摘要目的 探讨慢病毒介导血管内皮生长因子165(VEGF165)转染的内皮祖细胞(EPCs)移植在大鼠急性肺损伤(ALI)中的保护作用.方法 分离培养雄性SD大鼠单核细胞获得EPCs备用.构建携带人VEGF165基因的慢病毒载体.按随机数字表法将90只雄性SD大鼠分为ALI模型组、磷酸盐缓冲液(PBS)组、EPCs干预组、空载质粒EPCs干预组、VEGF165转染EPCs干预组,每组再分为4、12、48 h 3个时间点亚组,每个亚组6只.经尾静脉注射0.15 μL/g油酸建立大鼠ALI模型;各干预组经尾静脉相应给予PBS、EPCs、空载质粒EPCs和VEGF165转染EPCs各0.2 mL(含细胞数1×106).分别于各时间点取大鼠腹主动脉血进行血气分析;取左肺组织计算肺湿/干重比值(W/D),用酶联免疫吸附试验(ELISA)检测肺组织诱导型一氧化氮合酶(iNOS)、内皮素-1(ET-1)、VEGF165表达;苏木素-伊红(HE)染色后,光镜下观察肺组织病理学改变并进行肺损伤评分.结果 与ALI模型组比较,EPCs、空载质粒EPCs和VEGF165转染EPCs治疗组4 h开始动脉血氧分压(PaO2)明显升高,肺W/D比值及肺组织iNOS和ET-1表达均明显下降,VEGF165表达明显升高.与EPCs干预组比较,VEGF165转染EPCs干预组PaO2升高、肺W/D比值及肺组织iNOS和ET-1表达下降、以及VEGF165表达升高均随时间延长更加显著〔4 h:PaO2(mmHg,1 mmHg=0.133 kPa)为82.84±10.69比72.34±9.36,肺W/D为4.83±0.23比5.55±0.37,iNOS(ng/mg)为8.77±1.10比14.84±1.34,ET-1(ng/mg)为103.41±5.66比153.08±5.12,VEGF165(ng/mg)为130.56±12.16比83.03±5.95;12 h:PaO2(mmHg)为91.67±6.81比78.50±8.81,肺W/D比值为4.44±0.35比5.32±0.25,iNOS(ng/mg)为7.23±0.24比14.04±1.18,ET-1(ng/mg)为91.98±3.52比125.99±7.55,VEGF165(ng/mg)为164.49±5.71比96.61±6.12〕;48 h个别指标达到谷值或峰值〔肺W/D:4.26±0.30比4.89±0.15,iNOS(ng/mg):5.79±0.85比12.72±1.10,ET-1(ng/mg):74.53±7.10比108.33±5.84,VEGF165(ng/mg):237.43±10.79比134.24±11.99,均P<0.05〕.随时间延长,各组肺组织损伤逐渐加重,肺损伤评分逐渐升高,48 h EPCs、空载质粒EPCs和VEGF165转染EPCs干预组肺损伤评分已明显低于ALI模型组,且VEGF165转染EPCs干预组评分低于EPCs干预组(分:8.50±1.05比10.50±1.05, P<0.05).结论 慢病毒介导VEGF165转染的EPCs移植可明显改善ALI大鼠的氧合,减轻肺水渗出,降低肺组织iNOS、ET-1表达,从而对肺组织起到明显保护作用.

abstractsObjective To investigate the protective effects of vascular endothelial growth factor-165 (VEGF165) transfected the endothelial progenitor cells (EPCs) mediated by lentivirus on acute lung injury (ALI) in rats. Methods The mononuclear cells from the male Sprague-Dawley (SD) rats were isolated and cultured to get the EPCs for study. The lentivirus vector carrying the human VEGF165 gene was constructed. According to the random number table method, 90 male SD rats were divided into ALI model group, phosphate buffer solution (PBS) group, EPCs treatment group, none transfected EPCs treatment group and VEGF165 transfected EPCs treatment group, and the rats in each group were subdivided into 4, 12 and 48 hours subgroups, with 6 rats in each subgroup. The rat model of ALI was reproduced by intravenous injection of oleic acid (0.15 μL/g). Then each treatment group was given PBS, EPCs, none transfected EPCs and VEGF165 transfected EPCs respectively with the same volume of 0.2 mL. For the groups with cells, about 1×106cells were contained. Abdominal aortic blood and lung tissue were harvested at 4, 12 and 48 hours. Arterial blood gas analysis was performed. The lung wet/dry weight ratio (W/D) was calculated. The expressions of induced nitric oxide synthase (iNOS), endothelin-1 (ET-1) and VEGF165 were determined by enzyme-linked immunosorbent assay (ELISA). After dyed with hematoxylin-eosin (HE), the lung tissue pathology was observed and the lung injury score was performed. Results Compared with the ALI model group, the arterial partial pressure of oxygen (PaO2) in EPCs, none transfected EPCs and VEGF165 transfected EPCs treatment groups was significantly increased from 4 hours, and lung W/D, expressions of iNOS and ET-1 were significantly decreased, and VEGF165 expression was significantly increased. Compared with the EPCs treatment group, the increase in PaO2, the decrease in lung W/D and expressions of iNOS and ET-1, and the increase in VEGF165 expression in VEGF165 transfected EPCs treatment group were more significant [4 hours: PaO2(mmHg, 1 mmHg = 0.133 kPa) was 82.84±10.69 vs. 72.34±9.36, lung W/D ratio was 4.83±0.23 vs. 5.55±0.37, iNOS (ng/mg) was 8.77±1.10 vs. 14.84±1.34, ET-1 (ng/mg) was 103.41±5.66 vs. 153.08±5.12, VEGF165 (ng/mg) was 130.56±12.16 vs. 83.03±5.95; 12 hours: PaO2(mmHg) was 91.67±6.81 vs. 78.5±8.81, lung W/D ratio was 4.44±0.35 vs. 5.32±0.25, iNOS (ng/mg) was 7.23±0.24 vs. 14.04±1.18, ET-1 (ng/mg) was 91.98±3.52 vs. 125.99±7.55, VEGF165 (ng/mg) was 164.49±5.71 vs. 96.61±6.12]; individual parameters reached valley value or peak value at 48 hours [lung W/D ratio was 4.26±0.30 vs. 4.89±0.15, iNOS (ng/mg) was 5.79±0.85 vs. 12.72±1.10, ET-1 (ng/mg) was 74.53±7.10 vs. 108.33±5.84, VEGF165 (ng/mg) was 237.43±10.79 vs. 134.24±11.99, all P < 0.05]. Over time, lung tissue injury in each group was gradually increased, and the lung injury score was gradually increased. The lung injury score at 48 hours in the EPCs, none transfected EPCs and VEGF165 transfected EPCs treatment groups were lower than that in the ALI model group. Compared with the EPCs treatment group, the VEGF165 transfected EPCs treatment group had a lower score at 48 hours (8.50±1.05 vs. 10.50±1.05, P < 0.05). Conclusion The transplantation of EPCs which were transfected with VEGF165 mediated by lentivirus could obviously improve the oxygen pressure, reduce the lung water seepage, decrease the iNOS and ET-1 expressions in lung tissue, and had obvious protective effects on ALI.