Podcasts about CD31

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.07.527573v1?rss=1 Authors: Shalaby, R. A., Qureshi, M. M., Khan, M. A., Salam, S. M. A., Kwon, H. S., Lee, K. H., Chung, E., Kim, Y. R. Abstract: Background: Ischemic stroke typically accompanies numerous disorders ranging from somatosensory dysfunction to cognitive impairments, inflicting its patients with various neurologic symptoms. Among pathologic outcomes, post-stroke olfactory dysfunction is frequently observed. Despite the well-known prevalence, therapy options for such compromised olfaction are limited, likely due to the complexity of the olfactory bulb architecture, which encompasses both the peripheral and central nervous systems. As photobiomodulation (PBM) emerged for treating stroke-associated symptoms, the effectiveness of PBM on the stroke-induced impairment of the olfactory function was explored. Purpose: To address the efficacy of PBM therapy on the olfactory bulb damage caused by ischemic stroke using both behavioral and histologic and inflammatory markers in the newly developed stroke mouse models. Methods: Novel mouse models with olfactory dysfunction were prepared using photothrombosis (PT) in the olfactory bulb on day 0. Moreover, post-PT PBM was performed daily from day 2 to day 7 by irradiating the olfactory bulb using an 808 nm laser with the fluence of 40 J/cm2 (325 mW/cm2 for 2 minutes per day). The buried food test (BFT) was used for scoring behavioral acuity in the food-deprived mice to assess the olfactory function before PT, after PT, and after PBM. Histopathological examinations and cytokine assays were performed on the mouse brains harvested on day 8. Results: The results from BFT were specific to the individual, with positive correlations between the baseline latency time measured before PT and alterations at the ensuing stages for both the PT and PT+PBM groups. Also in both groups, the correlation analysis showed a significant positive relationship between the early and late latency time changes independent of PBM, implicating a common recovery mechanism. In particular, the PBM treatment largely accelerated the recovery of impaired olfaction after PT with the suppression of inflammatory cytokines while enhancing both the glial and vascular factors (e.g., GFAP, IBA-1, and CD31). Conclusions: The PBM therapy during the acute phase of ischemia improves the compromised olfactory function by modulating the microenvuronment and tissue inflammation. Keywords: Ischemic stroke, olfactory dysfunction, photothrombosis, photobiomodulation, buried food test, olfactory bulb, neuroinflammation. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.14.512258v1?rss=1 Authors: MARR, N., ZAMBOULIS, D. E., WERLING, D., FELDER, A. A., DUDHIA, J., PITSILLIDES, A. A., THORPE, C. T. Abstract: The interfascicular matrix (IFM) is critical to the mechanical adaptations and response to load in energy-storing tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT). We hypothesized that the IFM is a tendon progenitor cell niche housing an exclusive cell subpopulation. Immunolabelling of equine SDFT was used to identify the IFM niche, localising expression patterns of CD31 (endothelial cells), CD146 (IFM cells) and LAMA4 (IFM basement membrane marker). Magnetic-activated cell sorting was employed to isolate and compare in vitro properties of CD146+ and CD146- subpopulations. CD146 demarcated an exclusive interfascicular cell subpopulation that resides in proximity to a basal lamina which forms interconnected vascular networks. Isolated CD146+ cells exhibited limited mineralization (osteogenesis) and lipid pro-duction (adipogenesis). This study demonstrates that the IFM is a unique tendon cell niche, con-taining a vascular-rich network of basement membrane, CD31+ endothelial cells and CD146+ cell populations that are likely essential to tendon structure- and/or function. Interfascicular CD146+ subpopulations did not exhibit stem cell-like phenotypes and are more likely to represent a per-icyte lineage. Previous work has shown that tendon CD146 cells migrate to sites of injury, therefore mobilisation of endogenous tendon IFM cell populations may promote intrinsic repair. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

3:00 News5:04 Omnio14:01 Adocia24:28 Tridek-One29:49 Phenomix Sciences47:27 JLLThis week, we have four guests: Olivier Soula, deputy-CEO and director of R&D at Adocia; Ulrika Norin, CEO of Omnio; Mark Bagnall, CEO of Phenomix Sciences; and Laurence de Schoulepnikoff, CEO of Tridek-One.We also have our weekly chat with global commercial real estate services company JLL, with Travis McCready. This week's podcast is sponsored by Labforward.Adocia takes steps with implants to treat type 1 diabetesFrench biopharma company Adocia has established a first proof of concept for its AdoShell Islets implant by achieving glycemic control without insulin injections in immunocompetent diabetic rats during the 132-day study.AdoShell Islets is an immuno-protective synthetic biomaterial containing islets of Langerhans. After implantation in diabetic animals, the islets encapsulated in AdoShell secrete insulin in response to blood glucose levels. The physical barrier formed by the AdoShell biomaterial allows the implanted cells to be invisible to the host's immune system while allowing the necessary physiological exchanges to occur for the survival and function of the islets.Phenomix Sciences' precision obesity biobanking registry and outcomes studyPhenomix Sciences, a precision obesity biotechnology company,has launched a biobanking registry and outcomes study. The registry will evaluate variability in obesity treatment response by collecting patients' DNA, metabolomics, hormones, and behavioral assessments, in relation to treatment outcomes. The data collected will supplement the 20 billion data points in the Phenomix Sciences Obesity Platform. Mayo Clinic is the first to enroll in the registry and is expected to contribute outcomes from 2,000 patients undergoing obesity treatment.  Outcomes data from biobanks across the registry will supplement Phenomix's database of biological and clinical data matched to the four obesity phenotypes.  Insights from the database are being used to develop the company's first therapy selection test, the first of its kind in the obesity space.Tridek-One closes €16M funding round Tridek-One SAS, a French biotech startup specialized in the research and development of CD31 agonists to restore immune balance, recently closed a €16 million ($16.1 million) new financing round.The funds will primarily be used to identify development candidates against auto-immunediseases, to conduct IND-enabling studies and to further build the organization. The company previously raised €3 million in a first round in 2019.Omnio receives funding for plasminogen to treat chronic woundsSwedish company Omnio AB has shown plasminogen is a pro-inflammatory regulator of inflammation that can be used to treat chronic wounds with dysfunctional inflammation.The Umeå-based company, a spin off from Umeå University, said the drug could mean a global treatment revolution for wounds that never heal. The most problematic are diabetic ulcers, venous ulcers, and pressure ulcers. Omnio recently received a capital injection of €1.5 million from its shareholders. 

