背景:内皮功能障碍在主动脉重构中起着至关重要的作用。有氧糖酵解和内皮-间质转化(EndoMT)有,分别,被认为是许多心血管疾病中内皮功能障碍的原因。这里,我们测试了以下假设:糖酵解重编程通过转录共抑制因子CtBP1(C端结合蛋白1)介导的表观遗传机制对主动脉重塑中的EndoMT诱导至关重要,糖酵解衍生的NADH传感器。
方法:EndoMT计划,主动脉重塑,在注入Ang(血管紧张素)II的小鼠中评估了糖酵解激活剂PFKFB3(6-磷酸果糖-2-激酶/果糖-2,6-双磷酸酶同工型3)的内皮表达。具有内皮特异性Pfkfb3缺乏症或CtBP1失活的小鼠,免疫沉淀,染色质免疫沉淀,和荧光素酶报告基因测定用于阐明PFKFB3/CtBP1是否以及如何在表观遗传学上控制EndoMT。
结果:在重塑的胸主动脉中,EndoMT程序和内皮PFKFB3表达增加。在TGF(转化生长因子)-β处理的人内皮细胞中,激活的SMAD2/3转录上调PFKFB3表达。反过来,TGF-β/SMAD信号和EndoMT通过沉默或抑制PFKFB3而受损。机制研究表明,PFKFB3介导的糖酵解增加了NADH含量并激活了对NADH敏感的CtBP1。通过与转录抑制因子E2F4的相互作用,CtBP1增强了E2F4介导的SMURF2(SMAD泛素调节因子2)的转录抑制,TGF-β/SMAD2信号传导的负调节因子。此外,小鼠中EC特异性Pfkfb3缺陷或CtBP1失活导致AngII诱导的主动脉重塑减弱。
结论:我们的结果证明了糖酵解介导的TGF-β信号传导的正反馈环诱导EndoMT,并表明治疗靶向内皮PFKFB3或CtBP1活性可以为治疗EndoMT相关的主动脉重塑提供基础。
UNASSIGNED: Endothelial dysfunction plays a crucial role in aortic remodeling. Aerobic glycolysis and endothelial-to-mesenchymal transition (EndoMT) have, respectively, been suggested to contribute to endothelial dysfunction in many cardiovascular diseases. Here, we tested the hypothesis that glycolytic reprogramming is critical for EndoMT induction in aortic remodeling through an epigenetic mechanism mediated by a transcriptional corepressor CtBP1 (C-terminal binding protein 1), a sensor of glycolysis-derived NADH.
UNASSIGNED: EndoMT program, aortic remodeling, and endothelial expression of the glycolytic activator PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3) were evaluated in Ang (angiotensin) II-infused mice. Mice with endothelial-specific Pfkfb3 deficiency or CtBP1 inactivation, immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assay were employed to elucidate whether and how PFKFB3/CtBP1 epigenetically controls EndoMT.
UNASSIGNED: The EndoMT program and increased endothelial PFKFB3 expression were induced in remodeled thoracic aortas. In TGF-β (transforming growth factor-β)-treated human endothelial cells, activated SMAD2/3 (SMAD Family Member 2/3) transcriptionally upregulated PFKFB3 expression. In turn, the TGF-β/SMAD signaling and EndoMT were compromised by silencing or inhibition of PFKFB3. Mechanistic studies revealed that PFKFB3-mediated glycolysis increased NADH content and activated the NADH-sensitive CtBP1. Through interaction with the transcription repressor E2F4 (E2F Transcription Factor 4), CtBP1 enhanced E2F4-mediated transcriptional repression of SMURF2 (SMAD ubiquitin regulatory factor 2), a negative regulator of TGF-β/SMAD2 signaling. Additionally, EC-specific Pfkfb3 deficiency or CtBP1 inactivation in mice led to attenuated Ang II-induced aortic remodeling.
UNASSIGNED: Our results demonstrate a glycolysis-mediated positive feedback loop of the TGF-β signaling to induce EndoMT and indicate that therapeutically targeting endothelial PFKFB3 or CtBP1 activity could provide a basis for treating EndoMT-linked aortic remodeling.