title: Resident phenotypically modulated vascular smooth muscle cells in healthy human arteries.
abstract: Vascular interstitial cells (VICs) are non-contractile cells with filopodia previously described in healthy blood vessels of rodents and their function remains unknown. The objective of this study was to identify VICs in human arteries and to ascertain their role. VICs were identified in the wall of human gastro-omental arteries using transmission electron microscopy. Isolated VICs showed ability to form new and elongate existing filopodia and actively change body shape. Most importantly sprouting VICs were also observed in cell dispersal. RT-PCR performed on separately collected contractile vascular smooth muscle cells (VSMCs) and VICs showed that both cell types expressed the gene for smooth muscle myosin heavy chain (SM-MHC). Immunofluorescent labelling showed that both VSMCs and VICs had similar fluorescence for SM-MHC and αSM-actin, VICs, however, had significantly lower fluorescence for smoothelin, myosin light chain kinase, h-calponin and SM22α. It was also found that VICs do not have cytoskeleton as rigid as in contractile VSMCs. VICs express number of VSMC-specific proteins and display features of phenotypically modulated VSMCs with increased migratory abilities. VICs, therefore represent resident phenotypically modulated VSMCs that are present in human arteries under normal physiological conditions.
authors.affiliation: Pharmacology and Cell Physiology Research Group, Division of Biomedical Sciences, St. George's, University of London, London, United Kingdom. mharhun@sgul.ac.uk
authors.forename: Maksym I
authors.initials: MI
authors.lastname: Harhun
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Huggins
authors.forename: Kumaran
authors.initials: K
authors.lastname: Ratnasingham
authors.forename: Durgesh
authors.initials: D
authors.lastname: Raje
authors.forename: Ray F
authors.initials: RF
authors.lastname: Moss
authors.forename: Kinga
authors.initials: K
authors.lastname: Szewczyk
authors.forename: Georgios
authors.initials: G
authors.lastname: Vasilikostas
authors.forename: Iain A
authors.initials: IA
authors.lastname: Greenwood
authors.forename: Teck K
authors.initials: TK
authors.lastname: Khong
authors.forename: Andrew
authors.initials: A
authors.lastname: Wan
authors.forename: Marcus
authors.initials: M
authors.lastname: Reddy
mesh_terms: D000199:Actins / Q000378:metabolism; D001158:Arteries / Q000166:cytology*; D015415:Biomarkers / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D003599:Cytoskeleton; D005260:Female; D006801:Humans; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D010641:Phenotype; D000096985:Calponins
chemical_list: D000199:Actins; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D009219:Myosin-Light-Chain Kinase; D000096985:Calponins