Hepatology
Abstract
Authors
Dan Wang, Ania Baghoomian, Zhengyi Zhang, Ya Cui, Emily C. Whang, Xiang Li, Josue Fraga, Rachel Spellman, Tien S. Dong, We Li, Arpana Gupta, Jihane N. Benhammou, Tamer Sallam
Abstract
Neutrophil infiltration occurs in a variety of liver diseases, but it is unclear how neutrophils and hepatocytes interact. Neutrophils generally use granule proteases to digest phagocytosed bacteria and foreign substances or neutralize them in neutrophil extracellular traps. In certain pathological states, granule proteases play a destructive role against the host as well. More recently, non-destructive actions of neutrophil granule proteins have been reported, such as modulation of tissue remodeling and metabolism. Here we report a completely different mechanism by which neutrophils act non-destructively, by inserting granules directly into hepatocytes. Specifically, elastase-containing granules were transferred to hepatocytes where elastase selectively degraded intracellular calcium channels to reduce cell proliferation without cytotoxicity. In response, hepatocytes increased expression of serpin E2 and A3, which inhibited elastase activity. Elastase insertion was seen in patient specimens of alcohol-associated hepatitis, and the relationship between elastase-mediated ITPR2 degradation and reduced cell proliferation was confirmed in mouse models. Moreover, neutrophils from patients with alcohol-associated hepatitis were more prone to degranulation and more potent in reducing calcium channel expression than neutrophils from healthy subjects. This non-destructive and reversible action on hepatocytes defines a previously unrecognized role for neutrophils in the transient regulation of epithelial calcium signaling mechanisms.
Authors
Noriyoshi Ogino, M. Fátima Leite, Mateus T. Guerra, Emma Kruglov, Hiromitsu Asashima, David A. Hafler, Takeshi Ito, João P. Pereira, Brandon J. Peiffer, Zhaoli Sun, Barbara E. Ehrlich, Michael H. Nathanson
Abstract
It is unknown which post-transcriptional regulatory mechanisms are required for oncogenic competence. Here, we show that the LIN28 family of RNA-binding proteins (RBPs), which facilitate post-transcriptional RNA metabolism within ribonucleoprotein networks, are essential for the initiation of diverse oncotypes of hepatocellular carcinoma (HCC). In HCC models driven by NRASG12V/Tp53, CTNNB1/YAP/Tp53, or AKT/Tp53, mice without Lin28a and Lin28b were markedly impaired in cancer initiation. We biochemically defined an oncofetal regulon of 15 factors connected to Lin28 through direct mRNA and protein interactions. Interestingly, all were RBPs and only 1 of 15 is a Let-7 target. Polysome profiling and reporter assays showed that LIN28B directly increased the translation of 8 of these 15 RBPs. As expected, overexpression of LIN28B and IGFBP1-3 were able to genetically rescue cancer initiation. Using this platform to probe components downstream of LIN28, we found that 8 target RBPs were able to restore NRASG12V/Tp53 cancer formation in Lin28a/b deficient mice. Furthermore, these LIN28B targets promote cancer initiation through an increase in protein synthesis. LIN28B, central to an RNP regulon that increases translation of RBPs, is important for tumor initiation in the liver.
Authors
Meng-hsiung Hsieh, Yonglong Wei, Lin Li, Liem H. Nguyen, Yu-Hsuan Lin, Jung M. Yoon, Xuxu Sun, Xun Wang, Xin Luo, Sarah K. Knutson, Christina Bracken, George Q. Daley, John T. Powers, Hao Zhu
Abstract
Metabolic dysfunction–associated steatohepatitis (MASH) — previously described as nonalcoholic steatohepatitis (NASH) — is a major driver of liver fibrosis in humans, while liver fibrosis is a key determinant of all-cause mortality in liver disease independent of MASH occurrence. CCAAT/enhancer binding protein α (CEBPA), as a versatile ligand-independent transcriptional factor, has an important function in myeloid cells, and is under clinical evaluation for cancer therapy. CEBPA is also expressed in hepatocytes and regulates glucolipid homeostasis; however, the role of hepatocyte-specific CEBPA in modulating liver fibrosis progression is largely unknown. Here, hepatic CEBPA expression was found to be decreased during MASH progression both in humans and mice, and hepatic CEBPA mRNA was negatively correlated with MASH fibrosis in the human liver. CebpaΔHep mice had markedly enhanced liver fibrosis induced by a high-fat, high-cholesterol, high-fructose diet or carbon tetrachloride. Temporal and spatial hepatocyte-specific CEBPA loss at the progressive stage of MASH in CebpaΔHep,ERT2 mice functionally promoted liver fibrosis. Mechanistically, hepatocyte CEBPA directly repressed Spp1 transactivation to reduce the secretion of osteopontin, a fibrogenesis inducer of hepatic stellate cells. Forced hepatocyte-specific CEBPA expression reduced MASH-associated liver fibrosis. These results demonstrate an important role for hepatocyte-specific CEBPA in liver fibrosis progression, and may help guide the therapeutic discoveries targeting hepatocyte CEBPA for the treatment of liver fibrosis.
