Role of Ca2+ in the effects of shear stress and TNF-alpha on caveolin-1 expression.
The aim of this work was to study the influences of Ca2+ (medium free calcium, with BAPTA, with 100 mM Ca2+, 100 mM Ca2++10 microM ionomycin) on the expression of caveolin-1 (structural protein of caveolae) of endothelial cells (ECs) submitted to mechanical forces (shear stress) or biochemical stimulation (TNF-alpha). We found that shear stress enhanced the caveolin-1 expression. Simultaneously, the caveolin-1 expression is dependant on [Ca2+]i: [Ca2+]free medium+100 microM BAPTA<[Ca2+]free medium<[Ca2+]100 mM<[Ca2+]100 mM+10 microM ionomycin. In contrast, TNF-alpha induced a decrease of caveolin-1 in the cells, whatever the [Ca2+]i. These results suggest that there could be a synergistic effect between shear stress and Ca2+ on caveolin-1 expression but an inflammatory stimulation (TNF-alpha) induces a down regulation of caveolin-1 expression.
Fawzi-Grancher
S
S
Cell and Tissue Engineering and Mechanics, LEMTA-UMR CNRS 7563, Faculté de Médecine Plateau de Brabois, 54500 Vandoeuvre lès Nancy, France.
Sun
R J
RJ
Traoré
Mariama
M
Stoltz
J F
JF
Muller
S
S
D002118:Calcium / Q000493:pharmacokinetics* / Q000494:pharmacology; D051242:Caveolin 1 / Q000235:genetics*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D013314:Stress, Mechanical; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D051242:Caveolin 1; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium