Podcasts about Proteasome

John Maytham speaks with Nazir Ismail, Head of Clinical Microbiology and Infectious Diseases at Wits University, about an extraordinary new discovery in the immune system that could revolutionize the fight against antibiotic-resistant infections. Scientists have found that the proteasome, previously known for recycling proteins, has an unexpected ability to produce bacteria-killing chemicals.See omnystudio.com/listener for privacy information.

BUFFALO, NY- March 6, 2024 – A new #researchpaper was #published in Oncotarget's Volume 15 on March 5, 2024, entitled, “GZ17-6.02 interacts with proteasome inhibitors to kill multiple myeloma cells.” In this new study, researchers Laurence Booth, Jane L. Roberts, Cameron West, and Paul Dent from Virginia Commonwealth University and Genzada Pharmaceuticals investigated GZ17-6.02, a synthetically manufactured compound containing isovanillin, harmine and curcumin, in multiple myeloma cells. GZ17-6.02 has undergone phase I evaluation in patients with solid tumors (NCT03775525) with a recommended phase 2 dose (RP2D) of 375 mg PO BID. GZ17-6.02 was more efficacious as a single agent at killing multiple myeloma cells than had previously been observed in solid tumor cell types. “GZ17-6.02 interacted with proteasome inhibitors in a greater than additive fashion to kill myeloma cells and alone it killed inhibitor-resistant cells to a similar extent.” The drug combination of GZ17-6.02 and bortezomib activated ATM, the AMPK and PERK and inactivated ULK1, mTORC1, eIF2α, NFκB and the Hippo pathway. The combination increased ATG13 S318 phosphorylation and the expression of Beclin1, ATG5, BAK and BIM, and reduced the levels of BCL-XL and MCL1. GZ17-6.02 interacted with bortezomib to enhance autophagosome formation and autophagic flux, and knock down of ATM, AMPKα, ULK1, Beclin1 or ATG5 significantly reduced both autophagy and tumor cell killing. Knock down of BAK and BIM significantly reduced tumor cell killing. The expression of HDACs1/2/3 was significantly reduced beyond that previously observed in solid tumor cells and required autophagy. This was associated with increased acetylation and methylation of histone H3. Combined knock down of HDACs1/2/3 caused activation of ATM and the AMPK and caused inactivation of ULK1, mTORC1, NFκB and the Hippo pathway. HDAC knock down also enhanced ATG13 phosphorylation, increased BAK levels and reduced those of BCL-XL. “Collectively, our present studies support performing additional in vivo studies with multiple myeloma cells.” DOI - https://doi.org/10.18632/oncotarget.28558 Correspondence to - Paul Dent - paul.dent@vcuhealth.org Sign up for free Altmetric alerts about this article - https://oncotarget.altmetric.com/details/email_updates?id=10.18632%2Foncotarget.28558 Subscribe for free publication alerts from Oncotarget - https://www.oncotarget.com/subscribe/ Keywords - cancer, autophagy, ER stress, GZ17-6.02, bortezomib, proteasome inhibitor 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: Facebook - https://www.facebook.com/Oncotarget/ X - 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/ Spotify - https://open.spotify.com/show/0gRwT6BqYWJzxzmjPJwtVh Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.08.03.550647v1?rss=1 Authors: Ibtisam, I., Kisselev, A. F. Abstract: Rapid recovery of proteasome activity may contribute to intrinsic and acquired resistance to FDA-approved proteasome inhibitors. Previous studies have demonstrated that the expression of proteasome genes in cells treated with sub-lethal concentrations of proteasome inhibitors is upregulated by the transcription factor Nrf1 (NFE2L1), which is activated by a novel DDI2 protease. Here we demonstrate that the recovery of proteasome activity is DDI2-independent and occurs before the upregulation of proteasome gene expression. The recovery requires protein translation, but the efficiency of translation of proteasomal mRNA does not increase upon proteasome inhibition. Based on this data, we propose that the increased efficiency of proteasome assembly is responsible for the recovery of proteasome activity. 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/2023.06.25.546446v1?rss=1 Authors: Waite, K. A., Vontz, G., Lee, S. Y., Roelofs, J. Abstract: Stress conditions can cause the relocalization of proteasomes to condensates in yeast and mammalian cells. The interactions that facilitate the formation of proteasome condensates, however, are unclear. Here, we show that the formation of proteasome condensates in yeast depends on long K48-linked ubiquitin chains together with the proteasome shuttle factors Rad23 and Dsk2. These shuttle factors colocalize to these condensates. Strains deleted for the third shuttle factor gene, DDI1, show proteasome condensates in the absence of cellular stress, consistent with the accumulation of substrates with long K48-linked ubiquitin chains that accumulate in this mutant. We propose a model where the long K48-linked ubiquitin chains function as a scaffold for the ubiquitin binding domains of the shuttle factors and the proteasome, allowing for the multivalent interactions that further drive condensate formation. Indeed, we determined different intrinsic ubiquitin receptors of the proteasome (Rpn1, Rpn10, and Rpn13) are critical under different condensate inducing conditions. In all, our data support a model where the cellular accumulation of substrates with long ubiquitin chains, potentially due to reduced cellular energy, allows for proteasome condensate formation. This suggests that proteasome condensates are not simply for proteasome storage, but function to sequester soluble ubiquitinated substrates together with inactive proteasomes. 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/2023.04.12.536627v1?rss=1 Authors: Gilda, J. E., Nahar, A., Kasiviswanathan, D., Tropp, N., Gilinski, T., Lahav, T., Mandel-Gutfreund, Y., Park, S., Cohen, S. Abstract: Proteasome activity is crucial for cellular integrity, but how tissues adjust proteasome content in response to catabolic stimuli is uncertain. Here, we demonstrate that transcriptional coordination by multiple transcription factors is required to increase proteasome content and activate proteolysis in catabolic states. Using denervated mouse muscle as a model system for accelerated proteolysis in vivo, we reveal that a two-phase transcriptional program activates genes encoding proteasome subunits and assembly chaperones to boost an increase in proteasome content. Initially, gene induction is necessary to maintain basal proteasome levels, and in a more delayed phase (7-10 d after denervation) it stimulates proteasome assembly to meet cellular demand for excessive proteolysis. Intriguingly, the transcription factors PAX4 and -PALNRF-1 control the expression of proteasome among other genes in a combinatorial manner, driving cellular adaptation to muscle denervation. Consequently, PAX4 and -PALNRF-1 represent new therapeutic targets to inhibit proteolysis in catabolic diseases (e.g. type-2 diabetes, cancer). 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/2022.12.29.522265v1?rss=1 Authors: Le, T. K., Hirano, Y., Asakawa, H., Okamoto, K., Haraguchi, T., Hiraoka, Y. Abstract: Aberrant accumulation of inner nuclear membrane (INM) proteins has been associated with deformed nuclear morphology and certain mammalian diseases. However, the mechanisms by which INM homeostasis is maintained remain poorly understood. In this study, we explored the degradation mechanisms of the INM protein Bqt4 in the fission yeast Schizosaccharomyces pombe. We have previously shown that Bqt4 interacts with the transmembrane protein Bqt3 at the INM and is degraded in the absence of Bqt3. Here, we revealed that excess Bqt4 unassociated with Bqt3 was targeted for degradation by the ubiquitin-proteasome system localized in the nucleus and that Bqt3 antagonized this process. The degradation process involves the Doa10 E3 ligase complex at the INM. Bqt4 is a tail-anchored protein and extraction from the membrane by the Cdc48 complex is required for its degradation. The C-terminal transmembrane domain of Bqt4 is necessary and sufficient for proteasome-dependent protein degradation. Accumulation of Bqt4 at the INM impaired cell viability with nuclear envelope deformation, suggesting that the quantity control of Bqt4 plays an important role in nuclear membrane homeostasis. 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/2022.11.23.517709v1?rss=1 Authors: Ivaldo, C., Passalacqua, M., Furfaro, A. L., d'Abramo, C., Ruiz, S., Chatterjee, P. K., Metz, C. N., Nitti, M., Marambaud, P. Abstract: Classical cadherins, including vascular endothelial (VE)-cadherin, are targeted by matrix metalloproteinases (MMPs) and {gamma}-secretase during adherens junction (AJ) disassembly, a mechanism that might have relevance for endothelial cell (EC) integrity and vascular homeostasis. Here, we show that oxidative stress triggered by H2O2 exposure induced efficient VE-cadherin proteolysis by MMPs and {gamma}-secretase in human umbilical endothelial cells (HUVECs). The cytoplasmic domain of VE-cadherin produced by {gamma}-secretase, VE-Cad/CTF2 - a fragment that has eluded identification so far - could readily be detected after H2O2 treatment. VE-Cad/CTF2, released into the cytosol, was tightly regulated by proteasomal degradation and was sequentially produced from an ADAM10/17-generated C-terminal fragment, VE-Cad/CTF1. Interestingly, BMP9 and BMP10, two circulating ligands critically involved in vascular maintenance, significantly reduced VE-Cad/CTF2 levels during H2O2 challenge, as well as mitigated H2O2- mediated actin cytoskeleton disassembly during VE-cadherin processing. Notably, BMP9/10 pretreatments efficiently reduced apoptosis induced by H2O2, favoring endothelial cell recovery. Thus, oxidative stress is a trigger of MMP- and {gamma}-secretase-mediated endoproteolysis of VE-cadherin and AJ disassembly from the cytoskeleton in ECs, a mechanism that is negatively controlled by the EC quiescence factors, BMP9 and BMP10. 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/2022.10.17.512557v1?rss=1 Authors: Sun, C., Desch, K., Nassim-Assir, B., Giandomenico, S. L., Nemcova, P., Langer, J. D., Schuman, E. M. Abstract: The major protein-degradation machine, the proteasome, functions at brain synapses and regulates long-term information storage. Here we found that the two essential subcomplexes of the proteasome, the regulatory (19S) and catalytic (20S) particles that recognize and degrade substrates, are differentially distributed within individual rat cortical neurons. Using super-resolution microscopy, we discovered a surprising abundance of free particles (19S) near synapses. The free neuronal 19S particles bind and deubiquitylate Lys63-ubiquitin, a non-proteasome targeting ub-linkage. Pull-down assays revealed a significant over-representation of synaptic molecules as Lys63 interactors. Inhibition of 19S deubiquitylase activity significantly altered excitatory synaptic transmission and reduced the synaptic availability of AMPA receptors at multiple trafficking points in a proteasome-independent manner. Together, these results reveal a moonlighting function of the regulatory proteasomal subcomplex near synapses. 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/2022.09.22.509008v1?rss=1 Authors: Suzuki, M., Kuromi, H., Shindo, M., Sakata, N., Niimi, N., Fukui, K., Saitoe, M., Sango, K. Abstract: Diabetic peripheral neuropathy (DPN) is the most common chronic, progressive complication of diabetes mellitus. The main symptom is sensory loss; the molecular mechanisms are not fully understood. We found that Drosophila fed a high-sugar diet, which induces diabetes-like phenotypes, exhibit impairment of noxious heat avoidance. The impairment of heat avoidance was associated with shrinkage of the leg neurons expressing the Drosophila transient receptor potential channel Painless. Using a candidate genetic screening approach, we identified proteasome modulator 9 as one of the modulators of impairment of heat avoidance. We further showed that proteasome inhibition in the glia reversed the impairment of noxious heat avoidance, and heat-shock proteins and exosome secretion in the glia mediated the effect of proteasome inhibition. Our results establish Drosophila as a useful system for exploring molecular mechanisms of diet-induced peripheral neuropathy and propose that the glial proteasome is one of the candidate therapeutic targets for DPN. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

