Project description:To identify novel neurocircuits activated upon short-term HFD feeding, we employed phosphoribotrap-profiling, which allows for the unbiased identification of alterations in neuronal activation via immunoprecipitation of phosphorylated S6 ribosomal protein-tagged ribosomes from hypothalamic extracts of mice exposed to either 3 days of normal chow diet or HFD-feeding. We have analyzed mRNA selectively expressed in hypothalamic cells activated by a either normal chow diet (NCD)-feeding for 3 days or high fat diet (HFD)-feeding for 3 days. 10-week-old male C57/BL6N mice were put either on a normal chow diet or a high fat diet for 3 days. Afterwards, mice were sacrificed by cervical dislocation. The hypothalamus was rapidly dissected using a stainless steel brain matrix and immediately frozen in liquid nitrogen. Hypothalamic tissues were pooled (8 per IP).
Project description:Remyelination failure contributes to axonal dysfunction in neurodegenerative disorders. But whether astrocytes, the most abundant glial cell type in demyelinated lesions, support or impede remyelination is controversial. Following focal demyelinated lesions of the mouse corpus callosum induced with the myelin toxin lysolecithin, we used TRAP (translational ribosome affinity purification) sequencing to isolate and sequence ribosome-associated mRNAs which are being actively translated in astrocytes, and studied how the responses and molecular mechanisms in astrocytes are linked to remyelination.
Project description:Alzheimer’s disease is known to alter astrocytes, but the effect of Aß and Tau pathology on these cells remains poorly understood. We investigated the transcriptomic behaviour of astrocytes (via translating ribosome affinity purification (TRAP)), and bulk brain tissue, in mouse models of APP/PS1 ß-amyloidopathy and MAPT-P301S tauopathy, in a mouse model overexpressing cytoprotective Nrf2 specifically in astrocytes (GFAP-Nrf2 model), and in crosses between the amyloidopathy and tauopathy models with the GFAP-Nrf2 mouse.
Project description:Recent genome-wide association studies (GWAS) identified Dusp8, a dual-specificity phosphatase targeting MAP kinases, as type 2 diabetes risk gene. Here, we unravel Dusp8 as gatekeeper in the hypothalamic control of glucose homeostasis in mice and humans. Male but not female Dusp8 loss-of-function mice, either with global or CRH neuron-specific deletion, had impaired systemic glucose tolerance and insulin sensitivity when exposed to high-fat diet (HFD). Mechanistically, we found impaired hypothalamic–pituitary–adrenal (HPA) axis feedback, blunted sympathetic responsiveness, and chronically elevated corticosterone levels driven by hypothalamic hyperactivation of Jnk signaling. Accordingly, global Jnk1 ablation, AAV-mediated Dusp8 overexpression in the mediobasal hypothalamus, or metyrapone-induced chemical adrenalectomy rescued the impaired glucose homeostasis of male Dusp8 KO mice, respectively. This sex-specific and rheostatic role of murine Dusp8 in governing hypothalamic Jnk signaling, insulin sensitivity and systemic glucose tolerance was consistent with fMRI data in human volunteers that revealed an association of the DUSP8 rs2334499 risk variant with hypothalamic insulin resistance in men. In summary, our findings suggest GWAS-identified gene Dusp8 as novel hypothalamic factor that plays a functional role in the etiology of type 2 diabetes.
Project description:We demonstrate that high fat diet (HFD)-induced obesity alters the transcriptional state of lateral hypothalamic glutamate neurons in mice.
Project description:Purpose: Aim of the study is to identify changes in hepatic gene expression induced by either a 40kcal% coconut oil rich high fat diet (HFD), a 40kcal% soybean oil plus coconut oil high fat diet (SO-HFD) or a low fat vivarium chow diet (Viv). Methods: Livers from mice that had been fed one of the above mentioned diets for 35 weeks, were used to make cDNA libraries that were then sent for deep sequencing, using the Illumina TruSeq RNA. Result: Many genes involved in metabolism, lipid binding, transport and storage and many Cyp genes are dysregulated in the two high fat diets as compared to Viv HFDs in SO-HFD mice. Comparing the two HFDs shows more metabolism and disease related genes dysregulated in SO-HFD vs HFD. Conclusion: A diet high in soybean oil may be more detrimental to metabolic health than a diet high in saturated fats. cDNA isolated from livers from mice fed HFD, SO-HFD or Viv for 35 weeks, were 50bp pair-ended sequenced in triplicate using Illumina TruSeq RNA Sample Prep v2 Kit.
Project description:In order to establish an obese mouse model, female mice were continuously fed with a high-fat diet (HFD) or a normal diet (control) for 16 weeks beginning at three weeks of age. In this paper, these mice are termed ‘HFD mice’ and ‘control mice’, respectively. Accordingly, we call their oocytes ‘HFD oocytes’ and ‘control oocytes’. Substantial evidence indicates that the effects of maternal obesity on embryo/offspring development can be attributed to factors within the oocyte (9). To identify such potential effectors, we performed a comparative proteomic analysis of ovulated MII oocytes from control and HFD mice.
Project description:Psychiatric disorders, especially major depressive disorder, are prominent cause of disability worldwide, and in dire need of better diagnostic and therapeutic tools. In order to identify the cellular mechanisms underlying major depressive disorder we sought to understand the role of astrocytes, the most numerous subtype of glia, in this disease utilizing the TRAP gene expression analysis and chronic social defeat mouse model of depression. TRAP translational profiling is a method that allows investigators to genetically characterize specific cell types in complex tissues such as mouse brain. Using this technique we obtained RNA-Seq data from actively translating transcripts present in astrocytes. We generated the molecular profile of astrocytes from multiple brain regions affected by stress-induced depression, the prefrontal cortex, hippocampus, accumbens nucleus and caudate putamen of adult Aldh1l1-EGFP/Rpl10a (JD130) mice after chronic social defeat stress paradigm. The results of this study will further our understanding of depression pathophysiology and will provide possible targets for novel or supplementary therapies.