JCI insightPub Date : 2025-10-07DOI: 10.1172/jci.insight.191538
Nayden G Naydenov, Gaizun Hu, Dominik Robak, Atif Zafar, Khosiyat Makhmudova, Susana Lechuga, Yuta Ohno, Naseer Sangwan, Saikat Bandyopadhyay, Ryan Musich, Erin Jeffery, Lei Sun, Armando Marino-Melendez, Florian Rieder, Gloria Sheynkman, Andrei I Ivanov, Seham Ebrahim
{"title":"The septin cytoskeleton is a novel regulator of intestinal epithelial barrier integrity and mucosal inflammation.","authors":"Nayden G Naydenov, Gaizun Hu, Dominik Robak, Atif Zafar, Khosiyat Makhmudova, Susana Lechuga, Yuta Ohno, Naseer Sangwan, Saikat Bandyopadhyay, Ryan Musich, Erin Jeffery, Lei Sun, Armando Marino-Melendez, Florian Rieder, Gloria Sheynkman, Andrei I Ivanov, Seham Ebrahim","doi":"10.1172/jci.insight.191538","DOIUrl":"https://doi.org/10.1172/jci.insight.191538","url":null,"abstract":"<p><p>Intestinal epithelial barrier-integrity is essential for human health, and its disruption induces and exacerbates intestinal inflammatory disorders. While the epithelial cytoskeleton is critical for maintaining gut barrier-integrity, the role of septins- a family of GTP-binding, cytoskeletal proteins- is largely unknown. This highlights an important knowledge gap as dysfunction of septins, and specifically septin 9 (SEPT9), is associated with intestinal pathologies. We determined that SEPT9 localizes to the apical junctions of intestinal epithelial cells (IECs), overlapping with both tight and adherens junctions. IEC-specific ablation of SEPT9 in mice resulted in leaky gut, due to mislocalization of junctional proteins, and increased susceptibility to experimental colitis. Consistently, SEPT9 expression was significantly reduced in intestinal mucosa of inflammatory bowel disease (IBD) patients. Using affinity-purification mass spectrometry, super-resolution imaging, and genetic knockout, we determined that SEPT9 interacts with and is necessary to recruit non-muscle myosin IIC (NMIIC) to the IEC peri-junctional actomyosin belt. Loss of NMIIC also caused IEC barrier disruption. In summary, SEPT9 regulates intestinal barrier-integrity by supporting the assembly of tight and adherens junctions through NMIIC recruitment to the actomyosin belt. The septin cytoskeleton safeguards the intestinal mucosa during acute inflammation, and its disruption in IBD suggests a loss of this protective function.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-10-07DOI: 10.1172/jci.insight.193054
Melissa R Romoff, Preethi K Periyakoil, Edward F DiCarlo, Daniel Ramirez, Susan M Goodman, Christina S Leslie, Alexander Y Rudensky, Laura T Donlin, Melanie H Smith
{"title":"Rheumatoid arthritis synovial fibroblasts modulate T cell activation.","authors":"Melissa R Romoff, Preethi K Periyakoil, Edward F DiCarlo, Daniel Ramirez, Susan M Goodman, Christina S Leslie, Alexander Y Rudensky, Laura T Donlin, Melanie H Smith","doi":"10.1172/jci.insight.193054","DOIUrl":"https://doi.org/10.1172/jci.insight.193054","url":null,"abstract":"<p><p>In the rheumatoid arthritis (RA) synovium, resident fibroblast-like synoviocytes (FLS) express MHC class II molecules (HLA-D) but lack the co-stimulatory signals typically required for T cell activation. Here, we demonstrate that antigen presentation by FLS induces a distinct T cell activation state characterized by high CD69, yet reduced CD25 and HLA-DR expression, suppressed proliferation, and decreased effector cytokine production compared to professional antigen presenting cells (APCs), such as macrophages. FLS were also capable of suppressing macrophage-induced T cell activation, underscoring their dominant immunomodulatory role in the synovial microenvironment. Mechanistically, we identify indoleamine 2,3-dioxygenase (IDO1)-mediated tryptophan depletion as the primary driver of FLS-induced T cell hypo-responsiveness. Spatial transcriptomics revealed colocalization of IDO1 and CD69 within ectopic lymphoid structures in RA synovium, further supporting the in vivo relevance of this pathway. These findings provide the groundwork for positioning FLS as critical T cell regulators in RA and highlight the importance of preserving their immunosuppressive properties when therapeutically targeting pathogenic FLS functions.