbare Größe (Lupu et al. 2001). Wichtige Vermittler der gewebespezifischen Wirkungen von IGF-I und -II sind die IGF-Bindungsproteine (IGFBPs). Bislang sind sechs unterschiedliche IGFBPs bekannt, die durch eine hohe Affinität für die IGFs definiert sind und damit deren biologische Wirkungen beeinflussen. Unter den IGFBPs nimmt IGFBP-2 eine besondere Stellung ein, weil es ein in vivo relevanter Inhibitor für Wachstum ist. Es konnte gezeigt werden, dass IGFBP-2 die Effekte von GH auf die Zellgröße modulieren kann. Während GH in Zona fasciculata Zellen der Nebenniere 11 Wochen alter Mäuse sowohl Zellzahl als auch Zellgröße stimulierte, wirkte sich die Koexpression von IGFBP-2 in einer Normalisierung der GH-induzierten Zellgröße, nicht jedoch der GH-induzierten Zellzahlerhöhung aus (Hoeflich et al. 2002). Dieses Modell eignet sich somit ideal, um die Regulation von Zellgröße und Zellzahl getrennt zu untersuchen. In der vorliegenden Arbeit wurden die molekularen Grundlagen dieser Veränderungen sowohl auf der Ebene des Transkriptoms, als auch der Proteine untersucht. Um Fragen zur Altersabhängigkeit der Wachstumsregulation zu bearbeiten, wurde die Untersuchung an zwei verschiedenen Altersgruppen durchgeführt.

Fri, 11 Feb 2005 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/3404/ https://edoc.ub.uni-muenchen.de/3404/1/Fisch_Thomas_M.pdf Fisch, Thomas Martin

Thu, 15 Jul 2004 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/2453/ https://edoc.ub.uni-muenchen.de/2453/1/Dissertation_T_Pavicic.pdf Pavicic, Tatjana

Insulin-like growth factors (IGF-I and IGF-II) are expressed in many cell types and tissues and act in endocrine, autocrine or paracrine manner to regulate cellular proliferation, survival and differentiation. IGF actions are initiated upon binding to the type I IGF receptor (IGF-IR) and are modulated through interactions with a family of six secreted IGF-binding proteins (IGFBP-1 to -6). Although the six conserved IGFBPs are structurally related, each of them has specific characteristics and may have specific functions. Most knowledge about the IGFBPs has been gained from the numerous in vitro studies, their specific roles in vivo are largely unknown. Transgenic mice overexpressing a particular IGFBP allow us to investigate the specific functions of the corresponding IGFBP in vivo. To this end, IGFBP-4- and IGFBP-6-overexpressing models were established and analyzed in the present study. First, an expression vector containing the murine H-2Kb promoter and a human beta-globin splicing cassette was used to construct the transgenes, to obtain ubiquitous expression of the mouse Igfbp4 and Igfbp6 cDNA. Two lines of H-2Kb-mcIGFBP-4 and ten lines of H-2Kb-mcIGFBP-6 transgenic mice were generated. The transgene was ubiquitously expressed at RNA level in both transgenic models, however, at protein level, transgene expression was only detected in the spleen, thymus, lung and kidney of both H-2Kb-mcIGFBP-4 transgenic lines, but in no organ of H-2Kb-mcIGFBP-6 transgenic mice. Phenotypic analyses of the H-2Kb-mcIGFBP-4 transgenic model revealed that overexpression of IGFBP-4 had no significant effect on the postnatal body and organ growth, except that the weight and volume of thymus in 8- and 12-week-old transgenic mice were significantly reduced (p < 0.05) compared to the controls. Histomorphometric analysis demonstrated that the volume of the thymic cortex was significantly decreased in transgenic mice (p < 0.05), whereas that of the thymic medulla was not changed. The fractions of various cell types in the bone marrow, thymus, spleen, lymph node and peripheral blood were determined by flow cytometry. No significant difference was found between transgenic and control groups, suggesting that IGFBP-4 excess in the lymphoid organs did not affect the development of the lymphatic cells. The proliferative capacity of the splenocytes of transgenic animals was significantly reduced after Con A and LPS stimulation (p < 0.05), but not altered after the stimulation by anti-CD3 and anti-IgM/IL2. This is probably due to transgenic IGFBP-4 expression restricted in the non-lymphatic cells. However, detailed expression of the transgene warrants further investigation. In order to realize IGFBP-6-overexpressing mice, a second construct was designed, namely CMV-mgIGFBP-6, in which the mouse Igfbp6 genomic sequence was cloned under the control of the cytomegalovirus (CMV) promoter. Four independent lines of transgenic mice were generated. Transgene expression was high in the exocrine pancreas and relatively low in the lung and liver. The activities of serum IGFBPs were not different between transgenic mice and controls. In transgenic mice, high levels of active IGFBP-6 were detected in the luminal content of the duodenum, but neither in the luminal contents of other segments of the gastrointestinal tract (GIT), nor in tissue extracts of all GIT segments. Glucose homeostasis was not altered by IGFBP-6 expression. Postnatal body and organ growth was not affected in transgenic mice, except for the absolute and relative weight and length of duodenum which were significantly reduced in 4-month-old transgenic mice as compared to controls (p < 0.05). This reduction was mainly due to a significantly smaller volume and surface area of the tunica mucosa as determined by histomorphometric analsis. Our analysis of the first IGFBP-6 transgenic mouse model provides direct evidence for inhibition of intestinal growth by luminal IGFBP-6 excess. This finding is important in the context of neonatal intestinal growth of mammals, considering the fact that milk contains large amount of IGFBPs which may at least in part arrive intact in the intestine.