Paul G. Richardson, MD, and Christina Gasparetto, MD, offer insights into the use of proteasome inhibitors in relapsed or refractory multiple myeloma. As part of its Between the Lines™ video series, CancerNetwork® spoke with Paul G. Richardson, MD, clinical program leader and director of Clinical Research for the Jerome Lipper Multiple Myeloma Center at Dana-Farber Cancer Institute in Boston, Massachusetts, and Christina Gasparetto, MD, professor of medicine at Duke University Medical School in Durham, North Carolina, about recent updates in the use of proteasome inhibitors for patients with multiple myeloma. In the video series, Richardson and Gasparetto discussed the following: ·      Overview of proteasome inhibitor therapy in multiple myeloma ·      Real-world data with proteasome inhibitors ·      The phase 3 TOURMALINE-MM1 trial (NCT01564537) of ixazomib therapy in relapsed/refractory multiple myeloma ·      Ixazomib plus pomalidomide and dexamethasone in patients with relapsed or refractory multiple myeloma Be sure to tune in to other videos in the CancerNetwork® Between the Lines™ series.

Listen to a soundcast of the 2/28/2022 FDA approval of CARVYKTI (ciltacabtagene autoleucel) for the treatment of adults with relapsed or refractory multiple myeloma after 4 or more prior lines of therapy, including a proteasome inhibitor, immunomodulatory agent, and anti-CD38 monoclonal antibody.

In today's podcast Professor Selina Wray from University College London, meets four early career researchers, who know a great deal about the brain, human iPSC derived cells and the ubiquitin-proteasome pathway (not that isn't a new type of electric car). We'll be discussing their research, discovering more about super resolution microscopy, and how they're researching the ubiquitin proteasome system, and its connection to dementia. We're delighted to welcome our guests: PhD Students Liina Sirvio, Katiuska Daniela Pulgar Prieto from the UK Dementia Research Institute at Imperial College London. Georgie Lines, PhD Student from University College London and Dr Emma Mee Haynes a Postdoctoral Research Associate also from the UK Dementia Research Institute at Imperial College London. What is the purpose of ubiquitin proteasome system? In eukaryotic cells, proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development. You can find out more about our guests, and access a full transcript of this podcast on our website at: https://www.dementiaresearcher.nihr.ac.uk/podcast _________________________ Finally, please review, like, and share our podcast - and don't forget to subscribe to ensure you never miss an episode. Register on our website to receive your weekly bulletin, and to access more great content – blogs, science, career support + much more https://www.dementiaresearcher.nihr.ac.uk This podcast is brought to you in association with Alzheimer's Research UK and Alzheimer's Society, who we thank for their ongoing support.

Proteins perform a lot of different jobs within our cells. As proteins either age or mutate, they can begin to cause problems for the cells. The ubiquitin system, (present only in eukaryotic organisms - animals and plants), works to tag proteins that go bad. Proteins tagged by the ubiquitin system send a signal to proteasomes which then shred the bad protein, hence the expression “kiss of death.” Normally, a cell infected by a pathogen, (bacterium or virus), will undergo a process known as xenophagy, where an infected cell will kill itself to avoid becoming infectious to other cells around it. At the same time, the process of xenophagy kills the pathogens causing the infection. Even though pathogens don’t have a ubiquitin system, they have adapted their ability to survive by producing proteins that hijack the ubiquitin system of eukaryotic cells. Sebastian Kenny, PhD candidate the Department of Chemistry at Purdue University, explains the research he is doing to learn more about how pathogens are able to hijack the ubiquitin system.

