Role of silent mating type information regulation 2 homolog 1 on lipopolysacchride-induced mitochondrial injury in insulinoma cell lines-1 / 中华急诊医学杂志

ABSTRACT

Objective To investigate the role of silent mating type information regulation 2 homolog 1(SIRT-1) in lipopolysaccharide (LPS)-induced mitochondrial injury on INS-1(insulinoma cell lines-1)cells. Methods INS-1 cells were divided into 5 groups control group, 1 mg/L LPS group, LPS group with 10 μmol/L RSV (resveratrol) pretreatment for 1 h, LPS group with 20 μmol/L EX527 pretreatment for 1 h, LPS group together with EX527 pretreatment for 1 h, then incubated these INS-1 cells with RSV and LPS for 24 h. The cell viability and ATP generation were detected, then total, cytoplasmic and mitochondrial protein were isolated from INS-1 cells. The protein expression of SIRT1, TLR4, acetylated FoxO1, and cytochrome C (CytC), Mfn1 (mitofusion1), Mfn2 (mitofusion2), and Fis1 (fission1) were tested by Western-blot. Mfn1, Mfn2, and Fis1 genes expression were detected by real-time PCR. The comparison of multiple groups was performed by one-way ANOVA. LSD-t method was used to compare between every two groups. Results After 1 mg/L LPS stimulation for 24 h, there was decreased cell viability (n=4, F=13.98, P<0.01) and ATP generation (n=4, F=27.92, P<0.05) in INS-1 cells. RSV pretreatment could maintain ATP production, but it could not reverse the EX527-induced ATP decrease (P>0.05). Furthermore, RSV upregulated gene and protein expression of SIRT1, Mfn1 and Mfn2, whereas decreased TLR4 and Fis1 expression. LPS-induced CytC released to cytoplasm was alleviated by RSV (P<0.01), but there was no significant change about FoxO1 protein expression (P>0.05). Conclusions RSV may regulate FoxO1 acetylation followed by its effects on SIRT1 activity, which may be partly the mechanism of mitochondrial damage induced by LPS on INS-1 cells.