Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, Medical School, Southeast University, Nanjing 210009, China.
Int J Endocrinol. 2013;2013:592576. doi: 10.1155/2013/592576. Epub 2013 Nov 27.
Diabetic nephropathy (DN) has been associated with the presence of lipid deposition. We hypothesized that the disruption of intracellular cholesterol feedback may contribute to DN. Diabetes was induced by high fat/sucrose diet and low-dose intraperitoneal injection of streptozocin (STZ) in male Sprague-Dawley rats. Then diabetic rats were randomly divided into two groups: untreated diabetic group (DM) and atorvastatin-treated group (DM + AT). We found that the levels of serum blood urea nitrogen and creatinine, as well as 24-hour urine protein and urinary neutrophil gelatinase-associated lipocalin, were significantly increased in diabetic rats. This result indicated that the diabetic rats suffered from functional renal damage. We also observed lipid droplet accumulation and increase in 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR), low density lipoprotein receptor (LDLr), sterol regulatory element binding protein-2 (SREBP-2), and SREBP-cleavage activating protein (SCAP) in the kidneys of diabetic rats. However, atorvastatin ameliorated renal lipid accumulation and improved the renal function of diabetic rats despite an increase in mRNA and protein expressions of HMG-CoAR, LDLr, and SREBP-2. These results demonstrated that intracellular cholesterol feedback regulation is disrupted in rats with type 2 diabetes, thereby causing renal cholesterol accumulation. Atorvastatin ameliorated renal cholesterol accumulation by reducing renal cholesterol synthesis.
糖尿病肾病(DN)与脂质沉积的存在有关。我们假设细胞内胆固醇反馈的破坏可能导致 DN。雄性 Sprague-Dawley 大鼠通过高脂肪/蔗糖饮食和低剂量腹腔注射链脲佐菌素(STZ)诱导糖尿病。然后,糖尿病大鼠被随机分为两组:未治疗的糖尿病组(DM)和阿托伐他汀治疗组(DM + AT)。我们发现,糖尿病大鼠的血清血尿素氮和肌酐水平,以及 24 小时尿蛋白和尿中性粒细胞明胶酶相关脂质运载蛋白水平显著升高。这一结果表明糖尿病大鼠肾功能受损。我们还观察到糖尿病大鼠肾脏中脂质滴的积累增加,以及 3-羟基-3-甲基戊二酰辅酶 A 还原酶(HMG-CoAR)、低密度脂蛋白受体(LDLr)、固醇调节元件结合蛋白-2(SREBP-2)和 SREBP 切割激活蛋白(SCAP)的表达增加。然而,尽管 HMG-CoAR、LDLr 和 SREBP-2 的 mRNA 和蛋白表达增加,阿托伐他汀仍改善了糖尿病大鼠的肾脏脂质积累和肾功能。这些结果表明,2 型糖尿病大鼠细胞内胆固醇反馈调节紊乱,导致肾脏胆固醇积累。阿托伐他汀通过减少肾脏胆固醇合成来改善肾脏胆固醇积累。