PMID- 33605486 OWN - NLM STAT- MEDLINE DCOM- 20220331 LR - 20220401 IS - 1469-445X (Electronic) IS - 0958-0670 (Linking) VI - 106 IP - 4 DP - 2021 Apr TI - Endogenous production of n-3 polyunsaturated fatty acids protects mice from carbon tetrachloride-induced liver fibrosis by regulating mTOR and Bcl-2/Bax signalling pathways. PG - 983-993 LID - 10.1113/EP089328 [doi] AB - NEW FINDINGS: What is the central question of this study? What is the protective benefit of n-3 polyunsaturated fatty acids (PUFAs) on liver fibrosis and what are the relevant signalling pathways in a transgenic mouse model overexpressing the mfat-1 enzyme? What is the main finding and its importance? n-3 PUFA elevation strongly prevented carbon tetrachloride (CCl(4) )-induced hepatic damage and inhibited the activation of hepatic stellate cells. n-3 PUFAs suppressed CCl(4) -induced activation of mTOR, elevated Bcl-2 expression, and reduced Bax level, suggesting that n-3 PUFAs can render strong protective effects against liver fibrosis and point to the potential of mfat-1 gene therapy as a treatment modality. ABSTRACT: Liver fibrosis is a reversible wound healing response with excessive accumulation of extracellular matrix proteins. It is a globally prevalent disease with ultimately severe pathological consequences. However, very few current clinical therapeutic options are available. Nutritional addition of n-3 polyunsaturated fatty acids (PUFAs) can delay and lessen the development of liver fibrosis. Herein, this study examined the protective benefit of n-3 PUFAs on liver fibrosis and the relevant signalling pathways using a transgenic mouse model overexpressing the mfat-1 enzyme that converts n-6 to n-3 PUFAs. Male C57BL/6 wild-type and mfat-1 transgenic mice were administered carbon tetrachloride (CCl(4) ) or control corn oil by intraperitoneal injection. Blood alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were subsequently measured. CCl(4) -induced hepatic damage and fibrosis were assessed using haematoxylin-eosin and Masson's trichrome staining. Western blot assays were used to detect and quantify fibrosis-related proteins and mechanistic target of rapamycin (mTOR) and B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) signalling components. The direct effect of docosahexaenoic acid (DHA) on primary hepatic stellate cells (HSCs) was also investigated in a co-culture experiment. n-3 PUFAs, as a result of mfat-1 activity, had a strong protective effect on liver fibrosis. The elevation of ALT and AST induced by CCl(4) was significantly lessened in the mfat-1 mice. Histological determination revealed the protective effects of n-3 PUFAs on liver inflammation and collagen deposition. Co-incubation with DHA reduced the expression of profibrogenic factors in the primary HSCs. Moreover, mfat-1 transgenic mice showed significant reduction of proteins that are involved in mTOR and Bcl-2/Bax signalling pathways. Collectively, these results suggest that n-3 PUFA elevation strongly prevents CCl(4) -induced hepatic damage by directly inhibiting the activation of HSCs and regulating the basal activity of the mTOR and Bcl-2/Bax signalling pathways. Gene therapy applying mfat-1 and elevating n-3 PUFAs represents a promising treatment strategy to prevent liver fibrosis. CI - (c) 2021 The Authors. Experimental Physiology (c) 2021 The Physiological Society. FAU - Shan, Changfeng AU - Shan C AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Wang, Ronghua AU - Wang R AD - Rural Work Office of Longmen County Committee of the Communist Party of China, Longmen County Agricultural and Rural Bureau, Huizhou, Guangdong Province, People's Republic of China. FAU - Wang, Shuai AU - Wang S AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Zhang, Zongmeng AU - Zhang Z AUID- ORCID: 0000-0002-4144-6901 AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Xing, Chaofeng AU - Xing C AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Feng, Wenbin AU - Feng W AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Zhao, Zhenggang AU - Zhao Z AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Zhou, Sujin AU - Zhou S AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Zhao, Allan Zijian AU - Zhao AZ AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Mu, Yunping AU - Mu Y AUID- ORCID: 0000-0001-6184-4977 AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. FAU - Li, Fanghong AU - Li F AD - The School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong Province, People's Republic of China. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210305 PL - England TA - Exp Physiol JT - Experimental physiology JID - 9002940 RN - 0 (Fatty Acids, Omega-3) RN - 0 (bcl-2-Associated X Protein) RN - CL2T97X0V0 (Carbon Tetrachloride) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) SB - IM MH - Animals MH - *Carbon Tetrachloride/adverse effects/metabolism MH - *Fatty Acids, Omega-3/metabolism/pharmacology MH - Liver/metabolism MH - Liver Cirrhosis/chemically induced/drug therapy/prevention & control MH - Male MH - Mice MH - Mice, Inbred C57BL MH - TOR Serine-Threonine Kinases/metabolism MH - bcl-2-Associated X Protein/metabolism OTO - NOTNLM OT - Bcl-2/Bax OT - hepatic stellate cells OT - liver fibrosis OT - mTOR OT - n-3 PUFAs OT - transgenic mfat-1 mice EDAT- 2021/02/20 06:00 MHDA- 2022/04/01 06:00 CRDT- 2021/02/19 08:41 PHST- 2020/12/04 00:00 [received] PHST- 2021/02/15 00:00 [accepted] PHST- 2021/02/20 06:00 [pubmed] PHST- 2022/04/01 06:00 [medline] PHST- 2021/02/19 08:41 [entrez] AID - 10.1113/EP089328 [doi] PST - ppublish SO - Exp Physiol. 2021 Apr;106(4):983-993. doi: 10.1113/EP089328. Epub 2021 Mar 5.