Project description:We report changes in GR and Pol II binding profiles genome-wide upon treatment with corticosterone (Cort) for 20 minutes, treatment with Cort for 20 minutes followed by hormone withdrawal for 40 minutes, 60 minutes continuous stimulation with Cort, and 60 minutes continuous stimulation with Dexamethasone (Dex). We examine GR binding upon following treatments: 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant; Pol II binding upon following treatments: 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant, 60' Dex Constant; Pol II binding upon Mock treatments simulating 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant; CTCF binding profile of untreated cells.
Project description:Although glucocorticoids (GCs) are known to exert numerous effects in the hippocampus, their chronic regulatory functions remain poorly understood. Moreover, evidence is inconsistent regarding the longstanding hypothesis that chronic GC exposure promotes brain aging/Alzheimer's disease. Here, we adrenalectomized male F344 rats at 15-months-of-age, maintained them for 3 months with implanted corticosterone (CORT) pellets producing low or intermediate (glucocorticoid-receptor (GR)-activating) blood levels of CORT, and performed microarray/pathway analyses in hippocampal CA1. We defined the chronic GC-dependent transcriptome as 393 genes that exhibited differential expression between Intermediate- and Low-CORT groups. Short-term CORT (4 days) did not recapitulate this transcriptome. Functional processes/pathways overrepresented by chronic CORT-upregulated genes included learning/plasticity, differentiation, glucose metabolism and cholesterol biosynthesis, whereas processes overrepresented by CORT-downregulated genes included inflammatory/immune/glial responses and extracellular structure. These profiles indicate that GCs chronically activate neuronal/metabolic processes while coordinately repressing a glial axis of reactivity/inflammation. We then compared the GC-transcriptome with a previously-defined hippocampal aging transcriptome, revealing a high proportion of common genes. Although CORT and aging moved expression of some common genes in the same-direction, the majority were shifted in opposite directions by CORT and aging (e.g., glial inflammatory genes downregulated by CORT are upregulated with aging). These results contradict the hypothesis that GCs simply promote brain aging, and also suggest that the opposite-direction shifts during aging reflect resistance to CORT regulation. Therefore, we propose a new model in which aging-related GC resistance develops in some target pathways while GC overstimulation develops in others, together generating much of the brain aging phenotype. Forty male Fischer 344 rats aged 14-15 months (late mid-age) were either sham operated (n=10) or adrenalectomized (n=30) at Harlan, Inc. (Indianapolis) and shipped to University of Kentucky 7-10 d after surgery. Animals were allowed to acclimate for 2 weeks after receipt prior to pellet-implant and were provided with food and water ad lib. Adrenalectomized (ADX) animals were maintained on drinking water containing isotonic saline with 1% sucrose, and also given supplemental feed mash (standard chow mixed with water and warmed) and apple chunks, as well as subcutaneous injections of 1.25 mg corticosterone sulfate (Solu-DeltaCort, Pfizer). During pellet-implant surgery, subjects were anesthetized with isoflurane, placed on a warming pad, and a 3 cm2 area on the animal's flank was shaved and sterilized. A 1-cm incision was made through the skin to form a subcutaneous pocket. Each sham animal received an inert pellet. ADX animals were divided into two groups, low-dose animals (n = 20) received one 25 mg CORT pellet and intermediate-dose animals (n = 10) received one 200 mg CORT pellet (slow release pellets, Innovative Research of America, Sarasota, FL). Incisions were closed with wound clips (removed after 7-10 days). Following implant surgery, subjects were housed singly for 3 months prior to euthanasia at age 18 months. Low-dose animals continued to receive saline/ sucrose drinking water, but other supplementation (food mash, Solu-Delta CORT, apple chunks) was discontinued. One ADX animal was removed from the study for declining health. During the twelfth week, just prior to study termination, half of the ADX low-dose CORT subjects were given a short-term, high-dose regimen consisting of 4 daily IP injections of 5mg/d CORT (considered a relatively high dose- Makino et al., 1995). All animals were killed between 8 and 10 AM on the last two days of the study. After deep CO2 anesthesia and decapitation, trunk blood was collected for CORT radioimmunoassay and hippocampal CA1 brain tissue was dissected as described previously (Blalock et al., 2003) for microarray analysis (see below). Final treatment groups consisted of: 1) Sham (intact) control, 2) Low-CORT (ADX), 3) Intermediate-CORT (ADX), and 4) Low-CORT (ADX) + short-term high-dose injected (n=9-10/group).
Project description:We studied the effect of bacterial Lipopolysaccharides on inducing neuroinflammation in mice. In addition, we investigated the effect of novel LAT1-utilizing anti-inflammatory derivatives on reversing this LPS-induced neuroinflammation status. Thus, we performed deep proteome analysis of mouse brains after treatment with vehicle, LPS, and LPS with LAT1-utilizing derivatives. The objective is to follow the different inflammatory biomarkers in the mouse brain and explain the inflammatory process after the LPS treatment with and without the LAT1-utilizing prodrugs.