Oncotarget published "Carcinoma cells that have undergone an epithelial-mesenchymal transition differentiate into endothelial cells and contribute to tumor growth" which reported that the authors investigated whether EMT can confer endothelial attributes upon carcinoma cells, augmenting tumor growth and vascularization. Hypoxic regions, demarcated by HIF-1α staining, exhibited focal areas of E-cadherin loss and elevated levels of vimentin and the EMT-mediator FOXC2. Implantation of MCF-7 cells, co-mixed with human mammary epithelial cells overexpressing the EMT-inducer Snail, markedly potentiated tumor growth and vascularization, compared with MCF-7 cells injected alone or co-mixed with HMLE-vector cells. Intra-tumoral vessels contained CD31-positive cells derived from either donor cell type. FOXC2 knockdown abrogated the potentiating effects of HMLE-Snail cells on MCF-7 tumor growth and vascularization, and compromised endothelial transdifferentiation of mesenchymal cells cultured in endothelial growth medium. Hence, cells that have undergone EMT can promote tumor growth and neovascularization either indirectly, by promoting endothelial transdifferentiation of carcinoma cells, or directly, by acquiring an endothelial phenotype, with FOXC2 playing key roles in these processes. A fourth mechanism—termed vasculogenic mimicry—entails the de novo generation of microvessels, lined with highly invasive tumor cells embedded in a rich extracellular matrix, essentially mimicking a true vascular endothelium and, notably, lacking in the endothelial cell markers CD31 and CD34. Finally, newly formed blood vessels may emerge through transdifferentiation of neoplastic or tumor stem-like cells into CD31-positive endothelial-like cells, as has been documented in neuroblastoma, B-cell lymphoma, and glioblastoma. In addition, subcutaneous injection of B16 melanoma cells into Foxc2 haploinsufficient mice has been shown to lead to the impaired formation of tumor blood vessels and, accordingly, compromise tumor growth. Given the inherent plasticity of cells that have undergone EMT and the involvement of hypoxia in EMT and angiogenesis, the authors sought to ascertain whether cells, undergoing EMT in the hypoxic milieu, can acquire endothelial cell attributes and augment tumor growth by directly contributing to the tumor vasculature. These findings findings link the stemness, conferred through EMT, to the acquisition of endothelial cell traits and the augmentation of tumor angiogenesis in a FOXC2-dependent manner. The Sarkar Research Team concluded in their Oncotarget Research Output that their findings are consistent with the notion that the phenotypic attributes of cells within growing tumors are eminently pliable and that, as tumor size and the oxygen deficit increase, carcinoma cells become progressively dedifferentiated towards a mesenchymal, stem-like phenotype. DOI - https://doi.org/10.18632/oncotarget.27940

Oncotarget published "Carcinoma cells that have undergone an epithelial-mesenchymal transition differentiate into endothelial cells and contribute to tumor growth" which reported that the authors investigated whether EMT can confer endothelial attributes upon carcinoma cells, augmenting tumor growth and vascularization. Hypoxic regions, demarcated by HIF-1α staining, exhibited focal areas of E-cadherin loss and elevated levels of vimentin and the EMT-mediator FOXC2. Implantation of MCF-7 cells, co-mixed with human mammary epithelial cells overexpressing the EMT-inducer Snail, markedly potentiated tumor growth and vascularization, compared with MCF-7 cells injected alone or co-mixed with HMLE-vector cells. Intra-tumoral vessels contained CD31-positive cells derived from either donor cell type. FOXC2 knockdown abrogated the potentiating effects of HMLE-Snail cells on MCF-7 tumor growth and vascularization, and compromised endothelial transdifferentiation of mesenchymal cells cultured in endothelial growth medium. Hence, cells that have undergone EMT can promote tumor growth and neovascularization either indirectly, by promoting endothelial transdifferentiation of carcinoma cells, or directly, by acquiring an endothelial phenotype, with FOXC2 playing key roles in these processes. A fourth mechanism—termed vasculogenic mimicry—entails the de novo generation of microvessels, lined with highly invasive tumor cells embedded in a rich extracellular matrix, essentially mimicking a true vascular endothelium and, notably, lacking in the endothelial cell markers CD31 and CD34. Finally, newly formed blood vessels may emerge through transdifferentiation of neoplastic or tumor stem-like cells into CD31-positive endothelial-like cells, as has been documented in neuroblastoma, B-cell lymphoma, and glioblastoma. In addition, subcutaneous injection of B16 melanoma cells into Foxc2 haploinsufficient mice has been shown to lead to the impaired formation of tumor blood vessels and, accordingly, compromise tumor growth. Given the inherent plasticity of cells that have undergone EMT and the involvement of hypoxia in EMT and angiogenesis, the authors sought to ascertain whether cells, undergoing EMT in the hypoxic milieu, can acquire endothelial cell attributes and augment tumor growth by directly contributing to the tumor vasculature. These findings findings link the stemness, conferred through EMT, to the acquisition of endothelial cell traits and the augmentation of tumor angiogenesis in a FOXC2-dependent manner. The Sarkar Research Team concluded in their Oncotarget Research Output that their findings are consistent with the notion that the phenotypic attributes of cells within growing tumors are eminently pliable and that, as tumor size and the oxygen deficit increase, carcinoma cells become progressively dedifferentiated towards a mesenchymal, stem-like phenotype. DOI - https://doi.org/10.18632/oncotarget.27940

In this episode, Shane talks with Jimmy Clare, motivational speaker, autism advocate, and founder of crazyfitnessguy.com. They talk about getting fit, losing weight, and how exercise improves your mental health. Jimmy also shares what it's like growing up on the autism spectrum. Of course, you won't want to miss reminiscing about stinky lockers and recording bloopers! Be sure to write Lewis Howes to get Jimmy on his show! Twitter, Facebook, Instagram: @LewisHowes Resources Mentioned in this Episode Jimmy's website crazyfitnessguy.com Time Tune Follow Jimmy Instagram: @Jimmy.Clare.Speaker Twitter: @jimmyclarespeak Facebook: @Jimmy.Clare.Speaker LinkdIn: @Jimmy Clare --- This episode is sponsored by · Anchor: The easiest way to make a podcast. https://anchor.fm/app Support this podcast: https://anchor.fm/carpediemliving/support

Hello all! Today we feature the poetry of Mark Gordon!Mark Gordon is a novelist and poet who grew up in Halifax, Nova Scotia. His poetry has appeared in numerous literary journals in the United States and Canada. He is presently living in Toronto. "Raconteur" was recently published in Gravitas, edited by Andrew Lafleche. Please check out this wonderful literary magazine! https://andrewlafleche.com/gravitas-poetryVisit Mark on Twitter for updates on his latest work, and on his website http://www.markgordonauthor.com/ Thank you for your sharing your work with us, Mark!If you'd like to hear your short works of poetry, flash fiction, and dramatic writing on the podcast, submit your short work today!Don't be idle, make art! Much love,j