Prevention and Management of Cardiovascular Adverse Events in Multiple Myeloma: Safe and Appropriate Use of Proteasome Inhibitors

Prevention and Management of Cardiovascular Adverse Events in Multiple Myeloma: Safe and Appropriate Use of Proteasome Inhibitors

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.13.381962v1?rss=1 Authors: Cheng, C. L., Wong, M. K., Li, Y., Hochstrasser, M. Abstract: The proteasome is a large protease complex that degrades both misfolded and regulatory proteins. In eukaryotes, the 26S proteasome contains six different AAA+ ATPase subunits, Rpt1-Rpt6, which form a hexameric ring as part of the base subcomplex that drives unfolding and translocation of substrates into the proteasome core. Archaeal proteasomes contain only a single type of ATPase subunit, the proteasome-activating nucleotidase (PAN), which forms a trimer-of-dimers and is homologous to the eukaryotic Rpt subunits. A key PAN proline residue (P91) forms cis and trans peptide bonds in successive subunits around the ring, allowing efficient dimerization through upstream coiled coils. The importance of the equivalent Rpt prolines in eukaryotic proteasome assembly was unknown. We show an equivalent proline is strictly conserved in Rpt3 (in S. cerevisiae, P93) and Rpt5 (P76), well conserved in Rpt2 (P103), and loosely conserved in Rpt1 (P96) in deeply divergent eukaryotes, but in no case is its mutation strongly deleterious to yeast growth. However, the rpt2-P103A, rpt3-P93A, and rpt5-P76A mutations all cause synthetic defects with specific base assembly chaperone deletions. The Rpt5-P76A mutation decreases the levels of the protein and induces a mild proteasome assembly defect. The yeast rpt2-P103A rpt5-P76A double mutant has strong growth defects attributable to defects in proteasome base formation. Several Rpt subunits in this mutant form aggregates that are cleared, at least in part, by the Hsp42-mediated protein quality control (PQC) machinery. We propose that the conserved Rpt linker prolines promote efficient 26S proteasome base assembly by facilitating specific ATPase heterodimerization. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.20.305532v1?rss=1 Authors: Chen, L., Shu, X., Chen, Q., Wei, T., Wang, X., Wu, Q., Wang, H., Zhang, X., Liu, X., Zhang, Y., Zheng, S., Huang, L., Xiao, J., Jiang, C., Wang, Z., Yang, B., Guo, X. Abstract: Reversible phosphorylation has emerged as an important mechanism for regulating 26S proteasome function in health and disease. Over 100 phospho-tyrosine (pTyr) sites of the human proteasome have been detected, and yet their function and regulation remain poorly understood. Here we show that the 19S subunit Rpt2 is phosphorylated at Tyr439, a strictly conserved residue within the C-terminal HbYX motif of Rpt2 that is essential for 26S proteasome assembly. Unexpectedly, we found that Y439 phosphorylation depends on Rpt2 membrane localization mediated by its N-myristoylation. Multiple receptor tyrosine kinases (RTKs) can trigger Rpt2-Y439 phosphorylation by activating Src, a N-myristoylated tyrosine kinase. Src directly phosphorylates Rpt2-Y439 in vitro and negatively regulates 26S proteasome integrity and activity at cellular membranes, which can be reversed by the membrane-associated isoform of protein tyrosine phosphatase non-receptor type 2 (PTPN2). In H1975 lung cancer cells with activated Src, blocking Rpt2-Y439 phosphorylation by the Y439F mutation conferred partial resistance to the Src inhibitor saracatinib both in vitro and in a mouse xenograft tumor model, and caused significant changes of cellular responses to saracatinib at the proteome level. Our study has defined a novel mechanism involved in the spatial regulation of proteasome function and provided new insights into tyrosine kinase inhibitor-based anti-cancer therapies. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.14.217505v1?rss=1 Authors: Fuchs, A. C. D., Ammelburg, M., Martin, J., Hartmann, M. D., Lupas, A. N. Abstract: Genetic methods allow the recombinant production of any protein of interest, but yield the full-length construct in one step and are limited to native amino acids. For the "on demand" generation of chimeric, immobilized, fluorophore-conjugated or segmentally labeled proteins, these proteins must be modified using chemical, (split) intein, split domain or enzymatic methods. While each of these options comes with its own advantages and drawbacks, ligase enzymes are often used where small ligation motifs and good chemoselectivity are required. However, applications with the reference enzyme Sortase A are impeded by poor catalytic efficiencies, low substrate specificities and side reactions. Here, we present the discovery of Connectase, a monomeric proteasome homolog that ligates substrates via a highly conserved KDPGA motif originally identified in methyltransferase A (MtrA), a key enzyme in archaeal methanogenesis. Connectase displays nanomolar affinity and thus great specificity for its substrates, allowing efficient protein-protein ligations even in complex solutions and at low substrate concentrations. Compared to an optimized Sortase variant, Connectase catalyzes such ligations at substantially higher rates, with higher yields but without detectable side reactions and thus presents a valuable new tool for protein conjugations. Copy rights belong to original authors. Visit the link for more info

HOPA Now is the official podcast of the Hematology/Oncology/Pharmacy Association, an organization dedicated to supporting pharmacy practitioners and promoting the advancement of Hematology/Oncology/Pharmacy to optimize the care of individuals impacted by cancer.   These educational podcasts are part of our BCOP Preparatory and Recertification Course, which is designed to prepare oncology pharmacists preparing to sit for the BCOP Certification Exam, as well as meet the BPS requirement to complete a BCOP Preparatory/Recertification Review Course.   In this episode of HOPA Now, Dr. Kirollos Hanna details the top ten clinical pearls for managing patients with multiple myeloma. Topics include the goals of therapy, the proper approach to treatment and transplant options, details of inhibitors and administration guidelines, the role of the pharmacist in managing complex regimens, and more.   In this episode you will learn:   Multiple Myeloma: Top 10 Clinical Pearls The goals of therapy regarding the disease state of multiple myeloma C.R.A.B. symptoms as the hallmark representation of multiple myeloma patients The approach to treatment and transplant options is based on various patient factors. The efficacy and complexities of triplet therapies Details of the three main proteasome inhibitors, administration guidelines, and common adverse reactions Approved immuno module drugs and their associated increased patient risk factors Highlighting the role of the pharmacist in managing complex regimens Novel upcoming mechanisms for managing multiple myeloma patients   Mentioned in This Episode: HOPA   Quotes:   “It’s important to note that multiple myeloma remains, to date, an incurable disease.” — Dr. Kirollos Hanna   “Proteasome inhibitors are indicated in numerous frontline and relapse refractory regimens in multiple myeloma, regardless of transplant eligibility.” — Dr. Kirollos Hanna   “Pharmacists really play an integral role in managing these patients.”  — Dr. Kirollos Hanna   “It’s likely that we will see some of these therapies come to light within the next several years for the multiple myeloma patient population.” — Dr. Kirollos Hanna  

