25: Biochem Biophys Res Commun 2000 Dec 29;279(3):965-9

Angiotensin II increases calponin expression in cultured rat vascular smooth
muscle cells.

di Gioia CR, van de Greef WM, Sperti G, Castoldi G, Todaro N, Ierardi C,
Pieruzzi F, Stella A.

Istituto di Cardiologia, Universita Cattolica, Rome, Italy.

Angiotensin II (Ang II) action on vascular smooth muscle cells is not limited to
contraction, but includes long term effects such as hypertrophy and hyperplasia.
This implies a complex pattern of gene modulation, which remains largely
unknown. We used the mRNA differential display method to screen rat aortic
smooth muscle cells cultured with or without Ang II. We demonstrated that Ang II
induces the expression of calponin, a 34-kD protein, which has been shown to
regulate smooth muscle cell contraction and to be a marker of smooth muscle cell
differentiation. We demonstrated this induction both at gene and protein level
in vascular smooth muscle cells. Calponin mRNA was dose-dependently induced by
Ang II, with an effect still evident at 5 x 10(-9)M, and it did not require
active protein synthesis, since cycloheximide treatment did not suppress this
induction. Calponin gene expression was maximal at 3 h, while protein expression
was maximal at 8 h. Calponin expression was completely abolished by the AT1
receptor antagonist, losartan, at 1 x 10(-6)M. Our data demonstrate that Ang II
increases calponin gene expression and protein level in rat aortic smooth muscle
cells in vitro.

PMID: 11162458 [PubMed - indexed for MEDLINE]