Francesca D'Addio,Giovanni Amabile,Emma Assi,Anna Maestroni,Adriana Petrazzuolo,Cristian Loretelli,Ahmed Abdelasalam,Moufida Ben Nasr,Ida Pastore,Maria Elena Lunati,Vera Usuelli,Monica Zocchi,Andy Joe Seelam,Domenico Corradi,Stefano La Rosa,Virna Marin,Monique Zangarini,Marta Nardini,Stefano Porzio,Filippo Canducci,Claudia Nardini,Basset El Essawy,Manuela Nebuloni,Jun Yang,Massimo Venturini,Giovanni Maconi,Franco Folli,Silvio Danese,Gianvincenzo Zuccotti,Gianluca M Sampietro,Sandro Ardizzone,Paolo Fiorina
{"title":"TMEM219 signaling promotes intestinal stem cell death and exacerbates colitis.","authors":"Francesca D'Addio,Giovanni Amabile,Emma Assi,Anna Maestroni,Adriana Petrazzuolo,Cristian Loretelli,Ahmed Abdelasalam,Moufida Ben Nasr,Ida Pastore,Maria Elena Lunati,Vera Usuelli,Monica Zocchi,Andy Joe Seelam,Domenico Corradi,Stefano La Rosa,Virna Marin,Monique Zangarini,Marta Nardini,Stefano Porzio,Filippo Canducci,Claudia Nardini,Basset El Essawy,Manuela Nebuloni,Jun Yang,Massimo Venturini,Giovanni Maconi,Franco Folli,Silvio Danese,Gianvincenzo Zuccotti,Gianluca M Sampietro,Sandro Ardizzone,Paolo Fiorina","doi":"10.1172/jci185783","DOIUrl":"https://doi.org/10.1172/jci185783","url":null,"abstract":"Mechanisms by which mucosal regeneration is abrogated in inflammatory bowel disease (IBD) are still under investigation, and a role for an intestinal stem cell (ISC) defect is now emerging. Herein, we report an abnormal ISC death that occurs in Crohn's disease, which exacerbates colitis, limits ISC-dependent mucosal repair, and is controlled through the death factor Transmembrane protein 219 (TMEM219). Large alterations in TMEM219 expression were observed in patients with Crohn's disease, particularly in those with active disease and/or those who were nonresponders to conventional therapy, confirming that TMEM219 signaling is abnormally activated and leads to failure of the mucosal regenerative response. Mechanistic studies revealed a proapoptotic TMEM219-mediated molecular signature in Crohn's disease, which associates with Caspase-8 activation and ISC death. Pharmacological blockade of the IGFBP3/TMEM219 binding/signal with the recombinant protein ecto-TMEM219 restored the self-renewal abilities of miniguts generated from patients with Crohn's disease in vitro and ameliorated DSS-induced and T cell-mediated colitis in vivo, ultimately leading to mucosal healing. Genetic tissue-specific deletion of TMEM219 in ISCs in newly generated TMEM219fl/flLGR5cre mice revived their mucosal regenerative abilities both in vitro and in vivo. Our findings demonstrate that a TMEM219-dependent ISC death exacerbates colitis and that TMEM219 blockade reestablishes intestinal self-renewal properties in IBD.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"105 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Traffic jam in lung capillaries: inter-organ communication impedes gas exchange after acute kidney injury.","authors":"Ulrich Matt,Susanne Herold","doi":"10.1172/jci192917","DOIUrl":"https://doi.org/10.1172/jci192917","url":null,"abstract":"Acute kidney injury (AKI) is a frequent complication in critically ill patients and triggers a systemic inflammatory response that can contribute to lung injury, ultimately worsening clinical outcomes. However, diagnostic and therapeutic strategies remain unavailable. In this issue of the JCI, Komaru et al. explored leukocyte trafficking and vascular pooling following AKI in mice as an underlying mechanism of acute lung injury. Using intravital microscopy, the authors observed rapid accumulation of neutrophils in pulmonary capillaries within minutes of AKI onset. These neutrophils followed monocytes and slowed blood flow. Notably, disruption of this process improved oxygenation. The findings provide insights into this complex inter-organ crosstalk and open avenues for future research.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marta C Sallan,Filip Filipsky,Christina H Shi,Elena Pontarini,Manuela Terranova-Barberio,Gordon Beattie,Andrew Clear,Michele Bombardieri,Kevin Y Yip,Dinis Parente Calado,Mark S Cragg,Sonya James,Matthew J Carter,Jessica Okosun,John G Gribben,Tanya Klymenko,Andrejs Braun
