Cell biology
Abstract
While improvements in genetic analysis have greatly enhanced our understanding of the mechanisms behind pancreatitis, it continues to afflict many families for whom the hereditary factors remain unknown. Recent evaluation of a patient with a strong family history of pancreatitis sparked us to reexamine a large kindred originally reported over 50 years ago with an autosomal dominant inheritance pattern of chronic pancreatitis, diabetes and pancreatic adenocarcinoma. Whole exome sequencing analysis identified a rare missense mutation in the gene encoding pancreas-specific protease Elastase 3B (CELA3B) that cosegregates with disease. Studies of the mutant protein in vitro, in cell lines and in CRISPR-Cas9 engineered mice indicate that this mutation causes translational upregulation of CELA3B, which upon secretion and activation by trypsin leads to uncontrolled proteolysis and recurrent pancreatitis. Although lesions in several other pancreatitic proteases have been previously linked to hereditary pancreatitis, this is the first known instance of a mutation in CELA3B and a defect in translational control contributing to this disease.
Authors
Paul C. Moore, Jessica T. Cortez, Chester E. Chamberlain, Diana Alba, Amy C. Berger, Zoe Quandt, Alice Chan, Mickie H. Cheng, Jhoanne L. Bautista, Justin Peng, Michael S. German, Mark Anderson, Scott A. Oakes
Abstract
Metastatic castration-resistant prostate cancer (mCRPC) is a heterogeneous disease with diverse drivers of disease progression and mechanisms of therapeutic resistance. We conducted deep phenotypic characterization of CRPC metastases and patient-derived xenograft (PDX) lines using whole genome RNA sequencing, gene set enrichment analysis and immunohistochemistry. Our analyses revealed five mCRPC phenotypes based on the expression of well-characterized androgen receptor (AR) or neuroendocrine (NE) genes: (i) AR-high tumors (ARPC), (ii) AR-low tumors (ARLPC), (iii) amphicrine tumors composed of cells co-expressing AR and NE genes (AMPC), (iv) double-negative tumors (i.e. AR-/NE-; DNPC) and (v) tumors with small cell or NE gene expression without AR activity (SCNPC). RE1-silencing transcription factor (REST) activity, which suppresses NE gene expression, was lost in AMPC and SCNPC PDX models. However, knockdown of REST in cell lines revealed that attenuated REST activity drives the AMPC phenotype but is not sufficient for SCNPC conversion. We also identified a subtype of DNPC tumors with squamous differentiation and generated an encompassing 26-gene transcriptional signature that distinguished the five mCRPC phenotypes. Together, our data highlight the central role of AR and REST in classifying treatment-resistant mCRPC phenotypes. These molecular classifications could potentially guide future therapeutic studies and clinical trial design.
Authors
Mark P. Labrecque, Ilsa M. Coleman, Lisha G. Brown, Lawrence D. True, Lori Kollath, Bryce Lakely, Holly M. Nguyen, Yu C. Yang, Rui M. Gil da Costa, Arja Kaipainen, Roger Coleman, Celestia S. Higano, Evan Y. Yu, Heather H. Cheng, Elahe A. Mostaghel, Bruce Montgomery, Michael T. Schweizer, Andrew C. Hsieh, Daniel W. Lin, Eva Corey, Peter S. Nelson, Colm Morrissey
Abstract
Genetic susceptibility to type 2 diabetes is primarily due to β-cell dysfunction. However, a genetic study to directly interrogate β-cell function ex vivo has never been previously performed. We isolated 233,447 islets from 483 Diversity Outbred (DO) mice maintained on a Western-style diet, and measured insulin secretion in response to a variety of secretagogues. Insulin secretion from DO islets ranged >1,000-fold even though none of the mice were diabetic. The insulin secretory response to each secretagogue had a unique genetic architecture; some of the loci were specific for one condition, whereas others overlapped. Human loci that are syntenic to many of the insulin secretion QTL from mouse are associated with diabetes-related SNPs in human genome-wide association studies. We report on three genes, Ptpn18, Hunk and Zfp148, where the phenotype predictions from the genetic screen were fulfilled in our studies of transgenic mouse models. These three genes encode a non-receptor type protein tyrosine phosphatase, a serine/threonine protein kinase, and a Krϋppel-type zinc-finger transcription factor, respectively. Our results demonstrate that genetic variation in insulin secretion that can lead to type 2 diabetes is discoverable in non-diabetic individuals.
