Gastroenterology
Abstract
Acquired generalized lipodystrophy (AGL) is a rare metabolic disorder frequently associated with autoimmunity. Its etiology is incompletely understood, and the effect of adipose tissue loss on intestinal inflammation in AGL remains unclear. Using mass cytometry and single-cell RNA-seq, we observed an oligoclonal expansion of T cells in the periphery and inflamed intestine in a patient with AGL and Crohn’s disease (AGLCD). To explore if loss of adipose tissue triggers lymphoproliferation, we studied lipodystrophic mice as a model for AGL. Unexpectedly, lipodystrophic mice did not show T cell expansion, were protected from colitis, and displayed a defect in the development of proinflammatory T cells, which could be reversed by allogeneic fat transplantations, indicating that clonal T cell expansion in AGLCD is not primarily caused by lipodystrophy. Instead, gene sequencing revealed a T cell–intrinsic de novo neuroblastoma RAS viral oncogene homolog (NRAS) mutation, implicating somatic mosaicism as a facilitator of clonal T cell expansion and intestinal inflammation in AGLCD.
Authors
Marilena Letizia, Toka Omar, Patrick Weidner, Manuel O. Jakob, Inka Freise, Susanne M. Krug, Britt-Sabina Löscher, Elisa Rosati, Benedikt Obermayer, Reyes Gamez-Belmonte, Julia Hecker, Jörn-Felix Ziegler, Benjamin Weixler, Patrick Asbach, Desiree Kunkel, Michael Stumvoll, Konstanze Miehle, Christoph Becker, Christoph S.N. Klose, Rainer Glauben, Dieter Beule, Anja A. Kühl, Thomas Conrad, Frank Tacke, Stefan Wirtz, Andre Franke, Ashley D. Sanders, Britta Siegmund, Carl Weidinger
Abstract
Immune evasion is a major obstacle ahead of pancreatic cancer therapy. Recent data implicate pro-inflammatory macrophages in the progression of pancreatic ductal adenocarcinoma (PDAC) and its therapeutic response. However, whether or which of the pro-inflammatory macrophage subtypes play a crucial role in the immune escape of PDAC remains unclear. Here we identify a population of CD138+ tumor-associated macrophages (TAMs), characterized by their pro-inflammatory and neutrophil-chemotactic activity, which undergo significant expansion in both PDAC patients and mouse models. These cells are elicited by a local synergy between IL-34-syndecan-1 and PGE2-EP2 signaling and are associated with immune evasion and poor clinical outcomes in patients, while also promoting immune escape and disease progression in mouse models. Mechanistically, CD138+ TAMs establish a feedforward loop with immunosuppressive Siglec-F+ neutrophils, which exhibit elevated PGE2 expression, via the secretion of Saa3 and Cxcl1. Targeting CD138+ TAMs by disrupting IL-34-syndecan-1 signaling with anti-IL-34 neutralizing antibodies significantly suppresses PDAC progression, especially when combined with anti-PD-1 antibodies. Together, our study elucidates a CD138+ TAM-Siglec-F+ neutrophil axis that drives immune escape in PDAC and proposes a therapeutic strategy that integrates IL-34-syndecan-1 signaling blockade with anti-PD-1 immunotherapy for the treatment of PDAC.
Authors
Chao Wang, Qi Zhang, Jinyan Huang, Fangyu Lin, Danyang Zhao, Youling Mu, Junshuo Tong, Jinping Li, Yingjiqiong Liang, Tao Zeng, Fukang Shi, Hang Shen, Tingting Lu, Tingbo Liang
Abstract
Isolating commensal fungi from mouse intestines has been challenging, limiting our understanding of their role in intestinal immune homeostasis and diseases. Using an Fc fusion protein of the C-type lectin Dectin-2, we successfully purified the commensal Ascomycota fungus Engyodontium sp. from mouse feces. Engyodontium enhances the antimicrobial activity of colonic neutrophils via CARD9 pathway, and exacerbates colitis by impairing the colonization of intestinal Lactobacillus johnsonii (L. johnsonii) WXY strain. L. johnsonii produces high levels of L-glutamic acid by expressing the glutaminase-encoding gene glsA to facilitate Treg expansion via enhancing IL-2 receptor signaling. Patients with Crohn’s disease (CD) and ulcerative colitis harbored increased Engyodontium and decreased L. johnsonii abundance. Engyodontium directly induced calprotectin in human colonic neutrophils, and CD patients exhibited lower levels of L-glutamic acid which also promoted human Treg expansion. These findings highlight the Engyodontium-calprotectin axis against the Lactobacillus-glutamate-Treg cascade to aggravate colitis, suggesting commensal Engyodontium-triggered signaling as a therapeutic target for mucosal inflammatory diseases.
