激活蛋白激酶A信号对阿霉素肾病小鼠足细胞失分化的影响
Effect of activating PKA signaling on dedifferentiation of podocytes in adriamycin-induced nephropathy mice

目的 ·探讨体内激活蛋白激酶A（PKA）对阿霉素（ADR）肾病小鼠足细胞失分化以及蛋白尿的作用。方法 ·选择6～8周龄BALB/c雄性小鼠分为3组：ADR组予以 ADR 10 mg/kg尾静脉注射构建ADR肾病小鼠模型，A+P组为ADR肾病小鼠予PKA信号激动剂pCPT-cAMP 50 mg/(kg · d)腹腔注射，对照组不做任何干预。蛋白电泳+考马斯蓝染色方法观察小鼠尿白蛋白变化，WT-1免疫组化染色观察足细胞数量，免疫荧光双染观察足细胞的损伤。结果 ·与对照组相比，ADR肾病小鼠尿白蛋白/肌酐比值显著升高，肾小球足细胞数量显著降低，足细胞特异性蛋白synaptopodin和podocalyxin表达明显下降，足细胞受损伤失分化标志蛋白desmin表达增多。pCPT-cAMP干预后ADR小鼠白蛋白/肌酐比值降低，WT-1阳性细胞和synaptopodin和podocalyxin表达增多，desmin表达减少。结论 · pCPT-cAMP激活 PKA信号后可减轻ADR肾病小鼠足细胞损伤，防止足细胞数量减少，减轻蛋白尿。其作用可能与pCPT-cAMP防止ADR肾病小鼠足细胞失分化相关。
： Objective · To explore effects of pCPT-cAMP on proteinuria and dedifferentiation of podocytes in adriamycin (ADR)-induced nephropathy mice. Methods · Male BALB/c mice were divided into three groups. The control group did not make any intervention, and the other mice were administrated with ADR in a dose of 10 mg/kg by intravenous injection (ADR group). Some ADR-injected mice were treated with pCPT-cAMP [50 mg/(kg·d)] by intraperitoneal injection everyday (A+P group). Albumin urine was detected by Coomassie blue stain. Urine creatinine concentration was estimated by ELISA. The expression of WT-1 was detected by immunohistochemical staining. Immunofluorescence staining and Western blotting were used to evulate the dedifferentiation of podocytes. Results · Compared with the control group, the ratio of urinary albumin/creatinine in ADR nephropathy mice was significantly increased. WT-1 immunohistochemical staining showed that the number of podocytes was significantly decreased, while immunofluorescence double staining of podocyte-specific protein synaptopodin and podocalyxin remarkably reduced, and the expression of desmin was increased. pCPT-cAMP intervention decreased the ratio of albumin/creatinine in ADR mice, elevated the quantity of WT-1 positive cells and the expression of synaptopodin and podocalyxin, while desmin expression decreased. Conclusion · pCPT-cAMP activates the PKA signaling and protects ADR nephropathy mice by preventing the loss of podocytes and ameliorating the urine albumin/creatinine ratio, which may be mediated by pCPT-cAMPprevented dedifferentiation of podocytes