{"title":"Autophagy is an upstream mediator of chromatin dynamics in normal and autoimmune germinal centre B cells.","authors":"Marta C Sallan,Filip Filipsky,Christina H Shi,Elena Pontarini,Manuela Terranova-Barberio,Gordon Beattie,Andrew Clear,Michele Bombardieri,Kevin Y Yip,Dinis Parente Calado,Mark S Cragg,Sonya James,Matthew J Carter,Jessica Okosun,John G Gribben,Tanya Klymenko,Andrejs Braun","doi":"10.1172/jci178920","DOIUrl":"https://doi.org/10.1172/jci178920","url":null,"abstract":"Germinal centre (GC) B cells are pivotal in establishing a robust humoral immune response and long-term serological immunity while maintaining antibody self-tolerance. GC B cells rely on autophagy for antigen presentation and homeostatic maintenance. However, these functions, primarily associated with the light zone, cannot explain the spatiotemporal autophagy upregulation in the dark zone of GCs. Here, we define a functional mechanism controlling chromatin accessibility in GC B cells during their dark zone transition. This mechanism links autophagy and nuclear Lamin B1 dynamics with their downstream effects, including somatic hypermutation and antibody affinity maturation. Moreover, the autophagy-Lamin B1 axis is highly active in the aberrant ectopic germinal centres in the salivary glands of Sjogren's disease, defining its role in autoimmunity.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"136 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Asparagine endopeptidase cleaves apolipoprotein A1 and accelerates pathogenesis of atherosclerosis.","authors":"Mengmeng Wang,Bowei Li,Shuke Nie,Xin Meng,Guangxing Wang,Menghan Yang,Wenxin Dang,Kangning He,Tucheng Sun,Ping Xu,Xifei Yang,Keqiang Ye","doi":"10.1172/jci185128","DOIUrl":"https://doi.org/10.1172/jci185128","url":null,"abstract":"Atherosclerosis is a slowly progressing inflammatory disease characterized with cholesterol disorder and intimal plaques. Asparagine endopeptidase (AEP) is an endolysosomal protease that is activated under acidic conditions and is elevated substantially in both plasma and plaques of patients with atherosclerosis. However, how AEP accelerates atherosclerosis development remains incompletely understood, especially from the view of cholesterol metabolism. This project aims to reveal the crucial substrate of AEP during atherosclerosis plaque formation and to lay the foundation for developing novel therapeutic agents for Atherosclerosis. Here, we show that AEP is augmented in the atherosclerosis plaques obtained from patients and proteolytically cuts apolipoprotein A1 (APOA1) and impairs cholesterol efflux and high-density lipoprotein (HDL) formation, facilitating atherosclerosis pathologies. AEP is activated in the liver and aorta of apolipoprotein E-null (APOE-null) mice, and deletion of AEP from APOE-/- mice attenuates atherosclerosis. APOA1, an essential lipoprotein in HDL for cholesterol efflux, is cleaved by AEP at N208 residue in the liver and atherosclerotic macrophages of APOE-/- mice. Blockade of APOA1 cleavage by AEP via N208A mutation or its specific inhibitor, #11a, substantially diminishes atherosclerosis in both APOE-/- and LDLR-/- mice. Hence, our findings support that AEP disrupts cholesterol metabolism and accelerates the development of atherosclerosis.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"GALNT14 deficiency: connecting multiple links in the IgA nephropathy pathogenetic chain.","authors":"John Pell,Madhav C Menon","doi":"10.1172/jci192687","DOIUrl":"https://doi.org/10.1172/jci192687","url":null,"abstract":"IgA nephropathy (IgAN) is a highly prevalent type of primary glomerulonephritis. IgAN involves mesangial deposition of immune complexes leading to complement activation, inflammation, and glomerular injury. A key hit for pathogenesis involves aberrant O-glycosylation in the hinge region of IgA. Despite its prevalence, however, the mechanisms underlying IgAN remain incompletely understood. In this issue of the JCI, Prakash and colleagues used whole-exome sequencing of two IgAN probands to identify loss-of-function variants in GALNT14 leading to loss of the enzyme GalNAc-T14, which is involved in O-glycosylation. The authors then performed a classical bedside-to-bench investigation using a Galnt14-/- mouse model and connected loss of GalNAc-T14 to excess IgA production, impaired B lymphocyte homing, and defective intestinal mucus production. These findings build a more unified understanding of IgAN pathogenesis from defective O-glycosylation with loss-of-function variants in GALNT14.