Authors
Mark P. Keller, Mary E. Rabaglia, Kathryn L. Schueler, Donnie S. Stapleton, Daniel M. Gatti, Matthew Vincent, Kelly A. Mitok, Ziyue Wang, Takanao Ishimura, Shane P. Simonett, Christopher H. Emfinger, Rahul Das, Tim Beck, Christina Kendziorski, Karl W. Broman, Brian S. Yandell, Gary A. Churchill, Alan D. Attie
Abstract
Loss-of-function mutations in genes encoding TET DNA dioxygenase occur frequently in hematopoietic malignancy, but rarely in solid tumors which instead commonly have reduced activity. The impact of decreased TET activity in solid tumors is not known. Here we show that TET2 mediates interferon γ (IFNγ)-JAK-STAT signaling pathway to control chemokine and PD-L1 expression, lymphocyte infiltration and cancer immunity. IFNγ stimulated STAT1 to bind TET2 and recruit TET2 to hydroxymethylate chemokine and PD-L1 genes. Reduced TET activity was associated with decreased TH1-type chemokines and tumor-infiltrating lymphocytes (TILs) and the progression of human colon cancer. Deletion of Tet2 in murine melanoma and colon tumor cells reduced chemokine expression and TILs, enabling tumors to evade anti-tumor immunity and to resist anti-PD-L1 therapy. Conversely, stimulating TET activity by systematic injection of its co-factor, ascorbate/vitamin C, increased chemokine and TILs, leading to enhanced anti-tumor immunity and anti-PD-L1 efficacy and extended lifespan of tumor-bearing mice. These results suggest an IFNγ-JAK-STAT-TET signaling pathway that mediates tumor response to anti-PD-L1/PD-1 therapy and is frequently disrupted in solid tumors. Our findings also suggest TET activity as a biomarker for predicting the efficacy and patient response to anti-PD-1/PD-L1 therapy, and stimulating TET activity as an adjuvant immunotherapy of solid tumors.
Authors
Yan-ping Xu, Lei Lv, Ying Liu, Matthew D. Smith, Wen-Cai Li, Xian-ming Tan, Meng Cheng, Zhijun Li, Michael Bovino, Jeffrey Aubé, Yue Xiong
Abstract
Tumorigenicity is a well-documented risk to overcome for pluripotent or multipotent cell applications in regenerative medicine. To address the emerging demand for safe cell sources in tissue regeneration, we established a novel, protein-based reprogramming method that does not require genome integration or oncogene activation to yield multipotent fibromodulin (FMOD)-reprogrammed (FReP) cells from dermal fibroblasts. When compared with induced pluripotent stem cells (iPSCs), FReP cells exhibited a superior capability for bone and skeletal muscle regeneration with markedly less tumorigenic risk. Moreover, we showed that the decreased tumorigenicity of FReP cells was directly related to an upregulation of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression during the FMOD reprogramming process. Indeed, sustained suppression of CDKN2B resulted in tumorigenic, pluripotent FReP cells that formed teratomas in vivo that were indistinguishable from iPSC-derived teratomas. These results highlight the pivotal role of CDKN2B in cell fate determination and tumorigenic regulation and reveal an alternative pluripotent/multipotent cell reprogramming strategy that solely uses FMOD protein.
Authors
Zhong Zheng, Chenshuang Li, Pin Ha, Grace X. Chang, Pu Yang, Xinli Zhang, Jong Kil Kim, Wenlu Jiang, Xiaoxiao Pang, Emily A. Berthiaume, Zane Mills, Christos S. Haveles, Eric Chen, Kang Ting, Chia Soo
Abstract
Glycosylation of immune receptors and ligands, such as T cell receptor and coinhibitory molecules, regulates immune signaling activation and immune surveillance. However, how oncogenic signaling initiates glycosylation of coinhibitory molecules to induce immunosuppression remains unclear. Here we show that IL-6–activated JAK1 phosphorylates programmed death-ligand 1 (PD-L1) Tyr112, which recruits the endoplasmic reticulum–associated N-glycosyltransferase STT3A to catalyze PD-L1 glycosylation and maintain PD-L1 stability. Targeting of IL-6 by IL-6 antibody induced synergistic T cell killing effects when combined with anti–T cell immunoglobulin mucin-3 (anti–Tim-3) therapy in animal models. A positive correlation between IL-6 and PD-L1 expression was also observed in hepatocellular carcinoma patient tumor tissues. These results identify a mechanism regulating PD-L1 glycosylation initiation and suggest the combination of anti–IL-6 and anti–Tim-3 as an effective marker-guided therapeutic strategy.
