Effect of profilin-1 on the asymmetric dimethylarginine-induced vascular lesion-associated hypertension.

Previous studies have demonstrated that the levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, are strongly associated with hypertension, diabetes, and cardiovascular diseases. Profilin-1, an actin-binding protein, has been documented to be involved in endothelial injury and in the proliferation of vascular smooth muscle cells resulting from hypertension. However, the role of profilin-1 in ADMA-induced vascular injury in hypertension remains largely unknown. Forty healthy subjects and forty-two matched patients with essential hypertension were enrolled, and the related indexes of vascular injury in plasma were detected. Rat aortic smooth muscle cells (RASMCs) were treated with different concentrations of ADMA for different periods of time and transfected with profilin-1 small hairpin RNA to interrupt the expression of profilin-1. To determine the role of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway, RASMCs were pretreated with AG490 or rapamycin. The expression of profilin-1 was tested using real-time polymerase chain reaction (PCR) and western blot analysis. Cell proliferation was measured by flow cytometry and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazoliumbromide assays. Compared with healthy subjects, the levels of ADMA and profilin-1 were markedly elevated in hypertensive individuals, while the levels of NO were significantly decreased (p < 0.05). In vitro, studies showed ADMA-induced profilin-1 expression in a concentration- and time-dependent manner in RASMCs (p < 0.05), concomitantly with promoting the proliferation of RASMCs. Furthermore, ADMA-mediated proliferation of RASMCs and upregulation expression of profilin-1 were inhibited by blockade of the JAK2/STAT3 pathway or knockdown of profilin-1. Profilin-1 implicated in the ADMA-mediated vascular lesions in hypertension.

Involvement of profilin-1 in angiotensin II-induced vascular smooth muscle cell proliferation.

Profilin-1, a regulator of actin polymerization, has recently been linked to vascular hypertrophy and remodeling. Whether profilin-1 is involved in angiotensin (Ang) II-induced proliferation of vascular smooth muscle cells leading to vascular remodeling in hypertension remains unclear. The present study was designed to analyze the correlation of profilin-1 and vascular remodeling during hypertension and to evaluate the role of profilin-1 in proliferation of vascular smooth muscle cells and the underlying mechanisms. The vascular morphology and the expression of profilin-1 in arterial tissues of spontaneously hypertensive rats and Wistar-Kyoto rats were assessed. The profilin-1 expression was significantly increased concomitantly with definite vascular remodeling by evaluating the media thickness, lumen diameter, media thickness-to-lumen diameter ratio and mean nuclear area in artery media in spontaneously hypertensive rats, which was inhibited by treatment with losartan. In cultured rat aortic smooth muscle cells (RASMCs), Ang II induced profilin-1 expression in a dose- and time-dependent manner. Knockdown of profilin-1 using small hairpin RNA inhibited Ang II-induced proliferation of RASMCs. Moreover, blockade of JAK2/STAT3 signaling pathway also inhibited Ang II-induced proliferation of RASMCs and profilin-1 expression. These results suggest that profilin-1 mediates the proliferation of RASMCs induced by Ang II via activation of Ang II type 1 receptor/JAK2/STAT3 signaling pathway, which may contribute to vascular remodeling in hypertension.