Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Boston, MA, USA.
Broad Institute of MIT and Harvard, Cambridge, MA, USA.
Nat Commun. 2024 May 31;15(1):4646. doi: 10.1038/s41467-024-48885-y.
AgRP neurons in the arcuate nucleus of the hypothalamus (ARC) coordinate homeostatic changes in appetite associated with fluctuations in food availability and leptin signaling. Identifying the relevant transcriptional regulatory pathways in these neurons has been a priority, yet such attempts have been stymied due to their low abundance and the rich cellular diversity of the ARC. Here we generated AgRP neuron-specific transcriptomic and chromatin accessibility profiles from male mice during three distinct hunger states of satiety, fasting-induced hunger, and leptin-induced hunger suppression. Cis-regulatory analysis of these integrated datasets enabled the identification of 18 putative hunger-promoting and 29 putative hunger-suppressing transcriptional regulators in AgRP neurons, 16 of which were predicted to be transcriptional effectors of leptin. Within our dataset, Interferon regulatory factor 3 (IRF3) emerged as a leading candidate mediator of leptin-induced hunger-suppression. Measures of IRF3 activation in vitro and in vivo reveal an increase in IRF3 nuclear occupancy following leptin administration. Finally, gain- and loss-of-function experiments in vivo confirm the role of IRF3 in mediating the acute satiety-evoking effects of leptin in AgRP neurons. Thus, our findings identify IRF3 as a key mediator of the acute hunger-suppressing effects of leptin in AgRP neurons.
下丘脑弓状核中的 AgRP 神经元(ARC)协调与食物供应波动和瘦素信号相关的食欲的稳态变化。确定这些神经元中相关的转录调节途径一直是当务之急,但由于其丰度低和 ARC 细胞多样性丰富,这些尝试一直受到阻碍。在这里,我们从雄性小鼠在饱腹、禁食诱导性饥饿和瘦素诱导性饥饿抑制的三种不同饥饿状态下生成了 AgRP 神经元特异性转录组和染色质可及性图谱。对这些整合数据集的顺式调控分析,使我们能够在 AgRP 神经元中鉴定出 18 个潜在的促进饥饿和 29 个潜在的抑制饥饿的转录调节因子,其中 16 个被预测为瘦素的转录效应因子。在我们的数据集内,干扰素调节因子 3(IRF3)作为瘦素诱导性饥饿抑制的主要候选介质出现。体外和体内测量的 IRF3 激活显示,给予瘦素后,IRF3 的核占据增加。最后,体内的增益和损耗功能实验证实了 IRF3 在介导瘦素在 AgRP 神经元中引起急性饱腹感方面的作用。因此,我们的研究结果确定了 IRF3 作为瘦素在 AgRP 神经元中急性抑制饥饿作用的关键介质。