Gastroenterology
Abstract
The liver can fully regenerate after partial resection and its underlying mechanisms have been extensively studied. The liver can also rapidly regenerate after injury with most studies focusing on hepatocyte proliferation; however, how hepatic necrotic lesions during acute or chronic liver diseases are eliminated and repaired remains obscure. Here we demonstrated that monocyte-derived macrophages (MoMFs) were rapidly recruited to and encapsulate necrotic areas during immune-mediated liver injury, and this feature was essential in repairing necrotic lesions. At the early stage of injury, infiltrating MoMFs activated the JAG1-NOTCH2 axis to induce cell death-resistant SOX9+ hepatocytes near the necrotic lesions, which acted as a barrier from further injury. Subsequently, necrotic environment (hypoxia and dead cells) induced a cluster of C1q+MoMFs that promoted necrotic removal and liver repair, while Pdgfb+MoMFs activated hepatic stellate cells (HSCs) to express -smooth muscle actin and induce a strong contraction signal (YAP, pMLC) to squeeze and finally eliminate the necrotic lesions. In conclusion, MoMFs play a key role in repairing the necrotic lesions not only by removing necrotic tissues but also by inducing cell death resistant hepatocytes to form a perinecrotic capsule and by activating α-smooth actin expressing HSCs to facilitate necrotic lesion resolution.
Authors
Dechun Feng, Xiaogang Xiang, Yukun Guan, Adrien Guillot, Hongkun Lu, Chingwen Chang, Yong He, Hua Wang, Hongna Pan, Cynthia Ju, Sean P. Colgan, Frank Tacke, Xin Wei Wang, George Kunos, Bin Gao
Abstract
Although selenium deficiency correlates with colorectal cancer (CRC) risk, the roles of the selenium-rich antioxidant selenoprotein P (SELENOP) in CRC remain unclear. In this study, we defined SELENOP’s contributions to sporadic colorectal carcinogenesis. In human scRNA-seq datasets, we discovered that SELENOP expression rises as normal colon stem cells transform into adenomas that progress into carcinomas. We next examined the effects of Selenop KO in a mouse adenoma model that involves conditional, intestinal epithelial-specific deletion of the tumor suppressor adenomatous polyposis coli (Apc) and found that Selenop KO decreased colon tumor incidence and size. We mechanistically interrogated SELENOP-driven phenotypes in tumor organoids as well as CRC and noncancer cell lines. Selenop KO tumor organoids demonstrated defects in organoid formation and decreases in WNT target gene expression, which could be reversed by SELENOP restoration. Moreover, SELENOP increased canonical WNT signaling activity in noncancer and CRC cell lines. In defining SELENOP’s mechanism of action, we mapped protein-protein interactions between SELENOP and the WNT co-receptor low-density lipoprotein receptor-related protein 5/6 (LRP5/6). Lastly, we confirmed that SELENOP:LRP5/6 interactions contributed to SELENOP’s effects on WNT activity. Overall, our results position SELENOP as a modulator of the WNT signaling pathway in sporadic CRC.
Authors
Jennifer M. Pilat, Rachel E. Brown, Zhengyi Chen, Nathaniel J. Berle, Adrian P. Othon, M. Washington, Shruti A. Anant, Suguru Kurokawa, Victoria H. Ng, Joshua J. Thompson, Justin Jacobse, Jeremy A. Goettel, Ethan Lee, Yash A. Choksi, Ken S. Lau, Sarah P. Short, Christopher S. Williams
Abstract
Ras plays an essential role in the development of acinar to ductal metaplasia (ADM) and pancreatic ductal adenocarcinoma (PDAC). However, mutant Kras is an inefficient driver for PDAC development. The switching mechanisms from low Ras activity to high Ras activity that is required for development and progression of pancreatic intraepithelial neoplasia (PanIN) are unclear. In this study, we found that HPK1 was upregulated during pancreatic injury and ADM. HPK1 interacted with the SH3 domain and phosphorylated Ras GTPase activating protein (RasGAP) and upregulated RasGAP activity. Using the transgenic mouse models of HPK1 or M46, a kinase-dead mutant of HPK1, we showed that HPK1 inhibited Ras activity and its downstream signaling and regulated acinar cell plasticity. M46 promoted the development of ADM and PanINs. Expression of M46 in KrasG12D;Bac mice promoted the infiltration of myeloid-derived suppressor cells and macrophages, inhibited the infiltration of T cells, and accelerated the progression of PanINs to invasive and metastatic PDAC, while HPK1 attenuated mutant Kras-driven PanIN progression. Our results showed that HPK1 plays an important role in ADM and the progression of PanINs by regulating Ras signaling. Loss of HPK1 kinase activity promotes an immunosuppressive tumor microenvironment and accelerates the progression of PanINs to PDAC.
