Transcriptional Control of High-thermogenic Adipocyte Development

棕色脂肪组织由异质性脂肪细胞群组成，其共存证明了这一点。 低产热脂肪细胞（线粒体含量低，解偶联蛋白1（UCP 1）低）和高 组织内的产热脂肪细胞是脂肪细胞异质性和可塑性的基本特征。 然而，脂肪细胞异质性的潜在机制及其在代谢生理学和代谢过程中的意义， 疾病定义不明确。在我们的初步研究中，我们发现了一个富含JunB的种群， 棕色脂肪库内的脂肪细胞（JunB+脂肪细胞）表现出较低的产热能力和较少的 脂滴相比，高产热脂肪细胞。JunB+脂肪细胞的丰度增加 在肥胖期间。通过snRNA-seq和功能检测，我们观察到脂肪细胞中JunB的失活， 增加表现出高线粒体含量和产热能力的脂肪细胞的分数。 重要的是，在UCP 1+脂肪细胞中的JunB消融导致基础和冷诱导能量增加 消耗和保护小鼠免受饮食诱导的肥胖。基于这些新发现，我们 假设JunB在控制脂肪细胞异质性和系统能量方面起关键作用 和葡萄糖稳态。我们将阐明JunB抑制高产热的机制， 细胞分化，并通过检查JunB+脂肪细胞的身份，起源， 和这个独特亚群的命运我们还将使用白喉毒素基因A链（DTA）- 介导的方法来消融脂肪组织内的JunB+脂肪细胞，以确定这种介导的方法的生理作用。 调节能量和葡萄糖代谢。JunB对脂肪细胞的调控作用 异质性和可塑性将为棕色脂肪细胞的生物学和固体生物学提供新的知识。 该基金会旨在帮助开发肥胖及其相关疾病的治疗干预措施。

Brown adipose tissue is composed of heterogenous adipocyte populations evidenced by the coexistence of low-thermogenic adipocytes (mitochondria content low and uncoupling protein 1 (UCP1) low) and high- thermogenic adipocytes within the tissue, a fundamental feature of adipocyte heterogeneity and plasticity. However, the mechanisms underlying adipocyte heterogeneity and its significance in metabolic physiology and disease remain poorly defined. In our preliminary study, we discovered a population of JunB-enriched adipocytes (JunB+ adipocytes) within the brown fat depot that exhibits lower thermogenic capacity and less lipid droplets compared to high-thermogenic adipocytes. The abundance of JunB+ adipocytes is increased during obesity. Through snRNA-seq and functional assays, we observed that inactivation of JunB in adipocytes increased the fraction of adipocytes exhibiting high mitochondrial content and thermogenic capacity. Importantly, JunB ablation in UCP1+ adipocytes resulted in enhanced basal and cold-induced energy expenditure and protected mice against diet-induced obesity. Based upon these novel findings, we hypothesize that JunB serves a critical role in governing adipocyte heterogeneity and systemic energy and glucose homeostasis. We will elucidate the mechanisms by which JunB suppresses high-thermogenic cell differentiation and explore the regulation of JunB+ adipocyte development by examining the identity, origin, and fate of this distinct subpopulation. We will also use Diphtheria toxin gene A chain (DTA)- mediated approach to ablate JunB+ adipocytes within adipose tissue to determine the physiological role of this subpopulation in regulating energy and glucose metabolism. Characterization of JunB in regulating adipocyte heterogeneity and plasticity will provide novel knowledge to the biology of brown adipocyte and a solid foundation to aid in the development of therapeutic interventions for obesity and its associated disorders.