S-propargyl-cysteine, a novel water-soluble modulator of endogenous hydrogen sulfide, promotes angiogenesis through activation of signal transducer and activator of transcription 3

Conventional revascularization strategies or drug therapies for ischemic heart disease (IHD) are designed for reperfusion of coronary arteries to salvage cardiomyocytes, but occasionally, myocardial reperfusion injury can occur because of microcirculatory dysfunction. Therefore, a more microcirculation-friendly strategy should be explored to overcome and compensate for the shortcomings of conventional strategies. In this work, we investigated the proangiogenic effect of S-Propargyl-Cysteine (SPRC), a novel water-soluble modulator of endogenous hydrogen sulfide, and elucidated the possible mechanisms involved to provide an experimental basis for angiogenesis-mediated drug therapy for IHD. SPRC promoted cell proliferation, adhesion, migration, and tube formation of primary human umbilical vein endothelial cells (HUVEC) and increased angiogenesis in the rat aortic ring and Matrigel plug models. In a mouse model of hindlimb ischemia and a rat model of myocardial ischemia, SPRC also promoted angiogenesis after ligation of the left femoral artery or coronary artery to ameliorate ischemic conditions. In primary HUVEC, STAT3 phosphorylation was significantly induced after SPRC treatment. The critical roles of STAT3 in mediating the proangiogenic effect of SPRC were confirmed by RNA interference. Co-crystallization excluded the possible direct interaction between SPRC and STAT3, whereas co-immunoprecipitation revealed an enhanced interaction between VEGFR2 and STAT3 after SPRC treatment. Meanwhile, immunofluorescence and chromatin immunoprecipitation showed that SPRC induced the nuclear translocation of STAT3, followed by transcriptional activation of downstream promoters, particularly the Vegf promoter. We present a novel STAT3-mediated mechanism in SPRC-induced angiogenesis and demonstrate the therapeutic potential of SPRC in ischemic disease through angiogenesis promotion.