Guillaume Maeva, Riant Elodie, Fabre Aurélie, Raymond-Letron Isabelle, Buscato Melissa, Davezac Morgane, Tramunt Blandine, Montagner Alexandra, Smati Sarra, Zahreddine Rana, Palierne Gaëlle, Valera Marie-Cécile, Guillou Hervé, Lenfant Françoise, Unsicker Klaus, Metivier Raphaël, Fontaine Coralie, Arnal Jean-François, Gourdy Pierre
Institut des Maladies Métaboliques et Cardiovasculaires Unité Médicale de Recherche 1048, Institut National de la Santé et de le Recherche Médicale (INSERM), Université de Toulouse III Toulouse France.
Service d'Hépato-gastro-entérologie Centre Hospitalier Universitaire de Toulouse Toulouse France.
Hepatol Commun. 2019 Apr 29;3(7):908-924. doi: 10.1002/hep4.1363. eCollection 2019 Jul.
Hepatocyte estrogen receptor α (ERα) was recently recognized as a relevant molecular target for nonalcoholic fatty liver disease (NAFLD) prevention. The present study defined to what extent hepatocyte ERα could be involved in preserving metabolic homeostasis in response to a full (17β-estradiol [E2]) or selective (selective estrogen receptor modulator [SERM]) activation. Ovariectomized mice harboring a hepatocyte-specific deletion ( mice) and their wild-type (WT) littermates were fed a high-fat diet (HFD) and concomitantly treated with E2, tamoxifen (TAM; the most used SERM), or vehicle. As expected, both E2 and TAM prevented all HFD-induced metabolic disorders in WT mice, and their protective effects against steatosis were abolished in mice. However, while E2 still prevented obesity and glucose intolerance in mice, hepatocyte deletion also abrogated TAM-mediated control of food intake as well as its beneficial actions on adiposity, insulin sensitivity, and glucose homeostasis, suggesting a whole-body protective role for liver-derived circulating factors. Moreover, unlike E2, TAM induced a rise in plasma concentration of the anorectic hepatokine growth differentiation factor 15 (Gdf15) through a transcriptional mechanism dependent on hepatocyte ERα activation. Accordingly, ERα was associated with specific binding sites in the regulatory region in hepatocytes from TAM-treated mice but not under E2 treatment due to specific epigenetic modifications. Finally, all the protective effects of TAM were abolished in HFD-fed knockout mice. We identified the selective modulation of hepatocyte ERα as a pharmacologic strategy to induce sufficient anorectic hepatokine Gdf15 to prevent experimental obesity, type 2 diabetes, and NAFLD.
肝细胞雌激素受体α(ERα)最近被认为是预防非酒精性脂肪性肝病(NAFLD)的一个相关分子靶点。本研究确定了肝细胞ERα在响应完全激活(17β-雌二醇 [E2])或选择性激活(选择性雌激素受体调节剂 [SERM])时,在多大程度上参与维持代谢稳态。对具有肝细胞特异性缺失的去卵巢小鼠( 小鼠)及其野生型(WT)同窝小鼠喂食高脂饮食(HFD),并同时用E2、他莫昔芬(TAM;最常用的SERM)或赋形剂进行处理。正如预期的那样,E2和TAM都预防了WT小鼠中所有由HFD诱导的代谢紊乱,并且它们对脂肪变性的保护作用在 小鼠中被消除。然而,虽然E2仍然预防了 小鼠的肥胖和葡萄糖不耐受,但肝细胞缺失也消除了TAM介导的食物摄入控制及其对肥胖、胰岛素敏感性和葡萄糖稳态的有益作用,这表明肝脏衍生的循环因子具有全身保护作用。此外,与E2不同,TAM通过依赖于肝细胞ERα激活的转录机制诱导厌食性肝细胞因子生长分化因子15(Gdf15)的血浆浓度升高。因此,由于特定的表观遗传修饰,ERα与TAM处理小鼠肝细胞中 调控区域的特定结合位点相关,但在E2处理下则不然。最后,在喂食HFD的基因敲除小鼠中,TAM的所有保护作用都被消除。我们确定选择性调节肝细胞ERα是一种药理学策略,可诱导产生足够的厌食性肝细胞因子Gdf15,以预防实验性肥胖、2型糖尿病和NAFLD。