Angiotensin-converting enzyme 2 gene transfer attenuates neointimal formation after carotid artery ischemia-reperfusion injury in rats / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the effects of lentiviral recombinant angiotensin-converting enzyme 2 (LV-ACE2) gene transfer on the neointimal formation after carotid artery ischemia-reperfusion injury (IRI) and related mechanisms.</p><p><b>METHODS</b>IRI was induced in SD rats through the carotid artery clipping and rats were divided into IRI, IRI+LV-GFP, IRI+LV-ACE2, IRI+ paclitaxel groups (n = 10 each). Sham operated rats serve as normal control. Four weeks later, neointimal formation was observed on HE stained carotid artery sections. The protein expression of ACE2, α-SM-actin, CD31, AT1R and P-ERK were detected by immunohistochemistry.</p><p><b>RESULTS</b>(1) Carotid artery neointimal hyperplasia was readily shown in IRI group [I/M 1.517 ± 0.151 (4 weeks later) vs. 0.011 ± 0.004 (Sham), P < 0.01], which was significantly reduced in IRI+LV-ACE2 (0.71 ± 0.17) and IRI+ paclitaxel (0.89 ± 0.21) groups. (2) The growth of vascular smooth muscle cells and neovascularization were also significantly inhibited in IRI+LV-ACE2 group and the expression of α-SM-actin (5 843 ± 839 vs. 12 648 ± 1 760, P < 0.01) and CD31 [(12.40 ± 4.01)/mm(2) vs. (96.20 ± 17.79)/mm(2), P < 0.01], AT1R (1 219 ± 175 vs. 4 861 ± 545, P < 0.01) and P-ERK1/2 phosphorylation (1 040 ± 215 vs. 2 938 ± 286, P < 0.01) in the neointimal of the injury arteries in IRI+LV-ACE2 group were significantly downregulated compared to IRI group.</p><p><b>CONCLUSION</b>This data suggest that ACE2 gene overexpression is able to attenuate neointimal formation after ischemia-reperfusion injury possibly through downregulating AT1 receptor expression and signal pathway of ERK1/2 phosphorylation.</p>