Development of cystathionine gamma-lyase-specific microRNAs

The gasotransmitter role of H2S in mammalian has been extensively studied, and cystathionine gamma-lyase (CSE) is the major H2S-producing enzyme in vascular system. Dysregulation of CSE/H2S system was found in various pathophysiological conditions. MicroRNA (miRNA) and short interfering RNA (siRNA) are known to inhibit gene expression by mRNA degradation and/or translation repression. The regulation of CSE expression by miRNA and siRNA has been reported recently, but the offtarget effect of miRNA and the lower knockdown efficiency of siRNA have shadowed the application of these approaches. In the present study, we designed CSE-specific miRNAs based on the rules of miRNA–mRNA complementary and human CSE cDNA sequence. The CSE-specific miRNAs significantly inhibited CSE expression and H2S production, increased reactive oxygen species generation, and induced proliferation of human aorta smooth muscle cells (HASMCs). The designed CSE-specific miRNAs specifically targeted on CSE gene as evidenced by the direct inhibition of luciferase activity from reporter gene containing human CSE 3′-UTR sequence. The expression of other genes, such as estrogen receptor α, heme oxygenase 1, specificity protein 1, and 3-mercaptopyruvate sulfurtransferase, was not affected by the CSE-specific miRNAs. Compared with CSE-siRNAs, CSE-specific miRNAs displayed significantly higher efficacy in suppressing CSE expression and H2S production. miR-143, a highly expressed miRNA in vascular system, down-regulated the expressions of CSE as well as other genes, such as insulin-like growth factor binding protein 5 and kruppel-like factor 4. miR-143 suppressed H2S production but had no effect on HASMC proliferation. In conclusion, CSE-specific miRNAs designed in our study provide a highly effective research tool for regulating CSE expression and H2S production. These CSE-specific miRNAs have potential as being novel therapeutic agents for treating vascular disorders related to abnormal oxidative stress and SMC growth.