Objective To investigate the role and mechanism of EGCG on the differentiation of 3T3-L1 adipocytes into brown adipocytes.Methods 3T3-L1 adipocytes were grown and divided,and the influence of cell proliferation was detected by MTT assay with different concentrations of EGCG.3T3-L1 adipocytes were treated with different concentrations of 10,50,and 100 μmol/L of EGCG,and no treatment was done in the blank control group.AMPK inhibitor Compound C and AMPK activator AICAR were used to treat 3T3-L1 adipocytes respectively.The influence of EGCG was observed on the polarizing effect of 3T3-L1 cells with oil red O staining;the expression levels of factors related to 3T3-L1 adipocyte differentiation and browning were detected by qRT-PCR;the expression levels of proteins related to 3T3-L1 adipocyte differentiation and browning were detected by western blotting analysis;and the mit-ochondrial fluorescence was detected by Mitochondrial Green probe.Results The lipid droplets of 3T3-L1 cells de-creased with increasing EGCG levels in a concentration-dependent manner.Addition of the AMPK activator AICAR further reduced lipid droplets,whereas addition of the AMPK inhibitor Compound C reversed the lipid droplet reduc-tion.With the increase of EGCG concentration,the expression levels of PPARγ,FASNN mRNA and protein were de-creased,and the expression levels of UCP1,PGC-1α,Nrf1,Tfam,ATGL,HSL,AMPK mRNA and protein were in-creased(all P＜0.05),and this trend was further aggravated by the addition of the AMPK activator,AICAR,which could be further aggravated by the addition of the AMPK inhibitor Compound C.Fluorescence microscopy observa-tion revealed that the fluorescence intensity was significantly enhanced compared to the control group after EGCG treatment.Conclusions EGCG promotes adipocyte browning and mitochondrial biosynthesis by regulating the AMPKα/PGC-1 α signaling pathway in 3T3-L1 adipocytes.
NETL
NSTL
万方数据
