Yuan Fang, Liu Ying-Hong, Liu Fu-You, Peng You-Ming, Tian Jun-Wei
Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R. China.
Mol Med Rep. 2014 Jun;9(6):2293-300. doi: 10.3892/mmr.2014.2133. Epub 2014 Apr 9.
The present study investigated the potential effects of the long-term expression of exogenous adiponectin (ADPN) on normal and diabetic kidneys. Type 2 diabetes mellitus models were induced by high-lipid and high-sucrose feeding plus intraperitoneal injection of streptozotocin. The recombinant plasmid pIRES2-EGFP-gAd, which is able to co-express globular ADPN (gAd) and enhanced green fluorescent protein (EGFP), was intraperitoneally injected into rat models mediated by Lipofectamine. In total, 32 Wistar rats were randomly assigned into four groups: the normal control group, the diabetes group, the diabetes group treated with pIRES2-EGFP-gAd and the diabetes group treated with pIRES2-EGFP. After 12 weeks, serum biochemistry and urine albumin levels were measured. The kidneys were collected to assess the generation of reactive oxygen species (ROS) and the renal pathological changes were observed by light microcopy. The protein expression of endothelial nitric oxide synthase (eNOS), transforming growth factor-β1 (TGF-β1) and phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK) were determined by an immunohistochemical staining method and western blot analysis. Intraperitoneal injection of the human gAd gene via Lipofectamine resulted in abundant ADPN protein in the kidney. In the diabetic rats, the delivery of the exogenous gAd gene ameliorated the progression of diabetic nephropathy (DN). ADPN attenuated urine albumin excretion in the diabetic rats. ADPN also mitigated glomerular mesangial expansion, reduced the generation of ROS and prevented interstitial fibrosis. In addition, the expression of gAd inhibited the renal expression of TGF-β1, promoted the protein expression of eNOS and activated the opening of the AMPK signaling pathway in the renal tissues of the diabetic rats. Despite the effects of ADPN on DN being controversial, these observations indicate that the supplementation of ADPN is beneficial in ameliorating DN in rats.
本研究调查了外源性脂联素（ADPN）长期表达对正常肾脏和糖尿病肾脏的潜在影响。通过高脂高糖喂养加腹腔注射链脲佐菌素诱导2型糖尿病模型。将能够共表达球状ADPN（gAd）和增强型绿色荧光蛋白（EGFP）的重组质粒pIRES2-EGFP-gAd，经脂质体介导腹腔注射到大鼠模型中。总共32只Wistar大鼠随机分为四组：正常对照组、糖尿病组、用pIRES2-EGFP-gAd治疗的糖尿病组和用pIRES2-EGFP治疗的糖尿病组。12周后，检测血清生化指标和尿白蛋白水平。收集肾脏以评估活性氧（ROS）的产生，并通过光学显微镜观察肾脏病理变化。采用免疫组织化学染色法和蛋白质印迹分析测定内皮型一氧化氮合酶（eNOS）、转化生长因子-β1（TGF-β1）和磷酸化腺苷单磷酸激活蛋白激酶（p-AMPK）的蛋白表达。经脂质体腹腔注射人gAd基因后，肾脏中出现大量ADPN蛋白。在糖尿病大鼠中，外源性gAd基因的导入改善了糖尿病肾病（DN）的进展。ADPN减少了糖尿病大鼠的尿白蛋白排泄。ADPN还减轻了肾小球系膜扩张，减少了ROS的产生，并预防了间质纤维化。此外，gAd的表达抑制了糖尿病大鼠肾组织中TGF-β1的表达，促进了eNOS的蛋白表达，并激活了肾组织中AMPK信号通路的开放。尽管ADPN对DN的作用存在争议，但这些观察结果表明，补充ADPN有利于改善大鼠的DN。