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.27.222679v1?rss=1 Authors: Khan, T. K., You, Y., Nelson, T., Kundu, S., Pramanik, S., Das, J. J. Abstract: Modulation of proteasome function by pharmacological interventions and molecular biology tools is an active area of research in cancer biology and neurodegenerative diseases. Curcumin (diferuloylmethane) is a naturally occurring polyphenol that affects multiple signaling pathways and known to modulate PKC activities. The therapeutic significance of curcumin is often considered to reside in its anti-inflammatory, antioxidant, anti-angiogenic, or anti-apoptotic properties. However, recent research suggests that the therapeutic efficacy of curcumin may be due to its activity as a potent inhibitor of the proteasome. In this study, we show that both curcumin and its synthetic polyphenolic derivative (didemethylcurcumin), CUIII modulated proteasome activity in a biphasic manner. Curcumin and CUIII increased proteasome activity at nanomolar concentrations but inhibited proteasome activity at micromolar concentrations. Curcumin was more effective than CUIII in relative proteasome activity increase at nanomolar concentrations. Also, curcumin was more effective than CUIII in relative proteasome activity inhibition at micromolar concentration. The docking study was conducted on the 20S proteasome catalytic subunit. Estimated Kd values for curcumin and didemethylcurcumin are 0.0054{micro}M and 1.3167{micro}M, respectively. These values correlate well with the results of the effectiveness of modulation by curcumin compare to CUIII. The small size of CUIII makes its dock to the narrow cavity of the active site, but the binding interaction is not strong compare to curcumin. This study suggests that curcumin and its didemethyl derivative can be used to modulate proteasome activity. This communication implicates the reason why curcumin and its didemethyl derivative can be used to two different disease mechanisms, neurodegeneration, and cancer. Copy rights belong to original authors. Visit the link for more info

Host Kevin Patton summarizes the 2019 Nobel Prize in Physiology or Medicine to three scientists "for their discoveries of how cells sense and adapt to oxygen availability." A special bonus episode. 00:41 | Introduction to Bonus Episode 02:00 | Sponsored by HAPS 02:24 | Summary of Discovery 04:13 | Oxygen at Center Stage 05:24 | HIF Enters the Scene08:08 | Sponsored by AAA 08:26 | VHL - An Unexpected Partner 11:37 | Oxygen sHIFts the Balance 13:20 | Oxygen Shapes Physiology & Pathology 15:15 | Sponsored by HAPI Online Graduate Program 15:48 | Our Course 23:46 | Staying Connected If you cannot see or activate the audio player click here. Questions & Feedback: 1-833-LION-DEN (1-833-546-6336) Follow The A&P Professor on Twitter, Facebook, Blogger, Nuzzel, Tumblr, or Instagram! Singing is like a celebration of oxygen. (Björk)   1 | Introduction to the Bonus Episode 1 minute Kevin introduces the bonus episode, explaining that he's sharing the press release for the 2019 Nobel Prize in Physiology or Medicine. It's chunked for clarity. Press release: The Nobel Prize in Physiology or Medicine 2019. NobelPrize.org. Nobel Media AB 2019. Mon. 7 Oct 2019.   2 | Sponsored by HAPS 2 minutes The Human Anatomy & Physiology Society (HAPS) is a sponsor of this podcast.  You can help appreciate their support by clicking the link below and checking out the many resources and benefits found there. There are a bunch of 1-day regional workshops scattered all over the continent. There's probably one near you coming up this year (or next)! Anatomy & Physiology Society  theAPprofessor.org/haps     3 | Summary of the Discovery 2 minutes 2019-10-07: The Nobel Assembly at Karolinska Institutet has today decided to award the 2019 Nobel Prize in Physiology or Medicine jointly to William G. Kaelin Jr., Sir Peter J. Ratcliffe, and Gregg L. Semenza for their discoveries of how cells sense and adapt to oxygen availability. They identified molecular machinery that regulates the activity of genes in response to varying levels of oxygen.   4 | Oxygen at Center Stage 1 minute During evolution, mechanisms developed to ensure a sufficient supply of oxygen to tissues and cells.   5 | HIF Enters the Scene 3 minutes Gregg Semenza studied the EPO (erythropoietin) gene and how it is regulated by varying oxygen levels. In cultured liver cells he discovered a protein complex that binds to the identified DNA segment in an oxygen-dependent manner. He called this complex the hypoxia-inducible factor (HIF). HIF was found to consist of two different DNA-binding proteins, so called transcription factors, now named HIF-1α and ARNT.   6 | Sponsored by AAA 0.5 minutes A searchable transcript for this episode, as well as the captioned audiogram of this episode, are sponsored by the American Association for Anatomy (AAA) at anatomy.org. Searchable transcript Captioned audiogram      7 | VHL - An Unexpected Partner 3 minutes When oxygen levels are high, cells contain very little HIF-1α. However, when oxygen levels are low, the amount of HIF-1α increases so that it can bind to and thus regulate the EPO gene as well as other genes with HIF-binding DNA segments. See figure (if you can't see it, go to https://my-ap.us/35fm0O6). At about the same time as Semenza and Ratcliffe were exploring the regulation of the EPO gene, cancer researcher William Kaelin, Jr. was researching an inherited syndrome, von Hippel-Lindau's disease (VHL disease). VHL is part of a complex that labels proteins with ubiquitin, marking them for degradation in the proteasome. Ratcliffe and his research group then made a key discovery: demonstrating that VHL can physically interact with HIF-1α and is required for its degradation at normal oxygen levels. This conclusively linked VHL to HIF-1α. When oxygen levels are low (hypoxia), HIF-1α is protected from degradation and accumulates in the nucleus, where it associates with ARNT and binds to specific DNA sequences (HRE) in hypoxia-regulated genes (1). At normal oxygen levels, HIF-1α is rapidly degraded by the proteasome (2). Oxygen regulates the degradation process by the addition of hydroxyl groups (OH) to HIF-1α (3). The VHL protein can then recognize and form a complex with HIF-1α leading to its degradation in an oxygen-dependent manner (4). https://my-ap.us/35fm0O6   8 | Oxygen sHIFts the Balance 1.5 minutes It was also shown that the gene activating function of HIF-1α was regulated by oxygen-dependent hydroxylation. The Nobel Laureates had now elucidated the oxygen sensing mechanism and had shown how it works.   9 | Oxygen Shapes Physiology & Pathology 2 minutes Thanks to the groundbreaking work of these Nobel Laureates, we know much more about how different oxygen levels regulate fundamental physiological processes. For example, muscles, blood vessel formation, immunity, RBC production, placenta development, etc. Oxygen sensing is central to a large number of diseases. For example, patients with chronic renal failure often suffer from severe anemia due to decreased EPO expression. See figure (if you cant's see it, go to https://my-ap.us/2LW2cIb) The awarded mechanism for oxygen sensing has fundamental importance in physiology, for example for our metabolism, immune response and ability to adapt to exercise. Many pathological processes are also affected. Intensive efforts are ongoing to develop new drugs that can either inhibit or activate the oxygen-regulated machinery for treatment of anemia, cancer and other diseases. https://my-ap.us/2LW2cIb   10 | Sponsored by HAPI Online Graduate Program 1 minute The Master of Science in Human Anatomy & Physiology Instruction—the MS-HAPI—is a graduate program for A&P teachers. A combination of science courses (enough to qualify you to teach at the college level) and courses in contemporary instructional practice, this program helps you power up  your teaching. Kevin Patton is a faculty member in this program. Check it out! nycc.edu/hapi     11 | Our Course 8 minutes This set of discoveries touches on many of the core concepts of our course (the big ideas of our story of the human body). Nobel Prizes are a cultural touchstone that students can related to, and thus increase interest and motivation. Nobel Prizes can be a starting point for discussion the role of science in the context of society and culture. Additional resources: Main page for this prize: my-ap.us/31Wuc3Z Publications Semenza, G.L, Nejfelt, M.K., Chi, S.M. & Antonarakis, S.E. (1991). Hypoxia-inducible nuclear factors bind to an enhancer element located 3' to the human erythropoietin gene. Proc Natl Acad Sci USA, 88, 5680-5684 my-ap.us/2ontmP8 Wang, G.L., Jiang, B.-H., Rue, E.A. & Semenza, G.L. (1995). Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension. Proc Natl Acad Sci USA, 92, 5510-5514 my-ap.us/2IxLUD5 Maxwell, P.H., Wiesener, M.S., Chang, G.-W., Clifford, S.C., Vaux, E.C., Cockman, M.E., Wykoff, C.C., Pugh, C.W., Maher, E.R. & Ratcliffe, P.J. (1999). The tumour suppressor protein VHL targets hypoxia-inducible factors for oxygen-dependent proteolysis. Nature, 399, 271-275 my-ap.us/2op4XbP Mircea, I., Kondo, K., Yang, H., Kim, W., Valiando, J., Ohh, M., Salic, A., Asara, J.M., Lane, W.S. & Kaelin Jr., W.G. (2001) HIFa targeted for VHL-mediated destruction by proline hydroxylation: Implications for O2 sensing. Science, 292, 464-468 my-ap.us/2IxIf8t Jakkola, P., Mole, D.R., Tian, Y.-M., Wilson, M.I., Gielbert, J., Gaskell, S.J., von Kriegsheim, A., Heberstreit, H.F., Mukherji, M., Schofield, C.J., Maxwell, P.H., Pugh, C.W. & Ratcliffe, P.J. (2001). Targeting of HIF-α to the von Hippel-Lindau ubiquitylation complex by O2-regulated prolyl hydroxylation. Science, 292, 468-472 my-ap.us/35i4wR9   If the hyperlinks here are not active, go to TAPPradio.org to find the episode page. More details at the episode page. Transcript available at the script page. Listen to any episode on your Alexa device. Need help accessing resources locked behind a paywall? Check out this advice from Episode 32 to get what you need! https://youtu.be/JU_l76JGwVw?t=440   Sponsors   Transcript and captions for this episode are supported by the  American Association for Anatomy. anatomy.org     The Human Anatomy & Physiology Society  also provides marketing support for this podcast.  theAPprofessor.org/haps     Distribution of this episode is supported by  NYCC's online graduate program in  Human Anatomy & Physiology Instruction (HAPI)  nycc.edu/hapi   Clicking on sponsor links  helps let them know you appreciate their support of this podcast!   Referrals also help defray podcasting expenses.  Amazon TextExpander Snagit & Camtasia The A&P Professor Logo Items   Follow The A&P Professor on  Twitter, Facebook, Blogger, Nuzzel, Tumblr, or Instagram!   The A&P Professor® and Lion Den® are registered trademarks of Lion Den Inc. (Kevin Patton)  

