Endolysosomal-nuclear communication mediated through V-ATPase and NHE9 dependent epigenetic signaling

通过 V-ATP 酶和 NHE9 依赖的表观遗传信号介导的内溶酶体-核通讯

• 批准号: 9759328
• 负责人: Ronald Laribee
• 金额: $ 16.53万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759328
• 关键词: Acetylation; Affect; Alkylating Agents; Animals; Antineoplastic Agents; Attenuated; Binding; Biochemical; Cancer Biology; Cell model; Cells; Chromatin; Communication; Complex; Coupled; Critical Pathways; Cyclic AMP-Dependent Protein Kinases; Cytoplasmic Organelle; DNA; DNA Damage; DNA Repair; Data; Deacetylase; Defect; Drug Targeting; Environment; Enzymes; Epigenetic Process; Exposure to; FRAP1 gene; Family; Foundations; Gene Expression; Genes; Genetic Screening; Genetic Transcription; Genotoxic Stress; Glioblastoma; Growth; Growth Factor; Histone Acetylation; Histone H3; Histone H4; Homologous Gene; Human; Impairment; Knock-out; Libraries; Malignant Neoplasms; Malignant neoplasm of brain; Mammals; Mediating; Metabolic; Metabolic stress; Metabolism; Modeling; Modification; Neoplasm Metastasis; Nuclear; Nucleosomes; Nutrient; Orthologous Gene; Pathway interactions; Patients; Phenotype; Phosphorylation; Process; Proton Pump; Protons; Regulation; Repression; Resistance; Role; Saccharomycetales; Signal Pathway; Signal Transduction; Sirtuins; Stress; System; Testing; Yeasts; aerobic glycolysis; cancer cell; chemotherapeutic agent; chemotherapy; chromatin remodeling; drug development; epigenetic regulation; epigenome; extracellular; inhibitor/antagonist; innovation; mutant; neoplastic cell; novel; overexpression; response; standard of care; temozolomide; therapeutic candidate; therapeutic target; tool; tumor; tumorigenesis; vacuolar H+-ATPase; yeast genetics

Tumors are exposed to constantly changing nutrient environments which creates metabolic stress that impairs their growth and proliferation. Consequently, cancer cells evolve phenotypic adaptations to contend with this nutrient flux that require epigenetic and transcriptional reprogramming. These phenotypic adaptations also can affect tumor cell sensitivity to chemotherapeutic agents. How cytoplasmic organelles involved in nutrient signaling exert their effects on the nuclear epigenome remains a fundamental problem to define since these pathways are candidate therapeutic targets for anticancer drug development. The V-ATPase is an evolutionarily conserved multimeric proton pump that acidifies the endolysosomal compartment to regulate intracellular pH and activate essential nutrient signaling pathways. Na+/H+ exchanger (NHE) factors, specifically NHE9, antagonize V-ATPase dependent endosomal acidification. NHE9 is overexpressed in many tumors, and recent studies have demonstrated that NHE9 overexpression in glioblastoma (GBM) contributes directly to tumorigenesis. Intriguingly, genetic screens in budding yeast identified both the V-ATPase and the yeast NHE9 ortholog, Nhx1, as regulators of histone H3 and H4 (H3/H4) acetylation through unknown mechanisms. Our preliminary data demonstrate that V-ATPase signaling in human GBM cells also regulates H3/H4 acetylation, thus demonstrating that the V-ATPase is an evolutionarily conserved epigenetic regulator. This project will test the innovative hypothesis that the V-ATPase and Nhx1/NHE9 regulate the endolysosomal- nuclear communication required for epigenetic adaptation to altered nutrient states. Using yeast and human GBM models, we will perform the following Specific Aims. In Aim I, we will identify the key nutrient signaling pathways downstream of the V-ATPase controlling global H3/H4 acetylation, and then we will determine if this involves repression of the sirtuin family of deacetylases or if it involves non-sirtuin mechanisms. We will test specifically if V-ATPase dependent H3/H4 acetylation regulates the binding of ATP-dependent chromatin remodeling enzymes important for transcription of metabolic genes. In Aim II, we will determine if V-ATPase dependent H3/H4 acetylation controls the DNA damage response to alkylating agents, including the GBM standard of care chemotherapeutic agent temozolomide (TMZ), by anchoring ATP-dependent nucleosome remodeling enzymes onto chromatin. Upon the project's completion, we will have defined a novel paradigm by which the endolysosomal compartment regulates nuclear epigenetic pathways critical for metabolic gene expression and sensitivity to genotoxic stress.

肿瘤暴露于不断变化的营养环境中，从而产生代谢应激，从而损害 它们的生长和增殖。因此，癌细胞进化出表型适应来应对这种情况 需要表观遗传和转录重编程的营养通量。这些表型适应也可以 影响肿瘤细胞对化疗药物的敏感性。细胞质细胞器如何参与营养 信号传导对核表观基因组的影响仍然是一个需要定义的基本问题，因为这些 途径是抗癌药物开发的候选治疗靶点。 V-ATP 酶是 进化上保守的多聚体质子泵，酸化内溶酶体隔室以调节 细胞内 pH 值并激活必需的营养信号通路。 Na+/H+ 交换器 (NHE) 因子， 特别是 NHE9，拮抗 V-ATP 酶依赖性内体酸化。 NHE9 在许多细胞中过度表达 肿瘤，最近的研究表明 NHE9 在胶质母细胞瘤 (GBM) 中过度表达有助于 直接影响肿瘤发生。有趣的是，芽殖酵母的遗传筛选鉴定出了 V-ATP 酶和 酵母 NHE9 直系同源物 Nhx1，通过未知方式作为组蛋白 H3 和 H4 (H3/H4) 乙酰化的调节剂 机制。我们的初步数据表明，人类 GBM 细胞中的 V-ATPase 信号传导也调节 H3/H4 乙酰化，从而证明 V-ATP 酶是进化上保守的表观遗传调节因子。 该项目将测试 V-ATP 酶和 Nhx1/NHE9 调节内溶酶体的创新假设 表观遗传适应改变的营养状态所需的核通讯。使用酵母和人类 GBM 模型，我们将执行以下具体目标。在目标 I 中，我们将确定关键的营养信号 控制全局 H3/H4 乙酰化的 V-ATPase 下游途径，然后我们将确定这是否 涉及去乙酰化酶去乙酰化酶家族的抑制或涉及非去乙酰化酶机制。我们将测试 具体来说，如果 V-ATP 酶依赖性 H3/H4 乙酰化调节 ATP 依赖性染色质的结合 对代谢基因转录很重要的重塑酶。在目标 II 中，我们将确定 V-ATPase 是否 依赖的 H3/H4 乙酰化控制对烷化剂（包括 GBM）的 DNA 损伤反应 标准护理化疗剂替莫唑胺 (TMZ)，通过锚定 ATP 依赖性核小体 将酶重塑到染色质上。项目完成后，我们将定义一个新颖的范式 内溶酶体区室调节对代谢基因至关重要的核表观遗传途径 表达和对基因毒性应激的敏感性。