Project description:Expression of 757 neuroinflammaiton-associated genes in vehicle and complement inhibitor treated TBI brains at days 3, 7 and 28 post injury
Project description:Astrocytes, the most abundant glial cells in the central nervous system (CNS), play a critical role in brain injury responses. While NeuroD1 overexpression in astrocytes has been shown to reverse glial scar formation and promote tissue repair in mouse models of traumatic brain injury (TBI), the underlying molecular mechanisms remain incompletely understood. To address this, we performed single-cell transcriptomic analysis on a controlled cortical impact (CCI) mouse model using recombinant adeno-associated virus (rAAV)-mediated astrocyte-specific NeuroD1 overexpression.Our findings demonstrate that NeuroD1 overexpression suppresses microglial activation and mitigates brain damage post-TBI. Single-cell RNA sequencing revealed significant shifts in astrocyte subtypes, with upregulated neuroinflammatory pathways and downregulated oxygen metabolism in TBI mice. Conversely, NeuroD1 overexpression reshaped astrocyte subpopulation dynamics, enhanced oxygen metabolism-related gene expression, and attenuated neuroinflammatory signaling. This study provides a comprehensive transcriptomic dataset detailing cellular and astrocyte subtype-specific changes following NeuroD1-mediated brain repair. These insights advance our understanding of cell fate modulation in TBI and support the development of NeuroD1-based gene therapies, offering a valuable resource for future TBI research and therapeutic strategies.
Project description:We inflicted TBI to chemokine-deficient mouse lines in order to establish involvement of various signalling pathways that may be addressed therapeutically. Interacting chemokine pathways in brain regulate distinct inflammatory cells. Activated microglia are separate from invading phagocytes and dendritic cells. Findings show potential targets to interfere with specific inflammatory responses after brain injury. TBI was carried out in Ccl3-/- and Ccr2-/- mice, total RNA prepared from injured cerebral neocortex after three days. RNA samples were from uninjured Ccl3-/- and Ccr2-/- mice as reference for hybridization on Affymetrix microarrays.
Project description:Traumatic brain injury (TBI) induces neuroinflammatory innate immune responses that plays roles in both worsening brain damage and facilitating functional recovery. A major goal is to understand the heterogeneity of the immune responses to TBI, and to precisely identify key components that impact functional outcomes. We previously demonstrated that genetically targeting Ccr2 in a mouse model of controlled cortical impact led to neuroprotection in TBI. Our current studies of TBI use single cell RNA sequencing of over 10,000 TBI ipsilateral brain leukocytes to examine the mechanisms associated with the observed benefit in Ccr2-/- mice by comparing gene expression in leukocyte subsets from Ccr2-/- mice to gene expression in C57BL/6 wild type mice. Unbiased clustering identified two monocyte subsets, Chil3hi Ly6Chi classical monocytes and Gpnmbhi Ly6Clo nonclassical monocytes, and nine microglia states in the ipsilateral TBI brain. Comparative analysis between the genotypes revealed that Ccr2-/- TBI mice contained reduced numbers of inflammatory macrophages. In TBI, we observed a subset of microglia highly expressing several type I interferon-stimulated genes (ISGs) and is designated as Irf7hi microglia. Notably, unbiased differential expression analysis detected a two-fold reduction in the type I interferon response in multiple Ccr2-/- TBI microglia subsets compared to wild type TBI microglia. Treatment post-injury with a human CCR2 (hCCR2) inhibitor, CCX872, in hCcr2 knock-in mice improved cognitive function post-TBI, and also correlated with reduced expression of a key ISG, Irf7. We identified and characterized macrophage and microglia subsets during acute TBI. Our data showed that a reduction in macrophage expansion in TBI by both genetic and pharmacological methods, improved TBI and correlated with a reduction in the type I IFN response. These data indicate that macrophage expansion co-directs a type IFN response in microglia, and that targeting macrophage expansion in the brain can alter the profile of microglia subsets and lead towards improved functional outcomes.
Project description:Post-traumatic neuroinflammation is a key driver of secondary injury after traumatic brain injury (TBI). Pyroptosis, a proinflammatory form of programmed cell death, considerably activates strong neuroinflammation and amplifies the inflammatory response by releasing inflammatory contents. Therefore, treatments targeting pyroptosis may beneficially effects for the treatment of secondary brain damage after TBI. Herein, a cysteine-alanine-glutamine-lysine (CAQK) peptide-modified β-lactoglobulin (β-LG) nanoparticle was constructed to deliver disulfiram (DSF), C-β-LG/DSF, to inhibit pyroptosis and decrease neuroinflammation, thereby preventing TBI-induced secondary injury. In the post-TBI mice model, C-β-LG/DSF selectively targets the injured brain, increases DSF accumulation, and extends the time of the systemic circulation of DSF. C-β-LG/DSF can alleviate brain edema and inflammatory response, inhibit secondary brain injury, promote learning, and improve memory recovery in mice after trauma. Therefore, this study likely provided a new approach for reducing the secondary spread of TBI.