ABSTRACT
Objective To explore the inhibitory effects of endogenous hydrogen sulfide, a novel and important gas-eous transmitter generated in mammalian tissues mainly by cystathionine β-synthase (CBS) or cystathionineγ-lyase (CSE) on the apoptosis of the rat hepatic BRL cell line in physiological condition. Methods BRL cells were cultured, and divid-ed randomly into several groups in different phases of the experiment, including negative-siRNA (control) group, CBS siRNA (CBS 1~3) group and CSE siRNA (CSE 1~3) group, which were used to select the most efficient sequences of siRNAs at 48 or 24-hour transfection. Solution group and (CBS+CSE) siRNA group were added to detect the variation of apoptosis. The BRL cell line was observed and evaluated at 0, 4, 8, 12, and 24 hrs after siRNA transfection. When the mechanisms of the apoptosis were detected, CBS/CSE siRNAs were transfected individually or jointly into BRL cells, and compared with nega-tive-siRNA group to examine the variation. The genic and protein expression of CBS/CSE were detected by RT-PCR and Western blot assay. After transfection of CBS/CSE siRNA, the apoptosis of BRL cells was detected by Hoechst stain and flow cytometry (FCM). The mitochondrial membrane potential (MMP) changes were observed by fluorescent staining. Western blot assay was used to examine the protein expression of intracytoplasm cytochrome C (Cyt C) and cleaved-caspase 3. Re-sults CBS and CSE were observed in BRL cells. After transfection of CBS/CSE siRNA, endogenous H2S generation de-creased and the apoptosis of BRL cells increased. Accordingly, the expression of intracytoplasm-Cyt C and cleaved-caspase 3 increased. Conclusion The inhibition of endogenous H2S synthesis induced the apoptosis of BRL cells under physiologi-cal condition, which may be involved in mitochondrial pathway of apoptosis.