Stretch affects phenotype and proliferation of vascular smooth muscle cells.
The exertion of periodic dynamic strain on the arterial wall is hypothesized to be relevant to smooth muscle cell morphology and function. This study has investigated the effect of cyclic mechanical stretching on rabbit aortic smooth muscle cell proliferation and expression of contractile phenotype protein markers. Cells were cultured on flexible-bottomed dishes and cyclic stretch was applied (frequency 30 cycles/min, 15% elongation) using a Flexercell Strain unit. Cyclic stretch potentiated smooth muscle cell proliferation in serum-activated cultures but not in cultures maintained in 0.5% fetal calf serum. Stretching induced a serum-independent increase of h-caldesmon expression and this effect was reversible following termination of mechanical stimulation. Strain was without effect on smooth muscle myosin or calponin expression. In cells grown on laminin stretch-induced h-caldesmon expression was more prominent than in cells cultured on collagen types I and IV, poly-L-lysine and gelatin. These data suggest that cyclic mechanical stimulation possesses dual effect on vascular smooth muscle cell phenotype characteristics since it: 1) potentiates proliferation, an attribute of a dedifferentiated phenotype; and 2) increases expression of h-caldesmon considered a marker of a differentiated smooth muscle cell state.
Birukov
K G
KG
Laboratory of Molecular Endocrinology, Russian Academy of Medical Sciences, Moscow.
Shirinsky
V P
VP
Stepanova
O V
OV
Tkachuk
V A
VA
Hahn
A W
AW
Resink
T J
TJ
Smirnov
V N
VN
D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000096:biosynthesis*; D002148:Calmodulin-Binding Proteins / Q000096:biosynthesis*; D002417:Cattle; D002448:Cell Adhesion; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016326:Extracellular Matrix Proteins / Q000494:pharmacology; D005780:Gelatin / Q000494:pharmacology; D008840:Microfilament Proteins; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism; D009218:Myosins / Q000096:biosynthesis*; D011107:Polylysine / Q000494:pharmacology; D011817:Rabbits; D013314:Stress, Mechanical; D013997:Time Factors; D000096985:Calponins
D001798:Blood Proteins; D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; D016326:Extracellular Matrix Proteins; D005780:Gelatin; D008840:Microfilament Proteins; D009218:Myosins; D011107:Polylysine; D000096985:Calponins