Alpha v beta 3 and alpha v beta 5 integrins and their role in muscle precursor cell adhesion.
BACKGROUND
Functional adaptation of skeletal muscle is a requirement for different muscle groups (e.g. craniofacial, ocular and limb) to undergo site-specific changes. Such tissue remodelling depends on dynamic interactions between muscle cells and their extracellular matrix, via participation of multifunctional molecules such as integrins. In view of data suggesting a role in fundamental muscle biology and muscle development in other systems, the present study has focused on expression and function of alpha v integrins, in cultured adult human craniofacial muscle (masseter) precursor cells and myotubes, and the predominantly fibroblastic IC (interstitial cells) population.


CONCLUSIONS
Flow-cytometric phenotyping and immunofluorescence phenotyping show that alpha v, alpha v beta 3 and alpha v beta 5 are expressed in all mononuclear cells (muscle precursors and IC) seeded on muscle extracellular molecules such as gelatin, VN (vitronectin) and FN (fibronectin). In this system, blockade of alpha v activity using a function-perturbing antibody abrogates cell migration on VN and FN. alpha v integrins act predominantly as VN receptors as cell-substrate attachment is diminished when alpha v neutralizing agents are introduced into cultures seeded on VN, and this inhibition is reversible; these integrins also appear to be minor FN receptors. These results demonstrate that the alpha v subset of integrins present on both myogenic precursors and IC is an essential cohort of VN and, to a lesser extent, FN receptors mediating cell adhesion and, either directly or indirectly, arbiters of cell motility.
Sinanan
Andrea C M
AC
Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK.
Machell
Jon R A
JR
Wynne-Hughes
G Trevor
GT
Hunt
Nigel P
NP
Lewis
Mark P
MP
D000293:Adolescent; D000328:Adult; D002448:Cell Adhesion; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology*; D032446:Myoblasts / Q000737:chemistry* / Q000166:cytology*; D009924:Organ Culture Techniques; D019096:Vitronectin / Q000378:metabolism
D016326:Extracellular Matrix Proteins; D039302:Integrin alphaVbeta3; D019096:Vitronectin