gamma-linolenic-acid and Non-alcoholic-Fatty-Liver-Disease

As a primarily N6-methyladenosine methyltransferase, methyltransferase 3 (METTL3) plays a crucial role in nonalcoholic fatty liver disease. However, its regulatory mechanism in steatosis remains unknown.. Alpha mouse liver 12 (AML12) cells were induced by free fatty acids (FFA). Triglycerides, lipid droplet assay, and Oil Red O staining were performed to evaluate steatosis. The expression of METTL3 and cytochrome P450 family 4 subfamily f polypeptide 40 (CYP4F40) was measured using Western blotting, real-time quantitative polymerase chain reaction, and dual-luciferase reporter assay. Triglycerides, total cholesterol, almandine aminotransferase, and aspartate aminotransferase were assayed after cinnamaldehyde treatment. Transcriptomics and metabolomics were performed to determine how METTL3 and cinnamaldehyde regulate steatosis.. METTL3 protein level was reduced in FFA-induced steatosis in AML12 cells, and METTL3 knockdown aggravated the steatosis. Cinnamaldehyde alleviated steatosis by increasing METTL3 expression. A combined transcriptomics and metabolomics analysis revealed that METTL3 knockdown reduced CYP4F40 expression and reduced the level of capric acid, gamma-linolenic acid, arachidonic acid, and docosapentaenoic acid. Cinnamaldehyde promoted CYP4F40 expression by increasing METTL3 and increased the levels of capric acid, gamma-linolenic acid, arachidonic acid, and docosapentaenoic acid. Finally, the beneficial effects of cinnamaldehyde on steatosis were reversed after METTL3 knockdown.. METTL3 knockdown aggravated steatosis in AML12 cells through CYP4F40-mediated fatty acid metabolism, and cinnamaldehyde alleviated steatosis via the METTL3-CYP4F40 pathway.

Topics: Acrolein; Animals; Arachidonic Acids; Fatty Acids, Nonesterified; gamma-Linolenic Acid; Methyltransferases; Mice; Non-alcoholic Fatty Liver Disease; Triglycerides

Excessive fat deposition is the main character in nonalcoholic fatty liver disease (NAFLD), while γ-linolenic acid (GLA) is a polyunsaturated fatty acid that can reduce lipid deposition. This study investigated the effect and regulatory mechanism of GLA (100 μM) on lipid metabolism in alpha mouse liver 12 (AML-12) cells treated by 400 μM palmitic acid (PA). GLA reduced lipid content and increased fatty acid β oxidation, as indicated by decreasing triglyceride and cholesterol contents and increasing mRNA and protein expressions of CPT1α and PPARα. GLA relieved oxidative stress caused by PA, upregulated mRNA levels of superoxide dismutase and glutathione peroxidase, and decreased reactive oxygen species content. GLA reduced apoptosis, as indicated by decreases in the BAX/BCL2 expression level and apoptosis percentage. GLA activated autophagy, autophagosome-lysosome fusion, and LKB1-AMPK-mTOR signaling and upregulated mRNA and protein expressions of Beclin-1, autophagy-related 5, and liver kinase B1 (LKB1). These effects of GLA on lipid metabolism disorders of PA-treated hepatocytes were reversed by autophagy inhibitor 3MA and AMPK inhibitor compound C, confirming our conclusions. Overall, GLA can protect AML-12 cells from lipid metabolism disorder caused by PA via balancing autophagy and apoptosis mediated by the LKB1-AMPK-mTOR pathway. Consequently, GLA, as a dietary supplement, can help to prevent and treat NAFLD by regulating lipid metabolism and autophagy.

Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Autophagy; gamma-Linolenic Acid; Lipid Metabolism; Lipid Metabolism Disorders; Liver; Mice; Non-alcoholic Fatty Liver Disease; Palmitic Acid; TOR Serine-Threonine Kinases

Non-alcoholic fatty liver disease (NAFLD) given its association with obesity and diabetes may perhaps exert distinct free fatty acids (FFA) pattern, but the understanding of this phenomenon is limited. To this effect, we evaluated FFA profiles among healthy subjects and NAFLD patients stratified by body weight, to identify FFA valuable for early diagnosis of NAFLD.. Serum FFA profiles of healthy and NAFLD (lean, overweight and obese) subjects was determined using gas chromatography-mass spectrometry (GC-MS) and distinctions in FFA patterns were evaluated using one-way ANOVA while Receiver operating characteristics (ROC) and logistic regression models were used to explore FFA significant for diagnosing NAFLD.. NAFLD patients presented significantly higher (P < 0.05) serum FFA profiles compared to healthy controls (HC). While total FFA profiles were insignificantly different between lean (2093.33 ± 558.11 μg/ml) and overweight (2420.81 ± 555.18 μg/ml) NAFLD patients, obese NAFLD (2739.01 ± 810.35 μg/ml) presented most significantly elevated (P < 0.05) total FFA profiles compared with HC. Of the four FFA; myristic acid (14:0), palmitoleic acid (16:1), γ-linolenic acid (γ-18:3) and cis-7,10,13,16,19-docosapentaenoic acid (22:5), selected in ROC analysis given their high Youden's index and AUC, only 14:0; 5.58(1.37, 22.76) and 16:1; 4.36(1.34, 14.13) had statistical significant odd ratios.. Our findings suggest 14:0 and 16:1 are promising for early diagnosis of NAFLD.

Topics: Adult; Body Mass Index; Case-Control Studies; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Female; gamma-Linolenic Acid; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Myristic Acid; Non-alcoholic Fatty Liver Disease; Obesity; Overweight; Thinness