Sodium fluoride induces apoptosis in cultured splenic lymphocytes from mice

// Huidan Deng 1,* , Ping Kuang 1,* , Hengmin Cui 1,2 , Lian Chen 1 , Jing Fang 1,2 , Zhicai Zuo 1,2 , Junliang Deng 1,2 , Xun Wang 1,2 and Ling Zhao 1,2 1 College of Veterinary Medicine, Sichuan Agricultural University, Ya’an, China 2 Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, Ya’an, China * These authors have contributed equally to this work Correspondence to: Hengmin Cui, email: // Keywords : NaF; splenic lymphocytes; apoptosis; Bcl-2 family; caspases; Immunology and Microbiology Section; Immune response; Immunity Received : June 07, 2016 Accepted : September 12, 2016 Published : September 16, 2016 Abstract Though fluorine has been shown to induce apoptosis in immune organs in vivo , there has no report on fluoride-induced apoptosis in the cultured lymphocytes. Therefore, this study was conducted with objective of investigating apoptosis induced by sodium fluoride (NaF) and the mechanism behind that in the cultured splenic lymphocytes by flow cytometry, western blot and Hoechst 33258 staining. The splenic lymphocytes were isolated from 3 weeks old male ICR mice and exposed to NaF (0, 100, 200, and 400 μmol/L) in vitro for 24 and 48 h. When compared to control group, flow cytometry assay and Hoechst 33258 staining showed that NaF induced lymphocytes apoptosis, which was promoted by decrease of mitochondria transmembrane potential, up-regulation of Bax, Bak, Fas, FasL, caspase 9, caspase 8, caspase 7, caspase 6 and caspase 3 protein expression ( P < 0.05 or P <0.01), and down-regulation of Bcl-2 and Bcl-xL protein expression ( P <0.05 or P <0.01). The above-mentioned data suggested that NaF-induced apoptosis in splenic lymphocytes could be mediated by mitochondrial and death receptor pathways.