Authors
Hua Wang, Rohan Moniruzzaman, Lei Li, Baoan Ji, Yi Liu, Xiangsheng Zuo, Reza Abbasgholizadeh, Jun Zhao, Guangchao Liu, Ruiqi Wang, Hongli Tang, Ryan Sun, Xiaoping Su, Tse-Hua Tan, Anirban Maitra, Huamin Wang
Abstract
Authors
Pablo Canales-Herrerias, Yolanda Garcia-Carmona, Joan Shang, Hadar Meringer, Debra S. Yee, Lin Radigan, Sofija Buta, Gustavo Martinez-Delgado, Michael Tankelevich, Drew S. Helmus, Marla Dubinksy, Annelie Everts-van der Wind, Thierry Dervieux, Dusan Bogunovic, Jean-Frederic Colombel, Jason M. Brenchley, Jeremiah Faith, Charlotte Cunningham-Rundles, Andrea Cerutti, Saurabh Mehandru
Abstract
Pancreatic ductal adenocarcinoma (PDAC) frequently presents with metastasis, but the molecular programs in human PDAC cells that drive invasion are not well understood. Using an experimental pipeline enabling PDAC organoid isolation and collection based on invasive phenotype, we assessed the transcriptomic programs associated with invasion in our organoid model. We identified differentially expressed genes in invasive organoids compared to matched non-invasive organoids from the same patients, and we confirmed that the encoded proteins were enhanced in organoid invasive protrusions. We identified three distinct transcriptomic groups in invasive organoids, two of which correlated directly with the morphological invasion patterns and were characterized by distinct upregulated pathways. Leveraging publicly available single-cell RNA-sequencing data, we mapped our transcriptomic groups onto human PDAC tissue samples, highlighting differences in the tumor microenvironment between transcriptomic groups and suggesting that non-neoplastic cells in the tumor microenvironment can modulate tumor cell invasion. To further address this possibility, we performed computational ligand-receptor analysis and validated the impact of multiple ligands (TGFB1, IL6, CXCL12, MMP9) on invasion and gene expression in an independent cohort of fresh human PDAC organoids. Our results identify unique molecular programs driving morphologically defined invasion patterns and highlight the tumor microenvironment as a potential modulator of these programs.
Authors
Yea Ji Jeong, Hildur Knutsdottir, Fatemeh Shojaeian, Michael G. Lerner, Maria F. Wissler, Elodie Henriet, Tammy Ng, Shalini Datta, Bernat Navarro-Serer, Peter Chianchiano, Benedict Kinny-Köster, Jacquelyn W. Zimmerman, Genevieve Stein-O'Brien, Matthias M. Gaida, James R. Eshleman, Ming-Tseh Lin, Elana J. Fertig, Andrew J. Ewald, Joel S. Bader, Laura D. Wood
Abstract
Gastric cancer often shows malignant growth and insensitivity to chemotherapeutic drugs due to the regulation of complex molecular mechanisms, which results in poor prognosis for patients. However, the relevant molecular mechanisms remain unclear. In this study, we reported that family with sequence similarity 117, member B (FAM117B), promoted the growth of gastric cancer cells and reduced the sensitivity of cells to chemotherapeutic drugs. Mechanistically, FAM117B competed with nuclear factor E2–related factor 2 (NRF2) for Kelch-like ECH-associated protein 1 (KEAP1) binding, reduced the ubiquitination degradation of NRF2, and activated the KEAP1/NRF2 signaling pathway. Moreover, FAM117B-induced growth and chemoresistance of gastric cancer cells were NRF2 dependent. We found that FAM117B and NRF2 protein levels were highly expressed in tumor tissues of patients with gastric cancer and their co-overexpression represented an independent factor for poor prognosis. Collectively, our findings reveal that FAM117B is involved in promoting gastric cancer growth and drug resistance, and it could be exploited as a cancer therapeutic target.
