p38丝裂原活化蛋白激酶对大鼠肾脏分泌单核细胞趋化因子-1的影响

Effect of p38MAPK signal transduction pathway on monocyte chemoat tractant protein-1 expression in rats with unilateral ureteral obstruction

目的动态观察单核细胞趋化因子-1（MCP-1）在单侧输尿管结扎（UUO）大鼠肾小管的表达，探讨它与D38丝裂原活化蛋白激酶（p38MAPK）、核转录因子-κB（NF-κB）及肾损害之间的关系。方法雌性SD大鼠共36只，体质量150—170g。随机分为2组：假手术组作为对照组；手术组根据梗阻时间分3组，每组6只。皮下注射水合氯醛（4mg／kg）麻醉，开腹后结扎右侧输尿管，缝合腹腔，即制备UUO模型。假手术组开腹后不结扎输尿管，缝合腹腔。采用免疫组织化学检测NF-κB、MCP-1，Western印迹分析法检测p38MAPK的磷酸化水平和MCP-1蛋白水平，逆转录-聚合酶链反应（RT-PCR）方法检测MCP-1 mRNA的表达。光镜检查肾组织的形态改变。生化方法测定血尿素氮、血肌酐。结果与对照组比，随着梗阻时间的延长，MCP-1蛋白表达明显上调，[对照组：0．401±0．039，UUO组8h：0．894±0．137；24h：1．416±0．135；72h：1．894±0．143，与对照组相比，P〈0．05]，MC-1 mRNA表达明显上调，[对照组：50．08±3．210，UUO组8h：108．25±4．325；24h：179．34±3．237；72h：230．12±3．026，与对照组相比，P〈0．05]，同时NF-κB、p38MAPK蛋白活性增高，[p38MAPK蛋白对照组：110．65±9．734，UUO组8h：200．15±8．326；24h：272．74±7．244；72h：549．11±9．544，与对照组相比，P〈0．05]，肾小管MCP-1的表达与p38MAPK、NF-κB呈显著正相关（r=0．74、r=0．81，P〈0．01）。结论UUO大鼠肾小管MCP-1表达增加参与了UUO大鼠肾小管间质损害的发病机制；p38MAPK可能介导了NF-κB的表达，进而调节MCP-1的表达增多。

Objective To continually observe the monocyte chemoattractant protein-1 （MCP-1） expression in rats with unilateral ureteral obstruction, and to explore the relationship between MCP-1 and p38MAPK, and as well as the nuclear transcriptian factor-κB （NF-κB）. Method Thirty-six rats were randomly assigned to sham operation group （control group） and unilateral ureteral obstruction group （UUO group）. Renal tissues were examined under light microscope 8 h, 24 h and 72 h after operation. Immunhistochemistry was used to measure the expression of MCP-1 and NF-κB. RT-PCR and Western blot were employed to determine MCP-1 mRNA and p38MAPK prorein,respectively. Serum creatinine and urea nitrogen were examined with biochemistry methods. Results Compared with control group, the expression of MCP-1 mRNA in UUO group dramatically increased （control group： 0.401 ±0.039;UUO group 8 h： 0.894±0.137;24 h： 1.416±0.135;72 h： 1.894±0.14, P 〈0.05）.The expression of MCP-1 protein in renal interstitium of UUO group also markedly increased （control group： 50.08 ± 3.210. UUO group 8 h： 108.25±4.325;24 h： 179.34±3.237;72 h： 230.12±3.026, P 〈0.05）,and the expressions of NF-κB and p38MAPK in UUO group were also stimulated （p38MAPK： control group： 110.65 ± 9.734. UUO group 8 h：200.15± 8.326;24 h： 272.74± 7.244;72 h： 549.11±9.544, P 〈0.05）. There were positive correlations between MCP-1 and p38MAPK as well as NF-κB （r = 0.74, r = 0.81,P 〈 0.01）. Conclusions The increased expression of MCP-1 may participate in the injury mechanisms of renal tubulointestitium in UUO rats. The increased expression of p38MAPK may induce NF-κB expression in the tubules, and then NF-κB promotes the expressio±n of MCP-1.