Tovar Armando R, Murguía Fernanda, Cruz Cristino, Hernández-Pando Rogelio, Aguilar-Salinas Carlos A, Pedraza-Chaverri José, Correa-Rotter Ricardo, Torres Nimbe
Departments of Fisiología de la Nutrición, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, D.F, México.
J Nutr. 2002 Sep;132(9):2562-9. doi: 10.1093/jn/132.9.2562.
Nephrotic syndrome (NS) is characterized by the presence of proteinuria and hyperlipidemia. However, ingestion of soy protein has a hypolipidemic effect. The present study was designed to determine whether the ingestion of a 20% soy protein diet regulates the expression of hepatic sterol regulatory element binding protein (SREBP)-1, fatty acid synthase (FAS), malic enzyme, beta-hydroxy-beta-methylglutaryl-CoA (HMG-CoA) reductase (r) and synthase (s), and LDL receptor (r), and to assess whether soy protein improves lipid and renal abnormalities in rats with chronic NS. Male Wistar rats were injected with vehicle or with puromycin aminonucleoside to induce NS and were fed either 20% casein or soy protein diets for 64 d. NS rats fed 20% soy protein had improved creatinine clearance and reduced proteinuria, hypercholesterolemia, hypertriglyceridemia, as well as VLDL-triglycerides and LDL cholesterol compared with NS rats fed the 20% casein diet. In addition, the soy protein diet decreased the incidence of glomerular sclerosis, and proinflammatory cytokines in kidney. Ingestion of the soy protein diet by control rats reduced the gene expression of SREBP-1, malic enzyme, FAS and increased HMG-CoAr, HMG-CoAs and LDLr. However, NS rats fed either casein or soy protein diets had low insulin concentrations with reductions in SREBP-1, FAS and malic enzyme expression compared with control rats fed the casein diet. NS rats fed the soy diet also had lower HMG-CoAr and LDLr mRNA levels than NS rats fed casein. In conclusion, the beneficial effects of soy protein on lipid metabolism are modulated in part by SREBP-1. However, in NS rats, the benefit may be through a direct effect of this protein on kidney rather than mediated by changes in expression of hepatic lipid metabolism genes.
肾病综合征（NS）的特征是蛋白尿和高脂血症。然而，摄入大豆蛋白具有降血脂作用。本研究旨在确定摄入20%大豆蛋白饮食是否能调节肝脏固醇调节元件结合蛋白（SREBP）-1、脂肪酸合酶（FAS）、苹果酸酶、β-羟基-β-甲基戊二酰辅酶A（HMG-CoA）还原酶（r）和合成酶（s）以及低密度脂蛋白受体（r）的表达，并评估大豆蛋白是否能改善慢性NS大鼠的脂质和肾脏异常。雄性Wistar大鼠注射赋形剂或嘌呤霉素氨基核苷以诱导NS，并分别给予20%酪蛋白或大豆蛋白饮食64天。与喂食20%酪蛋白饮食的NS大鼠相比，喂食20%大豆蛋白的NS大鼠肌酐清除率提高，蛋白尿、高胆固醇血症、高甘油三酯血症以及极低密度脂蛋白甘油三酯和低密度脂蛋白胆固醇降低。此外，大豆蛋白饮食降低了肾小球硬化的发生率以及肾脏中的促炎细胞因子。对照大鼠摄入大豆蛋白饮食降低了SREBP-1、苹果酸酶、FAS的基因表达，并增加了HMG-CoAr、HMG-CoAs和LDLr。然而，与喂食酪蛋白饮食的对照大鼠相比，喂食酪蛋白或大豆蛋白饮食的NS大鼠胰岛素浓度较低，SREBP-1、FAS和苹果酸酶表达降低。喂食大豆饮食的NS大鼠的HMG-CoAr和LDLr mRNA水平也低于喂食酪蛋白的NS大鼠。总之，大豆蛋白对脂质代谢的有益作用部分由SREBP-1调节。然而，在NS大鼠中，这种益处可能是通过这种蛋白质对肾脏的直接作用，而不是由肝脏脂质代谢基因表达的变化介导的。
