慢性肾衰竭肺组织水通道1、5表达降低诱导肺损伤形成

The formation of lung injury induced by expressive reduction of aquaporin 1、5 in mice with chronic renal failure

目的 探讨水通道蛋白1、5在慢性肾功能衰竭小鼠肺组织中表达水平的变化及影响.方法 选用6～8周龄,雄性BALB/c小鼠,将小鼠分为正常组（N）、假手术组（S）和慢性肾功能衰竭模型组（CRF）.CRF模型小鼠通过对其右肾2/3肾皮质透热毁损,并在1周后将左肾完全切除的方法建立.假手术组小鼠只进行麻醉和手术切口,肾脏不做处理.正常组的小鼠不做任何处理.模型建立后10、40和70d三个时间点每组各处死5只小鼠,并留取小鼠的肾脏、血清和肺脏标本.检测三组小鼠的肾组织病理、血清肌酐和尿素氮、肺组织干湿比及肺组织病理;用Western Blotting及RT-PCR方法测定在造模后10、40和70d三组小鼠的肺组织内水通道蛋白1（AQP1）、水通道蛋白5（AQP5）及其mRNA的表达.结果 CRF模型组在造模后10d肾组织病理结果显示部分肾小囊扩张,球囊粘连,肾小管上皮细胞颗粒样变性.造模后40、70d表现为部分肾小球纤维化和增生硬化,部分肾小管萎缩.在三个时间点CRF模型组血肌酐和尿素氮与正常组和假手术组相比均显著升高（P＜0.05）,肺组织干湿比明显下降（P＜0.05）,提示肺水含量增加,肺组织病理学检查提示肺泡及肺间质水肿.Western Blotting检测肺组织AQP1、AQP5的表达,CRF模型组与正常组相比,在造模后10d肺组织中AQP1的表达下降了48％,40d AQP1表达下降了15％,70d AQP1表达下降了37％（P＜0.05）.AQP5在造模后10d肺组织中表达下降了26％,40d表达下降了67％（P＜0.05）,造模后70d表达下降了25％（P＜0.05）.在造模后10、40和70d RT-PCR检测小鼠的肺组织AQP1、5 mRNA的表达水平结果显示,慢性肾功能衰竭模型组与正常组和假手术组相比,AQP-1、5 mRNA表达明显下降（P＜0.05）.在造模后40、70d,AQP-1、5 mRNA表达水平在假手术组的表达量与正常组比较均无显著性差异.结论 CRF模型小鼠肺组织水含量明显增加,而其AQP1和AQP5及其mRNA的表达较正常组和假手术组明显下降,水通道蛋白1、5的表达变化可能诱导了慢性肾功能衰竭小鼠以肺水肿为特点的肺损伤。

Objectives To discuss the expression levels of aquaporin 1、5 in mice lung tissue induced by chronic renal failure.Methods We selected BALB/c mice and divided then into three groups randomly：the normal group,the sham operation group and the chronic renal failure group using renal cortical diathermy.Five mice in each group were sacrificed in 10 days,40 days and 70 days after modeling.We got serum specimens,lungs and kid neys.Serum creatinine,blood urea nitrogen,lung and kidney tissue pathology were detected,and western blotting were used to determine the AQPs and their mRNA expression in lung of mice.Results Prompted renal tubular and glomerular fibrosis were detected in histopathologic findings in the chronic renal failure group in 70 days after modeling,and serum creatinine and urea nitrogen in the chronic renal failure group increased significantly,Dry/wet ratio of lung tissue reduced significantly,compared with the normal group and the sham group（P 〈0.05） in 10 days,40 days and 70 days after modeling.The results of western blotting showed that the lung AQP1 expression in the model group reduced 48% （0.40 ± 0.02 vs 0.76 ± 0.05,P 〈 0.05） in 10 days after modeling,15 % （0.62 ± 0.01 vs 0.73 ± 0.04,P 〈 0.05） in 40 days after modeling,and 37% （0.50 ± 0.02 vs 0.79 ± 0.01,P 〈 0.05） in 70 days after modeling,compared with the control groups;The lung AQP5 expression in the model group reduced 26% （0.96 ±0.02 vs 1.30 ±0.03,P 〈0.05） in 10 days after modeling,67% （0.56 ±0.02 vs 1.71 ±0.04,P 〈0.05） in40 days after modeling,and 25 % （1.05 ± 0.03 vs 1.40 ± 0.05,P 〈 0.05） in 70 days after modeling.The lung AQP1、5 mRNA expression in the model group reduced significantly compared with the normal group and the sham operation group in 10days,40days and 70days after modeling（P 〈 0.05）.Conclusions The expression of AQP1、5 in lung tissue of the chronic renal failure mice decreased compared with the normal group and the sham group which may be related with the incidence of pulmonary edema of chronic renal failure mice.