title: Smooth muscle cells give rise to osteochondrogenic precursors and chondrocytes in calcifying arteries.
abstract: Vascular calcification is a major risk factor for cardiovascular morbidity and mortality. To develop appropriate prevention and/or therapeutic strategies for vascular calcification, it is important to understand the origins of the cells that participate in this process. In this report, we used the SM22-Cre recombinase and Rosa26-LacZ alleles to genetically trace cells derived from smooth muscle. We found that smooth muscle cells (SMCs) gave rise to osteochondrogenic precursor- and chondrocyte-like cells in calcified blood vessels of matrix Gla protein deficient (MGP(-/-)) mice. This lineage reprogramming of SMCs occurred before calcium deposition and was associated with an early onset of Runx2/Cbfa1 expression and the downregulation of myocardin and Msx2. There was no change in the constitutive expression of Sox9 or bone morphogenetic protein 2. Osterix, Wnt3a, and Wnt7a mRNAs were not detected in either calcified MGP(-/-) or noncalcified wild-type (MGP(+/+)) vessels. Finally, mechanistic studies in vitro suggest that Erk signaling might be required for SMC transdifferentiation under calcifying conditions. These results provide strong support for the hypothesis that adult SMCs can transdifferentiate and that SMC transdifferentiation is an important process driving vascular calcification and the appearance of skeletal elements in calcified vascular lesions.
authors.affiliation: Department of Bioengineering, University of Washington, Box 355061, 1705 NE Pacific St Foege N330L, Seattle, WA 98195, USA.
authors.forename: Mei Y
authors.initials: MY
authors.lastname: Speer
authors.forename: Hsueh-Ying
authors.initials: HY
authors.lastname: Yang
authors.forename: Thea
authors.initials: T
authors.lastname: Brabb
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Leaf
authors.forename: Amy
authors.initials: A
authors.lastname: Look
authors.forename: Wei-Ling
authors.initials: WL
authors.lastname: Lin
authors.forename: Andrew
authors.initials: A
authors.lastname: Frutkin
authors.forename: David
authors.initials: D
authors.lastname: Dichek
authors.forename: Cecilia M
authors.initials: CM
authors.lastname: Giachelli
mesh_terms: D000818:Animals; D001158:Arteries / Q000378:metabolism* / Q000473:pathology; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism; D002114:Calcinosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D054337:Cell Dedifferentiation / Q000235:genetics; D019902:Chondrocytes / Q000378:metabolism* / Q000473:pathology; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D000076182:Sp7 Transcription Factor; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014652:Vascular Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism; D060508:Wnt3 Protein; D060509:Wnt3A Protein
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D050659:Core Binding Factor Alpha 1 Subunit; D018398:Homeodomain Proteins; C084119:MSX2 protein; D011506:Proteins; D012333:RNA, Messenger; C493716:Runx2 protein, mouse; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D000076182:Sp7 Transcription Factor; C479466:Sp7 protein, mouse; D014157:Transcription Factors; C555510:WNT3A protein, human; D051153:Wnt Proteins; D060508:Wnt3 Protein; D060509:Wnt3A Protein; C555511:Wnt3a protein, mouse; C490508:Wnt7a protein, mouse; C039391:granuloma protein, mouse; D048049:Extracellular Signal-Regulated MAP Kinases