Long term N-acetylcysteine administration rescues liver steatosis via endoplasmic reticulum stress with unfolded protein response in mice

• Published in: Lipids in health and disease Vol. 19; no. 1; p. 105
• Main Authors: Tsai, Ching-Chou, Chen, Yu-Jen, Yu, Hong-Ren, Huang, Li-Tung, Tain, You-Lin, Lin, I-Chun, Sheen, Jiunn-Ming, Wang, Pei-Wen, Tiao, Mao-Meng
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 25.05.2020; BioMed Central; BMC
• Subjects: Acetylcysteine; Acetylcysteine - pharmacology; Acetylcysteine - therapeutic use; Activating Transcription Factor 4 - genetics; Analysis; Animals; Antioxidants; Antioxidants (Nutrients); Antioxidants - pharmacology; Antioxidants - therapeutic use; Apoptosis; Caspase-3; Chaperonin 60 - genetics; Diet; Diet, High-Fat; Endoplasmic reticulum; Endoplasmic Reticulum Stress; Enoyl-CoA Hydratase - genetics; ER stress; Fatty liver; Fatty Liver - drug therapy; Fatty Liver - metabolism; Fatty Liver - physiopathology; Gene Expression Regulation; Heat shock proteins; High fat diet; House mouse; Hsp60 protein; HSP70 Heat-Shock Proteins - genetics; Hsp70 protein; Inflammation; Kinases; Lipids; Liver; Liver - drug effects; Liver - metabolism; Liver - physiopathology; Liver diseases; Male; Membranes; Metabolism; Mice; Mice, Inbred C57BL; Mitochondrial Proteins - genetics; Non-alcoholic Fatty Liver Disease - drug therapy; Non-alcoholic Fatty Liver Disease - metabolism; Non-alcoholic Fatty Liver Disease - physiopathology; Oxidative stress; Protein folding; Proteins; Statistical analysis; Steatosis; Transcription factors; Unfolded Protein Response; Variance analysis; Weaning; United States > US; Acetylcysteine; ER stress; Liver; Steatosis
• ISSN: 1476-511X; 1476-511X
• DOI: 10.1186/s12944-020-01274-y

Fat accumulation in the liver contributes to the development of non-alcoholic fatty liver disease (NAFLD). N-acetylcysteine (NAC) is an antioxidant, acting both directly and indirectly via upregulation of cellular antioxidants. We examined the mechanisms of liver steatosis after 12 months high fat (HF) diet and tested the ability of NAC to rescue liver steatosis. Seven-week-old C57BL/6 (B6) male mice were administered HF diet for 12 months (HF group). Two other groups received HF diet for 12 months accompanied by NAC for 12 months (HFD + NAC(1-12)) or 6 months (HFD + NAC(1-6)). The control group was fed regular diet for 12 months (CD group). Liver steatosis was more pronounced in the HF group than in the CD group after 12 month feeding. NAC intake for 6 or 12 months decreased liver steatosis in comparison with HF diet (p < 0.05). Furthermore, NAC treatment also reduced cellular apoptosis and caspase-3 expression. In the unfolded protein response (UPR) pathway, the expression of ECHS1, HSP60, and HSP70 was decreased in the HFD group (p < 0.05) and rescued by NAC therapy. With regards to the endoplasmic reticulum (ER) stress, Phospho-PERK (p-PERK) and ATF4 expression was decreased in the HF group, and only the HFD + NAC(1-12), but not HFD + NAC(1-6) group, showed significant improvement. HF diet for 12 months induces significant liver steatosis via altered ER stress and UPR pathway activity, as well as liver apoptosis. NAC treatment rescues the liver steatosis and apoptosis induced by HF diet.