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: 10087919
• 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 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10087919
• 关键词: ATP Citrate (pro-S)-Lyase; Acetyl Coenzyme A; Acetylation; Address; Adipocytes; Adipose tissue; Antibodies; Appearance; Brown Fat; Caloric Restriction; Cells; 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; 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; base; blood glucose regulation; experimental study; fatty acid oxidation; glucose tolerance; implantation; improved; in vivo; insulin sensitivity; lipid biosynthesis; nanoparticle; nerve supply; neuregulin-4; neuronal growth; 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.

摘要 我们实验室的首要长期目标是了解和利用脂肪组织 对全身葡萄糖耐量和胰岛素敏感性进行有效控制。少量的 将小鼠棕色（BAT）或人“米色”脂肪细胞移植到受体小鼠中可以改善葡萄糖 内稳态，强调了解脂肪布朗宁机制的重要性。基于 认识到从头脂肪生成（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、转录调节底物）和脂肪细胞 DNL受肥胖、禁食、寒冷暴露和运动的高度调节，我们假设脂肪细胞DNL是 代谢中的主要调节节点。我们的目标是通过扰乱DNL通路来探究这一概念 通过选择性KO DNL酶ATP柠檬酸裂解酶（ACLY）和脂肪酸合酶（FATCH）。我们 初步的数据通过揭示FIGHKO上调脂肪细胞 神经营养因子神经调节蛋白4（Nrg 4）并增强sWAT交感神经元（SNS）的扩张， 即使在热中性（30 ℃）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 （棕榈酰辅酶A）似乎与控制脂肪SNS活性、脂肪能量消耗 和全身葡萄糖平衡。根据这些数据，该项目旨在确定蜂窝 以及脂肪细胞可以向局部SNS神经元发出信号并促进其生长的分子机制。 sWAT中米色脂肪细胞的发育。目的1将确定iAdFASNKO中的米色脂肪细胞是否 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 诱导祖细胞分化为米色脂肪细胞。为了解决潜在机制，目标2将 确定Nrg 4（和Negr 1，也可能是上调的）是否介导Fas缺失的效应， 脂肪细胞引起SNS在体内的扩张。这一目标是基于令人兴奋的初步数据显示， 来自这种脂肪细胞的条件培养基导致PC-12神经元中显著的神经突生长， 体外，其被Nrg 4沉默抑制。我们开发的新技术将用于删除脂肪细胞 在植入受体小鼠之前使用基于CRISPR的纳米颗粒对Nrg 4和Negr 1进行分析 对SNS神经支配的影响最后，目标3测试脂肪细胞DNL中间代谢物乙酰基 iAdFASNKO小鼠中的CoA/丙二酰CoA启动信号传导以引起Nrg 4表达和SNS扩增。这些 iAdFASNKO小鼠中的脂肪细胞代谢物及其细胞蛋白质的乙酰化和丙二酰化， 在双KO小鼠中，通过产生乙酰辅酶A的ATP柠檬酸裂解酶（ACLY）的KO逆转。识别 调节脂肪细胞功能的DNL中间体将使得能够定义它们的潜在机制。 总之，这些实验具有很高的潜力来定义由DNL驱动的新的信号通路 调节脂肪布朗宁的代谢物和2型糖尿病的新治疗策略。