Effect of transplantation of mesenchymal stem cells transfected with the human receptor activity modifying protein 1 gene on post-angioplasty proliferation and apoptosis of vascular smooth muscle cells in rabbits / 中华老年医学杂志

ABSTRACT

Objective To explore the effect of transplantation of mesenchymal stem cells (MSCs) transfected with the human receptor activity modifying protein 1 (hRAMP1) gene on proliferation and apoptosis of vascular smooth muscle cells (VSMCs) after carotid balloon angioplasty was performed in rabbits with carotid atherosclerosis.Methods Density gradient centrifugation and adherent culture were carried out to obtain MSCs,which were then transinfected with an adenovirus vector carrying the hRAMP1 gene or an empty adenovirus vector.A rabbit model of atherosclerotic stenosis and balloon angioplasty was successfully established.Results were randomly divided into three groupsthe hRAMP1-MSCs group,theadipose-derived MSCs (Ad-MSCs) group and the control group.MSCs were transinfected with Ad-EGFP-hRAMP1,Ad-EGFP or PBS by transplantation into the injured carotid arteries.Homing and differentiation were assessed with MSCs harvested at 7 d.With MSCs collected at 28 d,Western blotting was used to measure the expression of the hRAMP1 target gene in the carotid artery; the neointima and media area in the injured carotid arteries were estimated; carotid artery morphology was examined with H&E staining; and the proliferation and apoptosis of VSMCs were determined by immunohistochemistry and TUNEL.Results The expression of CD31 and EGFP was found in proliferating neointima lesions at 7d in the hRAMP1-MSCs group and the Ad-MSCs group.At 28d of MSC transplantation,the level of RAMP1 significantly increased in the hRAMP1-MSCs group,compared with the Ad-MSCs and control groups [(63.0±4.9) vs.(28.3±2.5) and (27.2±7.2),all P＜0.05],but there was no differencein the RAMP1 level between the Ad MSCs group and the control group (P＞0.05).Positive expression of the α-smooth muscle antibody (α-SMA) was found in all three groups at 28 d of MSC transplantation.The thickness of the hyperplastic neointima significantly decreased in the hRAMP1-MSCs group,compared with the other two groups (P＜0.05),and was lower in the Ad-MSCs group than in the control group (P＜0.05).The expression of proliferating cell nuclear antigen (PCNA) was lower in the hRAMP1-MSCs group than in the Ad-MSCs and control groups at 28d of MSC transplantation (P ＜0.05),while the PCNA level was lower in the Ad-MSCs group than in the control group (P＜ 0.05).The VSMC apoptosis rate significantly increased in the hRAMP1-MSCs group,compared with the Ad MSCs and control groups (P＜0.05),and was the lowest in the control group (P＜0.05).Conclusions Gene-modified stem cell therapy can effectively inhibit vascular intimal hyperplasia,thereby reducing restenosis after angioplasty.