title: Epigallocatechin-3-gallate inhibits proliferation of human aortic smooth muscle cells via up-regulating expression of mitofusin 2.
abstract: Previous studies have shown that epigallocatechin-3-gallate (EGCG) inhibits the proliferation of vascular smooth muscle cells (VSMCs) via the extracellular-signal-regulated kinase (ERK1/2) and mitogen activated protein kinases (MAPKs) pathway. Mitofusin 2 (Mfn-2) also suppresses VSMC proliferation through Ras-Raf-ERK/MAPK, suggesting a possible link between EGCG, Mfn-2 and ERK/MAPK. However, the effect of EGCG on Mfn-2 remains unknown. In this study, we investigated the role of Mfn-2 in the regulation of VSMC proliferation by EGCG, and assessed the underlying mechanisms. The effects of EGCG on the proliferation of cultured human aortic smooth muscle cells (HASMCs) were observed by 5-ethynl-2-deoxyuridine (EdU) incorporation assay. Mfn-2 gene and protein levels, and Ras, p-c-Raf and p-ERK1/2 protein levels were determined by quantitative real-time polymerase chain reaction and western blotting, respectively. Mfn-2 gene silencing was achieved by RNA interference. EGCG 50 μmol/L profoundly inhibited the proliferation of HASMCs in culture, up-regulated Mfn-2, and down-regulated the expression of p-c-Raf and p-ERK1/2. Furthermore, RNA interference-mediated gene knockdown of Mfn-2 antagonized EGCG-induced anti-proliferation and down-regulation of Ras, p-c-Raf and p-ERK1/2. These results suggest that EGCG inhibits the proliferation of HASMCs in vitro largely via Mfn-2-mediated suppression of the Ras-Raf-ERK/MAPK signaling pathway.
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China; Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Zhouwu
authors.initials: Z
authors.lastname: Shu
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China; Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yu
authors.affiliation: Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Guoning
authors.initials: G
authors.lastname: Zeng
authors.affiliation: Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Molecular Biology Laboratory, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Libiao
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China. Electronic address: shuzhw@163.com.
authors.forename: Xuerui
authors.initials: X
authors.lastname: Tan
mesh_terms: D001011:Aorta / Q000166:cytology / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects*; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D015854:Up-Regulation
chemical_list: D024101:Mitochondrial Proteins; D034741:RNA, Small Interfering; D002392:Catechin; C045651:epigallocatechin gallate; D019908:Proto-Oncogene Proteins c-raf; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020558:GTP Phosphohydrolases; C470018:MFN2 protein, human
keywords: Epigallocatechin-3-gallate; Human aortic smooth muscle cell; Mitofusin 2; Proliferation; Ras-Raf-ERK/MAPK; siRNA