高体积分数氧致慢性肺疾病新生大鼠肺泡上皮细胞紧密连接蛋白的表达及其调控作用

Expression and Regulation of Tight Junction Proteins Occludin in Alveolar Epithelia Cells in Hyperoxia Induced Chronic Lung Injury in Newborn Rats

目的探讨高体积分数氧(高氧)损伤状态下,新生大鼠肺组织内紧密连接蛋白occludin mRNA的动态变化及血小板源性生长因子(PDGFB)对其调控作用。方法新生大鼠320只。依据吸氧体积分数(FiO2)分组:实验1组(FiO2为800mL/L)、实验2组(FiO2为600mL/L)、实验3组(FiO2为400mL/L)、空气对照组(FiO2为210mL/L)。每组分别于实验第1、3、5、7、14天行肺组织occludin RT-PCR检测,同时采用免疫组织化学法检测各组肺组织PDGFB的表达。应用SPSS11.5软件进行统计学分析。结果实验1组及实验2组第1天肺组织PDGFB表达均低于空气对照组(Pa<0.05);实验1组第5、7天,实验2组及实验3组第7天肺组织PDGFB表达均高于空气对照组(Pa<0.05);实验1组第3、5、7、14天及实验2组第5、7天肺组织occludin mRNA表达均低于空气对照组(Pa<0.05);肺组织occludin基因表达与PDGFB表达呈负相关(r=-0.796P<0.001)。结论吸入高氧使新生大鼠肺组织PDGFB增加,也是改变occludin合成与分布异常导致其肺水肿可能途径之一。

Objective To explore the change of oecludin mRNA in the lung tissue under hyperoxia induced lung injury condition and their regulation of platelet - derived growth factor B （PDGFB）. Methods Three hundred and twenty newborn rats were divided into 4 groups according to different oxygen concentrations（ FiO2 ） ：experimental group l （FiO2 = 800 mL/L） ,experimental group 2 （FiO2 = 600 mL/L）, experimental group 3 （FiO2 =400 mL/L） and room -air control group （FiO2 =210 mL/L）. Rats were killed at 1^st ,3^rd ,5^th ,7^th and 14^th day respectively during the experiment ,the expression of oecladin was examined by reverse transcription polymerase chain reaction（ RT- PCR） method. The expression of PDGFB in the lung tissue was also observed by immunohistochemistry. SPSS 11.5 software was used to analyze the data. Results The expressions of PDGFB in the lung tissue in experimental group 1 and experimental group 2 were lower than those of the control group at 1th day（P~ 〈0.05）. The expressions of PDGFB in the lung tissue in experimental group 1^at ,5^th ,7^th day,and those in experimental group 2 and experimental group 3 at 7^th day were higher than that of control group （ Pa 〈 0.05 ）, compared with room - air control group, oxygen exposure could increase the expression of PDGFB. The expressions of occludin mRNA in the lung tissue at 3^rd ,5^th ,7^th , 14^th day in experimental group 1 and at 5^th ,7^th day in experimental group 2 were lower than those of control group （ Pa 〈 0. 05 ）. The expressions of occludin mRNA were negatively related to PDGFB （ r = - 0. 796 P 〈 0. 001 ）. Conclusion The increment of PDGFB expression in the lung tissues of newborn rats after oxygen exposure can be one of the mechanisms influencing the synthesis and distribution of occludin and result in pulmonary edema.