Zhou Jian-feng, Yuan Fa-Huan, Li Na, Yu Jun, Zhang Yao-Quan, Hou Wei-Ping
Department of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
Zhonghua Yi Xue Za Zhi. 2008 Feb 26;88(8):534-9.
To study the protective effects of metanephric mesenchymal cells (MMCs) on acute renal tubular damage and explore its possible mechanism.
MMCs were isolated and cultured from 13-day-old embryonic rats and labeled with 5-bromodeoxyuridine. Seventy-two male SD rats were randomly divided into 3 equal groups: MMC group, receiving MMC injection instantaneously when ischemia/reperfusion (I/R) renal injury was induced, I/R group, undergoing I/R to establish acute renal tubular damage models, and sham operation group. Six rats from each group were killed at different time points: 24 h, 48 h, 72 h, and 96 h later. Blood sample was collected from the vena cava inferior, to examine the serum creatinine (SCr) and blood urea nitrogen (BUN). Specimens of kidney underwent microscopy. Apoptosis was conformed by TUNEL assay. Immunohistochemistry was used to detect the protein expression of Bcl-2 and Bax. The distribution of MMCs labeled with 5-bromodeoxyuridine in kidney was observed by immunofluorescence technique.
The SCr and BUN levels in different time points of the MMC group were both significantly lower than those of the I/R group (both P <0.05), HE staining showed that pathological damage of the MMC group was less than that of the I/R group (P <0.05). TUNEL results investigated that the number of apoptosis renal tubular epithelial cells of the MMC group was (13.4 +/- 3.2/HPF), significantly less than that of the I/R group [(25.4 +/- 5.2/HPF)]. In comparison with the I/R group, there were more Bcl-2 positive cells and fewer Bax positive cells in the MMC group. BrdU-labeled MMCs began to occur in the renal tissue (60 +/- 6/HP) In the 72 h subgroup of MMC group, and number of BrdU-labeled MMCs, the 96 h subgroup was (143 +/- 8/HP), significantly higher than that of the 72 h subgroup (P<0.05).
MMCs have the ability to protect renal function in acute renal tubular damage in rats, migrate and repopulate in the I/R injured renal tubules, and inhibits renal tubular epithelial cell apoptosis. The mechanism may be involved in regulating the expression of Bcl-2 and Bax.
研究后肾间充质细胞（MMCs）对急性肾小管损伤的保护作用并探讨其可能机制。
从13日龄胚胎大鼠中分离培养MMCs并用5-溴脱氧尿苷进行标记。72只雄性SD大鼠随机分为3组，每组24只：MMC组，在诱导缺血/再灌注（I/R）肾损伤时即刻注射MMCs；I/R组，进行I/R以建立急性肾小管损伤模型；假手术组。每组分别于术后24 h、48 h、72 h和96 h处死6只大鼠。经下腔静脉采集血样检测血清肌酐（SCr）和血尿素氮（BUN）。取肾脏标本进行显微镜检查。采用TUNEL法检测细胞凋亡情况。免疫组织化学法检测Bcl-2和Bax蛋白表达。通过免疫荧光技术观察5-溴脱氧尿苷标记的MMCs在肾脏中的分布。
MMC组不同时间点的SCr和BUN水平均显著低于I/R组（均P<0.05），HE染色显示MMC组病理损伤程度低于I/R组（P<0.05）。TUNEL结果显示，MMC组肾小管上皮细胞凋亡数为（13.4±3.2/HPF），显著低于I/R组[（25.4±5.2/HPF）]。与I/R组相比，MMC组Bcl-2阳性细胞较多，Bax阳性细胞较少。在MMC组72 h亚组中，肾组织开始出现BrdU标记的MMCs（60±6/HP），96 h亚组BrdU标记的MMCs数量为（143±8/HP），显著高于72 h亚组（P<0.05）。
MMCs具有保护大鼠急性肾小管损伤肾功能的能力，可在I/R损伤的肾小管中迁移并重新分布，抑制肾小管上皮细胞凋亡。其机制可能与调节Bcl-2和Bax的表达有关。