Authors
Xinying Wang, Haiyang Sun, Ying Tan, Shaoting Xu, Zishan Liu, Kaile Ji, Ding Qiu, Jianping Deng, Bingbing Feng, Xueting Wu, Yoichiro Iwakura, Minhu Chen, Rui Feng, Chanyan Huang, Ce Tang
Abstract
The gastrointestinal tract varies in structure and function by region, yet the drivers of region-specific inflammatory disease remain elusive. Here, a TNF-overexpressing murine model (TnfΔARE/+) of Crohn’s disease (CD) was used to investigate how pathobionts interact with host immune susceptibilities to drive region-specific disease. We identified the pathobiont Chlamydia muridarum, an intracellular bacterium and murine counterpart to the human sexually transmitted C. trachomatis, as a necessary and sufficient trigger for disease manifestation in the proximal/ascending colon, a common site of CD. In genetically susceptible hosts, pathobiont-triggered proximal colonic inflammation is driven by goblet cell responses, one of which through tryptophan metabolism via indoleamine 2,3-dioxygenase (IDO1). Our findings translate to human disease, where we demonstrate upregulation of epithelia-derived IDO1 in actively inflamed ascending colon specimens, but not actively inflamed terminal ileum specimens, of CD patients. Our findings mechanistically reveal how genetic and microbial factors drive the manifestation of disease in a region-specific manner and provide a unique model to study CD specific to the ascending colon.
Authors
Paige N. Spencer, Monica E. Brown, Erin P. Smith, Jiawei Wang, William Kim, Luisella Spiga, Naila Tasneem, Alan J. Simmons, Taewoo Kim, Yilin Yang, Yanwen Xu, Lin Zheng, James Ro, Harsimran Kaur, Seung Woo Kang, Matthew D. Helou, Mason A. Lee, Deronisha Arceneaux, Katherine D. Mueller, Ozge S. Kuddar, Mariah H. Harned, Jing Li, Amrita Banerjee, Nicholas O. Markham, Keith T. Wilson, Lori A. Coburn, Jeremy A. Goettel, Qi Liu, M. Kay Washington, Raphael H. Valdivia, Wenhan Zhu, Ken S. Lau
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used medications for the management of chronic pain; however, they are associated with numerous gastrointestinal (GI) adverse events. Although many mechanisms have been suggested, NSAID-induced enteropathy has been thought to be primarily due to inhibition of both cyclooxygenases (COX) -1 and -2, which results in suppression of prostaglandin synthesis. Yet surprisingly, we found that concomitant postnatal deletion of Cox-1 and -2 over 10 months failed to cause intestinal injury in mice unless they were treated with naproxen or its structural analog, phenylpropionic acid, which is not a COX inhibitor. Cox double knockout mice exhibit a distinct gut microbiome composition and cohousing them with controls rescues their dysbiosis and delays the onset of NSAID-induced GI bleeding. In both the UK Biobank and All of Us human cohorts, coadministration of antibiotics with NSAIDs is associated with an increased frequency of GI bleeding. These results show that prostaglandin suppression plays a trivial role in NSAID-induced enteropathy. However, Cox deletion causes dysbiosis of the gut microbiome that amplifies the enteropathic response to NSAIDs.
