脐带间充质干细胞对重度烧伤大鼠肾脏保护作用的研究

目的：观察脐带间充质干细胞（UCMSCs）移植对大鼠严重烧伤后肾脏损伤的影响，为干细胞应用于烧伤后的脏器保护研究奠定基础。方法：获取并分离培养孕大鼠UCMSCs并用流式细胞技术鉴定细胞表面抗原。48只SD大鼠随机分为4组：正常对照组（n=12）、生理盐水组（n=12）、乌司他丁组（n=12）和UCMSCs组（n=12）。正常对照组不作任何处理，立即活杀取材；其余3组制备20％TBSAIII度烧伤模型（98℃，12s），于伤后48h分别静脉注射生理盐水0．1ml／g（生理盐水组）、乌司他丁1．6×105U／kg（乌司他丁组）和UCMSCs106／k（uCMSCs组），于给药后7、14d观察大鼠肾脏组织病理学，免疫组化法观察组织凋亡相关蛋白Bcl-2的表达，并进行血尿素氮（BUN）、肌酐（cr）水平的测定。结果：烧伤后7、14d的组织病理学观察显示，干细胞移植后的大鼠烧伤后肾脏组织充血、肿胀等病理学改变较乌司他丁组及生理盐水组有所减轻，随时间延长减轻更加明显；免疫组化观察显示UCMSCs组伤后7d和14d肾组织中Bcl-2的表达较乌司他丁组和生理盐水组明显增多，表明肾组织抗凋亡能力增强。大鼠烧伤后BUN和Cr均较正常对照组显著升高。乌司他丁治疗组除14dBUN较生理盐水组升高外，其余时间BUN和Cr均明显下降。UCMSCs组伤后7和14d两肾功能指标均明显下降，与生理盐水组和乌司他丁组比较差异均有显著性（P〈0．05），显示干细胞治疗对肾功能有明显改善作用。结论：UC—MSCs移植可有效减轻重度烧伤后大鼠‘肾脏组织的损伤并改善肾脏功能。

Protective effect of umbilical cord mesenchymal stem cells transplantation on kidney in rat with severe burn injury

Objective： To investigate the protective effect of umbilical cord mesenchymal stem cells （UCMSCs） transplantation on kidney against injury subsequent to full thickness burn in rat. Methods.. UCMSCs were isolated from umbilical cord of rat fetus. They were cultured, and expression of cell surface antigens （CD34, CD45, CD29, CD105） were analyzed by flow cytometry. Forty-eight SD rats were randomly divided into 4 groups： nor- mal control group （n= 12）, normal saline group （n= 12）, Ulinastatin group （n= 12） and UCMSCs group （n = 12）. Rats of normal control group received no burn injury or any treatment and rats in other groups received 20~ total body surface area of full thickness burn injury （98 ＊C ,12 seconds ）. After 48 hours, 0. 1 ml/g normal saline （normal saline group）, 1.6 ）〈 l0s U/kg Ulinastatin （Ulinastatin group） and 106/kg UCMSCs （UCMSCs group） were intravenously injected respectively. The pathological changes in kidney, the expression of apoptosis related proteins Bcl-2 were observed,and the levels of blood urea nitrogen （BUN） and creatinine （Cr） were determinated 7 days and 14 days after burn injury. Results： After 7 days and 14 days, the pathological changes in kidney including swelling and bleed- ing were improved and the expression of Bcl-2 were more obviously elevated in UCMSCs group than those of the Ulinasta- tin group and normal saline group, and the changes in improvement were parallel with passage of time （P〈0. 05）. The concentrations of BUN and BUN were increased obviously after burn, and they were lowered by Ulinastatin treatment af- ter 7 days, but BUN increased as compared with that in normal saline group after 14 days. They were lowered more sig- nificantly by UCMSCs treatment compared with those of the normal saline group and Ulinastatin group （P〈0. 05）. Conclusions： UCMSCs could alleviate the burn-induced kidney injury and prevent renal dysfunction.