Authors
Tingting Yan, Nana Yan, Yangliu Xia, Vorthon Sawaswong, Xinxin Zhu, Henrique Bregolin Dias, Daisuke Aibara, Shogo Takahashi, Keisuke Hamada, Yoshifumi Saito, Guangming Li, Hui Liu, Hualong Yan, Thomas J. Velenosi, Kristopher W. Krausz, Jing Huang, Shioko Kimura, Yaron Rotman, Aijuan Qu, Haiping Hao, Frank J. Gonzalez
Abstract
Authors
Yukun Guan, Brandon Peiffer, Dechun Feng, Maria A. Parra, Yang Wang, Yaojie Fu, Vijay H. Shah, Andrew M. Cameron, Zhaoli Sun, Bin Gao
Abstract
Uncontrolled accumulation of extracellular matrix leads to tissue fibrosis and loss of organ function. We previously demonstrated in vitro that the DNA/RNA-binding protein fused in sarcoma (FUS) promotes fibrotic responses by translocating to the nucleus, where it initiates collagen gene transcription. However, it is still not known whether FUS is profibrotic in vivo and whether preventing its nuclear translocation might inhibit development of fibrosis following injury. We now demonstrate that levels of nuclear FUS are significantly increased in mouse models of kidney and liver fibrosis. To evaluate the direct role of FUS nuclear translocation in fibrosis, we used mice that carry a mutation in the FUS nuclear localization sequence (FUSR521G) and the cell-penetrating peptide CP-FUS-NLS that we previously showed inhibits FUS nuclear translocation in vitro. We provide evidence that FUSR521G mice or CP-FUS-NLS–treated mice showed reduced nuclear FUS and fibrosis following injury. Finally, differential gene expression analysis and immunohistochemistry of tissues from individuals with focal segmental glomerulosclerosis or nonalcoholic steatohepatitis revealed significant upregulation of FUS and/or collagen genes and FUS protein nuclear localization in diseased organs. These results demonstrate that injury-induced nuclear translocation of FUS contributes to fibrosis and highlight CP-FUS-NLS as a promising therapeutic option for organ fibrosis.
Authors
Manuel Chiusa, Youngmin A. Lee, Ming-Zhi Zhang, Raymond C. Harris, Taylor Sherrill, Volkhard Lindner, Craig R. Brooks, Gang Yu, Agnes B. Fogo, Charles R. Flynn, Jozef Zienkiewicz, Jacek Hawiger, Roy Zent, Ambra Pozzi
Abstract
Nonalcoholic liver disease (NAFLD) encompasses a disease continuum from simple steatosis, to non-alcoholic steatohepatitis (NASH). However, there are currently no approved pharmacotherapies for NAFLD although several drugs are in advanced stages of clinical development. Because of the complex pathophysiology and heterogeneity of NALFD, identification of potential therapeutic targets is clinically important. Here, we demonstrated that TRIM56 protein abundance is markedly downregulated in the livers of individuals with NAFLD and mice fed a high-fat diet. Hepatocyte-specific ablation of TRIM56 exacerbated the progression of NAFLD, while hepatic TRIM56 overexpression suppressed it. Integrative analyses of interactomic and transcriptomic profiling revealed a pivotal role of TRIM56 in lipid metabolism and identified lipogenesis factor FASN as a direct binding partner of TRIM56. TRIM56 directly interacts with FASN and triggers its K48-linked ubiquitination-dependent degradation. Finally, by using AI-based virtual screening, we discovered an orally bioavailable small-molecule inhibitor of FASN (named FASstatin) which potentiates TRIM56-mediated FASN ubiquitination. Therapeutic administration of FASstatin improved NAFLD and NASH pathologies in mice with optimal safety, tolerability and pharmacokinetic profile. Our findings provide the proof-of-concept that targeting the TRIM56/FASN axis in hepatocytes may offer potential therapeutic avenues to treat NAFLD.
