Department of Morphology, Healthy Sciences Center, Federal University of Espírito Santo, Brazil.
Department of Morphology, Healthy Sciences Center, Federal University of Espírito Santo, Brazil.
Toxicol Lett. 2018 Dec 15;299:21-31. doi: 10.1016/j.toxlet.2018.08.018. Epub 2018 Aug 29.
White adipose tissue (WAT) dysfunction and obesity are a consequence of a low-grade inflammation state. These WAT irregularities could result from abnormal metabolic renin-angiotensin system (RAS) control. Recently, tributyltin (TBT) has been found to play a critical role in these metabolic irregularities. However, TBT actions on the WAT-RAS functions are not currently well understood. In this study, we assessed whether TBT exposure resulted in metabolic syndrome (MetS) development and other metabolic complications as a result of abnormal modulation of WAT-RAS pathways. TBT (100 ng/kg/day) was administered to adult female Wistar rats, and their WAT morphophysiology and adipokine profiles were assessed. We further assessed the expression of Angiotensin-II receptor proteins (AT1R and AT2R) and proteins involved in downstream pathways mediating inflammation and adipogenesis modulation. TBT-exposed rats exhibited increases in body weight and adiposity. TBT rats present dyslipidemia and insulin resistance, suggesting MetS development. TBT promoted WAT inflammatory infiltration, AT1R protein overexpression and reduced Angiotensin-(1-7) expression. These TBT WAT abnormalities are reflected by NFκB activation, with higher adipokine levels (leptin, TNF-α and IL-6) and overexpression of AKT, ERK, P38, FAS and PPARγ protein. In vitro, TBT exposure stimulates lipid accumulation, reduces AT2R protein expression, and increases leptin, AKT and ERK protein expression in 3T3L1 cells. These findings suggest that TBT exposure participates in MetS development via the improper function of WAT-RAS metabolic control.
白色脂肪组织(WAT)功能障碍和肥胖是低度炎症状态的结果。这些 WAT 异常可能是由于代谢肾素-血管紧张素系统(RAS)控制异常所致。最近,三丁基锡(TBT)被发现在这些代谢异常中起着关键作用。然而,TBT 对 WAT-RAS 功能的作用目前还不是很清楚。在这项研究中,我们评估了 TBT 暴露是否会导致代谢综合征(MetS)的发展和其他代谢并发症,这是由于 WAT-RAS 途径的异常调节。将 TBT(100ng/kg/天)施用于成年雌性 Wistar 大鼠,并评估其 WAT 形态生理学和 adipokine 谱。我们进一步评估了血管紧张素 II 受体蛋白(AT1R 和 AT2R)和参与炎症和脂肪生成调节的下游途径的蛋白质的表达。暴露于 TBT 的大鼠体重和肥胖增加。TBT 大鼠表现出血脂异常和胰岛素抵抗,提示 MetS 的发展。TBT 促进了 WAT 的炎症浸润,AT1R 蛋白过表达和 Angiotensin-(1-7)表达减少。这些 TBT 引起的 WAT 异常反映在 NFκB 的激活,导致更高的 adipokine 水平(瘦素、TNF-α 和 IL-6)和 AKT、ERK、P38、FAS 和 PPARγ 蛋白的过表达。在体外,TBT 暴露刺激脂肪积累,降低 3T3L1 细胞中 AT2R 蛋白表达,并增加瘦素、AKT 和 ERK 蛋白表达。这些发现表明,TBT 暴露通过 WAT-RAS 代谢控制的不当功能参与 MetS 的发展。