Authors
Kayla Barekat, Soumita Ghosh, Christin Herrmann, Karl Keat, Charles-Antoine Assenmacher, Ceylan Tanes, Naomi Wilson, Ronan Lordan, Antonijo Mrčela, Lubica Rauova, Arjun Sengupta, Ujjalkumar Subhash Das, Robin Joshi, Elliot Friedman, Marylyn D. Ritchie, Kyle Bittinger, Aalim Weljie, Ken Cadwell, Frederic D. Bushman, Gary D. Wu, Garret A. FitzGerald, Emanuela Ricciotti
Abstract
Despite overexpression of N-acetyltransferase 10 (NAT10) in colorectal cancer (CRC), its immunomodulatory role in the tumor microenvironment remains elusive. Here, we reveal that NAT10 promotes immune evasion through N4-acetylcytosine–dependent (ac4C-dependent) mRNA stabilization. Using syngeneic mouse models (MC38/CT-26), intestinal epithelial-cell specific Nat10 conditional KO (Nat10cKO) mice, patient-derived organoids, and clinical specimens, we show that Nat10 ablation enhanced CD8+ T cell–mediated antitumor immunity. Single-cell RNA-seq revealed increased cytotoxic CD8+ T cell infiltration in Nat10cKO tumors, which was corroborated by the inverse correlation of tumoral NAT10 expression and CD8+ T cell number in clinical specimens. Multi-omics integration analysis identified DKK2 as the predominant NAT10-regulated transcript. NAT10 stabilized DKK2 mRNA via ac4C modification, leading to high expression of the DKK2 protein. Secreted DKK2 engaged LRP6 receptors to activate AKT-mTOR signaling, inducing cholesterol accumulation in CD8+ T cells and impairing their cytotoxicity. Pharmacological NAT10 inhibition (Remodelin treatment) or DKK2 neutralization restored CD8+ T cell function and synergized with anti–PD-1 therapy. Our findings establish the NAT10/DKK2/LRP6/AKT-mTOR/cholesterol axis as a critical regulator of CD8+ T cell dysfunction in CRC, positioning NAT10/DKK2 as a potential target to enhance immunotherapy efficacy.
Authors
Mengmeng Li, Xiaoya Zhao, Jun Wu, Shimeng Zhou, Yao Fu, Chen Chen, Zhuang Ma, Jiawen Xu, Yun Qian, Zhangding Wang, Bo Wang, Qiang Wang, Qingqing Ding, Changyu Chen, Honggang Wang, Xiaozhong Yang, Weijie Dai, Wenjie Zhang, Shouyu Wang
Abstract
Dysregulation of cell cycle checkpoints is a cancer hallmark with ubiquitination controlled protein stability playing pivotal roles. Although p21, a key cyclin-dependent kinase inhibitor, is tightly regulated by ubiquitin-mediated degradation, the key upstream modulators of its ubiquitination remain incompletely defined. Here, we identify poly(ADP-ribose) glycohydrolase (PARG) as a regulator of p21 stability in gastric cancer (GC) cells. We show that PARG expression is markedly upregulated in GC tissues and correlates with poor patient prognosis. Functional assays revealed that genetic depletion of PARG triggers G2/M phase arrest and impairs GC cell proliferation. Mechanistically, we demonstrate that PARG loss enhances p21 PARylation, which disrupts its association with E3 ubiquitin ligase, thereby reducing K48-linked ubiquitination and leading to p21 protein stabilization. Moreover, we identify lysine residues K161 and K163 as critical sites for PARG-mediated regulation of p21 ubiquitination. Our findings reveal a post-translational regulatory axis in which PARG governs cell cycle progression by modulating the PARylation-dependent ubiquitination of p21. These results broaden the understanding of p21 regulation in cancer and highlight PARG as a potential therapeutic target for GC treatment.
Authors
Yangchan Hu, Qimei Bao, Yixing Huang, Yan Wang, Xin Zhao, Junjun Nan, Yuxin Meng, Mingcong Deng, Yuancong Li, Zirui Zhuang, Hanyi He, Dan Zu, Yuke Zhong, Chunkai Zhang, Bing Wang, Ran Li, Yanhua He, Qihan Wang, Min Liu, John A. Tainer, Yin Shi, Xiangdong Cheng, Ji Jing, Zu Ye
Abstract
Pancreatic ductal adenocarcinoma (PDAC) occurs as a complex, multifaceted event driven by the interplay of tumor-permissive genetic mutations, the nature of the cellular origin, and microenvironmental stress. In this study, using primary human pancreatic acinar 3D organoids, we performed a CRISPR-KO screen targeting 199 potential tumor suppressors curated from clinical PDAC samples. Our data revealed significant enrichment of a list of candidate genes, with neurofibromatosis type 2 associated gene (NF2) emerging as the top target. Functional validation confirmed that loss of NF2 promoted the transition of PDAC to an invasive state, potentially through extracellular matrix modulation. NF2 inactivation was found to enhance PDAC cell fitness under nutrient starvation. This adaptation not only reinforced the oncogenic state but also conferred therapeutic resistance. Additionally, we found that NF2 loss was associated with fibroblast heterogeneity and cancer-stroma communication in tumor evolution. These findings establish NF2 as a critical tumor suppressor in PDAC and uncover its role in mediating nutrient adaptation and drug resistance. Importantly, this study provides additional insights into drug resistance mechanisms and potential therapeutic targets in PDAC.
