中文摘要：

目的：通过了解整合素连接激酶（ILK）及心肌素（myocardin）在低氧性肺动脉高压（PAH）大鼠肺组织及肺血管中的表达,探讨ILK在低氧性肺动脉高压发病机制中的作用。方法：48只SD大鼠按随机数字表法分为常氧对照组和低氧1周、2周、4周组,低氧干预大鼠置于低氧仓内,氧浓度控制在（10.5±0.5）%,每日间断低氧8h（8：00~16：00）。测定各组大鼠肺动脉平均压（mPAP）、计算右室肥厚指数[右室/（左室＋室间隔）,RV/（LV＋S）]、管壁厚度占血管外径的百分比（WT%）和管壁面积占血管总面积的百分比（WA%）;采用髓鞘碱性蛋白为底物通过液体闪烁仪测定ILK活性;实时定量PCR法测定肺动脉内ILK、糖原合成激酶3β（GSK-3β）及myocardin mRNA相对表达量;Western印迹法检测肺动脉及培养的肺动脉平滑肌细胞（PASMC）胞质内ILK、GSK-3β及myocardin蛋白相对表达量。结果：低氧2周组mPAP、右室肥厚指数、WT%、WA%均显著高于常氧对照组（均P〈0.05）,低氧4周组差异更为显著。低氧1周组肺动脉内ILK活性即明显下降达36%（P〈0.05）,低氧2周、4周组ILK活性均较常氧对照组明显降低（均P〈0.05）。低氧4周组ILK mRNA和蛋白相对表达量均显著低于常氧对照组（均P〈0.05）,myocardin mRNA和蛋白表达变化与ILK相似（均P〈0.05）,而GSK-3β的mRNA和蛋白表达量则呈相反趋势,显著高于常氧对照组（均P〈0.05）。低氧培养PASMC 24h后ILK及myocardin蛋白表达明显低于常氧对照组,而GSK-3β蛋白水平则呈相反趋势,低氧可促进其表达增加（均P〈0.05）。结论：慢性低氧引起ILK活性和表达下调,使其下游靶点GSK-3β表达上调,进而降低myocardin表达水平,可能是导致PAH形成的重要机制。

英文摘要：

Objective：To explore the expression of integrin linked kinase and myocardin in the pathogenesis of hypoxia-induced pulmonary artery hypertension（PAH）in a rat model.Method：Forty-eight Sprague-Dawley rats were randomly divided into 4groups（n=12each）.And the rats were exposed to normoxia or hypoxia for 1,2,4weeks respectively.SD rats were exposed to chronic intermittent hypoxia[PO_2：（10.5±0.5）%,8：00-16：00].Mean pulmonary arterial pressure（mPAP）,right ventricular hypertrophy（RV/（LV＋S））and the index of wall thickness of small pulmonary artery（WT%and WA%）among groups were measured.The kinase activity of ILK was measured through myelin basic protein substrate by liquid scintillation counting.Real-time quantitative Polymerase Chain Reaction was performed to quantify the relatively mRNA levels of ILK,glycogen synthase kinase-3beta（GSK-3β）,and myocardin.And western blot assay were employed to determine the relative expressions of proteins of ILK,GSK-3βand myocardin.Result：The levels of mPAP,RV/（LV＋S）,WT% and WA% were significantly higher after 2week hypoxia than those in normoxic control（all P〈0.05）.And the levels of above in 4weeks were further increased compared with normoxic control.The kinase activity of ILK was significantly decreased at 36%（P〈0.05）in 1week after hypoxia compared with normoxic control,and the levels of kinase activity in 2,4weeks were also reduce compared with normoxic control（39%,43%,all P〈0.05）.The relative expression of ILK mRNA and protein were significantly decreased after 4week hypoxia than that in normoxic control（all P〈0.05）.And the similar variation tendency were observed in myocardin（all P〈0.05）.However,the relative expression of GSK-3βmRNA and protein were significantly increased after 4week hypoxia than that in normoxic control（all P〈0.05）.In vitro,the relative protein expression of ILK and myocardin were significantly reduced by hypoxia for 24 hcompared with normoxia treatment in cultured pulmonary