人基质金属蛋白酶1组织抑制剂转基因小鼠肾小管间质炎症的改变

目的观察基质金属蛋白酶1组织抑制剂(TIMP-1)过表达对肾小管间质炎症反应的影响。方法采用人TIMP-1转基因小鼠和野生型小鼠(n=8)构建单侧输尿管梗阻(UUO)模型。以3 d和14 d为时间点,Masson染色观察肾组织形态学变化,间接免疫荧光法观察肾组织内F4／80阳性细胞的表达;Western印迹检测TIMP-1、TIMP-2、MMP-2、MMP-9和ICAM-1的蛋白表达,明胶酶谱法检测MMP-2和MMP-9的活性,反向酶谱法检测TIMP-1的活性。结果UUO术后肾小管间质病理损伤加重肾间质纤维化面积(46．24±6．58)％比野生型(36．33±5．12)％．P< 0．05],F4／80阳性细胞数目增加(68．9±15．6)个／视野比野生型(52．4±13．3)个／视野,P< 0．05],ICAM-1蛋白表达显著上调,术后14 d上述改变在转基因组中更为显著(P<0．05)。UUO术后TIMP-1蛋白表达及活性上调,在术后14 d达高峰,在转基因组中增加更为显著(P< 0．05)。MMP-2和MMP-9的蛋白表达及活性在术后逐渐下降,UUO术后14 d转基因组降低更为显著(P<0．05)。结论TIMP-1过表达可通过增强炎症加重肾小管间质损伤。

Significance of the changes of renal tubulointerstitial inflammation in human tissue inhibitor of metalloproteinase-1 transgenic mice after unilateral ureteral obstruction

Objective To observe the effects of TIMP-1 overexpression on renal tubulointerstitial inflammation. Methods Human TIMP-1 transgenic mice and wild-type mice were randomly divided into UUO groups and sham groups respectively and sacrificed at 3 and 14 days after UUO or sham operation(n=6, each group). Masson staining was applied to observe the renal tubulointerstitial pathological changes,and indirect immunofluorescence was applied to detect F4/80 positive cells. Western blot was applied to analyze the protein expression of TIMP-1, TIMP-2, MMP-2, MMP-9 and ICAM-1. The activities of gelatinase and TIMP-1 were detected by gelatin zymography and reverse zymography respectively. Results The degree of renal tubulointerstitial fibrosisfibrosis area:trangenes(46.24±6.58)% vs wild-type (36.33±5.12)%,P < 0.05], the number of positive F4/80 cellstrangenes(68.9±15.6) vs wild-type (52.4±13.3)cell/field,P < 0.05], and the protein expression of ICAM-1 were increased after UUO, which were more significant in transgenic group than in wild-type group at day 14 after UUO(P < 0.05). The protein expression and activity of TIMP-1 were increased significantly after UUO and with a maximum at day 14 after UUO, and were higher in transgenic group than in wild-type group(P < 0.05). The protein expression and activities of MMP-2 and MMP-9 were decreased after UUO, and were lower in transgenic group than in wild-type group at day 14 after UUO (P < 0.05). Conclusions Overexpression of TIMP-1 exacerbates renal tubulointerstitial injury by enhancing inflammation.