LIFR-alpha/JAK/STAT3-dependent Adipose Inflammation Contributes to Obesity-Associated NAFLD - Resubmissi

LIFR-alpha/JAK/STAT3 依赖性脂肪炎症导致肥胖相关 NAFLD - Resubmissi

• 批准号: 10544176
• 负责人: Rodney E Infante
• 金额: $ 51.73万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10544176
• 关键词: Adenylate Cyclase; Adipocytes; Adipose tissue; Affect; Animals; Atlases; Blood Vessels; Cell Line; Cells; Complex; Cyclic AMP; Cytokine Signaling; Data; Dependence; Development; Diet; Equilibrium; Family; Fatty acid glycerol esters; Genetic; Genetic Models; Hepatic; High Fat Diet; Immune; Immune signaling; Inflammation; Inflammatory; Interleukin-6; Knockout Mice; LIF gene; LIFR gene; Lipid Mobilization; Lipolysis; Liver; Mediating; Mediator; Messenger RNA; Metabolic; Modeling; Molecular; Mus; Obesity; Pathway interactions; Phenotype; Phosphorylation; Recombinants; Regulation; Resolution; Role; STAT3 gene; Signal Pathway; Signal Transduction; Steatohepatitis; Techniques; Triglycerides; Wild Type Mouse; adipokines; cell type; comorbidity; comparison control; counterregulation; cytokine; diet-induced obesity; in vitro Assay; inhibitor; leukemia inhibitory factor receptor; mouse model; non-alcoholic fatty liver disease; novel; obesity development; programs; receptor; response; single-cell RNA sequencing; transcriptome; transcriptome sequencing

ABSTRACT Although adipose inflammation is associated with obesity, its role in reprogramming adipocytes and other cells in adipose towards the development of obesity’s metabolic comorbidities including steatosis remain unclear. The complex intracellular (stromal, vascular, immune, and adipocyte) interactions within adipose tissue ultimately regulate its size by balancing adipocyte triacylglyceride (TAG) lipolysis and synthesis. The inflammatory signaling of and between these cell types may also influence adipocyte responses to cAMP modulators. To understand the convergence of these interactions, we previously identified cytokine leukemia inhibitory factor (LIF) as a secretory molecule that increased adipose inflammation and lipolysis. Wild type mice on a high fat diet (HFD) demonstrated 7-fold higher LIF and IL-6 adipose mRNA than matched animals on normal diets. When recombinant LIF was administered to wild-type mice, it caused >50% loss of fat mass through JAK/STAT3- dependent reprogramming of adipose tissue, increasing lipolysis and amplifying inflammation by altering the expression of other cyto/adipokines. JAK inhibitor treatment of rLIF-administered mice suppressed adipose loss through 1) inhibition of adipose inflammation as determined by decreased STAT3 phosphorylation, 2) decreased adipocyte lipolysis, and 3) inhibition of cyto/adipokine changes. To establish the importance of this signaling pathway to adipose inflammation, we selectively silenced LIF receptor (LIFR-α, gene LIFR) or STAT3 in adipocytes and assessed murine development in diet-induced obesity. Both models had decreased adipose inflammation resulting in a 50% increase in adipose mass and a ~75% reduction in total hepatic TAG levels compared to controls, limiting non-alcoholic fatty liver disease (NAFLD) and steatohepatitis in these mice. Conversely, with adipocyte silencing of the JAK/STAT counter-regulator SOCS3 in mice on HFDs, we observed the opposite phenotype with a ~30% reduction in adipose mass compared to controls. We hypothesize that a LIFR-α/JAK/STAT3-dependent Cytokine-Adipose-Hepatic Axis facilitates adipose inflammation, leading to increased lipolysis and altered expression of other cyto/adipokines. The activation of this axis limits adipose expansion, resulting in TAG mobilization from adipose to the liver and ultimately contributing to NAFLD/steatohepatitis. This inflammatory-driven axis also affects adipose responses to systemic metabolic change, sensitizing adipocytes to lipolytic regulation by other cAMP modulators. Finally, we present preliminary data that the IL-6 family of cytokines signal through JAK/STAT3 inducing the expression of adenylyl cyclase 5 (ADCY5) to reprogram adipocytes in regulating lipid mobilization. SA1 will evaluate the contribution of the LIFR-α/JAK/STAT3 signaling cascade in adipocytes to the Cytokine-Adipose-Hepatic Axis. SA2 will use a genetics-based approach to verify that cytokine-mediated reprogramming of adipocytes in promoting lipid mobilization requires ADCY5 function. SA3 will use single cell RNA-Seq techniques in our multiple mouse models to identify non-adipocyte contributors to inflammation-regulated obesity and NAFLD.

