title: miRNA-221 and miRNA-222 synergistically function to promote vascular calcification.
abstract: Vascular calcification shares many similarities with skeletal mineralisation and involves the phenotypic trans-differentiation of vascular smooth muscle cells (VSMCs) to osteoblastic cells within a calcified environment. Various microRNAs (miRs) are known to regulate cell differentiation; however, their role in mediating VSMC calcification is not fully understood. miR-microarray analysis revealed the significant down-regulation of a range of miRs following nine days in culture, including miR-199b, miR-29a, miR-221, miR-222 and miR-31 (p < 0.05). Subsequent studies investigated the specific role of the miR-221/222 family in VSMC calcification. Real-time quantitative polymerase chain reaction data confirmed the down-regulation of miR-221 (32.4%; p < 0.01) and miR-222 (15.7%; p < 0.05). VSMCs were transfected with mimics of miR-221 and miR-222, individually and in combination. Increased calcium deposition was observed in the combined treatment (two-fold; p < 0.05) but not in individual treatments. Runx2 and Msx2 expression was increased during calcification, but no difference in expression was observed following transfection with miR mimics. Interestingly, miR-221 and miR-222 mimics induced significant changes in ectonucleotide phosphodiesterase 1 (Enpp1) and Pit-1 expression, suggesting that these miRs may modulate VSMC calcification through cellular inorganic phosphate and pyrophosphate levels.
authors.affiliation: Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.
authors.forename: N C W
authors.initials: NC
authors.lastname: Mackenzie
authors.forename: K A
authors.initials: KA
authors.lastname: Staines
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.forename: P
authors.initials: P
authors.lastname: Genever
authors.forename: V E
authors.initials: VE
authors.lastname: Macrae
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D002454:Cell Differentiation; D008297:Male; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000473:pathology; D010727:Phosphoric Diester Hydrolases / Q000235:genetics / Q000378:metabolism; D011755:Pyrophosphatases / Q000235:genetics / Q000378:metabolism; D050817:Transcription Factor Pit-1 / Q000235:genetics / Q000378:metabolism; D061205:Vascular Calcification / Q000378:metabolism* / Q000473:pathology
chemical_list: D035683:MicroRNAs; D050817:Transcription Factor Pit-1; D010727:Phosphoric Diester Hydrolases; C065962:ectonucleotide pyrophosphatase phosphodiesterase 1; D011755:Pyrophosphatases
keywords: Enpp1; calcification; miRNA; microarray; vascular smooth muscle cell