Preidis Geoffrey A, Soni Krishnakant G, Suh Ji Ho, Halder Tripti, Kim Kang Ho, Choi Jong Min, Li Feng, Devaraj Sridevi, Conner Margaret E, Coarfa Cristian, Jung Sung Yun, Moore David D
Section of Gastroenterology, Hepatology & Nutrition Department of Pediatrics Baylor College of Medicine and Texas Children's Hospital Houston TX USA.
Department of Molecular and Cellular Biology Baylor College of Medicine Houston TX USA.
Hepatol Commun. 2020 Oct 22;4(12):1835-1850. doi: 10.1002/hep4.1622. eCollection 2020 Dec.
Liver dysfunction, including coagulopathy, is a prominent feature of protein-energy malnutrition. To identify mechanisms underlying malnutrition-associated coagulopathy, we administered a low-protein low-fat diet to lactating dams and examined hepatic transcription and plasma coagulation parameters in young adult weanlings. Malnutrition impacted body composition to a greater extent in male versus female mice. Transcriptional profiles suggested opposing effects of nutrient-sensing nuclear receptors, namely induction of peroxisome proliferator-activated receptor α (PPARα) targets and repression of farnesoid-X-receptor (FXR) targets. Coagulopathy with decreased synthesis of fibrinogen-α (FGA) and factor 11 (F11) was observed in malnourished male animals but not female animals. In primary mouse hepatocytes, FXR agonist increased and PPARα agonist decreased and messenger RNA expression. Nuclear receptor DNA response elements were identified in the and gene regulatory regions, and opposing effects of FXR and PPARα were confirmed with luciferase assays. Unexpectedly, hepatic PPARα protein was markedly depleted in malnourished male liver and was not enriched on or response elements. Rather, there was loss of FXR binding at these response elements. Reduced PPARα protein was associated with loss of hepatocyte peroxisomes, which are necessary for bile acid biosynthesis, and with decreased concentrations of bile acids that function as FXR ligands, most notably the FXR agonist chenodeoxycholic acid. : Malnutrition impairs growth and liver synthetic function more severely in male mice than in female mice. Malnourished male mice are coagulopathic and exhibit decreased hepatocyte peroxisomes, FXR agonist bile acids, FXR binding on and gene regulatory elements, and coagulation factor synthesis. These effects are absent in female mice, which have low baseline levels of PPARα, suggesting that nutrient-sensing nuclear receptors regulate coagulation factor synthesis in response to host nutritional status in a sex-specific manner.
肝功能障碍,包括凝血病,是蛋白质 - 能量营养不良的一个显著特征。为了确定营养不良相关凝血病的潜在机制,我们给哺乳期母鼠喂食低蛋白低脂饮食,并检测了年轻成年断奶小鼠的肝脏转录和血浆凝血参数。与雌性小鼠相比,营养不良对雄性小鼠身体组成的影响更大。转录谱表明营养感应核受体具有相反的作用,即过氧化物酶体增殖物激活受体α(PPARα)靶标的诱导和法尼醇X受体(FXR)靶标的抑制。在营养不良的雄性动物中观察到凝血病,纤维蛋白原α(FGA)和因子11(F11)的合成减少,但雌性动物未出现。在原代小鼠肝细胞中,FXR激动剂增加而PPARα激动剂减少了 和 信使核糖核酸的表达。在 和 基因调控区域鉴定出核受体DNA反应元件,荧光素酶测定证实了FXR和PPARα的相反作用。出乎意料的是,营养不良的雄性肝脏中肝PPARα蛋白明显减少,并且在 或 反应元件上未富集。相反,这些反应元件处的FXR结合丧失。PPARα蛋白减少与胆汁酸生物合成所必需的肝细胞过氧化物酶体丧失以及作为FXR配体的胆汁酸浓度降低有关,最显著的是FXR激动剂鹅去氧胆酸。:营养不良对雄性小鼠生长和肝脏合成功能的损害比对雌性小鼠更严重。营养不良的雄性小鼠患有凝血病,表现出肝细胞过氧化物酶体减少、FXR激动剂胆汁酸减少、FXR在 和 基因调控元件上的结合减少以及凝血因子合成减少。雌性小鼠不存在这些影响,其PPARα基线水平较低,这表明营养感应核受体以性别特异性方式响应宿主营养状况调节凝血因子合成。