摘要 尽管脂肪炎症与肥胖有关，但它在脂肪细胞和其他细胞重新编程中的作用 在肥胖的发展过程中，包括脂肪变性在内的代谢合并症仍不清楚。这个 最终脂肪组织内复杂的细胞内(间质、血管、免疫和脂肪细胞)相互作用 通过平衡脂肪细胞三酰甘油(Tag)的脂解和合成来调节其大小。炎症信号 这些细胞类型之间的差异也可能影响脂肪细胞对cAMP调节剂的反应。要理解 这些相互作用的趋同，我们以前发现细胞因子白血病抑制因子(LIF)是一种 增加脂肪炎症和脂肪分解的分泌分子。高脂饮食(HFD)野生型小鼠 在正常饮食条件下，LIF和IL-6脂肪基因的mRNA值是匹配动物的7倍。什么时候 将重组LIF应用于野生型小鼠，通过JAK/STAT3-1途径使脂肪量减少50%。 依赖于脂肪组织的重编程，增加脂肪分解并通过改变 其他细胞/脂肪因子的表达。JAK抑制剂治疗RLIF抑制小鼠脂肪丢失 通过1)通过降低STAT3磷酸化确定的抑制脂肪炎症，2)减少 脂肪细胞脂解；3)抑制细胞/脂肪因子的变化。为了确定这一信号的重要性 途径，我们选择性地沉默了LIF受体(LIFR-α，基因LIFR)或STAT3在 脂肪细胞和评估饮食诱导的肥胖小鼠的发育。这两种模型都降低了脂肪含量 炎症导致脂肪质量增加50%，肝脏总TAG水平降低约75% 与对照组相比，限制了这些小鼠的非酒精性脂肪性肝病(NAFLD)和脂肪性肝炎。 相反，随着脂肪细胞沉默JAK/STAT反向调节因子SOCS3在HFD上的小鼠，我们观察到 相反的表型，与对照组相比脂肪质量减少了约30%。我们假设一个 LIFR-α/JAK/STAT3依赖的细胞因子-脂肪-肝轴促进脂肪炎症，导致 脂肪分解增加，其他细胞/脂肪因子的表达改变。这一轴的激活限制了脂肪 扩张，导致标签从脂肪到肝脏的动员，并最终有助于 非酒精性脂肪肝/脂肪性肝炎。这种炎症驱动的轴也会影响脂肪对全身代谢的反应。 改变，使脂肪细胞对其他cAMP调节剂的脂解调节敏感。最后，我们给出了初步的 IL-6家族细胞因子通过JAK/STAT3诱导腺苷环化酶5表达的研究 (ADCY5)在调节脂质动员中重新编程脂肪细胞。SA1将评估脂肪细胞中LIFR-α/JAK/STAT3信号级联对细胞因子-脂肪-肝轴的贡献。SA2将使用一种基于遗传学的方法来验证细胞因子介导的脂肪细胞重编程在促进脂肪动员方面的作用 需要ADCY5功能。SA3将在我们的多个小鼠模型中使用单细胞RNA-Seq技术来识别 非脂肪细胞对炎症调节性肥胖和NAFLD的贡献。