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SERPINB5-TGF-β signalling modulates desmoplakin membrane localization and ameliorates pemphigus vulgaris skin blistering.","authors":"Maitreyi Rathod, Mariam Petrosyan, Aude Zimmermann, Maike Märker, Tobias Gosau, Henriette Franz, Tomás Cunha, Dario Didona, Michael Hertl, Enno Schmidt, Volker Spindler","doi":"10.1172/jci.insight.183024","DOIUrl":"https://doi.org/10.1172/jci.insight.183024","url":null,"abstract":"<p><p>Impairment of desmosomal cell-cell adhesion leads to life-threatening diseases such as the autoimmune skin blistering disorder pemphigus vulgaris (PV). Disease management strategies that stabilize intercellular adhesion, in addition to the existing immunosuppression therapies, may result in improved clinical outcomes. Previous findings showed that the serine protease inhibitor SERPINB5 promotes intercellular adhesion by binding to and regulating the localization of the desmosomal adapter molecule desmoplakin (DSP) at the plasma membrane. We here show that SERPINB5 overexpression prevents PV-IgG-mediated loss of cell-cell adhesion and DSP dissociation from the cell membrane. We mechanistically demonstrate that SERPINB5 loss deregulates TGF-β signalling, a pathway known to destabilize DSP in keratinocytes. TGF-β signalling was also activated in skin biopsies of PV patients and keratinocytes treated with PV autoantibodies, suggesting a contribution to disease. Inhibition of TGF-β signaling ameliorated PV-IgG-mediated loss of cell-cell adhesion, increased DSP membrane expression, and prevented PV-IgG-induced blister formation in a human ex-vivo skin model. Together, SERPINB5 modulates DSP and intercellular adhesion through the regulation of TGF-β signalling. Further, TGF-β signalling was identified as a potential target for pemphigus treatment.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145212633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.194316
Janée D Terwoord, Laura E Norwood Toro, Shelby N Hader, Stephen T Hammond, Joseph C Hockenberry, Jasmine Linn, Ibrahim Y Vazirabad, Amanda L Kong, Alison J Kriegel, Ziqing Liu, Riikka M Kivelä, Gillian Murtagh, David D Gutterman, Andreas M Beyer
{"title":"Characterization of anti-cancer therapy-induced microvascular dysfunction in breast cancer patients with proof-of-concept of targeted intervention.","authors":"Janée D Terwoord, Laura E Norwood Toro, Shelby N Hader, Stephen T Hammond, Joseph C Hockenberry, Jasmine Linn, Ibrahim Y Vazirabad, Amanda L Kong, Alison J Kriegel, Ziqing Liu, Riikka M Kivelä, Gillian Murtagh, David D Gutterman, Andreas M Beyer","doi":"10.1172/jci.insight.194316","DOIUrl":"https://doi.org/10.1172/jci.insight.194316","url":null,"abstract":"<p><strong>Background: </strong>Cardiotoxicity is a major complication of anti-cancer therapy (CTx); yet, the impact of CTx on the human microcirculation is not well defined. This study evaluated the impact of CTx on microvascular function in breast cancer patients.</p><p><strong>Methods: </strong>Endothelial function and angiogenic potential were assessed in arterioles and adipose biopsies obtained from breast cancer patients before, during, and after CTx (longitudinal and cross-sectional) and in healthy arterioles exposed to doxorubicin (Dox), trastuzumab (TZM), or paclitaxel (PTX) ex vivo. Conditioned media containing VEGF-B protein was used to test feasibility of a targeted intervention.</p><p><strong>Results: </strong>Patients treated with Dox and/or TZM in vivo developed profound microvascular endothelial dysfunction that persisted for ≥9 months after treatment cessation. Angiogenic potential was reduced during CTx and recovered within one month after cessation. Gene expression related to angiogenesis and inflammation changed over the course of clinical treatment. Isolated adipose arterioles from healthy donors developed endothelial dysfunction when exposed to Dox or TZM ex vivo. In contrast, paclitaxel (PTX), which poses minimal cardiovascular risk, had no impact on vasomotor function. Ex vivo exposure to Dox or PTX suppressed angiogenic potential, whereas TZM had no effect. Treatment with VEGF-B protein preserved endothelial function in healthy arterioles exposed to Dox or TZM ex vivo.</p><p><strong>Conclusion: </strong>Breast cancer patients undergoing treatment with Dox and/or TZM develop prolonged microvascular endothelial dysfunction that is recapitulated in healthy arterioles exposed to Dox or TZM ex vivo. Targeted intervention with VEGF-B protects against direct Dox- or TZM-induced vascular toxicity in human arterioles ex vivo.</p><p><strong>Funding: </strong>National Institutes of Health grant R01 HL133029, HL173549 (AMB). National Institutes of Health grant T32 HL134643 (JDT, STH). American Heart Association grant SFRN847970 (AMB, DDG). We Care Foundation Grant (AMB, ALK). Medical College of Wisconsin Cardiovascular Center Pre-PPG Grant (AMB). Advancing a Healthier Wisconsin - Redox Biology Grant (AMB). Jenny and Antti Wihuri Foundation (RMK).</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.191697