Prevention and Management of Cardiovascular Adverse Events in Multiple Myeloma: Safe and Appropriate Use of Proteasome Inhibitors

Prevention and Management of Cardiovascular Adverse Events in Multiple Myeloma: Safe and Appropriate Use of Proteasome Inhibitors

Raul Andino joins Vincent and Amy to talk about the finding that a cricket paralysis virus protein restricts RNA-based immunity in insects by regulating the activity and stability of the Argonaute protein. Hosts: Vincent Racaniello and Amy Rosenfeld Guest: Raul Andino Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode TWiV 138: RISCy business with Raul Andino TWiV 33: Live in Philly Viral protein restricts insect immunity (Cell Host Micr) Timestamps by Jolene. Thanks! Weekly Science Picks Amy - Insectropolis Vincent- Genome-edited baby Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

Lonya and Jeremy take the TWiV team beTWIXt primate immunodeficiency virus proteins Vpx and Vpr and how they counteract transcriptional repression of proviruses by the HUSH complex. Hosts: Vincent Racaniello, Dickson Despommier, Rich Condit, Kathy Spindler, and Brianne Barker Guests: Leonid Yorkovetskiy and Jeremy Luban Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode Pan American Society for Clinical Virology San Diego and Houston Regional Meetings Vpr and Vpx counter HUSH (Nat Micro) Vpr and Vpx counter HUSH (bioRxiv version) Schematic of HUSH complex (Lehner lab) Olive colobus monkey sound credit Image credit: William (Ted) Diehl Letters read on TWiV 516 Timestamps by Jolene. Thanks! Weekly Science Picks Brianne - The Chimp and the River by David Quammen Rich- James Cook’s First Voyage Journal (20 sec Google Earth summary) Kathy- High resolution Antarctica map NYTimes 46MB Maps (more info and 43 tb maps) Dickson- Jellyfish Jeremy - Pictorial Guide to Living Primates; All The World's PrimatesLonya- Chougui et al. HIV-2/SIV Vpx counters HUSH Vincent - Research!America Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

Best Practices for Use of Proteasome Inhibitors in the Treatment of Relapsed/Refractory Multiple Myeloma

Best Practices for Use of Proteasome Inhibitors in the Treatment of Relapsed/Refractory Multiple Myeloma

Best Practices for Use of Proteasome Inhibitors in the Treatment of Relapsed/Refractory Multiple Myeloma

Best Practices for Use of Proteasome Inhibitors in the Treatment of Relapsed/Refractory Multiple Myeloma

The TWiVers discuss the declining readability of scientific texts, and review the use of self-inactivating rabies virus for tracing neural circuits. Hosts: Vincent Racaniello, Dickson Despommier, Rich Condit, and Kathy Spindler Guest: Brianne Barker Become a patron of TWiV! Links for this episode Meet the Microbiologist TWiV 1: West Nile Virus Decreasing readability of scientific texts (eLife) Measure text readability Tracing neural circuits with self-inactivating rabies virus (Cell) Cre driver network (NIH) Monosynaptic tracing with rabies virus (Neuron) Letters read on TWiV 461 This episode is brought to you by the Defense Threat Reduction Agency. Part of the U.S. Department of Defense, the Agency’s Chemical and Biological Technologies Department hosts the 2017 Chemical and Biological Defense Science & Technology Conference to exchange information on the latest and most dynamic developments for countering chemical and biological weapons of mass destruction. Find out more at http://www.cbdstconference.com Weekly Science Picks Kathy -Best eclipse video (to date) and solargraph Dickson - Photos by Will Eades Brianne - Pale Rider by Laura Spinney Rich - “Supergenes” Drive Evolution Vincent -Anatomy of a Moral Panic Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

​Prof Pieter Sonneveld (University Hospital Rotterdam, Netherlands) chairs a roundtable discussion for ecancer at the 16th International Myeloma Workshop in Delhi, India. Focusing on newly diagnosed multiple myeloma (NDMM) and the management of bone disease, he is joined by Prof Michele Cavo (Seràgnoli Institute of Hematology, Bologna, Italy), Dr Peter Voorhees (Levine Cancer Institute, North Carolina, USA) and Professor Evangelos Terpos (University of Athens, Greece). First discussed was the treatment of symptomatic transplant-eligible multiple myeloma patients, with Prof Cavo suggesting that although trials continue to explore old and new agents, high dose melphalan supported by ASCT should remain the standard of care for the treatment of fit NDMM patients. Trials assessing these agents were discussed, such as the StaMINA trial presented at ASH 2016, which showed that the addition of bortezomib, lenalidomide (Len) and dexamethasone (RVD) consolidation or a second Autologous Hematopoietic Cell Transplant (autoCHT) was not superior to a single autoHCT followed by Len maintenance in the upfront treatment of MM. Moving on to asymptomatic patients, Dr Voorhees provided an overview of the treatment of smoldering myeloma (SM). Discussion focused on the evolving therapeutic landscape in SM, with agents such as elotuzumab and checkpoint inhibitors pembrolizumab and nivolumab showing promise. Proteasome inhibition was also discussed, looking at the CESAR and ASCENT trials, with Dr Voorhees commenting that with the latter it will be “interesting to see if this leads to cure”. The panel then focussed on the management of bone disease – the most common complication of multiple myeloma with 80% of patients presenting with detectable lesions. Bisphosphonates such as zoledronic acid are the current mainstay for the treatment of myeloma bone disease, with several novel agents, including denosumab, showing positive results. These advances show that for NDMM patients the future is promising for both first-line treatment options and the management of common complications.