  This month on Episode 111 of the Discover CircRes podcast, host Cindy St. Hilaire highlights three featured articles from the March 27 issue of Circulation Research and talks with Dr. Matthias Nahrendorf  and Dr. Maximilian Schloss about their article Modifiable Cardiovascular Risk, Hematopoiesis and Innate Immunity.   Article highlights:   Liu et al. Genetics of Transposition of the Great Arteries   Park et al. Mild Lipid Abnormalities and ASCVD in the Young Yan, et al. Gut Flora Adjusts Blood Pressure By Corticosterone Transcript Cindy St. Hilaire:              Hello and welcome to Discover CircRes, the podcast of the American Heart Association's journal, Circulation Research. I'm your host, Dr Cindy St. Hilaire from the Vascular Medicine Institute at the University of Pittsburgh. Today, I'm going to share with you articles selected from the March 27th issue of Circulation Research, as well as give you a hint of the cutting-edge ideas in the Compendium on atherosclerosis. We'll also have a discussion with Dr Maximilian Schloss and Matthias Nahrendorf about their article On Modifiable Cardiovascular Risk, Hematopoiesis And Innate Immunity. So, first the highlights.                                            The first article I'm sharing with you is titled Exome-Based Case Control Analysis Highlights the Pathogenic Role of Ciliary genes and Transposition of the Great Arteries Exome-Based Case-Control Analysis Highlights the Pathogenic Role of Ciliary Genes in Transposition of the Great Arteries. The first authors are Xuanyu Liu and Wen Chen and the corresponding author is Zhou Zhou from Peking Union Medical College in Beijing, China. In normal healthy hearts, the aorta develops from the left ventricle and the pulmonary arteries from the right ventricle, but in the common congenital heart malformation called transposition of the great arteries or TGA, the plumbing of these two major vessels is switched. Thus, the pulmonary arteries arise from the left ventricle and the aorta from the right.                                            This is a life-threatening condition, requires surgery in the earliest days of life and currently, the genetic etiology of this congenital disease is largely unknown. To identify the genetic drivers of transposition of the great arteries, the authors of this study performed whole exome sequencing of 249 TGA patients and, in 66 cases, they were actually able to do exome sequencing on their parents as well. The analysis identified 82 candidate genes in which the allele variant or mutation that was found in TGA patients was predicted to alter protein function.                                            Interestingly, a quarter of these mutations or variants were found to be in genes that are involved in cilia function. So, the cilium is an organelle that's found on all eukaryotic cells and is in the shape of a slender protuberance that projects from the much larger cell body. Recently, cilia have been identified as playing a central role in the pathogenesis of congenital heart diseases, and it has been suggested that congenital heart disease may be a new class of ciliopathy. Transposition of the great arteries has been hypothesized to arise from disturbances in the left right patterning during embryo development, and cilia are required cellular organelles and they are essential for left-right axis determination in early development. These findings add to the growing body of evidence that has identified a role of cilia genes and congenital heart disease and may lead to future prenatal diagnostic screenings.                                            The next article I want to highlight is titled Mildly Abnormal Lipid Levels, but Not High Lipid Variability, Are Associated with Increased Risk of Myocardial Infarction and Stroke in ‘Statin-Naive’ Young Population: A Nationwide Cohort Study. The first author is Jun-Bean Park and the corresponding author is Hyung-Kwan Kim from Seoul National University Hospital in Seoul in the Republic of Korea. High levels of lipids in the blood increase a person's risk of cardiovascular disease, and evidence suggests that this risk builds over lifetime. However, in young adults, and in this case, young adult means any individual between 20 and 39 years of age. In young adults, relatively little evidence is available that identifies individuals at high risk for atherosclerotic cardiovascular diseases, except for very high LDLC levels.                                            Variability in lipid levels has recently emerged as a predictor of adverse clinical outcomes and lipid level variability may be causally linked with the atherosclerotic cardiovascular disease risk. This is because theoretically, high lipid levels can induce fluctuations in the atherosclerotic plaque composition. These fluctuations result in plaque instability and rupture and ultimately, plaque related clinical events, such as myocardial infarction. However, high lipid level variability may merely reflect other risk factors or confounders for atherosclerotic cardiovascular diseases, including unhealthy lifestyle and unrecognized comorbidities. This study therefore examined health data of close to two million Korean individuals aged 20 to 39. None of them had ever been treated for high cholesterol with statins nor had any of them suffered any myocardial infarctions or stroke.                                            Over a four-year period, the subjects had undergone at least three lipid measurements as part of their general health assessments and then they were followed for a further four years or until death. The data showed that high baseline lipid levels was linked with an increased risk of adverse cardiovascular events, and in particular, myocardial infarctions. They also found that individuals who exhibited high lipid variability, so sometimes getting high readings, sometimes getting low readings, these individuals who exhibited high variability and lipid level measurements were not at any greater risk of such cardiovascular events. While such up and downs have previously been linked to cardiovascular disease, this study argues that perhaps statin use in other cohorts may have contributed to the variability and thus confounded research interpretation, an issue that was specifically avoided in this study. Together the results indicate that lipid in young adults can indeed indicate future cardiovascular risk and therefore suggest lipid-lowering strategies could be beneficial for this age group.                                            The next article I want to share with you is titled Intestinal Flora Modulates Blood Pressure by Regulating the Synthesis of Intestinal-Derived Corticosterone in High Salt-Induced Hypertension. The first author is Xuefang Yan and the corresponding authors are Zhe Wang and Qunye Zhang from Shandong University in China. Hypertension is highly prevalent in the adult population all over the world and it is a major risk factor for heart disease and stroke. A high salt diet can help to drive hypertension pathogenesis, but complete details about the mechanisms by which high salt intake shapes vascular pathology are lacking.                                            Recent studies show that fecal transfer from salt hypertensive to salt normotensive animals can lead to hypertension in the recipients, and this suggests that perhaps gut flora may play a role in hypertension. In the article by Yan and colleagues, they show that rats on a high salt diet have altered gut flora profiles and in particular that levels of the bacterium, Bacteroides fragilis, was reduced. Analysis of intestinal metabolites and substrates in high salt diet fed rats also showed that levels of arachidonic acid, which is produced by this bacterium, were low and levels of the stress hormone, corticosterone, which regulates blood pressure, were elevated.                                            The team went on to show that supernatants from this bacterial culture could prevent corticosterone production in the intestinal tissue of high salt fed mice as could direct treatment with arachidonic acid. Moreover, both B. fragilis and arachidonic acid were found to be lower in the feces of humans with hypertension compared to that of healthy controls. The results suggest B. fragilis and arachidonic acid normally curb corticosterone production and could therefore be novel targets for hypertension treatment strategies.                                            