大鼠撞击性肝挫伤后MMP-2和MMP-9蛋白时序性表达

目的观察大鼠撞击性肝挫伤后不同时间肝组织中基质金属蛋白酶(matrix metalloproteinase,MMP)-2和MMP-9的蛋白表达规律。方法选取健康成年雄性SD大鼠50只,随机平均分入对照组和伤后1 h、3 h、6 h、12 h、18 h、24 h、3 d、5 d、7 d组。采用自由落体撞击法建立大鼠肝挫伤模型,在相应时间点处死大鼠,提取挫伤的肝叶,运用免疫组织化学染色法(SP法)和Western印迹法观察各组大鼠肝组织内MMP-2和MMP-9的蛋白表达情况。结果肝挫伤后,阳性细胞表达和蛋白半定量结果显示:MMP-2在伤后6 h表达开始增强,24 h达到峰值,3~5 d逐渐下降,7 d时接近正常水平,损伤6 h后各组(除18 h组)与相邻上组比较,差异均有统计学意义(P0.05);MMP-9在伤后1 h即明显上升,18 h达到高峰,3~7 d时逐渐下调,但仍高于对照组,伤后各组(除12 h、24 h组)与相邻上组比较,差异均有统计学意义(P0.05)。结论 MMP-2和MMP-9的蛋白表达在撞击性肝挫伤组织中有较好的时序性,有望作为肝挫伤的时间推断的参考指标。

Time-dependent Protein Expressions of MMP-2 and MMP-9 in Liver Contusion Rats after Impact

Objective To observe the protein expression patterns of matrix metalloproteinase (MMP)-2 and MMP-9 in the liver tissue of liver contusion rats at different time after impact. Methods Fifty healthy adult male SD rats were randomly and evenly divided into control group and experimental groups (1 h, 3 h, 6 h, 12 h, 18 h, 24 h, 3 d, 5 d, 7 d after liver contusion). A rat liver contusion model was established by a free-falling device. The rats were killed at corresponding time, and the contused hepatic lobes were extracted. The protein expressions of MMP-2 and MMP-9 in contused liver tissue of the rats in each group were observed by immunohistochemical staining (SP method) and Western blotting. Results After the liver contusion, the expression of positive cell and the protein semiquantitative result showed that the protein expression of MMP-2 enhanced at 6 h and peaked at 24 h, then decreased gradually at 3-5 d, and returned to normal levels at 7 d. The difference of expression between group and its previous adjacent group after 6 h (except 18 h) had statistical significance (P<0.05). The protein expression of MMP-9 rose obviously at 1 h after liver contusion and peaked at 18 h, then decreased gradually at 3-7 d which still higher than control group. The expression difference between group and its previous adjacent group (except 12 h and 24 h) had statistical significance (P<0.05). Conclusion The protein expressions of MMP-2 and MMP-9 in contused liver tissue after impact show good time-dependent patterns, which may provide important reference indicators for the time estimation of liver contusion.