Project description:A model of self-limiting acute brain inflammation induced by intracerebral injection of LPS was validated in the mouse tailored to enable study of inflammation resolution. Transcriptome-wide changes in gene expression were assessed by microarray at induction and resolution phases of the inflammatory response
Project description:The study was designed in order to identify genes differentially expressed when glucocorticoid signaling is blocked by a glucocorticoid-receptor antagonist (RU486 â?? mifepristone) in the context of brain inflammation induced by bacterial lipopolysaccharide (LPS). LPS is only able to cause murine brain damage in our experimental conditions upon RU486 pre-treatment. Hence, the study may reveal potential candidate genes to mediate neuroprotection or neurotoxicity. Due to the factorial design of the experiment, RU486 main-effect could be dissociated from the effects resultant of RU486/inflammation interaction. In addition, brain dissection was conducted to verify the effects in the brain side ipsilateral or contralateral to the site of intracerebral LPS infusion. Experiment Overall Design: C57Bl/6 mice received an i.p. injection of vehicle (DMSO - 50 microliters) or RU486 (50 mg/kg) and were submitted to surgery 4 h later. The mice receiving intraparenchymal injections were anesthetized and the right caudate putamen was reached, using a small cannula at the coordinates 0.0 mm anteroposterior, -2.0 mm lateral, and -3.0 mm dorsoventral according to a mouse brain atlas. The animals received an infusion of sterile pyrogen-free saline (1 microliter) or LPS (from Eschericia coli; serotype O55:B5; Sigma L2880 - 2.5 micrograms) over 2 min by means of a microinjection 18 pump. Animals were killed 12 h after the intracerebral infusion. The mice were anesthetized under isofluorane and blood was drawn via cardiac puncture before head decapitation. Brains were removed rapidly from the skulls and placed in cold phosphate buffered saline (PBS) solution. A brain region limited at plane anteroposterior +1.5 to -1.5 and dorsoventral -4.0 was dissected, separated in ipsilateral side and quickly immersed in liquid nitrogen. The tissue was stored at -80 oC until RNA extraction was performed. A total of 37 chips (MOE430A â?? Affymetrix, Santa Clara, CA) were used for oligonucleotide array analysis [one chip per biological sample; 8 groups (contralateral dmso/saline, dmso/LPS, RU486/saline, RU486/LPS and ipsilateral dmso/saline, dmso/LPS, RU486/saline, RU486/LPS) with 4 â?? 6 biological replicates each]. Expression values from the CEL files generated from scanning were obtained using RMA algorithm, available at http://www.bioconductor.org. The expression values were also inspected with GeneSpring software (Silicon Genetics). Statistical analysis was performed considering a factorial linear model according to the methods implemented in Limma package (R project packages are available at http://www.cran.r-project.org).
Project description:Cows were fed a lactation diet at ad libitum intake (n = 6). At 27±3 days in milk, cows were injected with 50 µg of LPS E. coli in one healthy rear mammary quarter. Milk samples were collected just before LPS challenge (LPS-) and 6.5 h after LPS challenge (LPS+) from the same cows. Microarray analysis was performed using customized 8x60K ruminant miRNA microarrays to compare LPS- to LPS+ miRNome. MiRNome comparison between LPS- and LPS+ identified 37 differentially abundant miRNAs (q-value ≤ 0.05)
Project description:To investigate age-dependent transcriptomic changes between young or aged intracerebral hemorrhage mice, we established collagenase IV-induced intracerebral hemorrhage mice models. Intracerebral hemorrhage was induced by infusion of sterile collagenase IV in ipsilateral caudate putamen of brain. We then performed gene expression profiling analysis using data obtained from RNA-seq of brain perihematomal tissues from young or aged ICH mice 24 hours after intracerebral hemorrhage.
Project description:Secondary injury causes death and dependence after spontaneous intracerebral haemorrhage (ICH). Having found that ICH is associated with activation of genes regulated by the transcription factor NRF2, we performed bulk RNA sequencing of perihaematomal and anatomically matched contralateral brain homogenate obtained at autopsy from a cohort of patients who died either within 24h of ICH or between 4-14 days of ICH onset, to investigate the spatiotemporal evolution of this Nrf2 activation.
Project description:Leukocyte infiltration accelerates brain injury following intracerebral hemorrhage (ICH). But the involvement of T lymphocytes in this process has not been fully elucidated.To further depict the landscape of the composition and functional states of brain-infiltrating immune cells following ICH, single-cell RNA sequencing was performed to compare the molecular characteristics of CD45+ cells from brain and spleen tissues in ICH and control mice.Our results revealed that brain-infiltrating T cells exhibited enhanced pro-inflammatory and pro-apoptotic signatures.
Project description:Intracerebral hemorrhage (ICH) is a life-threatening condition associated with significant morbidity and mortality. Understanding the molecular mechanisms underlying ICH and its severe form is crucial for developing effective therapeutic strategies. This study investigates transcriptomic alterations in rodent models of ICH and severe intracerebral hemorrhage to shed light on the genetic pathways involved in hemorrhagic brain injury. We performed principal component analysis, revealing distinct principal component segments of normal rats compared to intracerebral hemorrhage and severe intracerebral hemorrhage rats. We further employed heatmaps and volcano plots to identify differentially expressed genes and utilized bar plots and KEGG pathway analysis to elucidate the different molecular pathways involved. Using comprehensive RNA sequencing and bioinformatics analyses, we identified a multitude of differentially expressed genes in both the ICH and severe ICH models. Our results revealed 5679 common genes among the normal, intracerebral hemorrhage, and severe intracerebral hemorrhage groups in the upregulated genes group, and 1196 common genes in the downregulated genes. A volcano plot comparing the groups further highlighted common genes, including PDPN, TIMP1, SERPINE1, TUBB6, and CD44. These findings underscore the complex interplay of genes involved in inflammation, oxidative stress, and neuronal damage. Furthermore, pathway enrichment analysis uncovered key signaling pathways, including the TNF signaling pathway, protein processing in the endoplasmic reticulum, MAPK signaling pathway, and Fc gamma R-mediated phagocytosis, implicated in the pathogenesis of ICH.
Project description:The study was designed in order to identify genes differentially expressed when glucocorticoid signaling is blocked by a glucocorticoid-receptor antagonist (RU486 – mifepristone) in the context of brain inflammation induced by bacterial lipopolysaccharide (LPS). LPS is only able to cause murine brain damage in our experimental conditions upon RU486 pre-treatment. Hence, the study may reveal potential candidate genes to mediate neuroprotection or neurotoxicity. Due to the factorial design of the experiment, RU486 main-effect could be dissociated from the effects resultant of RU486/inflammation interaction. In addition, brain dissection was conducted to verify the effects in the brain side ipsilateral or contralateral to the site of intracerebral LPS infusion. Keywords: Brain, CNS, LPS, Glucocorticoid, RU486, Mifrespitone, Innate immune response, Inflammation, Affymetrix, Gene profile, Neuroprotection, Neurodegeneration, Factorial design.