title: Ceramide mediates Ox-LDL-induced human vascular smooth muscle cell calcification via p38 mitogen-activated protein kinase signaling.
abstract: Vascular calcification is associated with significant cardiovascular morbidity and mortality, and has been demonstrated as an actively regulated process resembling bone formation. Oxidized low density lipoprotein (Ox-LDL) has been identified as a regulatory factor involved in calcification of vascular smooth muscle cells (VSMCs). Additionally, over-expression of recombinant human neutral sphingomyelinase (N-SMase) has been shown to stimulate VSMC apoptosis, which plays an important role in the progression of vascular calcification. The aim of this study is to investigate whether ceramide regulates Ox-LDL-induced calcification of VSMCs via activation of p38 mitogen-activated protein kinase (MAPK) pathway. Ox-LDL increased the activity of N-SMase and the level of ceramide in cultured VSMCs. Calcification and the osteogenic transcription factor, Msx2 mRNA expression were reduced by N-SMase inhibitor, GW4869 in the presence of Ox-LDL. Usage of GW4869 inhibited Ox-LDL-induced apoptosis in VSMCs, an effect which was reversed by C2-ceramide. Additionally, C2-ceramide treatment accelerated VSMC calcification, with a concomitant increase in ALP activity. Furthermore, C2-ceramide treatment enhanced Ox-LDL-induced VSMC calcification. Addition of caspase inhibitor, ZVAD-fmk attenuated Ox-LDL-induced calcification. Both Ox-LDL and C2-ceramide treatment increased the phosphorylation of p38 MAPK. Inhibition of p38 MAPK by SB203580 attenuated Ox-LDL-induced calcification of VSMCs. These data suggest that Ox-LDL activates N-SMase-ceramide signaling pathway, and stimulates phosphorylation of p38 MAPK, leading to apoptosis in VSMCs, which initiates VSMC calcification.
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Liao
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Weikang
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences and Guangdong Cardiovascular Institute, Guangzhou, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Anesthesiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences and Guangdong Cardiovascular Institute, Guangzhou, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Meihong
authors.initials: M
authors.lastname: Ye
authors.affiliation: Department of Pathophysiolgy, Zhongshan Medical School, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Lihe
authors.initials: L
authors.lastname: Lu
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001597:Benzylidene Compounds / Q000494:pharmacology; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism* / Q000494:pharmacology; D005263:Femoral Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D061205:Vascular Calcification / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D000814:Aniline Compounds; D001597:Benzylidene Compounds; D002518:Ceramides; C468773:GW 4869; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D048051:p38 Mitogen-Activated Protein Kinases; D013108:Sphingomyelin Phosphodiesterase