The last thing I want to mention before we switch to our interview is the Circulation Research Compendium on Atherosclerosis. The last compendium on this topic was back in 2016 and this new compendium provides the most cutting-edge ideas in the field. The topics highlighted in this compendium are polygenic scores to assess atherosclerotic risk, clinical perspectives, and basic implications, epigenetic reader proteins and cardiovascular transcriptional programs, sex as a biological variable in atherosclerosis, neutrophil extracellular traps in cardiovascular diseases, CD31 as a therapeutic target in athero, interleukin-1 and the inflammasome as therapeutic targets in cardiovascular disease, non-coding RNAs in vascular diseases, intracellular aspects of macrophage immunometabolism in atherosclerosis, single cell RNA sequencing in atherosclerosis, vaccination strategies and immune modulation in atherosclerosis and we have an update from the group leading the One Brave Idea. Please check out this compendium.                                            All right. So, now we're going to switch over to our interview portion of the podcast. I have with me today Dr. Matthias Nahrendorf, who is a professor at the Center of Systems Biology at Massachusetts General Hospital Research Institute and Harvard Medical School and his research fellow, Dr. Maximilian Schloss. Today, we're going to be discussing the article Modifiable Cardiovascular Risk, Hematopoiesis, Innate Immunity, which is part of our Compendium on Atherosclerosis. Circulation Research puts together two to three compendiums annually and this current one is the Compendium on Atherosclerosis. We will have two additional compendiums planned for 2020. One on Obesity, Metabolic Syndrome and Cardiovascular Disease and that should come out in late May and another on Atrial Fibrillation scheduled for June. So stay tuned.                                            So, thank you very much for being with me here today, Matthias and Maximilian. Matthias Nahrendorf:    Thanks for having us. Maximilian Schloss:        Thanks for having us. Cindy St. Hilaire:              So, I really enjoyed this review article. I actually learned a lot. I also really liked your cartoons at the end, so maybe we can talk about those a little bit later, but what it's on is essentially the role of inflammation and cardiovascular disease and years of study, which have recently culminated in the completion of the CANTOS trial, have showed us that reducing inflammation can help reduce cardiovascular events. When we look at the factors that we know drive cardiovascular disease, it's things like bad diet choices, lack of exercise, stress, and inadequate or disrupted sleep and in this article you make the more nuanced argument that these modifiable factors are in fact influenced by the innate immunity. So, before we dig too deep into what you are really discussing in this article, could you maybe give us a brief introduction to the role of innate immunity and cardiovascular disease initiation and progression? Matthias Nahrendorf:    Sure. Yeah. So, I think one very instructive experiment that had been done by more than one lab actually almost two decades ago, is stopping innate immune cells from migrating to atherosclerotic plaque by deleting the chemokine MCP-1 or the chemokine receptor CCR2 in mice that have a propensity to develop atherosclerosis. What became apparent is that these mice, despite having very high blood cholesterol levels, they don't really develop atherosclerosis. This really led the whole field now almost 20 years ago, to the insight that it's not only the hypercholesterolemia, it's also the immune system that contributes to the disease. So, innate immune cells, most numerous neutrophils and monocytes then in tissue also macrophages and they're meant to defend us against infections and they support healing. In this particular setting, they are probably doing more harm than good because they promote inflammation in areas where inflammation shouldn't be i.e., in the vessel wall. Maximilian Schloss:        Yeah, I would add that what Matthias said is that basically it's all about a balance between necessary inflammation and too much inflammation. If we take, for instance, myocardial infarction as an example, we need a certain amount of inflammation, local inflammation. We need a recruitment of innate immune cells like neutrophils and monocytes and eventually macrophages, to do their job. For instance, phagocytizing a dying cardiomyocytes or inducing fibrosis. So in this example, we need inflammation, but what we see in different models where we can manipulate inflammation being at reducing or increasing inflammation, we can see that if we do either/or then wound healing and scar formation is impaired. I think that's all we are interested in studying not only the mechanisms, how inflammation can be increased or decreased, but also what is actually the perfect balance in view also of finding ways of improving outcomes in cardiovascular patients. Cindy St. Hilaire:              One of the things in my research, so I focus on cardiovascular calcification, which is very hard to do in a mouse. They don't like to calcify similarly like they don't like to make plaque without a proper genetic background. Are there aspects of the mouse versus the human innate immune system that are very different? I mean I know specific receptors are slightly different, but in general, are they matched up pretty well or is there things that are quite different about them? Matthias Nahrendorf:    I think the answer is both and there are very important parallels and then there are very important differences. So, one important difference is just if you look at sheer numbers and the contribution of immune cells in the blood and, possibly also in the plaque, can be quite different. So, recent studies that use unbiased profiling in human plaques, for instance, say that there's quite a lot of lymphocytes and we still have to understand whether this is due to the retrieval or if it says species difference or the situation, but I think there are important differences. On the other hand, I think that it really make sense to study mice because a lot of the important discoveries about the immune system in the setting have translated to humans. Cindy St. Hilaire:              Like the IL-1 beta story. Matthias Nahrendorf:    That's right. Yeah. Cindy St. Hilaire:              So, actually one of the topics that you started out with in your article is on the role of hematopoiesis in cardiovascular disease. You had a beautiful paper years ago actually with my colleague at University of Pittsburgh, Partha Dutta, who's right down the hall from me, where you guys showed that myocardial infarction itself further exacerbates atherosclerotic plaques mid part through recruiting monocytes from the spleen and mobilizing the immune system. So, I'm wondering, what are the role of the cells when they get mobilized? You talk about these modifiable risk factors of stress and sleep interruption, unhealthy diet. So, how can these risk factors help or promote this mobilization of hematopoietic cells? Matthias Nahrendorf:    Yeah. So, I think that early on when we thought about going down this road and studying these risk factors, even before going there, you realize that the cells that we're interested in, innate immune cells are very short lived. So they live on the order of hours or days. So, they're really produced just in time. That's different to lymphocytes and resident macrophages, which have much longer lifespans. So, this really triggered the insight that we should look at production and release because it's a just in time supply situation. So, what we were wondering is whether in the setting of cardiovascular disease, whether production rates are increased and we now know and a number of labs have studied hematopoiesis in this setting including Fil Swirski, Alan Tall, and some others.                                            We now know that this is really the case, so hematopoiesis increases in chronic atherosclerosis. It increases in acute myocardial infarction and increases in heart failure. What we don't know is what mechanisms actually ramp up blood cell production and we're beginning to understand that the sympathetic nervous system is involved. But I think we only see the tip of the iceberg here. That's why we wanted to study modifiable risk factors, because if you look at others such as high cholesterol, once the insight was gained that lowering cholesterol is helpful, we had the statins which make a huge change. So, we hope to repeat that. Cindy St. Hilaire:              Maximilian, one of the things that you brought up is this balance. The inflammation's a little bit good and then it's a little bit bad or a lot bad. So, where is that good and bad spectrum in terms of mobilizing hematopoiesis or hematopoietic cells? Maximilian Schloss:        Yeah. I think that depends a bit on the disease type or we're talking about a chronic disease or an acute disease? For instance, to stay at the example of myocardial infarction, once cardiomyocytes become ischemic, they will release certain chemokines and cytokines into the blood, which then circulate to the bone marrow and tell the cells that leukocytes need to leave the bone marrow to enter the blood circulation system and then go to the heart to fulfill their very important functions there. Once the cells leave the bone marrow, the bone marrow need to reproduce themselves, then this process starts of hematopoiesis and there we can go back again to the concept of a balance. Of course, there is a certain beneficial physiological need of cell production, but one sees mechanisms so to say maybe go out of control and too many leukocytes are produced and released to the blood.                                            