Die Vorhersage der Fertilität und die Aufklärung von Zusammenhängen zwischen der Befruchtungsfähigkeit und Parametern im Organismus ist in der Reproduktionsmedizin ein zentrales Anliegen, um eine effizientere Selektion hochfertiler Tiere zu erreichen. Das Seminalplasma wurde als geeigneter Parameter zur Beurteilung der Fertilität identifiziert, da die positive Beeinflussung der Spermienmotilität und die Vorverlegung der Ovulation durch Seminalplasma nachgewiesen wurde. Diese Arbeit hatte das Ziel anhand verschiedener Pietrainebergruppen und Hybridebergruppen einerseits Komponenten des IGF-Systems im Eberseminalplasma zu identifizieren und ihren Einfluss auf die Fertilität zu überprüfen, andererseits mittels der Proteomics-Technik das komplexe Proteingemisch im Eberseminalplasma zu analysieren. Es wurde das Vorhandensein von IGF-I/II im Eberseminalplasma nachgewiesen, ein Zusammenhang mit der Fertilität bestand nicht. Die Untersuchung der IGFBP-Aktivität ergab beim Vergleich der verschiedenen Pietrainebergruppen signifikante Unterschiede in der relativen Intensität der IGFBP-Banden, die Hybrideber bestätigten diese Ergebnisse nicht. Um eine möglichst einfache, nicht radioaktive Testung dieser IGFBP-Aktivität zu ermöglichen, war es nötig, zu ermitteln, um welche IGFBPs es sich bei diesen Banden handelte. In einer Seminalplasmaprobe wurde IGFBP-5 mittels MALDI-MS identifiziert. Ein Western-Blot mit gegen IGFBP-5 generierten Antikörpern wäre ein effektives Verfahren zur Ermittlung der IGFBP-5-Aktivität im Eberseminalplasma. Die Nutzung der Proteomics-Technik zur Darstellung des Proteinmusters im Eberseminalplasma erwies sich als problematisch, da eine vertikale Streifung und die starke Intensität einzelner Spots die Identifizierung erschwerte. Es wurden mittels MALDI-TOF-TOF PSP-I und b-Mikroseminoprotein identifiziert.Um möglicherweise von PSP-I maskierte Proteine geringerer Intensität darstellen zu können, war es nötig, den PSP-I Gehalt vor der 2D-Gelelektrophorese zu verringern. Antikörper, die gegen zwei Hauptisoformen des PSP-I generiert wurden, zeigten hohe Titer gegen PSP-I und waren auch in der Lage natives PSP-I zu erkennen. Damit ist die affinitätschromatographische Abreicherung von PSP-I möglich und dadurch die Verbesserung der Trennleistung, so dass die 2D-Gelelektrophorese zur Identifizierung positiv wirksamer Proteinkomponenten im Seminalplasmas effizient genutzt werden kann.