Norris Cotton Cancer Center Grand Rounds Alexei Kisselev, PhD Research Scientist, VA, White River Junction Associate Professor of Medicine and of Molecular and Systems Biology, Geisel

Hosts: Vincent Racaniello, Dickson Despommier, and Daniel Griffin The TWiPtoids solve the case of the Thai Fisherman with Chronic Diarrhea, and reveal a potential new drug for treatment of leishmaniasis, Chagas diseases, and sleeping sickness. Links for this episode: Capillaria philippensis (Wikipedia) Proteasome inhibitor for three parasitic diseases (Nature) Image credit Letters read on TWiP 116 This episode is sponsored by CuriosityStream, a subscription streaming service that offers over 1,400 documentaries and non­fiction series from the world's best filmmakers. Get unlimited access starting at just $2.99 a month, and for our audience, the first two months are completely free if you sign up at curiositystream.com/microbe and use the promo code MICROBE. This episode is also sponsored by Drobo, a family of safe, expandable, yet simple to use storage arrays. Drobos are designed to protect your important data forever. Visit www.drobo.com to learn more. Become a patron of TWiP. Case Study for TWiP 116 This week's case involves no math. 36 year old Thai man from the northeast part of the country. Comes in with abdominal distention. Eats a normal Thai diet - Som Tam, Koi Pla, lots of rice. Feels well, came in because he is getting yellowing of skin and whites of eyes - jaundiced. Previously healthy, no prior med prob or surgery. No diseases running in family. Fisherman in the northeast (freshwater). Wife and many children, monogamous, HIV negative. Lives in jungle area, near river, many dogs, chickens, monkeys, goats, cows, pigs. Bathroom is outside. No fever, thin. Distention going on for months. Getting bigger. Exam: jaundiced, has large palpable non-tender mass below liver on his right side. No enlarged liver or spleen. No travel.  Send your case diagnosis, questions and comments to twip@microbe.tv

Chronic obstructive pulmonary disease (COPD) is projected to be the third leading cause of death by 2020 with cigarette smoke exposure being the main risk factor. Cigarette smoke leads to oxidative stress in the lung, resulting in protein damage and adaptive immune responses. Also, smokers and COPD patients are more susceptible to viral infections often followed by acute exacerbations of COPD pathogenesis. Lungs of COPD patients exhibit increased numbers of innate and adaptive immune cells, among these CD8+ T cells, whose abundance correlates with disease severity. The proteasome degrades more than 90 % of intracellular proteins - including damaged ones - into small peptides and is important to protect the cell from proteotoxic stress. Furthermore, the immunoproteasome, a specialized proteasome subtype which is expressed by default in antigen presenting cells and induced during infection, is involved in shaping adaptive immune responses by enhancing antigen presentation via major histocompatibility complex (MHC) I to cytotoxic CD8+ T cells. The effects of cigarette smoke on (immuno-)proteasome function have not been investigated so far. The first publication included in this thesis (van Rijt et al. 2012) explored the effects of acute cigarette smoke exposure on proteasome expression and activity. We observed that short-term exposure of cells to extracts of cigarette smoke directly impaired proteasome activity, while proteasomal protein expression was not altered. Oxidatively modified and polyubiquitinated proteins accumulated, suggesting augmentation of oxidative stress in cigarette smoke-treated cells. In lungs of mice acutely exposed to cigarette smoke, a similar effect could be observed: one of the three proteasome activities was significantly reduced, and ubiquitinated substrates for the proteasome were found to be accumulated, while proteasome expression levels were not changed. The second publication in this thesis (Keller et al. 2015) shows for the first time the cell-specific expression of immunoproteasomes in the lung and their induction by interferon-γ in vitro and by murid herpesvirus 68 (MHV-68) infection in vivo. Within these experiments, activity-based probes were used to clearly define the kinetics of standard and immunoproteasome subunit incorporation. In human lungs from controls or early-stage COPD patients, immunoproteasome expression was not changed. Immunoproteasomes localized mainly to alveolar macrophages, but not to parenchymal cells in both donors and end-stage COPD. Results from recent experiments were accepted for publication in the meantime (Kammerl et al. 2016): we investigated MHC I antigen presentation in cigarette smoke extract-treated primary immune cells and bronchoalveolar lavage (BAL) cells from mice exposed to cigarette smoke for ten days. In vitro treatment of primary immune cells with cigarette smoke extract led to a decrease in the presentation of an immunoproteasome-dependent “self”-epitope. With the help of activity-based probes, we observed a shift from immuno- to standard proteasome activity in isolated alveolar macrophages from smoke exposed mice. This shift, however, was not sufficient to impact antigen presentation of an immunoproteasome-dependent epitope. The altered ratio of standard and immunoproteasome might be explained by transcriptional downregulation of immuno-, but not standard proteasomes by cigarette smoke in isolated alveolar macrophages of smoke-exposed mice, which was also observed in total BAL cells of early-stage COPD patients. In the lungs of end-stage COPD patients, activities of both standard and immunoproteasome subunits were significantly decreased, while total proteasome protein levels were not changed. Taken together, we show that cigarette smoke directly impairs proteasome function in vitro and in vivo, which may exacerbate oxidative stress resolution in response to cigarette smoke, since the degradation of oxidatively modified and misfolded proteins is impaired. In addition, we observed alterations in immunoproteasome-dependent MHC I antigen presentation, which may contribute to increased susceptibility to virus-induced exacerbations, prolonged infection and possibly result in autoimmune responses.

