Project description:To uncover the cellular identifies of the mouse hypothalamic Lepr cells, we used single nucleus RNA-seq (snRNA-seq) from enriched hypothalamic Lepr cells.
Project description:The hypothalamus is a central regulator of many behaviors essential for survival such as temperature regulation, food intake and circadian rhythms. However, the molecular pathways that mediate hypothalamic development are largely unknown. To identify genes expressed in developing mouse hypothalamus, microarray analysis at 12 different developmental time points was performed. Developmental in situ hybridization was conducted for 1,045 genes dynamically expressed by microarray analysis. In this way, we identified markers that stably labeled each major hypothalamic nucleus over the entire course of neurogenesis, and thus constructed a detailed molecular atlas of the developing hypothalamus. As proof of concept for the utility of this data, we used these markers to analyze the phenotype of mice where Sonic Hedgehog (Shh) was selectively deleted from hypothalamic neuroepithelium, demonstrating an essential role for Shh in anterior hypothalamic patterning. Our results serve as a resource for functional investigations of hypothalamic development, connectivity, physiology, and dysfunction. Affymetrix MOE430 microarrays were used to analyze the expression patterns of mouse hypothalamic and preoptic area tissues. The results were compared across the variables of Strain, Sex and Age.
Project description:The hypothalamus is a central regulator of many behaviors essential for survival such as temperature regulation, food intake and circadian rhythms. However, the molecular pathways that mediate hypothalamic development are largely unknown. To identify genes expressed in developing mouse hypothalamus, microarray analysis at 12 different developmental time points was performed. Developmental in situ hybridization was conducted for 1,045 genes dynamically expressed by microarray analysis. In this way, we identified markers that stably labeled each major hypothalamic nucleus over the entire course of neurogenesis, and thus constructed a detailed molecular atlas of the developing hypothalamus. As proof of concept for the utility of this data, we used these markers to analyze the phenotype of mice where Sonic Hedgehog (Shh) was selectively deleted from hypothalamic neuroepithelium, demonstrating an essential role for Shh in anterior hypothalamic patterning. Our results serve as a resource for functional investigations of hypothalamic development, connectivity, physiology, and dysfunction.
Project description:Hypothalamic nuclei which regulate homeostatic functions express leptin receptor (LepR), the primary target of the satiety hormone leptin. Single-cell RNA sequencing (scRNA-seq) has facilitated the discovery of a variety of hypothalamic cell types. However, low abundance of LepR transcripts prevented further characterization of LepR cells. Therefore, we perform scRNA-seq on isolated LepR cells and identify eight neuronal clusters, including three uncharacterized Trh-expressing populations as well as 17 non-neuronal populations including tanycytes, oligodendrocytes and endothelial cells. This includes food restriction to measure the response of Lepr positive cells to fasting. Using FACS sorting into 384 well plates and Celseq2 method, we generated a high-quality dataset containing a median of 12,082 unique counts and 4,756 genes per cell.
Project description:Leptin receptor (LEPR) identifies a subpopulation of hematopoietic stem cells (HSCs) with high repopulating potential. In this study, we demonstrated that LEPR-expressing HSCs while exhibiting significantly higher engrafting potential and self-renewing capacity in young mice showed early age-associated decline in these functions as compared to the LEPR- HSCs. LEPR+ HSCs have transcriptomic profiles significantly different from LEPR- HSCs in young mouse bone marrow, but middle-aged HSCs do not have distinct transcriptomic profiles based on LEPR status. The age-related phenotypes were associated with a proinflammatory transcriptomic profile at baseline in young LEPR+ HSCs, which was further exacerbated by age. In contrast, LEPR- HSCs did not show age-associated functional impairment at the ages tested. This suggested that subsets of HSCs are susceptible to age-related decline in function at varying ages and that LEPR+ HSCs are a potential target for early cellular therapeutic interventions in delaying the detrimental effects of aging in hematopoiesis.
Project description:To better understand the epigenetic mechanism underlying pubertal onset, the hypothalamic genome-wide chromatin accessibility patterns in mouse arcuate nucleus at early and late pubertal stages were explored. Female mice have been widely used in multiple studies on pubertal development as they present the similar molecular behaviors in HPG axis and stable cycles of menstrual calendar like human. Hypothalamic ARC underwent a huge epigenetic and genetic reprogramming to adapt to the response and feedback on sexual hormones during the stages of early pubertal (2-5-week of age) and late puberty (5-8-week of age) . We harvested 4- and 8-week hypothalamic ARC and employed ATAC-seq on a genome-wide scale. Combined with previous RRBS, RRHP and RNA-seq, the connections between DNA (hydroxyl)methylation in retroelements and gene expression were studied, emphasizing the importance of epigenetic alterations in regulating transcription in puberty onset.
Project description:Leptin receptors (Lepr) are expressed by various types of stem cells including mesenchymal stem cells, hematopoietic stem cells, embryonic stem cells, and induced pluripotent stem cells. Leptin/lepr signaling is also a central regulator of metabolism. However, the role of Lepr in pluripotency, metabolic disease progression and growth development is still controversial and poorly understood. In the present study, we explored the Lepr function in disease progression, pluripotency and metabolism using day 14.5 mouse embryonic fibroblasts (MEFs) and their reprogrammed induced pluripotent stem cells (iPSCs) as model system. We successfully reprogrammed mouse embryonic fibroblasts into iPSCs from control and db/db (Lepr deficient) mice. Using a global quantitative proteomic approach, we identified key pathways regulating pluripotency, metabolic homeostasis and protein synthesis during fetal growth and development. The Lepr MEFs show abnormal metabolic abnormalities and mitochondrial dysfunction as compared to control MEFs, while Lepr iPSCs show upregulated elongated factor 4 e (eIF4e) protein synthesis pathway and altered Oct4 and Stat3 pathways which are involved in normal fetal growth development. Furthermore, chip analysis revealed that higher Stat3 binding on the promoter of eIF4e in Lepr iPSCs leads to higher protein synthesis in these cell types as compared to control iPSCs. Finally, point mutation corrected Lepr iPSCs using CRISPR/Cas9 gene editing method showed recovered pluripotency, metabolic and protein synthesis pathways. In conclusion, we have shown that Lepr signaling is involved in the regulation of the metabolic properties and key developmental pathways in MEFs and stemness of pluripotent stem cells. Disruption of Lepr signaling has been shown to involve in the pathophysiology of various diseases including obesity and diabetes. The generated MEFs and iPSCs in this present study provide valuable tools to explore the role of Lepr in the progression of obesity, diabetes and metabolic abnormalities, and to find the putative targets of Lepr signaling during the development of these diseases.
Project description:The molecular mechanism regulating phasic corticotropin-releasing hormone (CRH) release from parvocellular neurons (PVN) remains poorly understood. Here, we find a cohort of parvocellular cells interspersed with magnocellular PVN neurons expressing secretagogin. Single-cell transcriptome analysis combined with protein interactome profiling identifies secretagogin neurons as a distinct CRH-releasing neuron population reliant on secretagoginM-bM-^@M-^Ys Ca2+ sensor properties and protein interactions with the vesicular traffic and exocytosis release machineries to liberate this key hypothalamic releasing hormone. single cells from the PVN region juvenile (21-28 days) mice were dissected and subject to whole transcriptome analysis