Then that again impairs patient outcome. There are very many papers, clinical papers, who have shown that leukocyte counts after myocardial infarction have a certain U shape relationship with the outcome. That I think is best described that if leukocyte counts are very high, that they actually negatively correlate with the outcome of MI patients. If you look at the bone marrow specifically, there are certain mechanisms, which we know, and what we are more closely looking at now, what are actually the modifier of this process, what are the signals which tell these cells to secrete more hematopoietic factors or quiescence factors? I think that's what also the Review is a little bit about. Cindy St. Hilaire:              Yeah, it's great. So, you were speaking about that kind of U-shaped curve in the release of these cells. Do we know based on some of the other things you spoke about, I guess I'm thinking about like diet or exercise or sleep in contributing to that release after an event like myocardial infarction. Is that known yet or has anyone looked into that? Matthias Nahrendorf:    Yeah. So, I think we're in the very beginning of understanding what's happening acutely. There's more knowledge on the chronic side and this is what we've been working on. Often the things that influenced the chronic situation can be quite different from what happens acutely. So I think in general, we're just beginning to understand what happens in acute myocardial infarction. Well, we know for instance is that exercise doesn't compromise the release and supply of leukocytes that's necessary in acute infection or acute myocardial infarction. So, if the mouse or the individual was exercising before the event, that may reduce overall leukocyte levels, but not to a degree that it's harmful. Cindy St. Hilaire:              Yeah. You can't exercise your way beyond a certain point. Matthias Nahrendorf:    Maybe that's also possible. If you run more than one marathon a day, I'm sure that's… Cindy St. Hilaire:              That will do something else. Matthias Nahrendorf:    Yeah. Cindy St. Hilaire:              Actually, so one of the interesting things that I saw in the article was when you were talking about diet and the role of diet in innate immunity, which is something I really never thought about, and you did bring up things like intermittent fasting. Can you discuss what's known at least scientifically about how that kind of diet timing can impact the immune system and therefore maybe cardiovascular disease? Matthias Nahrendorf:    So, that's a very emerging field. There's very little known about this. I think it's very interesting because very relevant and a lot of people are excited about it, but it's basically, from what I know, it's mostly two papers that were published, I think both in Cell, and they say that intermittent fasting leads to a decline of cells that are in circulation. So, that's a very exciting observation. I think it's similar insight as to discovering that immune cell levels circulate the circadian rhythms, which had been discovered a while ago. So, I think there's definitely an impact and we're just beginning to understand why this is and what regulates it. Cindy St. Hilaire:              Yeah, that segues nicely into the next thing I was wondering about and that is we all know not enough sleep, you get tired, your brain's not focused and stuff like that, but it really does impact the inflammatory system and also cardiovascular disease. So how is sleep involved in this innate immunity cardiovascular disease progression? Matthias Nahrendorf:    The way we approached this was actually thinking about lifestyle factors and their impact on cardiovascular disease. Maybe a decade ago, Fil, who's our middle author on this Review, and I started thinking about lifestyle factors and what struck us is that the association of some of these risk cardiovascular events is really high. So, if you look at sleep or if you look at psychosocial stress, psychosocial stress has an odds ratio of 2.4 for premature myocardial infarction. That is right on scale with all these powerful risk factors that everybody knows about like hypertension, but then what isn't really clear or maybe not entirely, is whether or not these risk factors also act via the innate immune system and that's where we were coming from.                                            I think at this point it's pretty clear that they do have an influence via the immune system. What I think what we've done is we uncovered a couple mechanisms that lead to the activation or dampening of inflammation depending on what you look at, but we don't really understand the broader network. I think there's a lot of work to be done looking into these pathways, which is exciting because I think that we can learn from nature what's dangerous and what's helpful. That this is how humans learn to fly. So, I think that observing what leads to cardiovascular disease, which behaviors are really harmful, will maybe lead us to new ways of mitigating it. Cindy St. Hilaire:              Yeah. Also, I think all of this, it's interesting. We all went after smoking for decades, stop smoking, reduce cardiovascular risk and maybe it's stress and sleep is the next smoking. Matthias Nahrendorf:    Smoking was so successful, right? I mean if you look 50 years back, it was promoted as this healthy thing that you should do. Then people really started to learn how bad it is and now we're at a time where smoking is declining and has declined and we see the results. Lung cancer is really on the decline. So, I think that's a good example how understanding health effects of behavior can be really helpful. Maximilian Schloss:        I think one thing I would like to add is when you ask more general question about innate immunity and when we talk about sleep and sleeping habits, I think what's generally quite interesting to know is that the immune system or these leukocyte numbers in circulation, they oscillate quite dramatically over the course of a day in a healthy human being and also in mouse models. I think one aspect also among others to consider is when we have unhealthy steeping habits, like for example, going to bed late or being a shift worker, drinking for example before going to bed. Then this will also confuse a system on the circadian entrainment, which then subsequently will lead to other problems.                                            I also think another thing is that what you were mentioning with the fasting is what we learned from this similar to these extreme circadian patterns seen when we fast or when a mouse is fasting, then monocyte levels drop into extreme low levels and these monocytes hone back into the bone marrow. I think this is interesting because it shows how dynamic actually a system like innate immune cells actually is. So, it's a very delicate system which responds to sleep disruption, exercise, diets in a very dramatic way. Cindy St. Hilaire:              All right, I'm going to bed early tonight and eating a good dinner. Well, this was a wonderful Review. I really enjoyed reading it. I really do think it's introducing the next targets that we have to go after in modifying cardiovascular disease. Thank you so much for taking the time to speak with me today. Matthias Nahrendorf:    Thank you. Maximilian Schloss:        Thank you so much. Cindy St. Hilaire:              That's it for our highlights from the March 27th and Compendium issue of Circulation Research. Thank you so much for listening. This podcast is produced by Rebecca McTavish, edited by Melissa Stoner, and supported by the editorial team of Circulation Research. Some of the copy text for highlighted articles was provided by Ruth Williams. Thank you to our guests, Max Schloss and Matthias Nahrendorf. I'm your host, Dr. Cindy St. Hilaire, and this is Discover CircRes, your on the go source for the most up-to-date and exciting discoveries in basic cardiovascular research.  

