Project description:Traumatic brain injury dysregulates microRNA expression in the brain. We hypothesized that injury-induced epigenetic changes contribute to neurodegeneration and learning and memory deficits after TBI. These changes may provide a mechanistic explanation for neuropsychiatric comorbidities in TBI patients. Our objective is to compare and contrast the effects of several neuroprotective drugs (JM6, PMI-006 and E33-estrogen) on the TBI-induced changes in microRNA expression in the hippocampus, a region of the brain that is critical for learning and memory. We will also study if different neuroprotective drugs have similar effects on common microRNAs which may cooperatively regulate a common set of gene targets. 3 biological samples each of Naïve, Sham control, TBI and TBI plus JM6, TI plus PMI-006, and TBI plus E33 rat hippocampi were obtained 24 hr post-sham injury or TBI, stored in RNA later and sent to GenUs Biosystems for microRNA microarray analysis.
Project description:Traumatic brain injury (TBI) alters and dysregulates the expression of thousands of genes in the brain. Since some of the most common problems in TBI patients are learning and memory deficits, we are studying the effects of TBI on the hippocampus, a region of the brain which is essential for learning and memory and which is known to be particularly vulnerable to TBI. We are interested in understanding how potential neuroprotective drugs alter the TBI-induced gene expression profile. The objective of this study is to elucidate and compare the differential gene expression profiles in the hippocampus of naive, sham-control, TBI and TBI plus drug treated rats. JM6, PMI-006 and E33 are three compounds with neuroprotective, anti-inflammatory and anti-oxidative effects. Our goal is to determine if different neuroprotective compounds have similar effects on common gene targets. These genes and the cell signaling pathways linked to them would then be the target of new therapeutic strategies for TBI. Rats were prepared for fluid percussion traumatic brain injury or sham injury (naïve rats had no anesthesia and were not handled in any way and gene expression in their brains serve as baseline data) and 24 hr post-injury, hippocampi were obtained, and stored in RNA later. Total RNA was isolated, quantitified and used for Agilent microarray analysis at GenUs Biosystems. Each group of naive, sham control, TBI and TBI plus JM6, TBI plus PMI-006 and TBI plus E33 (estrogen) has three biological replicates.
Project description:The current lack of proven pharmacological treatment options for traumatic brain injury (TBI) patients reflects the poor translation of successful preclinical studies in clinical trials. This may be due to poor choice of therapeutic agents based on incomplete knowledge of critical elements of neuroprotection. Our goal is to expedite discovery and translation of therapeutic agents that can improve functional outcome by identifying the common molecular profile of neuroprotective drugs. Since damage to the hippocampus is associated with TBI-induced deficits in learning and memory, we analyzed of the hippocampal transcriptional profiles of TBI rats treated with two clinically used drugs metyrapone and carbenoxolone, which have been shown to improve cognitive deficits in previous studies. Despite their different structures, we found that MT and CB have similar effects on several known biological pathways. The neuroprotective effects of these drugs are associated with a distinctive molecular signature which is characterized not by changes in expression of any individual gene but by a common global effect on multiple cell signaling pathways. These data suggest that drug treatments that induce a coordinated attenuation of multiple injury-induced cell signaling networks, both deleterious and protective, have high translational potential. There were 16 samples for array analysis, two biological replicates each for control (4 and 24 hour), TBI (4 and 24 hour), TBI plus MT (4 and 24 hour) and TBI plus CB (4 and 24 hour). Each biological sample, which is a pooled RNA sample (laser captured CA3 pyramidal neurons) from the hippocampus of 3-6 rats, was hybridized to duplicate arrays so that there were 32 gene arrays in this study.
Project description:To investigate the determinants of neuronal survival after traumatic brain injury, we compared the transcriptional profiles of dying (Fluoro-Jade-positive) and immediately adjacent surviving (Fluoro-Jade-negative) neurons from the CA3 subfield of the rat hippocampus 24 hours after experimental TBI. We found that hippocampal neurons that survive TBI invariably express high levels of genes that have cellular functions involved in survival, regeneration, development, proliferation, neuronal plasticity such as cAMP response element binding protein (CREB), brain-derived-neurotrophic factor (BDNF) and mitogen-activated protein kinase 1 (MAPK1). Dying neurons express high levels of genes involved in aberrant cell cycle progression, immune response, inflammation, oxidative stress and apoptosis such as Interleukin-1β (IL-1β), caspase 3 and B-cell linker (BLNK). We conclude that shifting the balance between the global levels of these proteins with pharmacotherapeutic drugs that induce expression of cell survival associated genes, is expected to alter the cellular rheostat that determines cell survival or cell death. Replicate pooled samples (approximately 600 laser capture microdissected hippocampal neurons per sample of dying neurons (labeled with Fluoro-Jade, a fluorescent stain for degenerating CNS neurons) and surviving neurons (Fluoro-Jade-negative) were hybridized in duplicate to rat Agilent whole genome arrays.
