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 我们实验室的总体长期目标是了解和利用脂肪组织的方式 对全身葡萄糖耐受性和胰岛素敏感性产生强大的控制。少量 小鼠棕色（蝙蝠）或移植到受体小鼠中的人“米色”脂肪细胞可以改善葡萄糖 体内稳态，强调理解脂肪褐变机制的重要性。基于 知道从头脂肪形成（DNL）途径中间的知识显示潜在信号传导 功能（例如，乙酰基COA作为组蛋白乙酰化的底物，转录调节）和脂肪细胞 DNL受肥胖，禁食，冷暴露和运动的高度调节，我们假设脂肪细胞DNL为 代谢中的主要调节节点。我们旨在通过扰动此DNL途径来审问这个概念 通过DNL酶ATP柠檬酸裂解酶（ACLY）和脂肪酸合酶（FASN）的选择性KO。我们的 初步数据通过揭示FASN KO上调脂肪细胞来鼓励这种方法 神经营养因子神经结合蛋白4（NRG4），并增强特警交感神经元（SNS）的膨胀 即使在热中性（30c）中。因此，DNL代谢产物（乙酰COA，malonyl COA）或DNL产物 （Palmitoyl COA）似乎与控制脂肪的社交媒体活动，脂肪能量消耗密切相关 和全身葡萄糖稳态。基于这些数据，该项目旨在确定细胞 和分子机制，脂肪细胞可以向局部的社交媒体神经元发出信号并促进 特警中米色脂肪细胞的发展。 AIM 1将确定iadfasnko中的米色脂肪细胞是否 小鼠是通过成熟白色到米色脂肪细胞的直接“转换”而得出的，或者通过旁分泌信号传导 诱导祖细胞的分化为米色脂肪细胞。为了解决潜在机制，AIM 2将 确定NRG4（和NEGR1（也可能也可以上调）是否介导FASN缺乏的效果 脂肪细胞在体内引起SNS的膨胀。此目标基于令人兴奋的初步数据 来自此类脂肪细胞的条件培养基在PC-12神经元中引起明显的神经蛋白神经落生 体外，通过NRG4沉默抑制。我们开发的新技术将用于删除脂肪细胞 NRG4和NEGR1在将基于CRISPR的纳米颗粒植入接受者之前使用基于CRISPR的纳米颗粒并分析 它们对SN神经的影响。最后，AIM 3测试是否脂肪细胞DNL中间代谢物乙酰代谢物是否 IADFASNKO小鼠中的COA/malonyl COA启动信号引起NRG4表达和SNS膨胀。这些 IADFASNKO小鼠中的脂肪细胞代谢产物及其乙酰化和细胞蛋白的误导化将是 在双KO小鼠中产生乙酰COA的ATP柠檬酸裂解酶（ACLY）的KO逆转。识别 DNL中间体调节脂肪细胞功能将启用其潜在机制。 总之，这些实验具有定义由DNL驱动的新型信号通路的高潜力 调节脂肪褐变和2型糖尿病的新治疗策略的代谢产物。