CIH致聋仔鼠内耳Cx26与Cx30蛋白的表达研究

Expression of Cx26 and Cx30 Proteins in the Inner Ear of Deafness Newborn Rats Induced by Intrauterine Chronic Hypoxia

目的研究宫内缺氧对仔鼠内耳听力损伤影响及内耳缝隙连接蛋白26(Cx26)和缝隙连接蛋白30(Cx30)蛋白的表达影响。方法建立宫内慢性缺氧(CIH)孕鼠模型,16只SD孕大鼠分为正常组和缺氧组,每组8只。仔鼠出生后8周,听性脑干反应(ABR)检测后再分2个亚组:正常仔鼠组、缺氧耳聋仔鼠组(各12只)。动脉血气分析各组孕鼠和仔鼠动脉血氧分压(PaO_2)和血氧饱和度(SaO_2),免疫荧光染色、蛋白质印迹法检测仔鼠内耳Cx26和Cx30蛋白表达水平。结果缺氧组孕鼠与正常组比较,PaO_2和SaO_2均显著下降(P<0.05),但比较两组孕鼠的PaCO_2、pH值,无统计学意义(P>0.05)。缺氧耳聋仔鼠组内耳组织Cx26和Cx30蛋白的表达水平明显低于正常仔鼠组(P<0.01)。结论缺氧耳聋仔鼠耳蜗组织Cx26和Cx30蛋白表达明显低于正常仔鼠,提示CIH致聋可能与Cx26和Cx30表达下降有关。

Objective This study aimed to investigate the effect of intrauterine hypoxia on hearing loss and the expression of gap junction protein 26 and 30(Cx26 and Cx30)in the inner ear of newborn rats.Methods The model of pregnant SD rat with intrauterine chronic hypoxia(CIH)was established.Sixteen pregnant rats were divided into normal group and hypoxia group,with 8 rats in each group.After 8 weeks of birth,the auditory brainstem response(ABR)was used to detect the auditory function of newborn rats,then the offspring were further divided into two subgroups,normal fetal mouse group and hypoxia-deafness group,12 rats in each.Arterial blood gas analysis was used to analyze arterial oxygen partial pressure(PaO2)and blood oxygen saturation(SaO2)in pregnant and neonatal rats.Immunofluorescence staining and Western blotting were used to detect the expression of Cx26 and Cx30 proteins in the inner ear of neonatal rats.Results Arterial blood gas analysis of pregnant rats showed that the PaO2 and SaO2 of the pregnant rats in the hypoxia group were significantly lower than those in the normal group(P<0.05),but the PaCO2 and pH values of pregnant rats in the two groups were not statistically significant(P>0.05).The expression of Cx26 and Cx30 proteins in hypoxic deafness group was significantly lower than that in normal group(P<0 01).Conclusion The expression of Cx26 and Cx30 proteins in cochlea of hypoxic deafness newborn rats is lower than that in normal newborn rats,indicating that CIH-induced deafness may be related to the decrease of Cx26 and Cx30 proteins’expression.