Idiopathic pulmonary fibrosis (IPF) is an irreversible and progressive disease of the lungs, which is characterized by aberrant tissue remodeling and massive deposition of extracellular matrix proteins. This process is mainly conducted by myofibroblasts, an activated fibroblast phenotype. During the pathogenesis of IPF, the fine alveolar structure is destroyed and gas exchange declines, finally resulting in organ failure. So far, pharmacological treatment options are very limited and lung transplantation still remains the only curative therapy. Pathologic tissue remodeling in IPF is closely connected to altered cell and protein homeostasis. The ubiquitin-proteasome system is critical for degradation of polyubiquitinated proteins in a spatially and timely controlled manner, thereby regulating protein levels. The proteasome is a multicatalytic enzyme complex consisting of a barrel shaped 20S catalytic core particle (CP) and one or two 19S regulatory particles (RP), thus forming active 26S/30S proteasomes. Dysregulation of the proteasome has been reported for several chronic diseases of the heart, brain, and also lung. Furthermore, inhibition of the proteasome has been shown to provide antifibrotic effects in different organs, including the lung. As nothing is known about proteasome function in the pathogenesis of IPF, the first aim of the present study was to analyze proteasomal regulation during tissue remodeling and myofibroblast differentiation. For that, lung fibroblasts were treated with transforming growth factor-β (TGF-β) and proteasome activity as well as composition was examined. For in vivo testing, the bleomycin mouse model of lung fibrosis was used and human lung tissue of IPF patients was analyzed. It was found that induction of myofibroblast differentiation by TGF-β mediated assembly of 19S RPs with 20S CPs, thereby forming 26S/30S complexes, which was critically dependent on the regulatory particle non ATPase 6 subunit (Rpn6). In addition, silencing of Rpn6 in primary human lung fibroblasts counteracted TGF β induced myofibroblast differentiation. During bleomycin-induced fibrotic remodeling of mouse lungs, increased formation of 26S/30S proteasomes was accompanied by augmented expression of Rpn6 in fibrotic lungs. Here, Rpn6 was highly expressed in hyperplastic alveolar epithelial cells and Clara cells. Overexpression of Rpn6 was also observed in myofibroblasts and hyperplastic bronchiolar basal cells of fibrotic lung tissue of IPF patients and accompanied by enhanced polyubiquitination of proteins. As therapeutic application of proteasome inhibitors in pulmonary fibrosis showed controversial results including beneficial antifibrotic effects but also toxicity, the second aim of this study was to test whether site specific inhibition of the proteasome, using the novel second generation inhibitor oprozomib, provides antifibrotic effects in the absence of systemic side effects after local pulmonary application. Oprozomib was compared to the FDA-approved proteasome inhibitor bortezomib and tested on the human alveolar epithelial cancer cell line A549 and on primary mouse alveolar epithelial type II cells regarding its cytotoxic effects. Oprozomib was less toxic than bortezomib and provided high selectivity for the chymotrypsin-like active site of the proteasome. In primary mouse lung fibroblasts, oprozomib showed significant antifibrotic effects like reduction of collagen I and α-smooth muscle actin expression at non-toxic doses. When applied locally into the lungs of healthy mice via instillation, oprozomib was well tolerated and effectively reduced pulmonary proteasome activity. In bleomycin-challenged mice, however, locally applied oprozomib resulted in accelerated weight loss and increased mortality. Furthermore, oprozomib failed to reduce fibrosis in these mice, but rather augmented fibrotic lung remodeling in bleomycin-challenged animals. To conclude, this study identified a novel mechanism for fibrotic remodeling of the lungs involving 26S/30S proteasome activation via Rpn6 upon TGF-β-mediated myofibroblast differentiation. Increased levels of Rpn6 and polyubiquitinated proteins in IPF lungs further suggest an important contribution of the ubiquitin-proteasome system to the pathogenesis of this disease. Inhibition of the proteasome with the novel site-specific proteasome inhibitor oprozomib provided low toxicity and antifibrotic effects in alveolar epithelial cells and pulmonary fibroblasts. These results could not be confirmed in pulmonary fibrosis of bleomycin-treated mice, as oprozomib treatment showed high toxicity in fibrotic animals. In light of these data, current proteasome inhibitors, which block the catalytic core, might be too toxic as therapeutic agents for the treatment of fibrotic lung diseases. However, interference with the formation of 26S/30S proteasomes, as shown by Rpn6 knockdown, might provide a novel concept for therapeutic regulation of proteasome activity in lung fibrosis.

Even though platelets are the smallest cells in circulating blood, they play an integral role in blood clotting where they are activated, adhere to the vessel wall, and contribute to hemostasis. But over the years it was discovered that those anucleate cells have more extended functions. They organize their cellular vitality similar to nucleated cells and have an active protein metabolism performing protein de novo synthesis as well as protein degradation. One of the main degradation systems in cells is the proteasome. Besides protein quality control, the proteasome is involved in important cellular processes like cell survival, transcription, development, selective elimination of abnormal proteins and antigen processing. A dysregulation of this multicatalytic protein complex leads to various disease developments. Proteasome inhibitors, for instance, have been studied for treating cancer. Platelets like nucleated cells contain a proteasome. However, the impact of the proteasome on platelet functions remains poorly investigated until today. A better knowledge of signaling pathways in platelets aids in understanding how alterations in proteasome functions affect platelet-mediated processes and diseases. This study confirms the existence of a functional proteasome in human platelets and illustrates an important role in platelet biology, as well as sepsis. With this study the role of the proteasome in anucleate platelets is demonstrated in more detail and a signaling pathway regulating its activity was observed. Here, the proteasome in platelets is linked to platelet aggregation. First, proteasome inhibitors epoxomicin and bortezomib reduce ADP- and collagen-induced aggregation. Furthermore, the 26S chymotrypsin-like activity of the proteasome is enhanced when platelets are incubated with the platelet agonist collagen. Additionally, cytoskeletal proteins Filamin A and Talin-1, which are crucial for platelet activation, were identified as proteasome substrates and increased cleavage of these proteins occurs with proteasome activation. To investigate possible mechanisms of regulating the proteasome, the signaling pathway related to NFκB was analyzed under platelet agonist treatment. The NFκB pathway, that mediates aggregation, is initiated when platelets are treated with collagen and the inhibitory protein of NFκB, IκBα, is degraded in collagen-stimulated platelets. More interestingly, NFκB inhibitors prevent collagen-stimulated enhancement of the proteasome activity. In return the connection of the proteasome and the NFκB pathway is further demonstrated as NFκB inhibitors restrict cleavage of the proteasome substrate Talin-1. These results propose a novel pathway that involves the proteasome and that is in return connected with non-genomic functions of NFκB in regulating platelet aggregation. In a second part this work shows for the first time that mitochondrial membrane depolarization in platelets correlates with the disease course and disease severity in patients with sepsis. Additionally, during these studies increased proteasome activity was observed in sepsis patients compared to control patients and pathogenic bacteria intensified the 26S trypsin-like activity of human platelets. Therefore, molecular markers of platelet vitality may be valuable parameters to help evaluating the clinical outcome of sepsis patients. In summary, the study confirms the existence of a functional proteasome in human platelets, contributes to our understanding how the proteasome affects platelet functions such as aggregation and how this may be regulated on a molecular basis. Furthermore, it allows for new insights in the disease course of sepsis and identifies new molecular markers for assessing the disease severity and clinical outcome of sepsis patients.

Fri, 11 Apr 2014 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/18241/ https://edoc.ub.uni-muenchen.de/18241/1/Kock_Malte.pdf Kock, Malte ddc:540, ddc:500, Faku

Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Rich Condit, and Kathy Spindler The complete TWiV team reviews evidence for sensing of herpesviral DNA in the nucleus by the cell protein IFI16.  Links for this episode IFI16 is a nuclear pathogen sensor (Cell Host Micr) Nuclear IFI16 sensing of and antagonism by herpesvirus (PNAS) Acetylation regulates IFI16 location (PNAS) Letters read on TWiV 269 Weekly Science Picks Kathy - Female conveners and speakersAlan - SandgrainsRich - 2013 Lamborghini AventadorVincent - Happy Birthday Mac and 128K Mac teardownDickson - Farmdominion Listener Pick of the Week Peter - The Microscope and The Next Global KillerRichard - Glass viruses Send your virology questions and comments (email or mp3 file) to twiv@twiv.tv

In this podcast, Attar and colleagues explore whether patients aged 60-75 who enter remission with bortezomib added to standard anthracycline plus cytarabine chemotherapy during induction can be safely treated with intermediate dose cytarabine along with dose escalating bortezomib during consolidation. This regimen was tolerated at the highest dose of bortezomib tested, 1.3 mg/m2, and further randomized studies of this regimen will be planned.