Authors
Li-Chuan Chan, Chia-Wei Li, Weiya Xia, Jung-Mao Hsu, Heng-Huan Lee, Jong-Ho Cha, Hung-Ling Wang, Wen-Hao Yang, Er-Yen Yen, Wei-Chao Chang, Zhengyu Zha, Seung-Oe Lim, Yun-Ju Lai, Chunxiao Liu, Jielin Liu, Qiongzhu Dong, Yi Yang, Linlin Sun, Yongkun Wei, Lei Nie, Jennifer L. Hsu, Hui Li, Qinghai Ye, Manal M. Hassan, Hesham M. Amin, Ahmed O. Kaseb, Xin Lin, Shao-Chun Wang, Mien-Chie Hung
Abstract
Cancer-associated fibroblasts (CAFs) are key actors in modulating the progression of many solid tumors such as breast cancer (BC). Herein, we identify an integrin α11/PDGFRβ+ CAF subset displaying tumor-promoting features in BC. In the preclinical MMTV-PyMT mouse model, integrin α11-deficiency led to a drastic reduction of tumor progression and metastasis. A clear association between integrin α11 and PDGFRβ was found at both transcriptional and histological levels in BC specimens. High stromal integrin α11/PDGFRβ expression was associated with high grades and poorer clinical outcome in human BC patients. Functional assays using five CAF subpopulations (one murine, four human) revealed that integrin α11 promotes CAF invasion and CAF-induced tumor cell invasion upon PDGF-BB stimulation. Mechanistically, integrin α11 pro-invasive activity relies on its ability to interact with PDGFRβ in a ligand-dependent manner and to promote its downstream JNK activation, leading to the production of tenascin C, a pro-invasive matricellular protein. Pharmacological inhibition of PDGFRβ and JNK impaired tumor cell invasion induced by integrin α11-positive CAFs. Collectively, our study uncovers an integrin α11-positive subset of pro-tumoral CAFs that exploits PDGFRβ/JNK signalling axis to promote tumor invasiveness in BC.
Authors
Irina Primac, Erik Maquoi, Silvia Blacher, Ritva Heljasvaara, Jan Van Deun, Hilde Y. H. Smeland, Annalisa Canale, Thomas Louis, Linda Stuhr, Nor Eddine Sounni, Didier Cataldo, Taina Pihlajaniemi, Christel Pequeux, Olivier De Wever, Donald Gullberg, Agnès Noel
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited arrhythmia syndrome characterized by severe structural and electrical cardiac phenotypes, including myocardial fibrofatty replacement and sudden cardiac death. Clinical management of ACM is largely palliative, owing to an absence of therapies that target its underlying pathophysiology, which stems partially from our limited insight into the condition. Following identification of deceased ACM probands possessing ANK2 rare variants and evidence of ankyrin-B loss of function on cardiac tissue analysis, an ANK2 mouse model was found to develop dramatic structural abnormalities reflective of human ACM, including biventricular dilation, reduced ejection fraction, cardiac fibrosis, and premature death. Desmosomal structure and function appeared preserved in diseased human and murine specimens in the presence of markedly abnormal β-catenin expression and patterning, leading to identification of a previously unknown interaction between ankyrin-B and β-catenin. A pharmacological activator of the WNT/β-catenin pathway, SB-216763, successfully prevented and partially reversed the murine ACM phenotypes. Our findings introduce what we believe to be a new pathway for ACM, a role of ankyrin-B in cardiac structure and signaling, a molecular link between ankyrin-B and β-catenin, and evidence for targeted activation of the WNT/β-catenin pathway as a potential treatment for this disease.