The putative effects of diabetes and metabolic control on circulating levels of insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) remain controversial. In the present study, serum levels of IGF-I and IGF-II and IGFBP-1, -2, and -3 were measured in 58 patients (age, 0.8-17 yr) with treated (51 subjects) or untreated (7 subjects) insulin-dependent diabetes mellitus (IDDM) and were compared with the levels in normal subjects. In the untreated patients IGF-I and IGF-II were decreased as compared with the healthy controls. In the treated diabetics IGF-I and IGF-II were reduced; IGFBP-2 (only in prepubertal subjects) and IGFBP-3 were increased. Furthermore, age-adjusted values of IGF-I, IGF-II, and IGFBP-3 were lower in prepubertal than in pubertal patients. Regression analysis revealed a negative correlation between hemoglobin (Hb)A1c and standard deviation scores (SDS) of IGF-I and a positive association between HbA1c and IGFBP-1 SDS or IGFBP-2 SDS. In the treated patients HbA1c was positively related to IGFBP-1 SDS and IGFBP-2 SDS when applying simple regression analysis and to IGFBP-2 SDS when using a multiple regression model. Strong correlations were observed between height SDS and IGF-I SDS, IGF-II SDS, and IGFBP-3 SDS in prepubertal subjects who had had IDDM for at least 2 yr, but not in adolescents. Such correlations have also been found in healthy children and adolescents. In conclusion; 1) IDDM is associated with alterations of the IGF-IGFBP system, which are partially accounted for by differences in metabolic control and pubertal status; 2) the lower plasma concentrations of serum IGF-I may play a role in the pathogenesis of growth impairment of poorly controlled prepubertal, but not pubertal, children and adolescents with IDDM; and 3) in addition, a potential role of the altered IGF-IGFBP system for the development of diabetic late complications is hypothesized.

Insulin-like growth factor-II (IGF-II) is an important regulator of embryonic growth and differentiation, but its function in postnatal life is unclear. To address this point, we generated transgenic mice harboring fusion genes in which a human IGF-II complementary DNA is placed under the transcriptional control of the rat phosphoenolpyruvate carboxykinase promoter. Transgene-specific messenger RNA was detected in liver, kidney, and several parts of the gut. Serum IGF-II levels in transgenic mice were 2-3 times higher than those in controls and increased after starvation. Circulating IGF-I correlated negatively and IGF-binding protein-2 (IGFBP-2) positively with IGF-II levels, suggesting that IGF-I is displaced from IGFBPs by IGF-II and that IGFII is a major regulator of IGFBP-2. Serum levels of IGFBP-3 and IGFBP-4 tended to be higher in phosphoenolpyruvate carboxykinase- IGF-II transgenic mice than in controls, as evaluated by ligand blot analysis. Starvation reduced serum IGF-I, but increased IGFBP-2 in transgenic mice more markedly than in controls. Fasting insulin levels were significantly reduced in transgenic mice, whereas glucose levels were not influenced by elevated IGF-II. The body growth of 4- and 12- week-old mice was not significantly influenced by elevated IGF-II, but transgenic mice displayed increased kidney and testis weight at the age of 4 weeks, and increased adrenal weight at the age of 12 weeks. Our results demonstrate that elevated IGF-II in postnatal life has multiple endocrine consequences and subtle time-specific effects on organ growth.