Angiotensin-converting Enzyme2Gene Transfer Attenuates Neointimal Formation After Carotid Artery Ischemia-reperfusion Injury

Objective To explore the effects of lentiviral recombinant angiotensin‐converting enzyme2gene transfer on the expression of neointimal formation after carotid artery ischemia‐reperfusion injury and related mechanism.Methods1.male250g SD rats were used in present study (10rats per group). Group CT: control; Group SHAM: Ischemia‐reperfusion sham injury; Group W1: Ischemia‐reperfusion injury+one week; Group W2: Ischemia‐reperfusion injury+two weeks; Group W4: Ischemia‐reperfusion injury+four weeks. HE stainning and computer image system were used to analyze the effect of Ischemia‐reperfusion injury on neointimal hyperplasia.2. SD rats were used to make the atherogenic model through the carotid artery clipping; The position of injury was intervented by LV‐ACE2gene; and paclitaxel treatment was acted as control. Group A: control; Group B: carotid artery Ischemia‐reperfusion injury; Group C: Ischemia‐reperfusion injury+LV‐GFP; Group D: Ischemia‐reperfusion injury+LV‐ACE2; Group E: Ischemia‐reperfusion injury+paclitaxel. HE stainning and computer image system were used to analyze the effect of gene transfection on neointimal hyperplasia. Both Van Gieson stainning and Masson stainning were used to analyze the effect of gene transfection on neointimal collagen deposition. Oil Red O staining was used to analyze the effect of gene transfection on lipid deposition. The content of plasma angiotensin II was surveyed and evaluated by the radioimmunoassay method. The transfection efficiency of lentiviral was detected according to the expression of GFP. The protein expression of ACE2、ɑ‐SM‐actin、CD31、AT1R、P‐ERK were detected by immunohistochemical.Results1. It was found that neointimal hyperplasia was significantly after carotid artery ischemia‐reperfusion injury, especially four weeks later.2. In vivo, overexpression of ACE2gene inhibited significantly neointimal formation after ischemia‐reperfusion injury.3. The content of Plasma angiotensin II was not significantly reduced by the overexpression of ACE2gene Intervention.4. According to Van Gieson stainning and Masson stainning, overexpression of ACE2gene inhibited significantly neointimal collagen deposition after ischemia‐reperfusion injury.5. According to Oil Red O staining, the content of lipid deposition was lower by the overexpression of ACE2gene.6. According to Immunohistochemistry, the gorwth of vascular smooth muscle cells and neovascularization was obviously inhibited according to the less expression of ɑ‐SM‐actin and CD31. Futher more, similar to ɑ‐SM‐actin and CD31protein expression, the protein expression of AT1receptor and signal ERK1/2phosphorylation was obviously inhibited while ACE2overexpression.Conclusion Our research suggests that the model of rat carotid artery neointimal formation was stabled and rational after carotid artery ischemia‐reperfusion injury. This data suggest that overexpression of ACE2gene was able to attenuate neointimal formation after ischemia‐reperfusion injury. The mechanism is inhibition the expression of VSMC and neovascularization by downregulating AT1receptor expression and signal pathway of ERK1/2phosphorylation. More over, overexpression of ACE2could reduce the content of neointimal collagen and lipid deposition. Therefore, it is indicating that ACE2gene transfer is a potential therapeutic approach to preventing neointimal formation after ischemia‐reperfusion injury.