Authors
Yi Xu, Michael H. Nipper, Angel A. Dominguez, Chenhui He, Francis E. Sharkey, Sajid Khan, Han Xu, Daohong Zhou, Lei Zheng, Yu Luan, Jun Liu, Pei Wang
Abstract
Vinculin (VCL), a linker between cells and their environment, has rarely been linked to disease. This study examines the role of VCL in the development of the enteric nervous system (ENS) and its relationship to Hirschsprung disease (HSCR). Using whole-genome sequencing and in vitro assays, we identified four VCL mutations associated with HSCR, most causing loss of function. Neural crest-specific Vcl knock-out mice (Vcl cKO) displayed ENS defects resembling short-segment HSCR, including partial colonic aganglionosis and abnormal gut musculature. Single-cell transcriptomics revealed dysregulation of genes involved in neuronal differentiation and MAPK signaling. Spatial RNA sequencing revealed reduced ENS-mesenchyme interactions in Vcl cKO mice, accompanied by significant disruption of the Pleiotrophin (PTN) pathway; Ptn knock-out mice exhibited phenotypes similar to those of Vcl cKO mice, underscoring the importance of ENS-mesenchyme crosstalk. VCL works as a hub gene crucial for cell connection and signaling pathways essential for ENS formation. VCL deficiency subtly impacts various developmental stages and neighboring cells, cumulatively leading to a phenotype similar to short-segment HSCR. This research highlights the role of VCL in maintaining cellular interactions and signaling pathways, such as MAPK and PTN, which are crucial for ENS development and may inform therapeutic targets for ENS disorders.
Authors
Lifang Liu, Xixin Wang, Mingxuan Liang, Peiting Li, Cindy Yifei Yan, Patrick Ho-Yu Chung, Kenneth Kak-Yuen Wong, Asif Javed, Maria-Mercedes Garcia-Barcelo, Elly Sau-Wai Ngan
Abstract
Emerging evidence demonstrates that chronic stress alters immunological, neurochemical and endocrinological functions, thereby promoting tumor progression. However, the underlying metabolic mechanism of chronic stress in tumor progression is still elusive. Using multi-omics analysis, we found that aminopeptidase N (ANPEP) was upregulated in tumors with chronic restraint, associating with the reprogramming of amino acid metabolism. Functional assays revealed that ANPEP promoted liver cancer growth and metastasis. Knockdown of ANPEP blocked chronic stress-induced liver cancer progression. Chronic stress-induced glucocorticoids promoted nuclear receptor subfamily 3 group C member 1 (NR3C1) nuclear translocation to activate ANPEP transcription by directly binding to its promoter. Furthermore, ANPEP promotes glutathione synthesis, subsequently inhibiting reactive oxygen species (ROS)-induced ferroptosis. Mechanistically, ANPEP interacted with solute carrier family 3 member 2 (SLC3A2) to block membrane associated ring-CH-type finger 8-mediated (MARCH8-mediated) lysosome-dependent degradation of SLC3A2, promoting intracellular L-cystine transport, thereby increasing glutathione synthesis. The combination of ANPEP silencing and sorafenib treatment showed a synergistic effect in inhibiting liver cancer progression. Finally, clinical data and mouse models demonstrated that chronic stress drove liver tumor progression via ANPEP-regulated SLC3A2. These findings reveal unanticipated communication between chronic stress and metabolic reprogramming during liver cancer progression, providing potential therapeutic implications for liver cancer.
Authors
Yongkang Wu, Yankun Zhang, Xiaojia Shi, Mengting Wu, Min Sun, Ying Feng, Wenmeng Ma, Xiule Jiang, Dingqi Fei, Mingjian Zhao, Zhuanchang Wu, Chunyang Li, Xiaohong Liang, Lifen Gao, Chunhong Ma, Xuetian Yue
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)