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Promoting mucosal healing by targeting TMEM219-dependent intestinal epithelial stem cell defects in inflammatory bowel disease.","authors":"Nicolas Schlegel","doi":"10.1172/jci192640","DOIUrl":"https://doi.org/10.1172/jci192640","url":null,"abstract":"Inflammatory Bowel Diseases (IBD), including Crohn's disease and ulcerative colitis, pose challenges due to their complex pathophysiology and high prevalence. Despite advances in immune-targeted therapies, a substantial number of patients fail to achieve mucosal healing, highlighting the need for alternative therapeutic strategies. In this issue of the JCI, D'Addio et al. identified another mechanism underlying impaired epithelial regeneration in Crohn's disease. They found that abnormal cell death in intestinal epithelial stem cells, mediated by altered TMEM219 signaling, led to impaired mucosal healing. Targeting TMEM219 with ecto-TMEM219, which blocks its activation, restored stem cell function and promoted mucosal healing in vitro and in vivo. These findings suggest a promising therapeutic avenue focusing on epithelial repair. Additionally, patient-derived organoids (PDOs) emerge as a valuable tool for personalized treatment strategies and for advancing the field of IBD research. This study underscores the importance of epithelial cell biology in developing innovative IBD therapies.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"199 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah Costantino,Shafeeq A Mohammed,Francesco Paneni
{"title":"Endothelial dysfunction in patients with type 2 diabetes: the truth is in the blood.","authors":"Sarah Costantino,Shafeeq A Mohammed,Francesco Paneni","doi":"10.1172/jci193128","DOIUrl":"https://doi.org/10.1172/jci193128","url":null,"abstract":"Endothelial dysfunction remains a cornerstone of diabetic vascular complications. RBCs emerge as pivotal players in endothelial dysfunction, yet the underlying mechanisms remain elusive. In this issue of the JCI, Collado et al. show that the detrimental action of RBCs on the endothelium is mediated by extracellular vesicles (EVs). EVs derived from RBCs (RBC-EVs) of patients with diabetes were taken up by the endothelium and were able to impair endothelium-dependent relaxation via an EV-mediated transfer of the prooxidant enzyme arginase-1 (Arg1) from RBCs to endothelial cells. These findings reveal events implicated in vascular oxidative stress and set the stage for personalized approaches preventing RBC-EVs' uptake by the endothelium.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Disease classification, diagnostic challenges, and evolving clinical trial design in MASLD.","authors":"Mette Munk Lauridsen,Kim Ravnskjaer,Lise Lotte Gluud,Arun J Sanyal","doi":"10.1172/jci189953","DOIUrl":"https://doi.org/10.1172/jci189953","url":null,"abstract":"Metabolic dysfunction-associated steatotic liver disease (MASLD) diagnosis and management have evolved rapidly alongside the increasing prevalence of obesity and related complications. Hepatology has expanded its focus beyond late-stage cirrhosis and portal hypertension to earlier, complex MASLD cases in younger patients, necessitating closer collaboration with endocrinology. The renaming of nonalcoholic fatty liver disease (NAFLD) to MASLD reflects its pathophysiology, reduces stigma, and has prompted new research directions. Noninvasive tests such as liver stiffness measurement now play a crucial role in diagnosis, reducing reliance on invasive liver biopsies. However, advanced omics technologies, despite their potential to enhance diagnostic precision and patient stratification, remain underutilized in routine clinical practice. Behavioral factors, including posttraumatic stress disorder (PTSD) and lifestyle choices, influence disease outcomes and must be integrated into patient management strategies. Primary care settings are critical for early screening to prevent progression to advanced disease, yet sizable challenges remain in implementing effective screening protocols. This Review explores these evolving aspects of MASLD diagnosis and management, emphasizing the need for improved diagnostic tools, multidisciplinary collaboration, and holistic care approaches to address existing gaps and ensure comprehensive patient care across all healthcare levels.