Dr Saga Lonial talks to ecancer about the first oral proteasome inhibitor at the ASCO 2012 Annual meeting in Chicago. Similar to bortezomib, but administered orally, MLN9708 is the first oral drug to go into clinical trial for myeloma. MLN9708 is boron-based making it a reversible inhibitor. Current trials using the experimental drug aim to determine the dosage and efficacy in myeloma. Patients receiving the drug have already been heavily treated with commonly available agents and had high efficacy, with very low rates of neuropathy, when used in combination with other drugs.

Phase I study of twice-weekly dosing of the investigational oral proteasome inhibitor MLN9708 in patients with relapsed and/or refractory multiple myeloma. Similar to bortezomib, but administered orally, MLN9708 is the first oral drug to go into clinical trial for myeloma. MLN9708 is boron-based making it a reversible inhibitor. Current trials using the experimental drug aim to determine the dosage and efficacy in myeloma. Patients receiving the drug have already been heavily treated with commonly available agents and had high efficacy, with very low rates of neuropathy, when used in combination with other drugs. en Español

Nobel laureate Avram Hershko, who determined cellular mechanisms for breaking down proteins, talks about his research in a conversation recorded at the Lindau Nobel Laureate Meeting in Lindau, Germany. And Scientific American Editor in Chief Mariette DiChristina discusses the recent inaugural Google Science Fair

Oxidative stress induces separation of the catalytic and regulatory portions of the yeast 26S proteasome, enabling the catalytic core to degrade toxic oxidized proteins.

Fri, 20 Nov 2009 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/11656/ https://edoc.ub.uni-muenchen.de/11656/1/Siepe_Dirk.pdf Siepe, Dirk ddc:570, ddc:500, F

Targets of natural anti-endothelial cell antibodies, PROTEOMICS Clinical Applications - Reviews Part II, Reports, Special Issue on the Human Brain Proteome Project, Proteasome subunit proteins and neuropathology in tauopathies and synucleinopathies

Targets of natural anti-endothelial cell antibodies, PROTEOMICS Clinical Applications - Reviews Part II, Reports, Special Issue on the Human Brain Proteome Project, Proteasome subunit proteins and neuropathology in tauopathies and synucleinopathies

Audio Journal of Medicine, September 18th, 2007 Reporting from: 47th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), Chicago, 2007 Bortezomib for Multiple Myeloma Can Cause Reactivation of Viruses GEORG HÄRTER, University Hospital, Ulm REFERENCE: Interscience Conference on Antimicrobial Agents and Chemotherapy, 17 – 20 September 2007, Chicago For patients with multiple myeloma being treated with the proteasome inhibitor bortezomib, doctor’s should be wary of viral reactivation – and they should give antiviral prophylaxis in all cases. This finding was unveiled at ICAAC by Georg Härter from the University Hospital in Ulm, and he shared his data with Derek Thorne.

Fri, 27 Apr 2007 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/8981/ https://edoc.ub.uni-muenchen.de/8981/1/Piwko_Wojciech.pdf Piwko, Wojciech ddc:500, ddc:570, Fakultät für Biologie

Die Funktion der Niere basiert auf einer intakten glomerulären Filtrationseinheit, für deren Aufrechterhaltung den Podozyten eine tragende Rolle zugeschrieben wird. Podozyten formen die Schlitzmembran und sind durch ihre anionische Glykokalix für die größen- und ladungsselektive Filtration des Blutes im Glomerulus zur Bildung eines proteinfreien Ultrafiltrats verantwortlich. Podozyten-Schädigung führt zu einem Verlust der Filtrationsschlitze, zu einem Ablösen der Podozyten von der GBM und zur Ausscheidung von hochmolekularen Proteinen im Urin (Proteinurie). Ziel der vorliegenden Arbeit war die Identifikation von molekularen Regulationsmechanismen. Vorarbeiten zeigten eine Induktion der ILK bei Podozyten- Schädigung in humanen Nierenerkrankungen, zwei Tiermodellen und in Podozyten- Zellkultur. Anhand eines ILK-Inhibitors konnte in vitro gezeigt werden, dass die ILKInduktion zu einer gesteigerten Proliferation und zu einer verminderten Zell-Matrix- Adhäsion führt. Durch den Einfluß der ILK auf GSK-3β wurden Elemente des Wnt- Signaltransduktionsweges rekrutiert. Die nucleäre Translokation von β-Catenin beeinflusste auf transkriptioneller Ebene das Schlitzmembranmolekül P-Cadherin in Podozyten. P-Cadherin wurde auf mRNA- und Protein-Ebene reprimiert (siehe Abbildung 8.1). Die Applikation des ILK-Inhibitors in einem Proteinuriemodell verminderte die strukturellen Schädigungen innerhalb der Glomeruli. Immunfluoreszenzen und Co-Immunpräzipitationen ermöglichten die Identifikation eines neuen, cytoskeletalen Interaktionspartners von ILK, bei dem es sich um das kürzlich beschriebene PDZ-LIM Domänen Protein CLP-36 (siehe Abbildung 8.1) handelt. In Podozyten wird CLP-36 an Serin- und Threonin-Resten phosphoryliert. Eine direkte Phosphorylierung von CLP-36 durch die ILK konnte mit den verwendeten in vitro Experimenten zunächst nicht nachgewiesen werden. CLP-36 assoziiert neben FActin mit den Alpha-Actinin-Isoformen 1 und 4. Die Expression und molekulare Interaktion von CLP-36 und Alpha-Actinin-4 in Podozyten konnte bestätigt werden. Mutierte Formen von Alpha-Actinin-4 führen bei Menschen zu einem Podozyten- Schaden, einhergehend mit starker Proteinurie.Über die Regulation von nativem Alpha-Actinin-4 und seinem Interaktionspartner CLP-36 war bei erworbenen Nierenerkrankungen noch nichts bekannt. Diese sollte im Rahmen dieser Arbeit untersucht werden. Bei humanen Nierenerkrankungen, insbesondere bei FSGS-Patienten, fand sich eine deutliche Reduktion von Alpha- Actinin-4 und CLP-36 Protein bei gleich bleibender mRNA-Expression. Die Analyse der Primärsequenz beider Moleküle ergab, dass diese durch Proteasomen degradiert werden könnten. Die Ubiquitinierung von Alpha-Actinin-4 konnte experimentell bestätigt werden, für CLP-36 fanden sich Hinweise auf eine Poly-Ubiquitinierung. Untersuchungen mit dem Translationsblocker Cycloheximid ergaben eine Halbwertszeit von mehr als 20 Stunden für beide Moleküle. Bei zusätzlicher Inhibition mit einem Proteasom-Inhibitor wurde deren proteasomale Degradation verhindert. Der Verlust beider Proteine bei oxidativem Stress konnte ebenfalls durch Inhibition der Proteasomen unterbunden werden. In dem murinen Proteinuriemodell entsprach die Regulation von CLP-36 und Alpha-Actinin-4 auf Protein- und mRNA-Ebene den Befunden an Patientenmaterial. Die Inhibition der Proteasome blockierte den Verlust von Alpha-Actinin-4 Protein in vivo. Die vorgestellten Daten identifizieren neue molekulare Regulationsmechanismen bei Podozyten-Schädigung und leisten einen Beitrag zum besseren Verständnis der zellulären Prozesse bei Nierenerkrankungen.