骨髓间充质干细胞通过抑制内皮细胞-间充质转分化减轻单侧输尿管梗阻模型肾脏纤维化

Bone marrow mesenchymal stem cells attenuate renal fibrosis in an irreversible model of unilateral ureteral obstruction via decreased endothelial mesenchymal transition

目的探讨骨髓间充质干细胞能否通过抑制内皮细胞-间充质转分化减轻单侧输尿管梗阻(unilateral ureteral obstruction,UUO)模型肾脏纤维化。方法健康雄性C57/BL6小鼠随机分为3组(每组18只),包括假手术组(Sham组)、单侧输尿管梗阻模型组(UUO组)及单侧输尿管梗阻模型+骨髓间充质干细胞治疗组(UUO+MSCs组)。分别于术后1 d、3 d和7 d处死,进行PAS及Masson染色观察小鼠肾间质病理形态学改变及评定肾间质损伤程度;激光共聚焦技术检测小鼠肾组织不同时间点α-SMA及CD31蛋白分布及表达,评定肾小管周围毛细血管(PTC)密度变化。结果与Sham组相比,UUO组术后3 d肾间质明显炎细胞浸润,7 d出现肾小管萎缩伴间质纤维化形成;UUO组α-SMA及CD31蛋白表达水平术后7 d显著增加及降低(P<0.05),UUO+MSCs组α-SMA蛋白表达术后7 d增加(P<0.05),CD31蛋白表达术后第3 d呈减低趋势(P>0.05)。与UUO组比较,UUO+MSCs组术后各时间点肾脏病理损伤减轻,7 d PTC密度显著增加(P<0.05),α-SMA及CD31蛋白表达水平术后7 d显著降低及增高(P<0.05)。结论骨髓间充质干细胞能够通过抑制内皮细胞-间充质转化减轻UUO模型肾脏纤维化。

Objective To explore bone marrow mesenchymal stem cells attenuate renal fibrosis in an irreversible model of unilateral ureteral obstruction （UUO） via decreased endothelial mesenchymal transition. Methods Healthy male C57/BL6 mice were randomly divided into three groups ： Sham group （ n = 18 ）, unilateral uretaral obstruction （ UUO ） group （ n = 18 ） and unilateral uretaral obstruction combined with bone marrow mesenchymal stem cells （UUO ＋ MSCs） group （n = 18） , and sacrificed on day 1, 3 and 7 after operation. PAS and Masson staining were used to observe histological changes of the mice kidneys and assess the degree of renal interstitial injury. The time-correlated protein expression and distribution of α-SMA and CD31 were measured by immunofluorescent staining, and the changes of capillary density of peritubular capillaries were assessed. Results Compared with Sham group, infiltration of inflammatory cells were found in the renal interstitium on 3 d after operation. Renal tubule atrophy and renal interstitial fibrosis were found in UUO group on 7 d after operation. The protein expression levels of α-SMA and CD31 increased and decreased respectively on 7 d after operation （P 〈 0.05 ）. The protein expression level of α-SMA increased in UUO ＋ MSCs group on 3 d after operation and increased markedly on 7 d after operation （P 〈 0.05 ）. The protein expression level of CD31 deceased on 3 d after operation. Compared with UUO group, very little structure damage was found in UUO ＋ MSCs group at the corresponding time and RTC increased on 7 d after operation （ P 〈 0. 05 ）. The protein expression levels of α-SMA and CD31 decreased and increased respectively on 7 d after operation （P 〈 0. 05 ）. Conclusion Bone marrow mesenchymal stem cells could attenuate renal fibrosis in an irreversible model of unilateral ureteral obstruction via decreased endothelial mesenchymal transition.