Iso-15:0 Alleviates Palmitic Acid-induced Fat Deposition In Hepatocytes By Promoting Autophagy

The global incidence of non-alcoholic fatty liver disease or metabolism-related fatty liver(NAFLD or MAFLD,MAFLD will be used thereafter)is on the rise,but its pathogenesis has not been clarified completely and there is no specific drug treatment.Autophagy plays an important role in lipid accumulation in hepatocytes.Branched chain fatty acids(BCFA)are active components in food,which have several activities including modifying biofilm fluidity,anti-tumor,anti-cancer,anti-inflammation,etc.However,the mechanism of BCFA in lipid deposition in hepatocytes is still unclear.Therefore,the purpose of this study is to explore the role of BCFA in autophagy-mediated hepatocellular fat deposition,so as to provide an experimental basis for the development of anti-MAFLD drugs or functional food.Normal mouse liver cells Am L-12 were cultured.Palmitic acid(PA,0.6mmol/L)was used to induce the cellular fat accumulation,and cells were treated with 0,0.2,0.4mmol/L iso-15:0(a typical BCFA)with/without autophagy inhibitor 3-MA,and intracellular TG was detected by Oil Red O staining and commercial kits.The levels of autophagy-related factors P62,LC3 B,Atg5 and Atg7 were measured by Western Blotting.The m RNA expressions of SREBP-1c,PPARa,ACC,FAS,CPT1 and ACO were detected by q PCR.The results showed that :(1)the intracellular TG level was significantly increased by palmitic acid induction compared with blank controls,while the iso-15:0 treatment alleviated the palmitic acid-induced fat deposition compared with PA induced cells.(2)the protein levels of P62 in hepatocytes treated with palmitic acid increased significantly compared with other groups,while that of LC3 B and Atg7 decreased significantly.Compared to the PA induced group,Atg7 and Atg5 protein levels were significantly increased in the iso-15:0 group,and LC3 B levels were significantly increased compared with the PA group.(3)compared with the blank control group,the m RNA abundance of key fatty acid synthesis factors SREBP-1c,ACC and FAS increased significantly in the PA group,while the m RNA abundance of key fatty acid synthesis factors PPARa,ACO and CPT1 decreased significantly.Compared with the PA group,the iso-15 treatment down-regulated the m RNA expression of SREBP-1c,ACC and FAS,and up-regulated the m RNA expression of PPARa,ACO and CPT1.Our data indicated that iso-15:0 could alleviate the fat deposition in vitro by enhancing autophagy,up-regulating the expression of fatty acid decomposition genes and down-regulating the expression of fatty acid synthesis genes.