title: Expression of versican isoform V3 in the absence of ascorbate improves elastogenesis in engineered vascular constructs.
abstract: A promising method to fabricate tissue-engineered blood vessels is to have cells synthesize the supportive extracellular matrix scaffold of the tissue-engineered blood vessel; however, a shortcoming of this method has been limited elastogenesis. Previously, we found that arterial smooth muscle cells (ASMCs) produced significant quantities of elastin when transduced with splice variant 3 of the proteoglycan versican (V3). In this study, we assessed whether elastogenesis and the structural properties of entirely cell-derived engineered vascular constructs could be improved by the incorporation of V3-transduced rat ASMCs. After 18 weeks of culture, V3 constructs had more tropoelastin, more elastin crosslinks, higher burst strengths, greater elasticity, and thicker collagen fiber bundles compared with empty-vector controls. The expression of elastin and elastin-associated proteins was increased in V3 and control ASMC monolayer cultures when ascorbic acid, which promotes collagen synthesis and inhibits elastogenesis, was removed from the medium. Engineered vascular constructs with ascorbate withdrawn for 14 weeks, after an initial 4-week exposure to ascorbate, exhibited increased elastin, desmosine content, elasticity, and burst strength compared with constructs exposed continuously to ascorbate. Our results show that V3 coupled with limited exposure to ascorbate promotes elastogenesis and improves the structural and functional properties of engineered vascular constructs.
authors.affiliation: The Hope Heart Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Keire
authors.forename: Nicolas
authors.initials: N
authors.lastname: L'Heureux
authors.forename: Robert B
authors.initials: RB
authors.lastname: Vernon
authors.forename: Mervyn J
authors.initials: MJ
authors.lastname: Merrilees
authors.forename: Barry
authors.initials: B
authors.lastname: Starcher
authors.forename: Elena
authors.initials: E
authors.lastname: Okon
authors.forename: Nathalie
authors.initials: N
authors.lastname: Dusserre
authors.forename: Todd N
authors.initials: TN
authors.lastname: McAllister
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Wight
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001205:Ascorbic Acid / Q000494:pharmacology*; D001807:Blood Vessel Prosthesis; D002478:Cells, Cultured; D003187:Compliance / Q000187:drug effects; D004548:Elasticity / Q000187:drug effects; D004549:Elastin / Q000096:biosynthesis* / Q000235:genetics; D024022:Fibrillar Collagens / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006025:Glycosaminoglycans / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects; D011312:Pressure; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014161:Transduction, Genetic; D053675:Versicans / Q000235:genetics / Q000378:metabolism*
chemical_list: D024022:Fibrillar Collagens; D006025:Glycosaminoglycans; D020033:Protein Isoforms; D053675:Versicans; D004549:Elastin; D001205:Ascorbic Acid