Adipocyte to neuron signaling in thermogenic programming of white adipose tissue

白色脂肪组织产热编程中的脂肪细胞至神经元信号传导

• 批准号: 10547782
• 负责人: MICHAEL P CZECH
• 金额: $ 58.29万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-07 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10547782
• 关键词: ATP Citrate (pro-S)-Lyase; Acetyl Coenzyme A; Acetylation; Address; Adipocytes; Adipose tissue; Antibodies; Appearance; Brown Fat; Caloric Restriction; Cellular Structures; Characteristics; Clustered Regularly Interspaced Short Palindromic Repeats; Cyclic AMP; Data; Denervation; Development; Energy Metabolism; Enzymes; Exercise; Fasting; Fatty Acids; Fatty acid glycerol esters; Fatty-acid synthase; Goals; Health; Histone Acetylation; Homeostasis; Human; Implant; In Vitro; Kinetics; Knockout Mice; Knowledge; Laboratories; Lentivirus; Link; Malonyl Coenzyme A; Mediating; Metabolic; Metabolic Diseases; Metabolism; Molecular; Mus; Neuregulins; Neurites; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Obesity; PC12 Cells; Palmitoyl Coenzyme A; Paracrine Communication; Pathway interactions; Physiological; Proteins; Publishing; Recombinant Proteins; Resolution; Role; Signal Pathway; Signal Transduction; Solid; Technology; Testing; Time; Transcriptional Regulation; Transplantation; Tyrosine 3-Monooxygenase; adipocyte differentiation; blood glucose regulation; experimental study; fat burning; fatty acid oxidation; glucose tolerance; implantation; improved; in vivo; insulin sensitivity; lipid biosynthesis; nanoparticle; nerve supply; neuregulin-4; neuronal growth; neurotransmission; neurotrophic factor; new technology; novel; novel therapeutic intervention; palmitoylation; response; small hairpin RNA; stem cells

Abstract The overarching long term goal of our laboratory is to understand and exploit how adipose tissues exert powerful control over whole body glucose tolerance and insulin sensitivity. Small amounts of mouse brown (BAT) or human “Beige” adipocytes transplanted into recipient mice can improve glucose homeostasis, highlighting the importance of understanding mechanisms of adipose browning. Based on the knowledge that intermediates of the de novo lipogenesis (DNL) pathway display potent signaling functions (e.g., Acetyl CoA as substrate for histone acetylation, transcriptional regulation) and that adipocyte DNL is highly regulated by obesity, fasting, cold exposure, and exercise, we hypothesize that adipocyte DNL is a major regulatory node in metabolism. We aim to interrogate this concept by perturbing this DNL pathway through selective KO of DNL enzymes ATP citrate lyase (ACLY) and fatty acid synthase (FASN). Our preliminary data encourage this approach by revealing that FASN KO upregulates adipocyte neurotrophic factor Neuregulin 4 (Nrg4) and enhances expansion of sWAT sympathetic neurons (SNS), even at thermo-neutrality (30C). Thus, DNL metabolites (Acetyl CoA, Malonyl CoA) or DNL product (Palmitoyl CoA) appear to be intimately linked to controlling adipose SNS activity, adipose energy expenditure and whole body glucose homeostasis. Based on these data, this project seeks to determine the cellular and molecular mechanisms whereby adipocytes can signal to localized SNS neurons and promote the development of Beige adipocytes in sWAT. Aim 1 will determine whether Beige adipocytes in iAdFASNKO mice are derived by direct “conversion” of mature white to beige adipocytes OR by paracrine signaling to induce differentiation of progenitor cells to Beige adipocytes. To address underlying mechanisms, Aim 2 will determine whether Nrg4 (and Negr1, which may also be upregulated) mediates the effect of FASN-depleted adipocytes to cause expansion of the SNS in vivo. This Aim is based on exciting preliminary data showing that conditioned media from such adipocytes cause marked neurite outgrowth in PC-12 neurons in vitro, which is inhibited by Nrg4 silencing. New technology we developed will be used to delete adipocyte Nrg4 and Negr1 using CRISPR-based nanoparticles prior to implantation into recipient mice and analysis of their effects on SNS innervation. Finally, Aim 3 tests whether adipocyte DNL intermediate metabolites Acetyl CoA/Malonyl CoA in iAdFASNKO mice initiate signaling to cause Nrg4 expression and SNS expansion. These adipocyte metabolites in iAdFASNKO mice, and their acetylation and malonylation of cellular proteins, will be reversed by KO of ATP citrate Lyase (ACLY), which generates the Acetyl CoA, in double KO mice. Identifying the DNL intermediates that modulate adipocyte function will enable defining their underlying mechanisms. Together, these experiments have high potential to define novel signaling pathways driven by DNL metabolites that regulate adipose browning and new therapeutic strategies for type 2 diabetes.

