Penna-de-Carvalho Aline, Graus-Nunes Francielle, Rabelo-Andrade Júlia, Mandarim-de-Lacerda Carlos Alberto, Souza-Mello Vanessa
Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Brazil.
Laboratory of Morphometry, Metabolism and Cardiovascular Disease, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Brazil
Exp Physiol. 2014 Dec 1;99(12):1663-78. doi: 10.1113/expphysiol.2014.081596. Epub 2014 Oct 16.
Telmisartan has previously been used to target obesity, showing peroxisome proliferator-activated receptor (PPAR) β/δ-related effects in white adipose tissue (WAT). We sought to evaluate whether telmisartan enhances gene and protein expression of all PPAR isoforms in WAT and brown adipose tissue (BAT), as well as their downstream effects upon insulin resistance, adipokine profile and adaptive thermogenesis. Male C57BL/6 mice were fed standard chow (SC; 10% lipids) or high-fat diet (HF; 50% lipids) for 10 weeks. Animals were then randomly allocated into the following four groups: SC, SC-T, HF and HF-T. Telmisartan [10 mg (kg diet)(-1)] was administered for 4 weeks in the diet. Animals in the HF group were overweight and exhibited hypertension, insulin resistance, decreased energy expenditure, a pro-inflammatory adipokine profile and abnormal fat pad mass distribution. Animals in the HF group showed decreased expression of PPARα, β/δ and γ in WAT and BAT, resulting in impaired glucose uptake and insufficient thermogenesis. Due to the improvement in the adipokine profile and enhanced insulin sensitivity with adequate insulin-stimulated glucose uptake after treatment with telmisartan, the activation of all PPAR isoforms in WAT was beneficial. In BAT, telmisartan induced sustained sympathetic activation, because the β3-adrenergic receptor was induced by PPARβ/δ, while uncoupling protein 1 was induced by PPARα to promote thermogenesis. Telmisartan exerted anti-obesity effects through higher pan-PPAR gene and protein expression. Upon PPARα, β/δ and γ (pan-PPAR) agonism in adipose tissue of obese mice, telmisartan ameliorates inflammation and insulin resistance, as well as inducing non-shivering thermogenesis. Our results point to new therapeutic targets for the control of obesity and comorbidities through pan-PPAR-related effects.
替米沙坦此前已被用于治疗肥胖症,在白色脂肪组织(WAT)中显示出与过氧化物酶体增殖物激活受体(PPAR)β/δ相关的作用。我们试图评估替米沙坦是否能增强WAT和棕色脂肪组织(BAT)中所有PPAR亚型的基因和蛋白表达,以及它们对胰岛素抵抗、脂肪因子谱和适应性产热的下游影响。雄性C57BL/6小鼠喂食标准饲料(SC;10%脂肪)或高脂饮食(HF;50%脂肪)10周。然后将动物随机分为以下四组:SC、SC-T、HF和HF-T。在饲料中给予替米沙坦[10 mg (kg饮食)(-1)] 4周。HF组动物超重,表现出高血压、胰岛素抵抗、能量消耗减少、促炎脂肪因子谱和脂肪垫质量分布异常。HF组动物的WAT和BAT中PPARα、β/δ和γ的表达降低,导致葡萄糖摄取受损和产热不足。由于替米沙坦治疗后脂肪因子谱改善且胰岛素敏感性增强,胰岛素刺激的葡萄糖摄取充足,WAT中所有PPAR亚型的激活是有益的。在BAT中,替米沙坦诱导持续的交感神经激活,因为PPARβ/δ诱导β3-肾上腺素能受体,而PPARα诱导解偶联蛋白1以促进产热。替米沙坦通过更高的泛PPAR基因和蛋白表达发挥抗肥胖作用。在肥胖小鼠的脂肪组织中,PPARα、β/δ和γ(泛PPAR)激动后,替米沙坦可改善炎症和胰岛素抵抗,并诱导非寒战产热。我们的结果指出了通过泛PPAR相关作用控制肥胖及其合并症的新治疗靶点。