title: MiR-29-mediated elastin down-regulation contributes to inorganic phosphorus-induced osteoblastic differentiation in vascular smooth muscle cells.
abstract: Vascular calcification increases the risk of cardiovascular mortality. We previously reported that expression of elastin decreases with progression of inorganic phosphorus (Pi)-induced vascular smooth muscle cell (VSMC) calcification. However, the regulatory mechanisms of elastin mRNA expression during vascular calcification remain unclear. MicroRNA-29 family members (miR-29a, b and c) are reported to mediate elastin mRNA expression. Therefore, we aimed to determine the effect of miR-29 on elastin expression and Pi-induced vascular calcification. Calcification of human VSMCs was induced by Pi and evaluated measuring calcium deposition. Pi stimulation promoted Ca deposition and suppressed elastin expression in VSMCs. Knockdown of elastin expression by shRNA also promoted Pi-induced VSMC calcification. Elastin pre-mRNA measurements indicated that Pi stimulation suppressed elastin expression without changing transcriptional activity. Conversely, Pi stimulation increased miR-29a and miR-29b expression. Inhibition of miR-29 recovered elastin expression and suppressed calcification in Pi-treated VSMCs. Furthermore, over-expression of miR-29b promoted Pi-induced VSMC calcification. RT-qPCR analysis showed knockdown of elastin expression in VSMCs induced expression of osteoblast-related genes, similar to Pi stimulation, and recovery of elastin expression by miR-29 inhibition reduced their expression. Our study shows that miR-29-mediated suppression of elastin expression in VSMCs plays a pivotal role in osteoblastic differentiation leading to vascular calcification.
authors.affiliation: Department of Tissue Regeneration, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Sudo
authors.affiliation: Department of Analytical Pathophysiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Sato
authors.affiliation: Department of Tissue Regeneration, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Azechi
authors.affiliation: Department of Tissue Regeneration, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wachi
mesh_terms: D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D015536:Down-Regulation; D004549:Elastin / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010758:Phosphorus / Q000494:pharmacology*; D061205:Vascular Calcification / Q000209:etiology
chemical_list: C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D010758:Phosphorus; D004549:Elastin; D002118:Calcium