二噁英诱导的肝纤维化中剂量依赖性代谢重编程和差异基因表达
Dose-Dependent Metabolic Reprogramming and Differential Gene Expression in TCDD-Elicited Hepatic Fibrosis.
作者信息
Nault Rance, Fader Kelly A, Ammendolia Dustin A, Dornbos Peter, Potter Dave, Sharratt Bonnie, Kumagai Kazuyoshi, Harkema Jack R, Lunt Sophia Y, Matthews Jason, Zacharewski Tim
机构信息
Biochemistry & Molecular Biology.
Institute for Integrative Toxicology.
出版信息
Toxicol Sci. 2016 Dec;154(2):253-266. doi: 10.1093/toxsci/kfw163. Epub 2016 Aug 25.
We have previously shown that in response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-elicited NAFLD progression, central carbon, glutaminolysis, and serine/folate metabolism are reprogrammed to support NADPH production and ROS defenses. To further investigate underlying dose-dependent responses associated with TCDD-induced fibrosis, female C57BL/6 mice were gavaged with TCDD every 4 days (d) for 28 d or 92 d. RNA-Seq, ChIP-Seq (2 h), and 28 d metabolomic (urine, serum, and hepatic extract) analyses were conducted with complementary serum marker assessments at 92 d. Additional vehicle and 30 µg/kg treatment groups were allowed to recover for 36 d following the 92-d treatment regimen to examine recovery from TCDD-elicited fibrosis. Histopathology revealed dose-dependent increases in hepatic fat accumulation, inflammation, and periportal collagen deposition at 92 days, with increased fibrotic severity in the recovery group. Serum proinflammatory and profibrotic interleukins-1β, -2, -4, -6, and -10, as well as TNF-α and IFN-γ, exhibited dose-dependent induction. An increase in glucose tolerance was observed with a concomitant 3.0-fold decrease in hepatic glycogen linked to increased ascorbic acid biosynthesis and proline metabolism, consistent with increased fibrosis. RNA-Seq identified differential expression of numerous matrisome genes including an 8.8-fold increase in Tgfb2 indicating myofibroblast activation. Further analysis suggests reprogramming of glycogen, ascorbic acid, and amino acid metabolism in support of collagen deposition and the use of proline as a substrate for ATP production via the proline cycle. In summary, we demonstrate that glycogen, ascorbic acid, and amino acid metabolism are also reorganized to support remodeling of the extracellular matrix, progressing to hepatic fibrosis in response to chronic injury from TCDD.
我们之前已经表明,在2,3,7,8-四氯二苯并对二恶英(TCDD)引发的非酒精性脂肪性肝病(NAFLD)进展过程中,中心碳代谢、谷氨酰胺分解代谢以及丝氨酸/叶酸代谢会被重新编程,以支持烟酰胺腺嘌呤二核苷酸磷酸(NADPH)的产生和活性氧(ROS)防御。为了进一步研究与TCDD诱导的纤维化相关的潜在剂量依赖性反应,每4天给雌性C57BL/6小鼠灌胃TCDD,持续28天或92天。在92天时进行RNA测序(RNA-Seq)、染色质免疫沉淀测序(ChIP-Seq,2小时)以及28天的代谢组学分析(尿液、血清和肝脏提取物),并进行补充血清标志物评估。在92天的治疗方案之后,另外的溶剂对照组和30微克/千克治疗组被允许恢复36天,以检查从TCDD引发的纤维化中恢复的情况。组织病理学显示,在92天时,肝脏脂肪堆积、炎症和门静脉周围胶原沉积呈剂量依赖性增加,恢复组的纤维化严重程度增加。血清促炎和促纤维化白细胞介素-1β、-2、-4、-6和-10,以及肿瘤坏死因子-α(TNF-α)和干扰素-γ(IFN-γ)表现出剂量依赖性诱导。观察到葡萄糖耐量增加,同时肝脏糖原减少3.0倍,这与抗坏血酸生物合成增加和脯氨酸代谢有关,与纤维化增加一致。RNA测序鉴定出许多基质体基因的差异表达,包括转化生长因子β2(Tgfb2)增加8.8倍,表明肌成纤维细胞活化。进一步分析表明,糖原、抗坏血酸和氨基酸代谢被重新编程,以支持胶原沉积,并利用脯氨酸作为通过脯氨酸循环产生三磷酸腺苷(ATP) 的底物。总之,我们证明糖原、抗坏血酸和氨基酸代谢也被重新组织,以支持细胞外基质的重塑,响应TCDD引起的慢性损伤而进展为肝纤维化。