Authors
Yunjiang Zhou, Yaxin Chen, Yongwei Shi, Leyin Wu, Yingying Tan, Tao Li, Yigang Chen, Jiazeng Xia, Rong Hu
Abstract
Aberrant immune responses to resident microbes promote inflammatory bowel disease and other chronic inflammatory conditions. However, how microbiota-specific immunity is controlled in mucosal tissues remains poorly understood. Here, we find that mice lacking epithelial expression of microbiota-sensitive histone deacetylase 3 (HDAC3) exhibit increased accumulation of commensal-specific CD4+ T cells in the intestine, provoking the hypothesis that epithelial HDAC3 may instruct local microbiota-specific immunity. Consistent with this, microbiota-specific CD4+ T cells and epithelial HDAC3 expression were concurrently induced following early-life microbiota colonization. Further, epithelial-intrinsic ablation of HDAC3 decreased commensal-specific Tregs, increased commensal-specific Th17 cells, and promoted T cell-driven colitis. Mechanistically, HDAC3 was essential for NFκB-dependent regulation of epithelial MHC class II (MHCII). Epithelial-intrinsic MHCII dampened local accumulation of commensal-specific Th17 cells in adult mice, and protected against microbiota-triggered inflammation. Remarkably, HDAC3 enabled the microbiota to induce MHCII on epithelial cells and limit the number of commensal-specific T cells in the intestine. Collectively, these data reveal a central role for an epithelial histone deacetylase in directing the dynamic balance of tissue-intrinsic CD4+ T cell subsets that recognize commensal microbes and control inflammation.
Authors
Emily M. Eshleman, Tzu-Yu Shao, Vivienne Woo, Taylor Rice, Laura Engleman, Bailey J. Didriksen, Jordan Whitt, David B. Haslam, Sing Sing Way, Theresa Alenghat
Abstract
Visceral pain (VP) is a global problem with complex etiologies and limited therapeutic options. Guanylyl cyclase C (GUCY2C), an intestinal receptor producing cyclic GMP which regulates luminal fluid secretion, has emerged as a therapeutic target for VP. Indeed, FDA-approved GUCY2C agonists ameliorate VP in patients with chronic constipation syndromes, although analgesic mechanisms remain obscure. Here, we reveal that intestinal GUCY2C is selectively enriched in neuropod cells, a type of enteroendocrine cell that synapses with submucosal neurons in mice and humans. GUCY2CHigh neuropod cells associate with co-cultured dorsal root ganglia neurons and induce hyperexcitability, reducing the rheobase and increasing the resulting number of evoked action potentials. Conversely, the GUCY2C agonist linaclotide eliminated neuronal hyperexcitability produced by GUCY2C-sufficient, but not GUCY2C-deficient, neuropod cells, an effect independent of bulk epithelial cells or extracellular cGMP. Genetic elimination of intestinal GUCY2C amplified nociceptive signaling and VP that was comparable to chemically-induced VP but refractory to linaclotide. Importantly, eliminating GUCY2C selectively in neuropod cells also increased nociceptive signaling and VP that was refractory to linaclotide. In the context of loss of GUCY2C hormones in patients with VP, these observations suggest a specific role for neuropod GUCY2C signaling in the pathophysiology and treatment of these pain syndromes.
