Effects of silencing fisson 1 gene on mitofusion and mitochondrial membrane potential in SH-SY5Y cells induced by fluoride

Abstract

Objective To investigate the influence of inhibited gene expression of fisson 1 (Fis1) gene on the level of Fis1, mitofusin 1 (Mfn1) and mitochondrial membrane potential in SH-SY5Y cells with fluorine, to study the role of mitochondrial dynamic balance in the pathogenesis of chronic fluorosis. Methods SH-SY5Y cells were cultured in vitro, when adherent cells entered the logarithmic phase, using a group design, they were divided into four groups: blank control group (control), fluoride group [2 mmol/L sodium fluoride (NaF)], fluoride negative control group (2 mmol/L NaF+ non-specific siRNA) and the gene-silencing group (2 mmol/L NaF+ specific siRNA-Fis1). The protein expression levels of Fis1 and Mfn1 were measured by Western blotting; the mRNA expression levels of Fis1 and Mfn1 were measured by Real-time PCR; and the levels of the mitochondrial membrane potential was detected by mitochondrial membrane potential detection kit. Results Compared with control (1.37 ± 0.18, 1.00 ± 0.04; 1.57 ± 0.19, 1.00 ± 0.04; 1.00 ± 0.10), the expression levels of Fis1 protein (1.72 ± 0.04) and mRNA (1.48 ± 0.13) in fluoride group were increased, the expression levels of Mfn1 protein (0.87 ± 0.02) and mRNA (0.69 ± 0.07) in fluoride group were decreased, the level of mitochondrial membrane potential (0.76 ± 0.13) was decreased (P < 0.05). Compared with control, the expression levels of Fis1 protein (0.79 ± 0.07) and mRNA (0.06 ± 0.03) in gene-silencing group were decreased, the expression levels of Mfn1 protein (1.71 ± 0.04) and mRNA (1.52 ± 0.05) in gene-silencing group were increased (P < 0.05), the level of mitochondrial membrane potential (0.94 ± 0.01) was decreased. Compared with fluoride group, the expression levels of Fis1 protein and mRNA in gene-silencing group were decreased, the expression levels of Mfn1 protein and mRNA in gene-silencing group were increased, the level of mitochondrial membrane potential in gene-silencing group was increased (P < 0.05). Conclusion Gene expression inhibition of Fis1 gene can reduce the mitochondrial division and damage of mitochondrial membrane potential in SH-SY5Y cells induced by fluoride. Key words: Fluorine; Human brain neuroblastoma cell line; Mitochondrial membrane potential; Mfn1; Fis1