Christian L Egly, Alex Shen, Tri Q Do, Carlos Tellet Cabiya, Paxton A Ritschel, Suah Woo, Matthew J Ku, Brian P Delisle, Brett Kroncke, Bjorn C Knollmann
{"title":"High throughput screens identify genotype-specific therapeutics for channelopathies.","authors":"Christian L Egly, Alex Shen, Tri Q Do, Carlos Tellet Cabiya, Paxton A Ritschel, Suah Woo, Matthew J Ku, Brian P Delisle, Brett Kroncke, Bjorn C Knollmann","doi":"10.1172/jci.insight.191697","DOIUrl":"https://doi.org/10.1172/jci.insight.191697","url":null,"abstract":"<p><p>Genetic diseases such as ion-channelopathies substantially burden human health. Existing treatments are limited and not genotype specific. Here, we report a two-step high-throughput approach to rapidly identify drug candidates for repurposing as genotype-specific therapy. We first screened 1,680 medicines using a new thallium-flux trafficking assay against KV11.1 gene variants causing Long QT Syndrome (LQTS), an ion-channelopathy associated with fatal cardiac arrhythmias. We identify evacetrapib as a suitable drug candidate that improves membrane trafficking and activates channels. We then use deep mutational scanning to prospectively identify all KV11.1 missense variants in a LQTS hotspot region responsive to treatment with evacetrapib. Combining high-throughput drug screens with deep mutational scanning establishes a new paradigm for mutation-specific drug discovery translatable to personalized treatment of patients with rare genetic disorders.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.192984
Sterling H Ramsey, Zixuan Zhao, Megan C Lee, Thales Hein da Rosa, Ava C Schneider, Miriam Bollmann, Nour Dada, Katie Frizzi, May M Han, Jaeyeon Kim, Martina Zoccheddu, Nigel A Calcutt, Gary S Firestein, James W Bryson, Mattias Nd Svensson, Eugenio Santelli, Stephanie M Stanford, Nunzio Bottini
{"title":"Optimization of synoviocyte-targeted biologic for inflammatory arthritis in combination or bispecific administration with TNF inhibitors.","authors":"Sterling H Ramsey, Zixuan Zhao, Megan C Lee, Thales Hein da Rosa, Ava C Schneider, Miriam Bollmann, Nour Dada, Katie Frizzi, May M Han, Jaeyeon Kim, Martina Zoccheddu, Nigel A Calcutt, Gary S Firestein, James W Bryson, Mattias Nd Svensson, Eugenio Santelli, Stephanie M Stanford, Nunzio Bottini","doi":"10.1172/jci.insight.192984","DOIUrl":"https://doi.org/10.1172/jci.insight.192984","url":null,"abstract":"<p><p>Rheumatoid arthritis (RA) is a common systemic autoimmune disorder. Fibroblast-like synoviocytes (FLS) have emerged as an attractive target for non-immunosuppressive RA therapy, but there are no approved drugs targeting FLS. The receptor protein tyrosine phosphatase sigma (PTPRS) negatively regulates FLS migration and has been proposed as a target for FLS-directed RA therapy. Here we examined the impact of sequence variations on efficacy of an FLS-targeted biologic comprised of Fc-fused PTPRS immunoglobulin (IgG)-like domains Ig1 and Ig2 (Ig1&2-Fc). Engineering the linker and Fc tag improved effectiveness of human Ig1&2-Fc in assays of FLS migration and a mouse model of arthritis. Treatment of mice with Ig1&2-Fc over four months revealed no signs of toxicity or organ pathology. Finally, we show potential of Ig1&2-Fc co-administration in combination or as a bispecific fusion with a tumor necrosis factor alpha inhibitor (TNFi). Combination treatment of mouse tumor necrosis factor receptor 2 (mTnfr2) with Ig1&2-Fc resulted in increased efficacy in suppressing arthritis beyond single agent treatment. When administered as a dual-action bispecific, Ig1&2 fused to mTnfr2 proved more efficacious at suppressing arthritis than mTnfr2 alone. This study illustrates the potential of Ig1&2-Fc as a combination or bispecific therapy with DMARDs to improve patient outcomes in RA.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.189615