CD31 Stay Green by Gurtej Singh & Rashmili Vemula

Hyperstyles. CD31 | Morning Generation |  Tracklist can be found at: https://soundcloud.com/lentej/ Enjoy and dance on!

Commentary by Dr. Valentin Fuster

Chemotherapeutic treatment of hepatocellular carcinoma often leads to chemoresistance during therapy or upon relapse of tumors. For the development of better treatments, a better understanding of biochemical changes in the resistant tumors is needed. Therefore, especially in vivo models are very important tools to generate standardized cell-material, which can be examined by high throughput techniques. Thus, it should be possible to find new targets for therapy or even for diagnostic. This thesis focusses on the characterization of the in vivo chemoresistant human hepatocellular carcinoma HUH-REISO established from a metronomically cyclophosphamide (CPA) treated HUH7 xenograft mouse model. First step of the work was the establishment of the xenograft mouse model. SCID mice bearing subcutaneous HUH7 tumors were treated i.p. with 75 mg/kg CPA every six days. After 10 weeks of response to the therapy, the tumor growth relapsed and tissue grew with very fast doubling time again, despite of ongoing treatment. This aggressive manner of growth under therapy could be also observed in a re-implantation study where the reisolated CPA chemoresistant HUH-REISO tumors grew without a lag phase, indicating an endogenous imprinted component. To evaluate this, tumors were examined by immunohistochemistry, a functional blood-flow Hoechst dye assay, and qRT-PCR for ALDH-1, Notch-1, Notch-3, HES-1, Thy-1, Oct-4, Sox-2 and Nanog mRNA levels. Histochemical analysis of HUH-REISO tumors revealed significant changes in host vascularization of tumors and especially in expression of the tumor-derived human endothelial marker gene PECAM-1/CD31 in HUH-REISO in comparison to parental HUH-7 cells and in vivo passaged HUH-PAS cells (in vivo grown without chemotherapeutic CPA pressure). The pronounced network of host murine vascularization in parental HUH-7 tumors was completely substituted by a network of human and murine vessel-like structures in HUH-REISO tumors under therapy. In addition, cell lines of these tumors were analyzed in endothelial trans-differentiation studies on matrigel. In those studies with limited oxygen and metabolite diffusion, followed by a matrigel assay, only the chemoresistant HUH-REISO cells exhibited tube formation potential and expression of human endothelial markers ICAM-2 and PECAM-1/CD31. Such a trans-differentiation capacity requires a lineage of cells with pluripotent capacities like so called tumor stem cells. Indeed, I could show in a comparative study on stemness and plasticity markers that Thy-1, Oct-4, Sox-2 and Nanog were upregulated in resistant xenografts. Furthermore, under therapeutic pressure by CPA, tumors of HUH-PAS and HUH-REISO displayed regulations in Notch-1 and Notch-3 expression, which I could also show by qRT-PCR. Notch-1 raised in HUH-PAS under therapeutic pressure, meanwhile it was conversely regulated in comparison to Thy-1, Oct-4, Sox-2 and Nanog in HUH-REISO. In both groups Notch-3 was inducible by 2 times CPA treatment and fell back on base level after further four therapeutic cycles in HUH-REISO. To conclude all these finding: chemoresistance of HUH-REISO was not manifested under standard in vitro, but only under in vivo conditions. HUH-REISO cells showed increased pluripotent capacities and the ability of trans-differentiation to endothelial like cells in vitro and in vivo. These cells expressed typical endothelial surface marker and functionality. Although the mechanism behind chemoresistance of HUH-REISO and involvement of plasticity remains to be clarified, we hypothesize that the observed Notch regulations and upregulation of stemness genes in resistant xenografts are involved in the observed cell plasticity.

Background To evaluate the in vivo response by detecting the anti-angiogenic and invasion-inhibiting effects of a triple-combination-therapy in an experimental-small-animal-squamous-cell-carcinoma-model using the “flash-replenishment” (FR) method to assess tissue hemodynamics via contrast-enhanced-ultrasound (CEUS). Methods Human hypopharynx-carcinoma-cells were subcutaneously injected into the left flank of 22-female-athymic-nude-rats. After seven days of subcutaneous tumor growth, FR-measurements were performed on each rat. Treatment-group and control-group were treated every day for a period of one week, with the treatment-group receiving solvents containing a triple therapy of Upamostat®, Celecoxib® and Ilomastat® and the control-group solvents only. On day seven, follow-up measurements were performed using the same measurement protocol to assess the effects of the triple therapy. VueBox® was used to quantify the kinetic parameters and additional immunohistochemistry analyses were performed for comparison with and validation of the CEUS results against established methods (Proliferation/Ki-67, vascularization/CD31, apoptosis/caspase3). Results Compared to the control-group, the treatment-group that received the triple-therapy resulted in a reduction of tumor growth by 48.6% in size. Likewise, the immunohistochemistry results showed significant decreases in tumor proliferation and vascularization in the treatment-group in comparison to the control-group of 26%(p≤0.05) and 32.2%(p≤0.05) respectively. Correspondingly, between the baseline and follow-up measurements, the therapy-group was associated with a significant(p ≤ 0.01) decrease in the relative-Blood-Volume(rBV) in both the whole tumor(wt) and hypervascular tumor(ht) areas (p≤0.01), while the control-group was associated with a significant (p≤0.01) increase of the rBV in the wt area and a non-significant increase (p≤0.16) in the ht area. The mean-transit-time (mTT) of the wt and the ht areas showed a significant increase (p≤0.01) in the follow-up measurements in the therapy group. Conclusion The triple-therapy is feasible and effective in reducing both tumor growth and vascularization. In particular, compared with the placebo-group, the triple-therapy-group resulted in a reduction in tumor growth of 48.6% in size when assessed by CEUS and a significant reduction in the number of vessels in the tumor of 32% as assessed by immunohistochemistry. As the immunohistochemistry supports the CEUS findings, CEUS using the “flash replenishment”(FR) method appears to provide a useful assessment of the anti-angiogenic and invasion-inhibiting effects of a triple combination therapy.