抽象的 我们实验室的首要长期目标是了解和利用脂肪组织如何 对全身葡萄糖耐量和胰岛素敏感性发挥强大的控制作用。少量 将小鼠棕色（BAT）或人类“米色”脂肪细胞移植到受体小鼠体内可以改善血糖 体内平衡，强调了解脂肪褐变机制的重要性。基于 了解从头脂肪生成 (DNL) 途径的中间体显示出有效的信号传导 功能（例如，乙酰辅酶 A 作为组蛋白乙酰化、转录调节的底物）以及脂肪细胞 DNL 受到肥胖、禁食、寒冷暴露和运动的高度调节，我们假设脂肪细胞 DNL 新陈代谢的主要调节节点。我们的目标是通过扰乱 DNL 通路来质疑这个概念 通过选择性敲除 DNL 酶 ATP 柠檬酸裂解酶 (ACLY) 和脂肪酸合酶 (FASN)。我们的 初步数据表明 FASN KO 上调脂肪细胞，从而鼓励了这种方法 神经营养因子 Neuregulin 4 (Nrg4) 并增强 swat 交感神经元 (SNS) 的扩张， 即使在热中性 (30C) 下也是如此。因此，DNL 代谢物（乙酰辅酶 A、丙二酰辅酶 A）或 DNL 产物 （棕榈酰 CoA）似乎与控制脂肪 SNS 活性、脂肪能量消耗密切相关 和全身葡萄糖稳态。根据这些数据，该项目旨在确定细胞 以及脂肪细胞向局部 SNS 神经元发出信号并促进 swat 中米色脂肪细胞的发育。目标 1 将确定 iAdFASNKO 中是否存在米色脂肪细胞 小鼠是通过将成熟的白色脂肪细胞直接“转化”为米色脂肪细胞或通过旁分泌信号传导至 诱导祖细胞分化为米色脂肪细胞。为了解决底层机制，目标 2 将 确定 Nrg4（和 Negr1，也可能上调）是否介导 FASN 耗尽的影响 脂肪细胞导致体内 SNS 扩张。该目标基于令人兴奋的初步数据显示 来自此类脂肪细胞的条件培养基导致 PC-12 神经元显着的神经突生长 体外，它被 Nrg4 沉默所抑制。我们开发的新技术将用于删除脂肪细胞 Nrg4 和 Negr1 在植入受体小鼠之前使用基于 CRISPR 的纳米粒子并进行分析 它们对 SNS 神经支配的影响。最后，目标3测试脂肪细胞DNL中间代谢产物Acetyl是否 iAdFASNKO 小鼠中的 CoA/丙二酰辅酶 A 启动信号传导以引起 Nrg4 表达和 SNS 扩展。这些 iAdFASNKO 小鼠的脂肪细胞代谢物及其细胞蛋白的乙酰化和丙二酰化将被 在双 KO 小鼠中，ATP 柠檬酸裂解酶 (ACLY) 被 KO 逆转，ACLY 产生乙酰辅酶 A。识别 调节脂肪细胞功能的 DNL 中间体将能够定义其潜在机制。 总之，这些实验具有很大的潜力来定义由 DNL 驱动的新信号通路 调节脂肪褐变的代谢物和 2 型糖尿病的新治疗策略。