Project description:Here, we investigated the role of mononuclear phagocytes associated nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX-2) in inflammatory neurodegeneration. Cybb-deficient mice NOX-2 knock-out (KO) and control wild type (WT) mice were treated intraperitoneally daily over four consecutive days with 1 µg/gbw/day LPS. Repeated LPS injections led to inflammation and neuronal loss in the brains of WT mice, which was attenuated after knockout of NOX-2. Transcriptome analysis by RNA-seq of total brain tissue indicated increased LPS-induced upregulation of genes belonging to the reactive oxygen species (ROS) and reactive nitrogen species (RNS) production, complement and lysosome activation as well as apoptosis and necroptosis in WT compared to NOX-2 KO mice.
Project description:Although glucocorticoids (GCs) are known to exert numerous effects in the hippocampus, their chronic regulatory functions remain poorly understood. Moreover, evidence is inconsistent regarding the longstanding hypothesis that chronic GC exposure promotes brain aging/Alzheimer's disease. Here, we adrenalectomized male F344 rats at 15-months-of-age, maintained them for 3 months with implanted corticosterone (CORT) pellets producing low or intermediate (glucocorticoid-receptor (GR)-activating) blood levels of CORT, and performed microarray/pathway analyses in hippocampal CA1. We defined the chronic GC-dependent transcriptome as 393 genes that exhibited differential expression between Intermediate- and Low-CORT groups. Short-term CORT (4 days) did not recapitulate this transcriptome. Functional processes/pathways overrepresented by chronic CORT-upregulated genes included learning/plasticity, differentiation, glucose metabolism and cholesterol biosynthesis, whereas processes overrepresented by CORT-downregulated genes included inflammatory/immune/glial responses and extracellular structure. These profiles indicate that GCs chronically activate neuronal/metabolic processes while coordinately repressing a glial axis of reactivity/inflammation. We then compared the GC-transcriptome with a previously-defined hippocampal aging transcriptome, revealing a high proportion of common genes. Although CORT and aging moved expression of some common genes in the same-direction, the majority were shifted in opposite directions by CORT and aging (e.g., glial inflammatory genes downregulated by CORT are upregulated with aging). These results contradict the hypothesis that GCs simply promote brain aging, and also suggest that the opposite-direction shifts during aging reflect resistance to CORT regulation. Therefore, we propose a new model in which aging-related GC resistance develops in some target pathways while GC overstimulation develops in others, together generating much of the brain aging phenotype.
Project description:Rbfox1 regulates the alternative splicing of many transcripts in neurons. We have characterized the Rbfox1-dependent changes in expression and alternative splicing by comparing Rbfox1-KO brain to WT brain. In this dataset, we include the splicing and expression data obtained from dissected WT and Rbfox1 KO mouse brains. 6 total samples were analyzed: brains from 3 WT male mice and 3 Rbfox1 KO male mice, all 1 month of age.
Project description:WT mice and mPGES-1 KO mice were treated with 120 mikrogram/kg LPS and sacrificed 5 h later. The preoptic region was dissected by LCM and analyzed using GeneChip Mouse Genome 430 2.0 arrays (Affymetrix). Groups: WT LPS-treated versus mPGES-1 KO LPS-treated mice.
Project description:Bone marrow was harvested from Rosa26CreER; Stk40+/+ (WT; n = 3) and Rosa26CreER; Stk40loxp/loxp (Stk40 KO; n = 3) mice and differentiated for 6 days in the presence of 100 nM 4-OHT to generate WT and Stk40 KO bone-marrow derived macrophages (BMDMs). 2. On day 7 following differentiation BMDMs were treated with 100 ng x ml-1 LPS and harvested at 0 hrs, 6 hrs, 16 hrs, and 32 hrs following LPS exposure. 3. The cells were snap-frozen at the time of harvest. RNA was extracted using the Qiagen RNeasy mini kit as per manufacturer’s protocol including the on-column DNase digestion. Groups: There are cells from 3 mice x 2 genotypes x 4 time points G1: WT 0 hr LPS G2: WT 6 hr LPS G3: WT 16 hr LPS G4: WT 32 hr LPS G5: Stk40 KO 0 hr LPS G6: Stk40 KO 6 hr LPS G7: Stk40 KO 16 hr LPS G8: Stk40 KO 32 hr LPS
Project description:Mutations in the E3 ubiquitin ligase Mkrn3 are associated with precocious puberty in humans. In order to determine the targets of Mkrn3, we performed a TMT-based proteomic analysis of Mkrn3 WT vs KO mouse brains.