Valentin J Weber, Alice Reschigna, Maximilian J Gerhardt, Thomas Heigl, Klara S Hinrichsmeyer, Sander van den Engel, Dina Y Otify, Zoran Gavrilov, Frank Blaser, Isabelle Meneau, Christian Betz, Hanno J Bolz, Martin Biel, Stylianos Michalakis, Elvir Becirovic
{"title":"CRISPR/Cas-mediated activation of genes associated with inherited retinal dystrophies in human cells for diagnostic purposes.","authors":"Valentin J Weber, Alice Reschigna, Maximilian J Gerhardt, Thomas Heigl, Klara S Hinrichsmeyer, Sander van den Engel, Dina Y Otify, Zoran Gavrilov, Frank Blaser, Isabelle Meneau, Christian Betz, Hanno J Bolz, Martin Biel, Stylianos Michalakis, Elvir Becirovic","doi":"10.1172/jci.insight.189615","DOIUrl":"https://doi.org/10.1172/jci.insight.189615","url":null,"abstract":"<p><p>Many patients suffering from inherited diseases do not receive a genetic diagnosis and are therefore excluded as candidates for treatments, such as gene therapies. Analyzing disease-related gene transcripts from patient cells would improve detection of mutations that have been missed or misinterpreted in terms of pathogenicity during routine genome sequencing. However, the analysis of transcripts is complicated by the fact that a biopsy of the affected tissue is often not appropriate, and many disease-associated genes are not expressed in tissues or cells that can be easily obtained from patients. Here, using CRISPR/Cas-mediated transcriptional activation (CRISPRa) we developed a robust and efficient approach to activate genes in skin-derived fibroblasts and in freshly isolated peripheral blood mononuclear cells (PBMCs) from healthy individuals. This approach was successfully applied to blood samples from patients with inherited retinal dystrophies (IRD). We were able to efficiently activate several IRD-linked genes and detect the corresponding transcripts using different diagnostically relevant methods such as RT-qPCR, RT-PCR and long- and short-read RNA sequencing. The detection and analysis of known and unknown mRNA isoforms demonstrates the potential of CRISPRa-mediated transcriptional activation in PBMCs. These results will contribute to ceasing the critical gap in the genetic diagnosis of IRD patients and other inherited diseases.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.194304
Xiaoyue Pan, John O'Hare, Cyrus Mowdawalla, Samantha Mota, Nan Wang, M Mahmood Hussain
{"title":"Bmal1 is involved in the regulation of macrophage cholesterol homeostasis.","authors":"Xiaoyue Pan, John O'Hare, Cyrus Mowdawalla, Samantha Mota, Nan Wang, M Mahmood Hussain","doi":"10.1172/jci.insight.194304","DOIUrl":"https://doi.org/10.1172/jci.insight.194304","url":null,"abstract":"<p><p>Atherosclerotic cardiovascular disease is a major contributor to the global disease burden. Atherosclerosis initiation depends on cholesterol accumulation in subendothelial macrophages (Mφs). To clarify the role of Bmal1 in Mφ function and atherosclerosis, we used several global and myeloid-specific Bmal1 deficient mouse models. Myeloid-specific Bmal1 deficient mice had higher Mφ cholesterol and displayed greater atherosclerosis compared to controls. Bmal1-deficient Mφs exhibited: (1) elevated expression of Cd36 and uptake of oxLDL; (2) diminished expression of Abca1 and Abcg1, and decreased cholesterol efflux and reverse cholesterol transport; and (3) reduced Npc1 and Npc2 expression, and diminished cholesterol egress from lysosomes. Molecular studies revealed that Bmal1 directly regulates basal and cyclic expression of Npc1 and Npc2 by binding the E-boxes in their promoters and indirectly regulates the basal and temporal regulation of Cd36 and Abca1/Abcg1 involving Rev-erbα and Znf202 repressors, respectively. In conclusion, Mφ Bmal1 is a key regulator of the uptake of modified lipoproteins, cholesterol efflux, lysosomal cholesterol egress and atherosclerosis, and therefore may be a master regulator of cholesterol metabolism in Mφs. Restoration of Mφ Bmal1 expression or blocking of factors that decrease its activity may be effective in preventing atherosclerosis.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-30DOI: 10.1172/jci.insight.196933
