肾缺血再灌注损伤后内源性转化生长因子β1表达的动态研究

Study of expression changes of endogenous transforming factor-β1 in renal following ischemia-reperfusion injury

关键词:  转化生长因子β1  缺血再灌注损伤  肾脏  大鼠

Key words:  transforming growth factor-β1  ischemia-reperfusion injury  kidney  rat

摘要:

［目的］ 探讨鼠肾缺血再灌注发生中不同时点转化生长因子β1(TGFβ1)在肾小管上皮细胞及肾小球中的表达的动态变化。［方法］ 将SD大鼠随机分成正常对照组(假手术组)、单纯缺血组、再灌注2 h组、4 h组、12 h组、24 h组，制备双侧肾蒂夹闭模型后，腹主动脉取血测血肌酐、尿素氮，行肾脏组织病理学检查，免疫组化(SABC)法检测TGFβ1 蛋白，RT-PCR法检测TGFβ1 mRNA。［结果］ 缺血再灌注后肾脏出现病理改变，肾小管上皮细胞刷状缘脱落，管腔扩张，在12 h病理改变最重，可见管型，间质充血，炎性细胞浸润，24 h时病理改变明显减轻。缺血再灌注后肾功能出现损害并随着再灌注时间的延长而逐渐加重，尿素氮(BUN)及肌酐(Cre)在各组分别是单纯缺血组(225.62±3.05) 及( 89.36±3.97)、再灌注2 h组(280.58±4.89)及( 110.25±6.46)、4 h组(358.36±5.35)及(120.32±6.42)、12 h组(456.56±23.6)及( 148.58±2.98)，24 h组(540.24±3.08)及( 170.26±4.63)损害最重。正常肾脏组织中有少量TGFβ1 mRNA及蛋白的表达，主要在肾小管上皮细胞中，肾小球中极少量。与正常对照组TGFβ1 mRNA (0.2077±0.0114)及蛋白(0.01166±0.00104)相比，单纯缺血45 min组(0.2934±0.0411)及(0.02154±0.00135)、再灌注2 h组(0.4550±0.0351)及(0.03039±0.00357)、再灌注4 h组(0.5049±0.0168)及(0.03621±0.00447)和再灌注12 h组(0.6462±0.0249)及(0.07223±0.01290)的肾组织中表达增加，差异有显著性意义(P<0.05)；再灌注24 h组 (0.2083±0.0098)及 (0.01624±0.00119)表达基本恢复，与正常对照组比较差异无显著性意义(P>0.05)。［结论］ TGFβ1 mRNA及蛋白的表达参与了大鼠肾缺血-再灌注损伤的发生过程。

Abstract:

［Objective］To investigate expression changes of endogenous transforming factor beta-1 (TGFβ1) and its mRNA in renal tubular cell and renal glomerulus following ischemia-reperfusion in rat. ［Methods］ Healthy SD rats were divided randomly into 6 group, including: normal control group(sham-operation), ischemia for 45 min (reperfusion 0h, n=6), reperfusion 2,4,12 and 24 hr group. Renal ischemia reperfusion injury models were founded in other five groups, opened abdominal and placed atraumatic vascular champ in dual kidney pedicle for 45 minutes,followed by reperfusion 2,4,12 and 24 hr.The distribution and content changes of TGFβ1 and its mRNA in renal were observed by means of immunohistochemistry and reverse transcription polymerase chain reaction(RT-PCR). ［Results］ The pathologial change of ischemia and ischemia-reperfusion: was most serious in 12 hr. group and clearly lighten in 24 hr. TGFβ1 mRNA and protein level increased at 45 minutes after ischemia than normal control and continued to increase at 2 hours (P<0.05). TGFβ1 mRNA and protein were expressed in normal and injured renal, mainly in renal tubular cell.a small quantity in renal glomerulus. TGFβ1 mRNA and protein level increased at 45 minutes after ischemia than normal control and continue to increase at 2 hr. (P<0.05). TGFβ1 gene expression markedly increased at 4 hr. and reach the peak at 12 hr. after reperfusion compared with normal control (P<0.05).It returned to normal level after 24 hr. reperfusion. ［Conclusions］ Expression of TGFβ1 play a role in injury after ischemia-reperfusion in rat.