Authors
Joshua R. Barton, Annie K. Londregan, Tyler D. Alexander, Ariana A. Entezari, Shely Bar-Ad, Lan Cheng, Angelo C. Lepore, Adam E. Snook, Manuel Covarrubias, Scott A. Waldman
Abstract
BACKGROUND A pilot, single-center study showed that first-degree relatives of probands with nonalcoholic fatty liver disease (NAFLD) cirrhosis have a high risk of advanced fibrosis. We aimed to validate these findings using 2 independent cohorts from the US and Europe.METHODS This prospective study included probands with NAFLD with advanced fibrosis, NAFLD without advanced fibrosis, and non-NAFLD, with at least 1 first-degree relative. A total of 396 first-degree relatives — 220 in a derivation cohort and 176 in a validation cohort — were enrolled in the study, and liver fibrosis was evaluated using magnetic resonance elastography and other noninvasive imaging modalities. The primary outcome was prevalence of advanced fibrosis in first-degree relatives.RESULTS Prevalence of advanced fibrosis in first-degree relatives of probands with NAFLD with advanced fibrosis, NAFLD without advanced fibrosis, and non-NAFLD was 15.6%, 5.9%, and 1.3%, respectively (P = 0.002), in the derivation cohort, and 14.0%, 2.6%, and 1.3%, respectively (P = 0.004), in the validation cohort. In multivariable-adjusted logistic regression models, age of ≥50 years (adjusted OR [aOR]: 2.63, 95% CI 1.0–6.7), male sex (aOR: 3.79, 95% CI 1.6–9.2), diabetes mellitus (aOR: 3.37, 95% CI 1.3–9), and a first-degree relative with NAFLD with advanced fibrosis (aOR: 11.8, 95% CI 2.5–57) were significant predictors of presence of advanced fibrosis (all P < 0.05).CONCLUSION First-degree relatives of probands with NAFLD with advanced fibrosis have significantly increased risk of advanced fibrosis. Routine screening should be done in the first-degree relatives of patients with advanced fibrosis.FUNDING Supported by NCATS (5UL1TR001442), NIDDK (U01DK061734, U01DK130190, R01DK106419, R01DK121378, R01DK124318, P30DK120515, K23DK119460), NHLBI (P01HL147835), and NIAAA (U01AA029019); Academy of Finland grant 309263; the Novo Nordisk, EVO, and Sigrid Jusélius Foundations; and the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement 777377. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation program and the EFPIA.
Authors
Nobuharu Tamaki, Noora Ahlholm, Panu K. Luukkonen, Kimmo Porthan, Suzanne R. Sharpton, Veeral Ajmera, Yuko Kono, Shravan Dave, Aijaz Ahmed, Vinay Sundaram, Michael J. Wilkinson, Heather Patton, Hersh Gupta, Vanessa Cervantes, Christie Hernandez, Scarlett J. Lopez, Ria Loomba, Amanda Baumgartner, Lisa Richards, Perttu E.T. Arkkila, Katriina Nemes, Helena Isoniemi, Hannele Yki-Järvinen, Rohit Loomba
Abstract
The stomach corpus epithelium is organized into anatomical units that consist of glands and pits and contain different specialized secretory cells. Acute and chronic injury of the corpus are associated with characteristic changes of cellular differentiation and proliferation. Processes that control cellular differentiation under homeostatic conditions and upon injury are not well understood. R-spondin 3 (Rspo3) is a Wnt signalling enhancer secreted by gastric stromal cells, which controls stem cell homeostasis in different organs. Here we investigated the function of Rspo3 in the corpus during homeostasis, acute injury, and H. pylori infection. Using organoid culture and conditional mouse models, we demonstrate that RSPO3 is a critical driver of secretory cell differentiation in the corpus gland towards parietal and chief cells, while its absence promoted pit cell differentiation. Acute loss of chief and parietal cells induced by high dose tamoxifen - or merely the depletion of LGR5+ chief cells – caused an upregulation of RSPO3 expression, which was required for the initiation of a coordinated regenerative response via the activation of yes-associated protein (YAP) signaling. This response enabled a rapid recovery of the injured secretory gland cells. However, in the context of chronic H. pylori infection, the R-spondin-driven regeneraton was maintained long-term, promoing severe glandular hyperproliferation and the development of premalignant metaplasia.
Authors
Anne-Sophie Fischer, Stefanie Müllerke, Alexander Arnold, Julian Heuberger, Hilmar Berger, Manqiang Lin, Hans-Joachim Mollenkopf, Jonas Wizenty, David Horst, Frank Tacke, Michael Sigal
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)