Commentary by Dr. Valentin Fuster

Background: Chemotherapeutic treatment of hepatocellular carcinoma often leads to chemoresistance during therapy or upon relapse of tumors. For the development of better treatments a better understanding of biochemical changes in the resistant tumors is needed. In this study, we focus on the characterization of in vivo chemoresistant human hepatocellular carcinoma HUH-REISO established from a metronomically cyclophosphamide (CPA) treated HUH7 xenograft model. Methods: SCID mice bearing subcutaneous HUH7 tumors were treated i.p. with 75 mg/kg CPA every six days. Tumors were evaluated by immunohistochemistry, a functional blood-flow Hoechst dye assay, and qRT-PCR for ALDH-1, Notch-1, Notch-3, HES-1, Thy-1, Oct-4, Sox-2 and Nanog mRNA levels. Cell lines of these tumors were analyzed by qRT-PCR and in endothelial transdifferentiation studies on matrigel. Results: HUH-REISO cells, although slightly more sensitive against activated CPA in vitro than parental HUH-7 cells, fully retained their in vivo CPA chemoresistance upon xenografting into SCID mice. Histochemical analysis of HUH-REISO tumors in comparison to parental HUH-7 cells and passaged HUH-PAS cells (in vivo passaged without chemotherapeutic pressure) revealed significant changes in host vascularization of tumors and especially in expression of the tumor-derived human endothelial marker gene PECAM-1/CD31 in HUH-REISO. In transdifferentiation studies with limited oxygen and metabolite diffusion, followed by a matrigel assay, only the chemoresistant HUH-REISO cells exhibited tube formation potential and expression of human endothelial markers ICAM-2 and PECAM-1/CD31. A comparative study on stemness and plasticity markers revealed upregulation of Thy-1, Oct-4, Sox-2 and Nanog in resistant xenografts. Under therapeutic pressure by CPA, tumors of HUH-PAS and HUH-REISO displayed regulations in Notch-1 and Notch-3 expression. Conclusions: Chemoresistance of HUH-REISO was not manifested under standard in vitro but under in vivo conditions. HUH-REISO cells showed increased pluripotent capacities and the ability of transdifferentiation to endothelial like cells in vitro and in vivo. These cells expressed typical endothelial surface marker and functionality. Although the mechanism behind chemoresistance of HUH-REISO and involvement of plasticity remains to be clarified, we hypothesize that the observed Notch regulations and upregulation of stemness genes in resistant xenografts are involved in the observed cell plasticity.

Background: Tissue engineering represents a promising new method for treating heart valve diseases. The aim of this study was evaluate the importance of conditioning procedures of tissue engineered polyurethane heart valve prostheses by the comparison of static and dynamic cultivation methods. Methods: Human vascular endothelial cells (ECs) and fibroblasts (FBs) were obtained from saphenous vein segments. Polyurethane scaffolds (n = 10) were primarily seeded with FBs and subsequently with ECs, followed by different cultivation methods of cell layers (A: static, B: dynamic). Group A was statically cultivated for 6 days. Group B was exposed to low flow conditions (t(1)=3 days at 750 ml/min, t(2)=2 days at 1100 ml/min) in a newly developed conditioning bioreactor. Samples were taken after static and dynamic cultivation and were analyzed by scanning electron microscopy (SEM), immunohistochemistry (IHC), and real time polymerase chain reaction (RT-PCR). Results: SEM results showed a high density of adherent cells on the surface valves from both groups. However, better cell distribution and cell behavior was detected in Group B. IHC staining against CD31 and TE-7 revealed a positive reaction in both groups. Higher expression of extracellular matrix (ICAM, Collagen IV) was observed in Group B. RT-PCR demonstrated a higher expression of inflammatory Cytokines in Group B. Conclusion: While conventional cultivation method can be used for the development of tissue engineered heart valves. Better results can be obtained by performing a conditioning step that may improve the tolerance of cells to shear stress. The novel pulsatile bioreactor offers an adequate tool for in vitro improvement of mechanical properties of tissue engineered cardiovascular prostheses.

Deregulation of epidermal growth factor receptor (EGFR) pathways contributes to the progression of a wide range of cancers, and the EGFR is an attractive therapeutic target. The humanized EGFR-specific monoclonal antibody EMD72000 has shown potent inhibitory activity in preclinical experiments and is under investigation in clinical studies. Using the human L3.6pl pancreatic cancer cell line, we investigated whether the efficacy of EMD72000 can be enhanced in combination with gemcitabine. Nude mice were orthotopically injected with L3.6pl cells followed by biweekly treatment of 40 mg/kg EMD72000 and 100 mg/kg gemcitabine (either alone or in combination). Under two treatment schedules we evaluated a) the influence of different time points of initiation of single agent and combined treatment after tumor cell injection into nude mice and b) the influence of different treatment durations. In the first experiment, treatment was initiated at four different time-points after tumor cell injection (days 8 - 28). Exposure to EMD72000 or gemcitabine alone resulted in detectable tumor shrinkage and reduced lymph node and liver metastases, however, these effects were enhanced in the EMD72000 plus gemcitabine groups. Furthermore, combination treatment as well as EMD72000 monotherapy led to a significant reduction of microvessel density and tumor cell proliferation in primary pancreatic tumors following immunohistochemical analysis for CD31 and Ki67, respectively. Overall, the effects were strongest when treatment was initiated at early time points after tumor cell injection. In a second experimental set-up, treatment was initiated at day 8 after tumor cell injection in all cases and stopped at four different time-points (days 15 - 33). Interestingly, there was no significant difference in the average tumor weight of the groups treated for short versus longer time periods. The treatment was most effective when given shortly after tumor cell injection, whereas the duration of the treatment appeared less important in this model. In conclusion, in this model the anti-angiogenic and anti-tumor activity of EMD72000 in combination with gemcitabine was substantially more effective than either treatment alone.