Authors
Suowen Xu, Xiumei Wu, Sichen Wang, Mengyun Xu, Tingyu Fang, Xiaoxuan Ma, Meijie Chen, Jiajun Fu, Juan Guo, Song Tian, Tian Tian, Xu Cheng, Hailong Yang, Junjie Zhou, Zhenya Wang, Yanjun Yin, Wen Xu, Fen Xu, Jinhua Yan, Zhihua Wang, Sihui Luo, Xiao-Jing Zhang, Yan-Xiao Ji, Jianping Weng
Abstract
Non-alcoholic fatty liver disease (NAFLD) is prevalent in the majority of obese individuals, but in a subset, this progresses to non-alcoholic steatohepatitis (NASH) and fibrosis. The mechanisms that prevent NASH and fibrosis in the majority of NAFLD patients remain unclear. Here we report that NAD(P)H oxidase (NOX)-4 and nuclear factor erythroid 2-related factor 2 (NFE2L2) were elevated in hepatocytes early in disease progression to prevent NASH/fibrosis. Mitochondrial-derived reactive oxygen species (ROS) activated NFE2L2 to induce the expression of NOX4, which in turn generated H2O2 to exacerbate the NFE2L2 antioxidant defense response. The deletion or inhibition of NOX4 in hepatocytes decreased ROS and attenuated antioxidant defense to promote mitochondrial oxidative stress, damage proteins and lipids, diminish insulin signalling and promote cell death upon oxidant challenge. Hepatocyte NOX4 deletion in high fat fed obese mice, which otherwise develop steatosis, but not NASH, resulted in hepatic oxidative damage, inflammation and T cell recruitment to drive NASH and fibrosis, whereas NOX4 overexpression tempered the development of NASH/fibrosis in mice fed a NASH-promoting diet. Thus, mitochondrial- and NOX4-derived ROS function in concert to drive a NFE2L2 antioxidant defense response to attenuate oxidative liver damage and the progression to NASH/fibrosis in obesity.
Authors
Spencer Greatorex, Supreet Kaur, Chrysovalantou E. Xirouchaki, Pei Kee Goh, Florian Wiede, Amanda J. Genders, Melanie Tran, YaoYao Jia, Arthe Raajendiran, Wendy A. Brown, Catriona A. McLean, Junichi Sadoshima, Matthew J. Watt, Tony Tiganis
Abstract
Many cancers harbour homologous recombination defect (HRD), the therapeutic target being successfully applied in treating breast/ovarian cancer via synthetic lethality. However, canonical HRD caused by BRCAness mutations is not explicit in liver cancer. Here we report a subtype of HRD caused by the perturbation of a proteasome variant (CDW19S) in hepatitis B virus (HBV) bearing cells. This amalgamate protein complex contained the 19S proteasome decorated with CRL4WDR70 ubiquitin ligase, and assembled at broken chromatin in a PSMD4Rpn10 and ATM- MDC1-RNF8 dependent manner. CDW19S promoted DNA end processing via segregated modules that promote nuclease activities of MRE11 and EXO1. Contrarily, a proteasomal component, ADRM1Rpn13, inhibited resection and was removed by CRL4WDR70-catalysed ubiquitination upon commitment of extensive resection. HBx interfered with ADRM1Rpn13 degradation, leading to the imposition of ADRM1Rpn13-dependent resection barrier and consequent viral HRD subtype distinguishable from that caused by BRCA1 defect. Finally, we demonstrated that viral HRD in HBV-associated hepatocellular carcinoma (HBVHCC) can be exploited to restrict tumor progression. Our work clarifies the underlying mechanism of a viral-induced HRD subtype.
Authors
Ming Zeng, Zizhi Tang, Laifeng Ren, Haibin Wang, Xiaojun Wang, Wenyuan Zhu, Xiaobing Mao, Zeyang Li, Xianming Mo, Jun Chen, Junhong Han, Daochun Kong, Jianguo Ji, Antony M. Carr, Cong Liu
Abstract
X-linked myotubular myopathy (XLMTM) is a fatal congenital disorder caused by mutations in the MTM1 gene. Currently, there are no approved treatments, though AAV8-mediated gene transfer therapy has shown promise in animal models and preliminarily in patients. However, four patients with XLMTM treated with gene therapy have died from progressive liver failure, and hepatobiliary disease has now been recognized more broadly in association with XLMTM. In an attempt to understand whether loss of MTM1 itself is associated with liver pathology, we have characterized a novel liver phenotype in a zebrafish model of this disease. Specifically, we have found that loss-of-function mutations in mtm1 lead to severe liver abnormalities including impaired bile flux, structural abnormalities of the bile canaliculus, and improper endosomal-mediated trafficking of canalicular transporters. Using a reporter tagged Mtm1 zebrafish line, we have established localization of Mtm1 in the liver in association with Rab11 and canalicular transport proteins, and demonstrated that hepatocyte specific re-expression of Mtm1 can rescue the cholestatic phenotype. Lastly, we completed a targeted chemical screen, and found that Dynasore, a dynamin II inhibitor, is able to partially restore bile flow and transporter localization to the canalicular membrane. In summary, we demonstrate for the first time liver abnormalities that are directly caused by MTM1 mutation in a pre-clinical model, thus establishing the critical framework for better understanding and comprehensive treatment of the human disease.
Authors
Sophie Karolczak, Ashish R. Deshwar, Evangelina Aristegui, Binita M. Kamath, Michael W. Lawlor, Gaia Andreoletti, Jonathan R. Volpatti, Jillian L. Ellis, Chunyue Yin, James J. Dowling
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)