Project description:Traumatic brain injury (TBI) causes hospitalizations and mortality worldwide with no approved neuroprotective treatments available, partly due to a poor understanding of the molecular mechanisms underlying TBI neuropathology and neuroprotection. We previously reported that the administration of low-dose methamphetamine (MA) induced significant functional/cognitive improvements following severe TBI in rats. We further demonstrated that MA mediates neuroprotection in part, via dopamine-dependent activation of the PI3K-AKT pathway. Here, we further investigated the proteomic changes within the rat cortex and hippocampus following mild TBI (TM), severe TBI (TS), or severe TBI plus MA treatment (TSm) compared to sham operated controls (n=78 in total). We quantified >7,000 unique proteins in total and identified 402 and 801 altered proteins (APs) with high confidence in cortical and hippocampal tissues, respectively. The overall profile of APs observed in TSm rats more closely resembled those seen in TM rather than TS rats. Pathway analysis suggested beneficial roles for acute signaling through IL-6, TGFβ, and IL-1β. Moreover, changes in fibrinogen levels observed in TSm rats suggested a potential role for these proteins in reducing/preventing TBI-induced coagulopathies. These data facilitate further investigations to identify specific pathways and proteins that may serve as key targets for the development of neuroprotective therapies.
Project description:The epidemiologic association between statin use and decreased risk of advanced prostate cancer suggests that statins may inhibit prostate cancer development and/or progression. Studies were performed to determine the effects of a model statin, atorvastatin (ATO), on the proliferation and differentiation of prostate cancer cells, and to identify possible mechanisms of ATO action. ATO inhibited the in vitro proliferation of both LNCaP and PC3 human prostate cancer cells in dose-dependent fashion. The greater inhibitory activity of ATO in PC3 cells was associated with induction of autophagy in that cell line, as demonstrated by increased expression of LC3-II. miR-182 was consistently upregulated by ATO in PC3 cells, but not in LNCaP cells. ATO upregulation of miR-182 in PC3 cells was p53-independent and was reversed by geranylgeraniol. Transfection of miR-182 inhibitors decreased expression of miR-182 by >98% and attenuated the antiproliferative activity of ATO. miR-182 expression in PC3 cells was also increased in response to stress induced by serum withdrawal, suggesting that miR-182 upregulation can occur due to nutritional stress. Bcl2 and p21 were identified to be potential target genes of miR-182 in PC3 cells. Bcl2 was downregulated and p21 was upregulated in PC3 cells exposed to ATO. These data suggest that miR-182 may be a stress-responsive miRNA that mediates ATO action in prostate cancer cells. Gene and miRNA expression in two prostate cancer cell lines treated with Atorvastatin vs. untreated control.
Project description:In a previous study, 50% calorie restriction in mice from days 1.5-11.5 of pregnancy resulted in reduced placental weights and areas, relatively sparing of labyrinth zone area compared to junctional zone area, and dramatic changes in global gene expression profiles. Here we examined placental gene expression at day 18.5, after the return to normal feeding to see whether differences were reversible Mice were randomized to 2 treatment groups on day 1.5 of pregnancy: (1) ad libitum fed (control) (2) 50% food restriction (restricted). Mice were returned to ad libitum feed on d11.5, sacrificed on d18.5 and placentas were collected.
Project description:In humans and other species, Longlong-term hypoxia (LTH) during pregnancy can lead to intrauterine growth restriction with reduced body/brain weight, dysregulation of cerebral blood flow (CBF), and other problems in humans and rodents. In contrast, sheep appear to undergo relatively successful acclimatization, not demonstrating any of the above-mentioned problems except at extremely high altitude. To identify the signal transduction genetic pathways and those critical molecules, which may be involved in acclimatization to high altitude LTH, we conducted microarray with advanced bioinformatic analysis on carotid arteries (CA) from the normoxic near-term ovine fetus at sea-level and those acclimatized to high altitude for 110+ days during gestation. In response to LTH acclimatization, in fetal CA we identified, mRNA from 38 genes upregulated (> 2 fFold; (P < 0.05) and 9 genes downregulated (> 2-f Fold; (P < 0.05). The major genes with upregulated mRNA were SLC1A3, Insulin-like growth factor (IGF) binding protein 3, IGF type 2 receptor, transforming growth factor (TGF) Beta-3, and genes involved in the AKT and BCL2 signal transduction networks. The majority of genes with upregulated mRNA have a common motif for Pbx/Knotted homeobox in the promoter region, and Sox family binding sites in the 3M-bM-^@M-^Y un -translated region (UTR). Genes with downregulated mRNA included those involved in the P53 pathway and 5-lipoxygenase activating proteins. The promoter region of all genes with downregulated mRNA, had a common 49 bp region, with a binding site for DOT6 and TOD6, components of the RPD3 histone deacetylase complex RPD3C(L). We also identified miRNA complementary to a number of the altered genes. Thus, the present study identified molecules in the ovine fetus, which may help it to play a role in the acclimatizatione successfully response to high-altitude associated LTH. In these series of experiments we examined changes in gene expression in sheep carotids. Pregnant sheep and non-pregnant adult sheep were exposed to 110 days of hypoxia at 3801 meters of altitude. Carotid arteries from fetuses from non-pregnant adult from sea-level controls and those from high-altitude were compared by Agilent ovine custom array