Der Nachweis von disseminierten Tumorzellen im Knochenmark von Patientinnen mit primärem Mammakarzinom ist ein wichtiger prognostischer Parameter. In der vorliegenden Arbeit wurde der Nachweis von CD31 am Primärtumor Mammakarzinom mit dem Auftreten von Mikrometastasen im Knochenmark korreliert. Ferner wurde die prognostische Bedeutung von disseminierten Tumorzellen im Knochenmark und die prognostische Bedeutung von CD31 evaluiert. Bei 50 Patientinnen des Gesamtkollektivs von 195 (25,6%) wurde zum Zeitpunkt der Primärdiagnose des Mammakarzinoms eine positive CD31-Expression festgestellt. In Relation zu den bekannten etablierten Prognoseparametern Tumorgröße, axillärer Lymphknotenstatus, histopathologisches Grading, Menopausenstatus und Hormonrezeptorstatus fand sich keine signifikante Korrelation. Es zeigte sich jedoch, dass eine CD31-Expression signifikant häufiger bei postmenopausalen Frauen auftrat. Bei 52 Patientinnen des Gesamtkollektives von 195 (27%) wurden zum Zeitpunkt der Primärdiagnose des Mammakarzinoms disseminierte Tumorzellen im Knochenmark festgestellt. Gegenüber den bekannten etablierten Prognoseparametern Tumorgröße, axillärer Lymphknotenstatus, histopathologisches Grading, Menopausenstatus und Hormonrezeptorsstatus fand sich keine signifikante Korrelation. Des Weiteren fand sich keine Korrelation p=0,805 bei den 50 Patientinnen mit einer Überexpression von CD31 am Primärtumor und den 52 Patientinnen mit positiven Knochenmarkstatus. In Bezug auf des Gesamtüberleben ergab sich weder zwischen den Patientenkollektiven bei positivem CD31 Status (n=50; mediane Gesamtüberlebenszeit 90 Monate {82-98, 95%CI}) und negativem CD31 Status (n=145; mediane Gesamtüberlebenszeit 88 Monate {84-92; 95% CI}), p=0,74, Log-rank Test, noch zwischen den Patientenkollektiven bei positiven Knochenmarkstatus (n=52; mediane Gesamtüberlebenszeit 90 Monate {82-97 CI 95%};) und negativem Knochenmarkstatus (n=143 ; mediane Gesamtüberlebenszeit 89 Monate {85-92 CI 95%}); eine Signifikanz. P=(0,498) Log-rank Test. Dasselbe gilt ebenfalls für die rezidivfreie Überlebenszeit. Ein statistisch signifikanter Unterschied zwischen den Patientenkollektiven bei positivem CD31 Status (n=50; mediane rezidivfreie Überlebenszeit 74 Monate {73-93, 95%CI}) und negativem CD31 Status (n=145; mediane rezidivfreie Überlebenszeit 76 Monate {70-82; 95% CI}), P=0,78, Log-rank Test, konnte nicht festgestellt werden. Ein statistisch signifikanter Unterschied zwischen den Patientenkollektiven bei positiven Knochenmarkstatus (n=52; mediane rezidivfreie Überlebenszeit 89 Monate {82-97 CI 95%}) und negativem Knochenmarkstatus (n=143; mediane rezidivfreie Überlebenszeit 88 Monate {85-92 CI 95%}); konnte nicht festgestellt werden. P=0,98 Log-rank Test. In der multivariaten Analyse zeigte sich, dass die klassischen Prognoseparameter Grading (p=0,039) und Lymphknotenstatus (p=0,013) als unabhängige Prognosefaktoren für das Gesamtüberleben stehen. Die Schlussfolgerung dieser Arbeit ist, dass die Bestimmung der CD31-Expression am Primärtumor von Mammakarzinomen nicht zur Prognoseeinschätzung geeignet ist.

The endothelium is among the largest organs in the body. Stimuli originating from the blood or from neighbouring cells, like inflammatory cytokines (IC), lead to structural and functional alterations of vascular endothelial cells (EC). These alterations are often referred to as “EC activation”. Activated EC play a key role in different physiological processes like during immune response, in menstruation and in pathological processes like inflammation, allergy, viral infections, atherosclerosis and tumour angiogenesis. The human guanylate binding protein-1 (GBP-1) is a protein of the family of large GTPases. GBP-1 is characterized by a high turnover GTPase activity. Previous work showed that GBP-1 mRNA expression is induced by IC in EC and that GBP-1 is the specific mediator of the anti-proliferative effect of IC on EC in vitro. The main goals of this work were first, to investigate whether GBP-1 may be a molecular marker of IC-activated EC at the protein level in vitro. Second, to investigate GBP-1 expression in human healthy and/or disease tissues and to determine whether GBP-1 may be a molecular marker of IC-activated EC in vivo. To this goal mono- and poly-clonal antibodies against GBP-1 were generated. In vitro studies showed that GBP-1 expression in EC is induced by IFN-, IFN-, IL-1, IL-1 or TNF- but not by other cytokines, chemokines or growth factors. Moreover, simultaneous addition of bFGF and VEGF and IC reduced the IC-induced GBP-1 expression. This indicated that GBP-1 characterizes cells that are preferentially exposed to IC. In vivo studies using immunohistochemistry and immunofluorescence showed that GBP-1 expression is highly associated with vascular EC in a broad range of human tissues. This was confirmed by the simultaneous detection of GBP-1 and the EC-associated marker CD31. Notably, GBP-1 expression was undetectable in healthy skin. In contrast, GBP-1 was highly expressed in vessels of skin diseases with a high inflammatory component including psoriasis, adverse drug reactions and Kaposi’s sarcoma. This indicated that GBP-1 characterizes IC-activated EC in vivo. Further immunohistochemical studies on Kaposi’s sarcoma demonstrated that GBP-1 expression and EC cell proliferation are inversely related. This indicated that GBP-1 may also mediate the anti-proliferative effect of IC on EC in vivo. Finally, GBP-1 was found to be secreted by EC stimulated with IFN- and IFN- in vitro. This finding was confirmed by immunoprecipitation of GBP-1 from cell culture supernatants and by a novel ELISA developed for the detection of GBP-1 in solution. Further characterization of the mechanism of secretion demonstrated that GBP-1 release is due to an 3 Summary energy-dependent mechanism and is not due to cell death. Most importantly, circulating GBP-1 could be detected in increased concentrations in the blood of patients that were subjected to IFN–-therapy or in patients with inflammatory diseases. These findings indicated that GBP-1 is a novel marker of inflammatory vessel activation. Specifically, the serological detection of GBP-1 may open new perspectives for the early detection of inflammatory activation of EC in patients with inflammatory diseases.