肾外细胞在移植肾组织损伤修复中的作用

Roles of extrarenal cells in the regeneration of tissue injury in renal allografts

目的 :研究移植肾组织损伤修复过程中有无肾外来源细胞的参与。 方法 :选择两例接受女性供肾的男性肾移植病例。分别于移植后第 10天、80天和 2 0 0天行移植肾活检 ,动态观察肾组织中肾外细胞的植入情况。荧光原位杂交法 (FISH)观察Y染色体阳性细胞 (肾外细胞 )在移植肾内分布与变化。结合荧光免疫双套色 ,观察上述细胞上皮细胞标志物cytokeratin和间充质细胞标志物smoothmuscleα actin (α SMA)的表达。 结果 :移植后第 10天 ,移植肾肾小管上皮内即可见肾外细胞存在。移植后 80天 ,肾小管上皮内肾外细胞增加 ,且其中部分细胞表达cytokeratin。肾外细胞还存在于小血管壁 ,且同时表达α SMA。此外 ,这些肾外细胞亦出现于肾间质、管周毛细血管和肾小囊壁内。移植肾发生亚临床急性排斥时 ,肾外细胞在肾小管内定居减少。 结论 :在移植肾组织损伤修复的过程中有肾外细胞的参与。它们不仅出现在肾小管上皮细胞和肾组织血管壁上 ,而且表现出同原固有细胞相似的表型特征。

Objective:To evaluate the roles of extrarenal cells in the regeneration of tissue injury in renal allografts Two male patients received a kidney transplant from a female donor were chosen for this study To observe the sequential changes, renal biopsies were performed at 10 days, 80 days and 200 days after the renal transplantation All of renal tissues were examined by fluorescence in situ hybridization (FISH) to determine whether Y-chromosome-positive cells (extrarenal cells) were present in the renal allografts Then the expression of the epithelial marker (cytokeratin) or the mesenchymal marker (smooth-muscle α-actin, α-SMA) was identified in those extrarenal cells by double immunostaining At 10 days after transplantation, extrarenal cells were observed in the tubular epithelium in the renal allografts There were more such cells within the tubular epithelium at 80 days post transplantation, and some of them were positive for cytokeratin Extrarenal cells also appeared in the walls of arterioles and expressed α-SMA Meanwhile, extrarenal cells were observed in renal interstitium, peritubular capillaries, and Bowman's capsule When acute renal rejection occurred, extrarenal cells decreased in the tubular epithelium We demonstrate that the extrarenal cells are presented in the tubular epithelium and the walls of arterioles, and acquired a mature phenotype similar to those parenchymal renal cells after renal transplantation They maybe play an important role on the regeneration and remodeling of the injured tissues in renal allografts