摘要
目的观察腺苷1型受体（adenosine A1 receptor，A1AR）在1型糖尿病（diabetes mellitus，DM）小鼠模型早期肾小管megalin表达下调中的作用。方法选取周龄、基线体重及空腹血糖匹配的野生型C57BL／6J小鼠，实验前适应性饲养1周后随机分2组，对照组（n=6）和野生型DM组（n=6），另外同样方法选取雄性A1AR基因敲除C57BL／6J小鼠作为A1AR-/-DM组（n=6），通过腹腔注射链脲菌素建立1型DM模型，测定4周时血糖、体重及肾重量；代谢笼收集24h尿液测定尿总蛋白及尿白蛋白肌酐比；观察肾脏病理改变；免疫组化检测。肾脏megalin表达；Western印迹法检测肾脏组织caspase-1、IL-18及MAR的蛋白表达。结果4周时野生型DM组小鼠的血糖、体重、肾质量及尿白蛋肌酐比均显著高于对照组（P〈0．01）；肾脏病理表现为肾小球体积增大、系膜细胞增生、细胞外基质增多和肾小管肥大；位于近端小管刷状缘上的大分子多配体糖蛋白megalin表达显著降低并与24h尿蛋白量呈负相关（r=-0．645，P〈0．01）；野生型DM组小鼠caspase-1、IL-18及A1AR表达显著高于对照组（P〈0．05）。A1AR-/-DM组小鼠蛋白尿更重，肾脏病理损害更重，megalin降低更为显著，并伴有caspase．1更显著的增加。结论MAR在糖尿病小鼠肾病早期megalin表达中具有一定保护作用，机制可能与caspase一1焦亡信号通路相关，具体机制尚需进一步探索。
Objective To observe the effect of adenosine A1 receptor （A1AR） on the megalin defect in type 1 diabetic mice with early kidney disease. Methods 7- 8 week-old, baseline body weight and fasting blood glucose matched wild type （WT） C57BL/6J mice were selected, and randomly divided into two groups： control group （n=6） and WT DM group （n=6）. In the same way, male A1AR knock-out C57BL/6J mice were selected as A1AR~ DM group （n=6）. DM model was established by intraperitoneal injection of streptozocin. The blood glucose （BG）, body weight （BW）, kidney weight （KW）, 24 h proteinuria （24hUP） and albumin creatine ratio （ACR） were measured at 4 weeks. The renal pathological lesion was observed and the expression of megalin in proximal tubules was examined by immunohistoehemistry. The expression of easpase- 1, IL- 18 and A1AR were detected by Western blotting. Results At 4th week, compared with WT control mice, the BG, BW, KW and 24hUP of WT DM mice were increased significantly （n=6, P 〈 0.01）, with the pathological glomerular enlargement, mesangial cell proliferation, extracellular matrix accumulation and renal tubule hypertrophy being observed. Immunohistochemistry revealed decreased expression of megalin, an important muhiligand protein receptor on the brush border of proximal tubular epithelial cells in WT DM mice, which was correlated with 24hUP （r=-0.645, P 〈 0.01）. Compared with the control mice, the expressions of caspase-1, IL-18 and A1AR were significantly increased in WT DM mice （P 〈 0.05）. For A1AR-/- DM mice, more serious pathological lesion and megalin defect, together with increasing of casapase- 1 and heavier proteinuria were observed than those in WT DM mice. Conclusion A1AR may play a protective role in megalin expression of diabetic mice with early kidney disease, in which the mechanism may be associated with caspase-1 related pyroptosis pathway. The details need further exploration.
出处
《中华肾脏病杂志》
CAS
CSCD
北大核心
2017年第2期120-125,共6页
Chinese Journal of Nephrology
基金
国家自然科学基金（81470937）
国家重点基础研究发展计划（973项目）（2012CB517803）
中国医学科学院协和学者基金
中国医学科学院医学与健康科技创新工程（2016-12M-2-004）
