Transcriptome profiling of rat brain samples in two age groups in responding to intracerebral hemorrhage
Ontology highlight
ABSTRACT: Aging-induced decline of endogenous neuroprotection has been shown to aggravate intracerebral hemorrhage (ICH)-induced acute brain injury, however, the underlying mechanisms in brain are still little known. In this study, we applied a rat ICH model to study the transcriptional responses in the early and late aging (13-month and 22-month old) rats that show substantial differences in brain damage and recovery. Transcriptome analysis (RNA-seq) reveals that brain expression of neuroinflammation genes is similarly and selectively upregulated in ICH, which includes genes in the cellular response to interferon gamma function. We show that the anti-IFN-γ treatment effectively reduces ICH-induced acute brain injury.
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: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:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
Project description:Intracerebral hemorrhage (ICH) is a devastating form of stroke with a high mortality rate and few treatment options. Discovery of therapeutic interventions has been slow given the challenges associated with studying acute injury, particularly over time, in the human brain. Inflammation induced by exposure of brain tissue to blood appears to be a major part of brain tissue injury. Here we longitudinally profiled blood and cerebral hematoma effluent from a patient enrolled in the Minimally Invasive Surgery with Thrombolysis in Intracerebral Haemorrhage Evacuation (MISTIEIII) trial, offering a rare window into the local and systemic immune responses to acute brain injury. Using single-cell RNA-sequencing, we characterized the local cellular response during ICH in the brain of a living patient at single-cell resolution for the first time. Our analysis revealed rapid shifts in the activation states of myeloid and T cells in the brain over time, suggesting that leukocyte responses are dynamically reshaped by the hematoma microenvironment. Interestingly, the patient had an asymptomatic re-bleed (second local exposure to blood) that our transcriptional data indicated occurred more than 30 hours prior to detection by CT scan. This case highlights the rapid immune dynamics in the brain after ICH and suggests that sensitive methods like scRNA-seq can inform our understanding of complex intracerebral events.
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: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:Post-transcriptional regulation and RNA-binding proteins (RBPs) play vital roles in the occurrence and secondary injury after intracerebral hemorrhage (ICH) and post-transcriptional regulation, respectively. Therefore, we screened out the differentially expressed RBPs after ICH and found thioredoxin1 (Txn1) as one of the most significantly differentially expressed RBPs. We also used an ICH model and in vitro experiments to investigate the role of Txn1 in clarifying the mechanism of Txn1 in ICH. First, we found that Txn1 was majorly expressed in microglia and neurons in the central nervous system, and its protein level was significantly reduced in perihematoma tissues. Furthermore, we established a Txn1-overexpressing ICH model by stereotaxic injection of adeno-associated virus (AAV) and discovered that the overexpression of Txn1 reduced secondary injury and improved prognosis after ICH. Moreover, to understand the mechanism of Txn1 after ICH, RNA immunoprecipitation combined with high-throughput sequencing (RIP-seq) showed that Txn1 binds to inflammation-and apoptosis-related mRNAs and affects RNA expression through RNA splicing and translational initiation. Finally, RNA pull-down assays and in vitro experiments confirmed that Txn1 binds to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) to reduce inflammation and apoptosis. Collectively, our results show that Txn1 reduces ICH-induced brain injury by affecting the post-transcriptional regulation of MALAT1. Consequently, Txn1 may represent a potential therapeutic target for alleviating ICH-induced brain injury.
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, particularly in mononuclear myeloid cells (for example, monocyte-derived cells (MdC) and microglia), we sought to determine the importance of Nrf2 to mononuclear myeloid cell responses and their impact on ICH pathology. We used intrastriatal injection of collagenase to induce ICH in both wild-type mice, and knockout mice with Cx3cr1-Cre-mediated excision of Nrf2 (Nfe2l2) exon 5.
Project description:To investigate the effect of Pterostilbene(PTE) on gene expression after intracerebral hemorrhage injury, we employed RNA sequencing (RNA-seq) to profile the mRNA expression ensuing PTE treatment after ICH. Different gene distribution could be clearly seen on the volcano plot between diferent comparisions among Sham, ICH, and ICH+PTE group. Finally, we showed that 1021 shared genes overlapping between those differentially expressed genes, which was reversed by PTE treatment
Project description:To investigate the effect of P7C3-A20 on gene expression after intracerebral hemorrhage injury, we employed RNA sequencing (RNA-seq) to profile the mRNA expression ensuing P7C3-A20 treatment after ICH. Different gene distribution could be clearly seen on the volcano plot between diferent comparisions among Sham, ICH, and ICH+P7C3-A20 group. Finally, we showed that 1047 shared genes overlapping between those differentially expressed genes, which was reversed by P7C3-A20 treatment