Kevin M Buck, Holden T Rogers, Zachery R Gregorich, Morgan W Mann, Timothy J Aballo, Zhan Gao, Emily A Chapman, Andrew J Perciaccante, Scott J Price, Ienglam Lei, Paul C Tang, Ying Ge
{"title":"Extracellular matrix alterations in chronic ischemic cardiomyopathy revealed by quantitative proteomics.","authors":"Kevin M Buck, Holden T Rogers, Zachery R Gregorich, Morgan W Mann, Timothy J Aballo, Zhan Gao, Emily A Chapman, Andrew J Perciaccante, Scott J Price, Ienglam Lei, Paul C Tang, Ying Ge","doi":"10.1172/jci.insight.196933","DOIUrl":"10.1172/jci.insight.196933","url":null,"abstract":"<p><p>Ischemic cardiomyopathy (ICM) is a leading cause of heart failure characterized by extensive remodeling of the cardiac extracellular matrix (ECM). While initially adaptive, ECM deposition following ischemic injury eventually turns maladaptive, promoting adverse cardiac remodeling. The strong link between the extent of fibrosis and adverse clinical outcomes has led to growing interest in ECM targeted therapies to prevent or reverse maladaptive cardiac remodeling in ICM; yet, the precise composition of the ECM in ICM remains poorly defined. In this study, we employed a sequential protein extraction enabled by the photocleavable surfactant Azo to enrich ECM proteins from left ventricular tissues of patients with end-stage ICM (n=16) and nonfailing donor hearts (n=16). High-resolution mass spectrometry-based quantitative proteomics identified and quantified over 6,000 unique protein groups, including 315 ECM proteins. We discovered significant upregulation of key ECM components, particularly glycoproteins, proteoglycans, collagens, and ECM regulators. Notably, LOXL1, FBLN1, and VCAN were among the most differentially expressed. Functional enrichment analyses revealed enhanced TGFβ signaling, integrin-mediated adhesion, and complement activation in ICM tissues, suggesting a feedback loop driving continued ECM deposition in the end-stage failing heart. Together, our findings provide a comprehensive proteomic landscape of ECM alterations in the end-stage ICM myocardium and identify promising molecular targets for therapeutic intervention.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JCI insightPub Date : 2025-09-25DOI: 10.1172/jci.insight.190780
Jeong-Yeon Mun, Chang Shu, Qiuqiang Gao, Zhe Zhu, Hasan O Akman, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D Siegelin
{"title":"CDK12 regulates cellular metabolism to promote glioblastoma growth.","authors":"Jeong-Yeon Mun, Chang Shu, Qiuqiang Gao, Zhe Zhu, Hasan O Akman, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D Siegelin","doi":"10.1172/jci.insight.190780","DOIUrl":"https://doi.org/10.1172/jci.insight.190780","url":null,"abstract":"<p><p>Glioblastoma IDH-wildtype is the most common and aggressive primary brain tumor in adults, with poor prognosis despite current therapies. To identify new therapeutic vulnerabilities, we investigated the role of CDK12, a transcription-associated cyclin-dependent kinase, in glioblastoma. Genetic or pharmacologic inactivation of CDK12 impaired tumor growth in patientderived xenograft (PDX) models and enhanced the efficacy of temozolomide. Metabolic profiling using extracellular flux analysis and stable isotope tracing with U-¹³C-glucose and U-¹³Cglutamine showed that CDK12 inhibition disrupted mitochondrial respiration, resulting in energy depletion and apoptotic cell death characterized by caspase activation and Noxa induction. Mechanistically, we identified a direct interaction between CDK12 and GSK3β. CDK12 inhibition activated GSK3β, leading to downregulation of PPARD, a transcriptional regulator of oxidative metabolism. This CDK12-GSK3β-PPARD axis was required for glioblastoma cell proliferation and metabolic homeostasis. In vivo, CDK12 inhibition significantly extended survival without overt toxicity and induced complete tumor regression in a subset of animals. Strikingly, combined CDK12 inhibition and temozolomide treatment led to complete tumor eradication in all animals tested. These findings establish CDK12 as a key regulator of glioblastoma metabolism and survival, and provide strong preclinical rationale for its therapeutic targeting in combination with standard-of-care treatments.</p>","PeriodicalId":14722,"journal":{"name":"JCI insight","volume":" ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145149188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}