Effect Of Angiotensin-converting Enzyme2Gene Transfer On The Neointimal Formation In High-fat Feeding Rats After Carotid Artery Ischemia-reperfusion Injury

Objective：The aim of this study is to establish a model for cardiovascularresearch of atherosclerosis (AS) in rats and to assess the influence of theneointimal formation through virus recombinant lentiviral vector encodingangiotensin converting enzyme gene (LV-ACE2) in high-fat feeding rats aftercarotid ischemia-rePerfusion injury (IRI).Method：70male SD rats (weighted270±20g) were randomly divided into7grouPs: normal control grouP (grouP A),control grouP (grouP B), high fat dietgrouP (grouP C), IRI grouP (grouP D), high fat diet+IRI grouP (E), high-fat diet+IRI+LV-ACE2intervention grouP (grouP F), high fat diet+LV-GFP)intervention grouP (grouP G),10in each grouP. LV-ACE2transfer was done in thecarotid artery immediately after the ischemia rePerfusion injury oPeration.High-fat diet(4%v/v) was sustained for4weeks after oPeration. Serumcholesterol (TC), triglyceride (TG) were detected at the fourth week once the ratswere killed. Transfecting efficiency was detected using fluorescence microscoPe;Neointimal hyPerPlasia was measured with HE staining. Oil red O staining wasused to observe the neointimal liPid accumulation; The level of CD68and MMP-9exPression were detected using immunohistochemical method. Results: This study found that (1) TC and TG were significantly increased ingrouP C and grouP E comPared with those in grouP A and grouP D. TC（C:A6.27±0.92vs1.38±0.31, P<0.05E:D6.21±0.84vs1.40±0.34, P<0.05,resPectively），TG（C:A1.53±0.39vs0.56±0.22，P<0.05E:D1.60±0.40vs0.49±0.20, P<0.05, resPectively), otherwise, they were significantly decreased ingrouP F vs grouP C, grouP E. TC(E:F6.21±0.84vs3.54±0.54, P<0.05resPectively), TG(1.60±0.40vs0.84±0.53, P<0.05resPectively).(2) The area ofthe neointima was significantly increased in GrouP D and grouP E, comPared withthat in grouP A and B, however, that was reduced in grouP F comPared with that ingrouP D and E (1.95±0.13vs1.30±0.12,1.19±0.75P<0.05, resPectively).(3)TheIOD value the oil red staining in grouP E was higher than that in grouP D（1710.17±81.93vs868.83±73.42,936.24±77.29P<0.01）. OD value higher thanthat of grouP D and F intervention grouP, the ratio （1710.17±81.93vs868.83±73.42,936.24±77.29P<0.01）(4)Immunohistochemical about α-SM-actin,macroPhages CD68and MMP-9,α-SM-actin in E grouP value is higher than ingrouP D and grouP F(12648.40±1760.41vs5842.19±839.42,7355.80±1211.82P<0.01). MacroPhages CD68in E grouP value is higher than in grouP D andgrouP F（4716.3117±581.45vs1478.04±91.33,1570.04±84.87, P<0.01）. MMP–9in E grouP value is higher than in grouP D and grouP F（1698.75±98.47vs864.81±41.44,1097.53±71.28, P<0.01）.Conclusion: High-fat feeding can aggravate neointimal formation after carotidischemia-rePerfusion injury,and endothelial injury is the key factor for theformation of the AS. ACE2can inhibits neointimal formation though inhibitsmooth muscle cells, macroPhages and MMP-9.