Project description:This study investigated the effect of Vagus Nerve Stimulation (VNS) on innate neuroinflammation and remyelination in lysolecithin (LPC) induced demyelination, a preclinical model for Multiple Sclerosis (MS). In a first experiment (demyelination experiment), LPC was injected in the corpus callosum of 33 Lewis rats, inducing a demyelinated lesion, and rats were treated with either continuously-cycled VNS (cVNS) or one-minute per day VNS (1minVNS) or sham VNS, from two days before the injection until three days post-injection (dpi), when they were killed for immunohistochemistry and proteomics analysis. This timepoint corresponded with a demyelinated lesion and peak inflammation. In a second experiment (remyelination experiment), 13 rats were analogously treated with either cVNS or sham from two days before LPC injection until 11 dpi, when they were killed for tissue prelevation for immunohistochemistry and proteomics. This timepoints corresponded with partial remyelination of the lesion. For proteomics analysis, 20 rats were randomly selected, namely five cVNS and five sham rats of the demyelination experiment, and five cVNS and five sham rats of the remyelination experiment.
Project description:Vagus nerve stimulation (VNS) has been shown to enhance learning and memory, yet the mechanisms behind these enhancements are unknown. We show that VNS altered the hippocampal, cortical, and blood epigenetic transcriptomes in male Sprague Dawley rats whether or not the rats performed a novelty preference behavioral task. In the hippocampus, novelty preference correlated with decreased histone deacetylase 11 (HDAC11), a transcriptional repressor enriched in CA1 cells important for memory consolidation. In the cortex, the immediate early gene (IEG) ARC was increased in VNS rats and correlated with transcription of plasticity genes and epigenetic regulators, including HDAC3. For rats performing the novelty preference task, ARC correlated with performance. Surprisingly, VNS did not significantly reduce transcription of cortical or hippocampal proinflammatory cytokines. However, TNFRSF11B (osteoprotegerin) correlated with novelty preference as well as plasticity, stress–response signaling, and epigenetic regulation in both hippocampus and cortex. Together, our findings provide the first evidence that VNS induces widespread changes in the cognitive epigenetic landscape and specifically affects epigenetic modulators associated with novelty preference, stress–response signaling, memory consolidation, and cortical neural remodeling.
Project description:Our previous findings suggest that the nucleus of the solitary tract (NTS), a pivotal region for regulating the set-point of arterial pressure, exhibits abnormal inflammation in pre-hypertensive and spontaneously hypertensive rats (SHRs) together with elevated anti-apoptotic and low apoptotic factor levels compared with that of normotensive Wistar–Kyoto (WKY) rats. Whether this chronic condition affects neuronal growth and plasticity in the NTS remains unknown. To unveil the characteristics of the neurodevelopmental environment in the NTS of hypertensive rats, we investigated the gene expression profile of neurotrophins and their receptors in SHRs compared to that of normotensive rat WKY.
Project description:Effects of voluntary exercise in rat aorta. Spontaneously hypertensive rats (SHR) performed 5 weeks of voluntary exercise (wheel-cage running). Aortic tissue was collected and samples were pooled (3 aortae/chip). Aortae from running rats were compared to aortae from non-running rats. Keywords: parallel sample
Project description:Time-course gene expression profiles were obtained from lung tissues of the rats treated with room air, intermittent- (IH) or sustained hypoxia (SH) for 1, 3, 7, 14 and 30 days using CodeLink microarrays. Using a systems biology approach, we observed that two different mechanisms are involved in the lung responses to IH and SH: IH leads to increased G-protein coupled signaling-, ion transport-, neuronal- and steroid hormone receptor activities; whereas SH causes increased blood vessel morphogenesis and immune responses. Our results provide insight into molecular mechanisms underlying IH and SH. Keywords: gene expression array-based, count rats were treated with intermittent- (IH) or sustained hypoxia (SH) for 1, 3, 7, 14 and 30 days; rats treated with room air were used as controls; gene expression profiles were obtained from these rats
Project description:We investigated morphometric structure and gene expression by microarray analysis in a small diameter artery, branch of the saphenous artery (a resistance artery), in representative models of renin-angiotensin system (RAS)-dependent and glucocorticoid hypertension, using the spontaneously hypertensive rat (SHR) and adrenocorticotropic hormone (ACTH)-induced hypertensive rat, respectively. Sixteen-week-old male Wistar-Kyoto (WKY) and age-matched spontaneously hypertensive rats (SHR) were used. Keywords: Comparison of global gene expression in resistance arteries of normotensive and genetically hypertensive rats and ACTH-treated rats.
