title: Activation of receptor for advanced glycation end products induces osteogenic differentiation of vascular smooth muscle cells.
abstract: OBJECTIVE
  Vascular calcification is prevalent in patients with diabetes and chronic kidney disease. Receptor for advanced glycation end products (RAGE) and its multiple ligands have been implicated in the pathogenesis of accelerated atherosclerosis; however, little is known about the effects of RAGE activation on vascular calcification.
  
  
  RESULTS
  Cultured rat and human aortic smooth muscle cells (HASMC) were transduced with adenovirus expressing RAGE. Expression of myocardin and the SMC-marker genes was significantly repressed in these cells. RAGE activation inhibited myocardin-induced expression of the SMC genes in mouse embryonic mesenchymal C3H10T1/2 cells. Interestingly, RAGE activation induced alkaline phosphatase (ALP) expression, calcium deposition, and Msx2 expression, a crucial transcription factor for osteogenic differentiation, in HASMC. RAGE-induced osteogenic differentiation was significantly inhibited by endogenous secretory RAGE. RAGE-induced ALP and Msx2 expression was completely abrogated by DAPT, an inhibitor of the Notch signaling pathway. PD98059 (MEK inhibitor) effectively blunted RAGE-induced Notch1 and Msx2 gene expression. Simultaneous stimulation with bone morphogenetic protein 2 (BMP2) and RAGE signaling synergistically induced expressions of Msx2 and ALP in HASMC. Immunohistochemistry revealed that the human calcifying atherosclerotic plaque expressed RAGE, Notch components and Msx2. The ALP activity induced in RAGE-overexpressing HASMCs by human serum was positively correlated with the serum creatinine level, but not with phosphate and hemoglobin A1c levels.
  
  
  CONCLUSIONS
  These results indicate that activation of RAGE not only inhibits myocardin-dependent SMC gene expression, but also induces osteogenic differentiation of vascular SMC through Notch/Msx2 induction. These results provide a novel insight into the role of RAGE axis in vascular calcification.
authors.affiliation: Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suga
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Iso
authors.forename: Takehisa
authors.initials: T
authors.lastname: Shimizu
authors.forename: Toru
authors.initials: T
authors.lastname: Tanaka
authors.forename: Sho-ichi
authors.initials: S
authors.lastname: Yamagishi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Imaizumi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D050197:Atherosclerosis; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D008024:Ligands; D051379:Mice; D008809:Mice, Inbred C3H; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D061205:Vascular Calcification
chemical_list: D000469:Alkaline Phosphatase; D055396:Bone Morphogenetic Protein 2; D002118:Calcium; D006442:Glycated Hemoglobin; D008024:Ligands; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D051880:Receptors, Notch; C525718:BMP2 protein, human; C517652:hemoglobin A1c protein, human