缺血再灌注损伤对新生鼠肾小管上皮细胞β_1-整合素及其mRNA表达的影响

The Changes of β_1-integrin and Its mRNA Distribution in Renal Tubular Epithelial Cells During Kidney Ischemia/Reperfusion Injury in Neonatal Rats

目的 探讨新生动物肾脏缺血再灌注损伤中 β1 -整合素的变化特点。方法 建立新生大鼠不同时段的肾脏缺血再灌注模型 ,应用免疫荧光法和原位杂交法检测 β1 -整合素及其 m RNA在肾小管上皮细胞的分布和表达量。结果 1β1 -整合素在正常时主要分布在肾小管上皮细胞基底侧的细胞膜上 ;缺血 0 .5 h后其分布的变化不明显 ;再灌注 0 .5 h后 β1 -整合素开始向细胞侧壁和顶部转移 ;再灌注 2 h后这种改变最明显并伴表达的减少和肾小管结构的破坏 ,但肾小管腔中没有表达 ;从再灌注 2 4 h起开始进入恢复阶段 ,β1 -整合素逐渐重新回到基底部 ;再灌注 12 0 h后恢复阶段基本结束 ,但表达量仍低于正常。 2 β1 -整合素 m RNA主要在细胞浆中表达 ,缺血再灌注0 .5～ 2 h其表达量较正常时无减少反而有一定程度的增加 ,再灌注 2 4～ 12 0 h后仍未降至正常水平。结论 β1 -整合素在缺血再灌注时分布发生“去极化“现象并伴随表达减少 ,而其 m RNA的表达不降反升高 ,说明在缺血再灌注损伤中同时存在影响 β1 -整合素分布和其合成的因素。

Objective By studying the distribution and expression of β 1-integrin and its mRNA in renal tubular epithelial cell at different ischemia/reperfusion time phases we probe the role of β 1-integrin in I/R injury of neonatal animals. Methods The neonatal SD rat ischemia/reperfusion model was set up. Immunofluorescent staining and in situ hybridization (ISH) were used to show the distribution and expression of β 1-integrin with its mRNA in renal tubular epithelial cells and the quantities of β 1-integrin and its mRNA were counted by ImagePlus-Pro system. Results ① β 1-integrin was located at the basal plasma membrane in normal renal tubular epithelial cells. After ischemia for 0.5 h, the redistribution was not significant. After reperfusing for 0.5 h, β 1-integrin began to move onto the lateral and apex surfaces of cells. This kind of change was most apparent after reperfusion for 2 h and was accompanied with reduced expression and destruction of renal tubular. No positive dying was seen in the lumen. The regeneration started 24 hours post-ischemia. β 1-integrin was redistributed onto the basal plasma membrane. After reperfusion for 120 hours, the regeneration ended, but the expression did not gain the normal level. ② The mRNA of β 1-integrin was mainly expressed in the cell plasma. Its expression was increased while reperfusion for 0.5 h to 2 h and was still above normal level after 24 h to 120 h of reperfusion. Conclusion The distribution of β 1-integrin was “depolarized” and its expression was reduced. But the level of mRNA was raised, which indicated that during ischemia/reperfusion injury, there were mechanisms that influenced the distribution and synthesis of β 1-integrin at the same time.