Premium
Selective involvement of Serum Response Factor in pressure‐induced myogenic tone in resistance arteries
Author(s) -
retailleau kevin,
toutain Bertrand,
Galmiche Guillaume,
Kauffenstein Gilles,
SharifNaeini Reza,
Mericskay Mathias,
Duprat Fabrice,
Feil Robert,
henrion daniel,
li zhenli,
Loufrani Laurent
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.817.15
Serum Response Factor (SRF) is essentiel for cellular growth, cytoskeleton and contractile homeostasis. We hypothesised that SRF deletion will affect mechanotransduction in resistance arteries. Artery from inducible smooth muscle cell‐specific SRF KO mice (SRFsmko) and their control was cannulated in an arteriograph. Mechanosensitive channels were also studied by patch clamp analysis. Pressure‐induced myogenic tone (MT) was lower in SRFsmko (5.9±2.3% of passive diameter) than in control (16.3±3.2%). This decrease was accompanied by decreased activity, sensitivity of mechanosensitive channels, and decreased filamin A, MLCK and MLC expression level. In contrast, contractions induced by Phenylephrine, thromboxane‐A2 mimetic U46619 were not modified. FAK expression and MAPK p38 phosphorylation were higher in SRFsmko than in control. Contraction induced by Phenylephrine and U46619 were more sensitive to p38 blockade. Thus, a compensatory pathway, through p38 activation, allows maintaining receptor‐dependent contraction. Endothelium (flow)‐mediated dilation was not affected by the absence of SRF. This study shows that SRF is involved in pressure‐induced myogenic tone in resistance arteries. Due to the central role of myogenic tone in vascular homeostasis this finding opens new perspectives in vascular disorders.