Gastroenterologies
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
Abstract
Initiation and maintenance of transcriptional states are critical for controlling normal tissue homeostasis and differentiation. Cyclin Dependent Kinases CDK8/CDK19 (Mediator kinase) are regulatory components of Mediator, a highly conserved complex that orchestrates enhancer-mediated transcriptional output. While Mediator kinase has been implicated in the transcription of genes necessary for development and growth, its function in mammals has not been well defined. Using a suite of genetically defined models and pharmacological inhibitors, we show that Cdk8/19 function in a redundant manner to regulate intestinal lineage-specification in human and mouse. Mechanistically, we find that the Mediator kinase module binds and phosphorylates key components of the chromatin remodelling complex SWI/SNF in intestinal epithelial cells. Concomitantly, SWI/SNF and MED12-Mediator co-localise at distinct lineage-specifying enhancers in a CDK8/19 dependent manner. As such, these studies reveal a novel transcriptional mechanism of intestinal cell specification, coordinated by the interaction between the chromatin remodelling complex SWI/SNF and Mediator kinase.
Authors
Marius V. Dannappel, Danxi Zhu, Xin Sun, Hui Kheng Chua, Marle Poppelaars, Monica Suehiro, Subash Khadka, Terry C.C. Lim Kam Sian, Dhanya Sooraj, Melissa Loi, Hugh Gao, Daniel Croagh, Roger J. Daly, Pouya Faridi, Thomas Boyer, Ron Firestein
Abstract
Vessel co-option has been demonstrated to mediate colorectal cancer liver metastasis (CRCLM) resistance to anti-angiogenic therapy. The current mechanisms underlying vessel co-option have mainly focused on the "hijacker" tumor cells, whereas the function of the “hijackee” sinusoidal blood vessels has not been explored. Here, we found that the occurrence of vessel co-option in bevacizumab-resistant CRCLM xenografts was associated with increased expression of fibroblast activation protein alpha (FAPα) in the co-opted hepatic stellate cells (HSCs), which was dramatically attenuated in HSC-specific conditional Fap-knockout mice bearing CRCLM allografts. Mechanistically, bevacizumab treatment induced hypoxia to upregulate the expression of fibroblast growth factor-binding protein 1 (FGFBP1) in tumor cells. Gain- or loss-of-function experiments revealed that the bevacizumab-resistant tumor cell-derived FGFBP1 induced FAPα expression by enhancing the paracrine FGF2-FGFR1-ERK1/2-EGR1 signaling pathway in HSCs. FAPα promoted CXCL5 secretion in HSCs, which activated CXCR2 to promote the epithelial-mesenchymal transition of tumor cells and the recruitment of myeloid-derived suppressor cells. These findings were further validated in CRCLM patient-derived tumor tissues. Targeting FAPα+ HSCs effectively disrupted the co-opted sinusoidal blood vessels and overcame bevacizumab resistance. Our study highlights the role of FAPα+ HSCs in vessel co-option and provides an effective strategy to overcome the vessel co-option-mediated bevacizumab resistance.
Authors
Ming Qi, Shuran Fan, Maohua Huang, Jinghua Pan, Yong Li, Qun Miao, Wenyu Lyu, Xiaobo Li, Lijuan Deng, Shenghui Qiu, Tongzheng Liu, Weiqing Deng, Xiaodong Chu, Chang Jiang, Wenzhuo He, Liangping Xia, Yunlong Yang, Jian Hong, Qi Qi, Wenqian Yin, Xiangning Liu, Changzheng Shi, Minfeng Chen, Wencai Ye, Dongmei Zhang
Abstract
Intrahepatic neutrophil infiltration has been implicated in severe alcoholic hepatitis (SAH) pathogenesis; however, the mechanism underlying neutrophil-induced injury in SAH remains obscure. This translational study aims to describe the patterns of intrahepatic neutrophil infiltration and its involvement in SAH pathogenesis. Immunohistochemistry analyses of explanted livers identified two SAH phenotypes despite a similar clinical presentation, one with high intrahepatic neutrophils (Neuhi), but low levels of CD8+ T cells, and vice versa. RNA-Seq analyses demonstrated that neutrophil cytosolic factor 1 (NCF1), a key factor in controlling neutrophilic ROS production, was upregulated and correlated with hepatic inflammation and disease progression. To study specifically the mechanisms related to Neuhi in AH patients and liver injury, we used the mouse model of chronic-plus-binge ethanol feeding and found that myeloid-specific deletion of the Ncf1 gene abolished ethanol-induced hepatic inflammation and steatosis. RNA-Seq analysis and the data from experimental models revealed that neutrophilic NCF1-dependent ROS promoted alcoholic hepatitis (AH) by inhibiting AMP-activated protein kinase (a key regulator of lipid metabolism) and microRNA-223 (a key antiinflammatory and antifibrotic microRNA). In conclusion, two distinct histopathological phenotypes based on liver immune phenotyping are observed in SAH patients, suggesting a separate mechanism driving liver injury and/or failure in these patients.
Authors
Jing Ma, Adrien Guillot, Zhihong Yang, Bryan Mackowiak, Seonghwan Hwang, Ogyi Park, Brandon J. Peiffer, Ali Reza Ahmadi, Luma Melo, Praveen Kusumanchi, Nazmul Huda, Romil Saxena, Yong He, Yukun Guan, Dechun Feng, Pau Sancho-Bru, Mengwei Zang, Andrew MacGregor Cameron, Ramon Bataller, Frank Tacke, Zhaoli Sun, Suthat Liangpunsakul, Bin Gao
Abstract
Epithelial cells lining mucosal surfaces of the gastrointestinal and respiratory tracts uniquely express ERN2/IRE1β, a paralogue of the most evolutionarily conserved endoplasmic reticulum stress sensor ERN1/IRE1α. How ERN2 functions at the host-environment interface and why a second paralogue evolved remain incompletely understood. Using conventionally raised and germ-free Ern2-/- mice, we found that ERN2 was required for microbiota-induced goblet cell maturation and mucus barrier assembly in the colon. This occurred only after colonization of the alimentary tract with normal gut microflora, which induced Ern2 expression. ERN2 acted by splicing Xbp1 mRNA to expand ER function and prevent ER stress in goblet cells. Although ERN1 can also splice Xbp1 mRNA, it did not act redundantly to ERN2 in this context. By regulating assembly of the colon mucus layer, ERN2 further shaped the composition of the gut microbiota. Mice lacking Ern2 had a dysbiotic microbial community that failed to induce goblet cell development and increased susceptibility to colitis when transferred into germ-free wild type mice. These results show that ERN2 evolved at mucosal surfaces to mediate crosstalk between gut microbes and the colonic epithelium required for normal homeostasis and host defense.
Authors
Michael J. Grey, Heidi De Luca, Doyle V. Ward, Irini A.M. Kreulen, Katlynn Bugda Gwilt, Sage E. Foley, Jay R. Thiagarajah, Beth A. McCormick, Jerrold R. Turner, Wayne I. Lencer
Abstract
Functional constipation (FC) with intractable nature is the most severe form of constipation, but its etiology has long been unknown. In light of the intractable nature, we hypothesized that such intractable FC (IFC) sufferers were caused by intractable infection of a pathogenic bacterium. Here, we isolated a bacterium of Shigella sp. PIB from IFC patients that significantly inhibited the peristaltic contraction of colon by production of docosapentaenoic acid (DPA). PIB could colonize mice at least for six months. Oral administration of PIB was sufficient to induce constipation, which was reversed by PIB-specific phages. The mutated PIB with reduced DPA was incapable of inhibiting colonic function and inducing constipation, suggesting that DPA produced by PIB was the key mediator for the genesis of constipation. The PIB were detected in stools of 56% (38/68) of the IFC patients, but not in non-IFC or healthy populations (0/180). DPA levels in stools were elevated in 44.12% (30/68) of the IFC patients, but none of the healthy volunteers (0/97). Our results suggest Shigella sp. PIB may be the critical causative pathogen for IFC, and detections of fecal PIB bacteria plus DPA may be reliable methods for IFC diagnosis and classification.
Authors
Xin Chen, Tian-Tian Qiu, Ye Wang, Li-Yang Xu, Jie Sun, Zhi-Hui Jiang, Wei Zhao, Tao Tao, Yu-Wei Zhou, Lisha Wei, Yeqiong Li, Yanyan Zheng, Guo-Hua Zhou, Huaqun Chen, Jian Zhang, Xiao-Bo Feng, Fangyu Wang, Ning Li, Xue-Na Zhang, Jun Jiang, Min-Sheng Zhu
Copyright © 2023 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)