Project description:The long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting “programming” effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 – 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes. Apnea is the most common cause of neonatal hypoxia affecting about 50% of preterm births (30 – 31 weeks), usually due to immature respiratory development. Upregulation of inflammatory genes and pathways in children 7 – 10 years of age has been shown, and there is a known increased risk of insulin resistance in adulthood when the fetus is exposed to maternal hypoxia, but the mechanism is unclear. The long-term metabolic, endocrine, and immunological effects of neonatal intermittent hypoxia (IH) exposure, an accepted model of apnea-induced hypoxia, have not been thoroughly evaluated. Recent studies in rats have shown that perinatal IH exposure can result in oxidative stress, causing a permanent immune response subsequently resulting in features of diabetes mellitus. We have previously examined adult rats exposed to neonatal intermittent hypoxia and perinatal continuous hypoxia, and have found lasting “programming” effects on the HPA axis. We now assess the long term effects of an accepted model of apnea-induced hypoxia using a validated transcriptional bioassay to study the extracellular milieu of adult rats exposed to neonatal intermittent hypoxia. We hypothesize that exposure to neonatal intermittent hypoxia will result in an increased inflammatory state in the adult as a result of long-lasting programming.
Project description:To determine if there exists a consistent gene signature associated with vascular hypertrophy among different rat hypertensive models: treated and untreated Wistar Kyoto (WKY) rats and treated and untreated Spontaneous Hypertensive Rat (SHR) rats. Keywords: strain comparison, treatment vs control
Project description:The long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting âprogrammingâ effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 â 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes. Apnea is the most common cause of neonatal hypoxia affecting about 50% of preterm births (30 â 31 weeks), usually due to immature respiratory development. Upregulation of inflammatory genes and pathways in children 7 â 10 years of age has been shown, and there is a known increased risk of insulin resistance in adulthood when the fetus is exposed to maternal hypoxia, but the mechanism is unclear. The long-term metabolic, endocrine, and immunological effects of neonatal intermittent hypoxia (IH) exposure, an accepted model of apnea-induced hypoxia, have not been thoroughly evaluated. Recent studies in rats have shown that perinatal IH exposure can result in oxidative stress, causing a permanent immune response subsequently resulting in features of diabetes mellitus. We have previously examined adult rats exposed to neonatal intermittent hypoxia and perinatal continuous hypoxia, and have found lasting âÂÂprogrammingâ effects on the HPA axis. We now assess the long term effects of an accepted model of apnea-induced hypoxia using a validated transcriptional bioassay to study the extracellular milieu of adult rats exposed to neonatal intermittent hypoxia. We hypothesize that exposure to neonatal intermittent hypoxia will result in an increased inflammatory state in the adult as a result of long-lasting programming. Sprague-Dawley (SD) rat pups were treated with neonatal normoxia (21% O2, control), 5% intermittent hypoxia (IH), or 10% IH on postnatal days (PD) 2-6, daily over 1 hr. They were reared normally by birth dams and weaned at PD22. Males were allowed to mature and sacrificed at age PD114 after an overnight fast. Whole blood collected by decapitation into tubes with EDTA, and plasma saved for further analysis. Two adult (~180 day) male Brown Norway (BN) rats served as PBMC donors. Cells were incubated with 20% plasma that was either autologous BN (self-control), or one of 3 pools: a) SD normoxic N=8, b) SD 5% IH treated N=5, and c) SD 10% IH N=3.