Lycopene alleviates Bisphenol a-induced lipid accumulation via activating the SIRT1/PGC-1α signaling in PK15 cells

Abstract

The present study sought to investigate the protective effect of Lycopene (LYC) on Bisphenol A (BPA)-induced lipid accumulation and elucidate the potential molecular mechanism. In vitro, the PK15 cells with or without LYC were exposed to BPA for 6 h to detect the lipid accumulation using Nile red’s and Oil Red O’ staining. Meanwhile, redox status, mitochondrial function, gene expression and protein levels relating to lipid accumulation were evaluated by cellular biochemical assays, immunofluorescence staining, quantitative real-time PCR (qRT-PCR) and Western blot, respectively. In addition, ROS scavenger N-acetylcysteine (NAC), SIRT1 inhibitor EX527, SIRT1 siRNA and PGC-1α siRNA were used to verify the target signaling pathways responsible for the protective effect of LYC against BPA-indcued lipid accumulation. In vivo, the twenty four male Wistar rats were randomly divided into three groups, received either BPA (50 mg/kg/day BW) or LYC (10 mg/kg/day BW) orally for 60 days. The kidney tissues were evaluated by HE’s and Oil Red O’s staining, lipid-associated genes and proteins expression were detected through qRT-PCR and Western blot. The results showed that BPA-exposed PK15 cells and rats had increased lipid droplets with elevated transcription of lipogenic factors SREBP1 and PPARγ, and down-regulated PPARα expression, and which is accompanied by redox imbalance and abnormal mitochondrial function. Conversely, LYC prevented BPA-induced lipid metabolism disorder and lipid accumulation through impeding ROS overproduction. Moreover, PK15 cells and rats exposed to BPA showed decrease in SIRT1 and PGC-1α levels, whereas LYC blocked the decrease of SIRT1 and PGC-1α protein levels. Furthermore, inhibition or silence of SIRT1 and PGC-1α abrogated the improvements of LYC on ROS generation, mitochondrial mass impairement and lipid accumulation in BPA-treated PK15 cells. Collectively, these findings indicate that SIRT1/PGC-1α signaling pathway is involved in the protective effect of LYC on BPA-induced lipid accumulation. These results also provide a potential promising therapeutic of LYC against BPA-induced lipid accumulation in kidney cells and organs.