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metabolic dysfunction-associated steatotic liver disease and pregnancy.","authors":"Monika Sarkar,Tatyana Kushner","doi":"10.1172/jci186426","DOIUrl":"https://doi.org/10.1172/jci186426","url":null,"abstract":"Metabolic dysfunction-associated steatotic liver disease (MASLD) is rising among reproductive-aged individuals and in pregnancy. MASLD in pregnancy does increase such risks as gestational diabetes, preeclampsia, and preterm birth. Although routine screening for MASLD has not been established in pregnancy, individuals with metabolic comorbidities, such as type 2 diabetes mellitus, should be evaluated by liver imaging and liver panel. Preconception counseling should address potential risks as well as need for optimized metabolic health before and during pregnancy. Fibrosis assessment should ideally be completed before pregnancy, to identify cases of cirrhosis that may warrant additional preconception management, such as variceal screening, as well as comanagement with maternal-fetal medicine specialists. In patients with MASLD, aspirin is advised at 12 weeks of gestational age to lower preeclampsia risk. In the absence of cirrhosis, no additional blood test monitoring is needed. In the general population, breastfeeding has beneficial effects on metabolic health in birthing parents and offspring and thus should be encouraged in the setting of MASLD, including access to enhanced lactation support. Research needs include evaluation of the long-term risks of MASLD in pregnancy on metabolic health in birthing parents and infants, as well as safety data for MASLD-directed therapies during pregnancy and lactation.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Gou,Micaela Glat,Vincent Damian,Caeley L Bryan,Bao Anh Phan,Chelsea L Faber,Arikta Trivedi,Matthew K Hwang,Jarrad M Scarlett,Gregory J Morton,Michael W Schwartz
{"title":"AgRP neuron hyperactivity drives hyperglycemia in a mouse model of type 2 diabetes.","authors":"Yang Gou,Micaela Glat,Vincent Damian,Caeley L Bryan,Bao Anh Phan,Chelsea L Faber,Arikta Trivedi,Matthew K Hwang,Jarrad M Scarlett,Gregory J Morton,Michael W Schwartz","doi":"10.1172/jci189842","DOIUrl":"https://doi.org/10.1172/jci189842","url":null,"abstract":"Growing evidence suggests that the pathogenesis of type 2 diabetes (T2D) involves dysfunctional central mechanisms, and, hence, the brain can be targeted to treat this disease. As an example, a single intracerebroventricular (icv) injection of fibroblast growth factor 1 (FGF1) can normalize hyperglycemia for weeks or months in rodent models of T2D. Convergent evidence implicates inhibition of a particular subset of neurons as a mediator of this FGF1 effect. Specifically, AgRP neurons, which are located in the hypothalamic arcuate nucleus (ARC) and are hyperactive in Lepob/ob mice and other rodent models of T2D. To investigate whether chronic AgRP neuron inactivation mimics the antidiabetic action of FGF1, we directed an adeno-associated virus (AAV) containing a cre-inducible tetanus toxin-GFP (TeTx-GFP) cassette (or cre-inducible AAV GFP control) to the ARC of obese, diabetic male Lepob/ob mice in which cre recombinase is expressed solely by AgRP neurons (Lepob/ob AgRP-Cre mice). We report that over a 10-wk period of observation, hyperglycemia was fully normalized by AgRP neuron inactivation. In contrast, changes in energy homeostasis parameters (food intake, energy expenditure, body weight, and fat mass) were not observed. We conclude that in diabetic male Lepob/ob mice, AgRP neuron hyperactivity is required for hyperglycemia but is dispensable for obesity.","PeriodicalId":520097,"journal":{"name":"The Journal of Clinical Investigation","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}