Laboratory of Exercise Biochemistry and Physiology, Programa de Pós-Graduação em Ciências da Saúde, Unidade em Ciênicas da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil.
Horm Metab Res. 2012 Nov;44(12):885-90. doi: 10.1055/s-0032-1321819. Epub 2012 Aug 29.
The literature has associated hepatic insulin action with NAFLD. In this sense, treatments to revert steatosis and improve hepatic insulin action become important. Our group has demonstrated that inhibition of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) reverses hepatic steatosis. However, insulin signals after NAFLD reversion require better investigation. Thus, in this study, we investigated if the reversal of NAFLD by SREBP-1c inhibitor results in improvement in the hepatic insulin signal in obesity mice. After installation/achievement of diet-induced obesity and insulin resistance, Swiss mice were divided into 3 groups: i) Lean, ii) D-IHS, diet-induced hepatic steatosis [no treatment with antisense oligonucleotide (ASO)], and iii) RD-IHS, reversion of diet-induced hepatic steatosis (treated with ASO). The mice were treated with ASO SREBP-1c as previously described by our group. After ASO treatment, one set of animals was anesthetized and used for in vivo test, and another mice set was anesthetized and used for histology and Western blot analysis. Reversion of diet-induced hepatic steatosis did not change blood glucose, glucose decay constant (k(ITT)), body weight, or serum insulin levels. In addition, results showed that the protocol did not improve insulin pathway signaling, as confirmed by the absence of changes in IR, IRS1, Akt and Foxo1 phosphorylation in hepatic tissue. In parallel, no alterations were observed in proinflammatory molecules. Thus, our results suggest that the inhibition of SREBP-1c reverts steatosis, but without improving insulin hepatic resistance.
文献将肝胰岛素作用与非酒精性脂肪性肝病相关联。从这个意义上说,逆转脂肪变性和改善肝胰岛素作用的治疗方法变得很重要。我们的研究小组已经证明抑制固醇调节元件结合蛋白-1c(SREBP-1c)可以逆转肝脂肪变性。然而,非酒精性脂肪性肝病逆转后的胰岛素信号需要更好的研究。因此,在这项研究中,我们研究了 SREBP-1c 抑制剂逆转非酒精性脂肪性肝病是否会改善肥胖小鼠的肝胰岛素信号。在建立/实现饮食诱导的肥胖和胰岛素抵抗后,将瑞士小鼠分为 3 组:i)瘦鼠,ii)D-IHS,饮食诱导的肝脂肪变性[未用反义寡核苷酸(ASO)治疗],和 iii)RD-IHS,饮食诱导的肝脂肪变性逆转(用 ASO 治疗)。我们的研究小组以前曾用 ASO SREBP-1c 对小鼠进行治疗。ASO 治疗后,一组动物被麻醉并用于体内试验,另一组小鼠被麻醉用于组织学和 Western blot 分析。饮食诱导的肝脂肪变性的逆转并没有改变血糖、葡萄糖衰减常数(k(ITT))、体重或血清胰岛素水平。此外,结果表明该方案并没有改善胰岛素通路信号,因为肝组织中 IR、IRS1、Akt 和 Foxo1 磷酸化没有变化得到了证实。同时,也没有观察到促炎分子的变化。因此,我们的结果表明,SREBP-1c 的抑制可以逆转脂肪变性,但不能改善肝胰岛素抵抗。