Regulation of Liver Fibrosis by Pyruvate Kinase M2 (PKM2)

我们已经确定了PKM 2在HSC生物学和肝脏中的重要和以前未知的作用 纤维化这项工作将使我们对PKM 2如何调节肝星状细胞的机制有一个全面的了解。 (HSC)代谢和活化，并测试PKM 2结合的新化学实体的抗纤维化活性。 HSC是肝纤维化发展的核心。有大量的信息， 与HSC激活相关的转录变化，但这些变化是如何启动的， 监管还没有得到很好的理解。从目前的优异奖的工作，我们已经确定了一个 丙酮酸激酶M2（PKM 2）在促糖酵解、促炎症和 肝巨噬细胞（LM）中的促活性氧基因。HSC一旦激活， 与巨噬细胞和其他从静止状态过渡到静止状态的细胞相同的组织挑战 高度增殖和合成代谢状态。 假设：丙酮酸激酶M2（PKM 2）是肝纤维化的关键调节因子。目标1：确定 PKM 2介导的HSC活化的调节机制。a）鉴定TGF-β1诱导的后 翻译修饰（PTM）是PKM 2核转位所必需的。测试的能力 Erk 1/2 MAP激酶磷酸化PKM 2的关键位点，并使用PKM 2的位点特异性Flag突变体， 确定哪些突变导致核定位丢失。B）确定核反应机制 PKM 2介导HSC激活和纤维化反应的反式激活。 目的2：研究PKM 2在肝纤维化中的内在和外在作用。（a）确定HSC PKM 2在肝纤维化中的内在作用：确定PKM 2在调节HSC代谢中的作用 适应和下游事件。B）鉴定肝细胞PKM 2在肝纤维化中的作用： 肝细胞PKM 2在肝细胞产生TGF-β1和其他细胞因子中的作用， 调节TGF-β1通路。 目的3：测试新型PKM 2抑制剂的抗纤维化活性的体内功效。我们将测试 TEPP-45和另外的新型PKM 2结合剂在预防和逆转肝纤维化中的作用。 目前的工作将使我们对PKM 2在不同肝细胞中的作用机制有一个全面的了解。 群体调节HSC活化和肝纤维化。

We have identified an important and previously unknown role for PKM2 in HSC biology and liver fibrosis. This work will give us a full mechanistic understanding of how PKM2 regulates hepatic stellate (HSC) metabolism and activation, and test PKM2-binding new chemical entities for anti-fibrotic activity. HSC are central to the development of liver fibrosis. There is extensive information on the many transcriptional changes associated with HSC activation but how these changes are initiated and regulated is still not well understood. From the work in the current Merit award we have identified a novel role for pyruvate kinase M2 (PKM2) in nuclear regulation of pro-glycolytic, pro-inflammatory and pro-reactive oxygen species genes in liver macrophages (LM). HSC, upon activation, are faced with the same organizational challenges as macrophages and other cells which transition from a quiescent to a highly proliferative and anabolic state. Hypothesis: Pyruvate Kinase M2 (PKM2) is a key regulator of liver fibrosis. Aim 1: Identify the regulatory mechanisms of PKM2 mediated HSC activation. a) Identify the TGF-β1 induced post- translational modifications (PTM) in PKM2 required for PKM2 nuclear translocation. Test the ability of Erk 1/2 MAP kinases to phosphorylate key sites of PKM2 and use site specific Flag mutants of PKM2 to identify which mutations result in loss of nuclear localization. b) Identify the nuclear mechanism of PKM2 mediated transactivation of HSC activation and fibrotic response. Aim 2: Identify the HSC intrinsic and extrinsic roles of PKM2 in liver fibrosis. a) Identify the HSC intrinsic roles of PKM2 in liver fibrosis: Determine the role of PKM2 in regulating HSC metabolic adaptation and downstream events. b) Identify the role of hepatocyte PKM2 in liver fibrosis: Determine the role of hepatocyte PKM2 in the production by hepatocytes of TGF-β1 and other cytokines that regulate the TGF-β1 pathway. Aim 3: Test the in vivo efficacy of novel PKM2 inhbitors for anti-fibrotic activity. We will test the ability of TEPP-45, and additional novel PKM2 binders, in preventing and reversing liver fibrosis. The current work will give us a full mechanistic understanding of how PKM2 in different liver cell populations regulates HSC activation, and liver fibrosis.