GSTp Regulates Ang Ⅱ Induced Proliferation Of VSMCs Through JAK/STAT3 Signaling Pathways

The glutathione S-transferases (GSTs) are identified as a multi-gene family of isozymes that catalyze the nucleophilic attack of the sulfur atom of glutathione (GSH) on electrophilic groups of substrate molecules. The mammalian GSTs are divided into six classes:α,μ,ω,π,θandξ. Among these isozymes, glutathione S-transferase P1 (GSTP1, GSTπ) is the most prevalent one in mammalian cells. Here, we report that GSTP1 inhibits vascular smooth muscle cells proliferation and arrests the cell cycle at G0/G1 phase. MTT assay demonstrated that cell transfected with Xpress-GSTp plasmid increased less than cell transfected with pcDNA, stimulated by AngiotensinⅡ(P<0.01) and PDGF-BB (P<0.001). Flow cytometry analysis also showed that GSTp significantly blocked cell-cycle progression. The percentage of cells in G0/G1 phase was increased in cells transfected with GSTp compared with control group, stimulated by AngiotensinⅡand PDGF-BB. Meanwhile, GSTp prevented AngiotensinⅡ-induced phosphorylation of STAT3. Our data suggest that GSTp is a novel regulator of VSMC proliferation and cell-cycle progression, which probably exert its effects through blocking JAK/STAT3 signaling pathways.