Nagao Koji, Matsumoto Akiko, Kai Shunichi, Kayashima Tomoko, Yanagita Teruyoshi
Department of Applied Biochemistry and Food Science, Saga University.
J Oleo Sci. 2017 Feb 1;66(2):161-169. doi: 10.5650/jos.ess16145. Epub 2017 Jan 18.
Lipodystrophies are acquired and genetic disorders characterized by the complete or partial absence of body fat with a line of metabolic disorders, including hepatic steatosis. Because soy protein isolate (SPI) has been reported to reduce cholesterol and triglyceride levels in animals and humans, we explored the effect of SPI on the pathophysiology of hepatic lipid accumutaion in a diet-induced lipodystrophy model mice. Four weeks of the lipodystrophy model diet induced hepatic lipid accumulation concomitant with marked deficiencies of adipose tissue and serum adipocytokines in mice. However, supplementing the lipodystrophy model diet with SPI could alleviate the hepatic lipid acculation without affecting the lipoatrophic effect of the diet. Enhanced lipogenesis is the principal mechanism of hepatic steatosis in this model, but SPI supplementation significantly attenuated the increase in enzyme activity and/or mRNA expression. Additionally, SPI supplementation upregulated the hepatic mRNA expression of an enzyme involved in cholesterol catabolism. In conclusion, our results indicate the possibility of dietary SPI to attenuate lipodystorophy-induced hepatic steatosis through the direct reduction of hepatic lipogenesis without affecting adipocytokine production.
脂肪营养不良是一种获得性和遗传性疾病,其特征是身体脂肪完全或部分缺失,并伴有一系列代谢紊乱,包括肝脂肪变性。由于已有报道称大豆分离蛋白(SPI)可降低动物和人类的胆固醇及甘油三酯水平,我们在饮食诱导的脂肪营养不良模型小鼠中探讨了SPI对肝脏脂质蓄积病理生理学的影响。四周的脂肪营养不良模型饮食可诱导小鼠肝脏脂质蓄积,同时伴有明显的脂肪组织和血清脂肪细胞因子缺乏。然而,在脂肪营养不良模型饮食中补充SPI可减轻肝脏脂质蓄积,而不影响该饮食的脂肪萎缩作用。增强的脂肪生成是该模型中肝脂肪变性的主要机制,但补充SPI可显著减弱酶活性和/或mRNA表达的增加。此外,补充SPI可上调参与胆固醇分解代谢的一种酶的肝脏mRNA表达。总之,我们的结果表明,饮食中的SPI有可能通过直接减少肝脏脂肪生成来减轻脂肪营养不良诱导的肝脂肪变性,而不影响脂肪细胞因子的产生。