Hydrogen sulfide promotes angiogenesis by downregulating miR-640 via the VEGFR2/mTOR pathway

• Published in: American Journal of Physiology: Cell Physiology 2016-02, Vol.310 (4), p.C305-C317
• Main Authors: Zhou, Yu, Li, Xing-Hui, Zhang, Cai-Cai, Wang, Ming-Jie, Xue, Wen-Long, Wu, Dong-Dong, Ma, Fen-Fen, Li, Wen-Wen, Tao, Bei-Bei, Zhu, Yi-Chun
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; Angiogenesis; Angiogenesis Inducing Agents - pharmacology; Binding Sites; Cell Movement - drug effects; Cell Proliferation - drug effects; Cells, Cultured; Down-Regulation; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - enzymology; Humans; Hydrogen sulfide; Hydrogen Sulfide - pharmacology; Hypoxia-Inducible Factor 1, alpha Subunit - genetics; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; Mutation; Neovascularization, Physiologic - drug effects; RNA Interference; Signal transduction; Signal Transduction - drug effects; TOR Serine-Threonine Kinases - genetics; TOR Serine-Threonine Kinases - metabolism; Transcription factors; Transfection; Vascular endothelial growth factor; Vascular Endothelial Growth Factor Receptor-2 - genetics; Vascular Endothelial Growth Factor Receptor-2 - metabolism
• ISSN: 0363-6143; 1522-1563
• DOI: 10.1152/ajpcell.00230.2015

We previously found hydrogen sulfide (H2S) to be a new proangiogenic factor. However, the mechanisms underlying the cardiovascular effect of this small gas molecule remain largely unknown. The aim of the present study was to identify the essential microRNAs (miRNAs) involved in the transduction of H2S signals in vascular endothelial cells (ECs). The expression of miR-640 and its signaling elements, vascular endothelial growth factor receptor 2 (VEGFR2), hypoxia inducible factor 1-α (HIF1A), and mammalian target of rapamycin (mTOR), was measured using quantitative PCR and Western blotting. Overexpression and inhibition of miR-640 were performed to clarify their roles in mediating the effect of H2S. In addition, knockdown of VEGFR2, HIF1A, and mTOR was performed using siRNAs, dominant negative mutants, or inhibitors to examine their roles in the transduction of the H2S signals. miR-640 levels decreased in vascular ECs that were treated with H2S, whereas overexpression of miR-640 blunted the proangiogenic effect of H2S. Knockdown of either VEGFR2 or mTOR blunted the downregulation of miR-640 and the proangiogenic effect induced by H2S. In addition, miR-640 bound to the 3'-UTR of HIF1A mRNA and then inhibited the expression of HIF1A. The inhibition could be recovered by treating cells with H2S. Thus we concluded that miR-640 plays a pivotal role in mediating the proangiogenic effect of H2S; H2S acts through downregulation of the expression of miR-640 and increasing the levels of HIF1A through the VEGFR2-mTOR pathway.