Translational Profiling Reveals the Transcriptome of Leptin Receptor Neurons and Genes It's Reulation By Leptin

[摘要] Two thirds of American adults are overweight and at risk for complications such as Type 2 diabetes, heart disease, stroke, and fertility problems. The adipose hormone, leptin, signals via the long isoform of its receptor (LepRb) in the central nervous system to regulate diverse determinants of energy balance, including food intake, energy expenditure, and neuroendocrine output. Previous studies have demonstrated that the lack of leptin or its receptor promotes hyperphagic obesity among other phenotypes.Importantly, the identity of many LepRb subpopulations, as well as the transcriptional effects of leptin in these populations, remain almost entirely unknown. Recently, the optimization of Translating Ribosome Affinity Purification (TRAP) technology has allowed for the isolation of mRNA from specific neuronal populations via the cre-dependent induction of affinity-tagged ribosomes. We first examined the transcriptome of LepRb neurons to identify markers for LepRb subpopulations. We isolated mRNA from mouse hypothalamic and brainstem LepRb cells by TRAP and analyzed it by RNA-seq (TRAP-Seq). TRAP-Seq defined the LepRb neuron transcriptome and revealed novel markers for previously unrecognized subpopulations of LepRb neurons. LepRb mRNA was enriched for markers of peptidergic neurons, including Pdyn. Pdyn-cre-mediated ablation of Lepr-flox in Pdyn neurons (LepRb-Pdyn-KO mice) blunted energy expenditure to promote obesity during high-fat feeding.To determine the regulation of the LepRb transcriptome by leptin, we employed LepRb-specific TRAP-seq on mRNA isolated from the hypothalami of mice treated with exogenous leptin, genetically leptin-deficient (ob/ob) mice, mice exposed to diet induced obesity (DIO), and mice in which STAT3 had been specifically ablated from LepRb neurons. Exogenous leptin treatment induced a number of transcription factors and intracellular proteins but did not affect neuropeptide transcription/translation. In contrast, states of extreme leptin deprivation or repletion, such as in untreated ob/ob mice or in DIO mice, induced changes in multiple neuropeptide species, many of which were also altered in LepRb-specific STAT3 ablated mice. This analysis revealed a small number of transcripts that were altered in multiple treatment conditions, including Socs3, Atf3, Asb4 and members of the Serpina3 family, and which may represent direct and essential targets of hypothalamic LepRb action in the control of energy balance.

[发布机构] University of Michigan

[效力级别] Neuroendocrinology

[关键词] Leptin action in the hypothalamus;Neuroendocrinology;Physiology;Health Sciences;Mol & Integrtv Physiology PhD