Authors
Jason D. Roberts, Nathaniel P. Murphy, Robert M. Hamilton, Ellen R. Lubbers, Cynthia A. James, Crystal F. Kline, Michael H. Gollob, Andrew D. Krahn, Amy C. Sturm, Hassan Musa, Mona El-Refaey, Sara Koenig, Meriam Åström Aneq, Edgar T. Hoorntje, Sharon L. Graw, Robert W. Davies, Muhammad Arshad Rafiq, Tamara T. Koopmann, Shabana Aafaqi, Meena Fatah, David A. Chiasson, Matthew R.G. Taylor, Samantha L. Simmons, Mei Han, Chantal J.M. van Opbergen, Loren E. Wold, Gianfranco Sinagra, Kirti Mittal, Crystal Tichnell, Brittney Murray, Alberto Codima, Babak Nazer, Duy T. Nguyen, Frank I. Marcus, Nara Sobriera, Elisabeth M. Lodder, Maarten P. van den Berg, Danna A. Spears, John F. Robinson, Philip C. Ursell, Anna K. Green, Allan C. Skanes, Anthony S. Tang, Martin J. Gardner, Robert A. Hegele, Toon A.B. van Veen, Arthur A. M. Wilde, Jeff S. Healey, Paul M. L. Janssen, Luisa Mestroni, J. Peter van Tintelen, Hugh Calkins, Daniel P. Judge, Thomas J. Hund, Melvin M. Scheinman, Peter J. Mohler
Abstract
Elevated blood glucose (hyperglycemia) is a hallmark metabolic abnormality in diabetes. Hyperglycemia is associated with protein kinase A (PKA)-mediated stimulation of L-type Ca2+ channels in arterial myocytes resulting in increased vasoconstriction. However, the mechanisms by which glucose activates PKA remain unclear. Here, we showed that elevating extracellular glucose stimulates cAMP production in arterial myocytes, and that this was specifically dependent on adenylyl cyclase 5 (AC5) activity. Super-resolution imaging suggested nanometer proximity between subpopulations of AC5 and the L-type Ca2+ channel pore-forming subunit CaV1.2. In vitro, in silico, ex vivo and in vivo experiments revealed that this close association is critical for stimulation of L-type Ca2+ channels in arterial myocytes and increased myogenic tone upon acute hyperglycemia. This pathway supported the increase in L-type Ca2+ channel activity and myogenic tone in two animal models of diabetes. Our collective findings demonstrate a unique role for AC5 in PKA-dependent modulation of L-type Ca2+ channel activity and vascular reactivity during acute hyperglycemia and diabetes.
Authors
Arsalan U. Syed, Gopireddy R. Reddy, Debapriya Ghosh, Maria Paz Prada, Matthew A. Nystoriak, Stefano Morotti, Eleonora Grandi, Padmini Sirish, Nipavan Chiamvimonvat, Johannes W. Hell, Luis F. Santana, Yang K. Xiang, Madeline Nieves-Cintrón, Manuel F. Navedo
Abstract
Calcineurin acts as a calcium-activated phosphatase that dephosphorylates various substrates, including members of the nuclear factor of activated T cells (NFAT) family, to trigger their nuclear translocation and transcriptional activity. However, the detailed mechanism regulating the recruitment of NFATs to calcineurin remains poorly understood. Here, we report that calcineurin A (CNA), encoded by PPP3CB or PPP3CC, is constitutively ubiquitinated on lysine 327, and this polyubiquitin chain is rapidly removed by ubiquitin carboxyl-terminal hydrolase 16 (USP16) in response to intracellular calcium stimulation. The K29-linked ubiquitination of CNA impairs NFAT recruitment and transcription of NFAT-targeted genes. USP16 deficiency prevents calcium-triggered deubiquitination of CNA in a manner consistent with defective maintenance and proliferation of peripheral T cells. T cell–specific USP16 knockout mice exhibit reduced severity of experimental autoimmune encephalitis and inflammatory bowel disease. Our data reveal the physiological function of CNA ubiquitination and its deubiquitinase USP16 in peripheral T cells. Notably, our results highlight a critical mechanism for the regulation of calcineurin activity and a novel immunosuppressive drug target for the treatment of autoimmune diseases.
Authors
Yu Zhang, Rong-bei Liu, Qian Cao, Ke-qi Fan, Ling-jie Huang, Jian-shuai Yu, Zheng-jun Gao, Tao Huang, Jiang-yan Zhong, Xin-tao Mao, Fei Wang, Peng Xiao, Yuan Zhao, Xin-hua Feng, Yi-yuan Li, Jin Jin
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Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)