GPR34 senses demyelination to promote neuroinflammation and cognition impairment in Alzheimer's disease
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ABSTRACT:
PROVIDER: PRJNA892590 | ENA |
REPOSITORIES: ENA
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Project description:Sterile neuroinflammation initiated by damage-associated molecular patterns (DAMPs) has been regarded as an important driver in Alzheimer's disease (AD) and can occur prior or independently of the deposition of extracellular amyloid-β (Aβ) plaques and intracellular tau neurofibrillary tangles (NFTs). Genetic ablation or pharmacological inhibition of GPR34 reduced microglia activation, Aβ deposition and cognition impairment. Moreover, GPR34 inhibition prevented aging associated neuroinflammation and cognition impairment without the presence of Aβ plaques.
2025-02-05 | GSE216209 | GEO
Project description:Sterile neuroinflammation is a major driver of multiple neurological diseases. Myelin debris, which is released from the damaged myelin sheaths during demyelination, can act as an inflammatory stimulus to promote sterile inflammation and neurological pathologies, but the mechanism is poorly understood. Here, we show that lysophosphatidylserine (LysoPS)-GPR34 axis plays a critical role in microglia-mediated myelin debris sensing and the subsequent neuroinflammation. Myelin debris-induced microglia activation and proinflammatory cytokine expression relied on its lipid component LysoPS. Both myelin debris and LysoPS promoted microglia to produce IL-1and IL-6 via GPR34 and its downstream PI3K-AKT and ERK signaling. In vivo, LysoPS production and GPR34 signaling were found to be essential for neuroinflammation and pathologies in the mouse models of multiple sclerosis and stroke. Importantly, pharmacologic blockade of GPR34 showed potential therapeutic effects on these disease models. Thus, our results identify GPR34 as a key receptor to sense myelin debris and promote neuroinflammation, and suggest it as a potential target for demyelination-associated diseases.
2025-01-30 | GSE195741 | GEO
Project description:GPR34 senses myelin debris to promote neuroinflammation and pathology
| PRJNA802043 | ENA
Project description:Background: Cystatin F is a secreted lysosomal cysteine protease inhibitor that has been implicated in affecting the severity of demyelination and enhancing remyelination in pre-clinical models of immune-mediated demyelination. How cystatin F impacts neurologic disease severity following viral infection of the central nervous system (CNS) has not been well characterized and was the focus of this study. We used cystatin F null-mutant mice (Cst7-/-) with a well-established model of murine coronavirus-induced neurologic disease to evaluate the contributions of cystatin F in host defense, demyelination and remyelination. Methods: Wildtype controls and Cst7-/- mice were intracranially (i.c.) infected with a sublethal dose of the neurotropic JHM strain of mouse hepatitis virus (JHMV), with disease progression and survival monitored daily. Immune cell infiltration into the brain and spinal cord was determined by flow cytometry. Spinal cord demyelination was determined by luxol fast blue (LFB) and Hematoxylin/Eosin (H&E) staining and remyelination evaluated by electron microscopy (EM) and calculation of g-ratios. Immune cell infiltration into the CNS and microglia activation were determined by flow cytometry and 10X genomics chromium 3’ single cell RNA sequencing (scRNAseq). Results: JHMV-infected Cst7-/- mice were able to control viral replication within the CNS, indicating that cystatin F is not essential for an effective Th1 anti-viral immune response. Infiltration of T cells and monocytes/macrophages into the spinal cords of JHMV-infected Cst7-/- mice was increased compared to infected controls, and this correlated with amplified demyelination and impaired remyelination. Single-cell RNA-seq of CD45+ cells enriched from spinal cords of infected Cst7-/- and control mice at day 21 post-infection (p.i.) revealed enhanced expression of transcripts encoding macrophage chemoattractant, Ccl2, and T cell chemoattractants, Cxcl9 and Cxcl10, combined with elevated expression of interferon-g (Ifng) transcripts and activation markers in CD8+ T cells from Cst7-/- mice compared to controls. Conclusions: Cystatin F is not required for immune-mediated control of JHMV replication within the CNS. However, JHMV-infected Cst7-/- mice exhibited more severe clinical disease associated with increased demyelination and impaired remyelination. The increase in disease severity was associated with elevated expression of macrophage and T cell chemoattractant chemokines, concurrent with increased neuroinflammation. These findings support the theory that one mechanism by which cystatin F affects chronic disease in mice persistently infected with JHMV is through regulating expression of pro-inflammatory molecules that impact neuroinflammation and neurologic disease.
2024-10-07 | GSE244656 | GEO
Project description:Enhanced meningeal lymphangiogenesis and glymphatic drainage ameliorates neuroinflammation and white matter demyelination
| PRJNA1003004 | ENA
Project description:It is important to maintain cognitive integrity during underwater operations, which may also trigger cognitive alterations. Cognitive effect of underwater operations and the underlying mechanism remain elusive. Here, we found a single underwater operation affects cognition in a time-dependent model. Prolonged exposure elicits significant cognitive impairment and hippocampal dysfunction, which was accompanied by activation of microglia and upregulation of pro-inflammatory cytokines. RNA-sequencing supported the involvement of neuroinflammation and indicated the critical role of CCR3. Knockdown of CCR3 significantly rescued cognitive impairment and hippocampal dysfunction. Furthermore, the upregulation of pro-inflammatory cytokines was also reversed. Mechanistically, CCR3 knockdown switched the activated microglia from a pro-inflammatory to neuroprotective phenotype. Taken together, these results highlighted the time-dependent effects of a single underwater operation on cognitive function. Knocking down CCR3 can attenuate neuroinflammation by regulating polarization of activated microglia, thereby alleviating prolonged underwater operation-induced cognitive impairment.
2024-05-20 | GSE247651 | GEO
Project description:BACKGROUND:Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive loss of cognitive abilities and memory leading to dementia. Electroacupuncture (EA) is a complementary alternative medicine approach, applying an electrical current to acupuncture points. In clinical and animal studies, EA causes cognitive improvements in AD and vascular dementia. However, EA-induced changes in cognition and microglia-mediated amyloid ? (A?) degradation have not been determined yet in AD animals. Therefore, this study investigated the EA-induced molecular mechanisms causing cognitive improvement and anti-inflammatory activity in five familial mutation (5XFAD) mice, an animal model of AD. METHODS:5XFAD mice were bilaterally treated with EA at the Taegye (KI3) acupoints three times per week for 2 weeks. To evaluate the effects of EA treatment on cognitive functions, novel object recognition and Y-maze tests were performed with non-Tg, 5XFAD (Tg), and EA-treated 5XFAD (Tg + KI3) mice. To examine the molecular mechanisms underlying EA effects, western blots, immunohistochemistry, and micro-positron emission tomography scans were performed. Furthermore, we studied synapse ultrastructures with transmission electron microscopy and used electrophysiology to investigate EA effects on synaptic plasticity in 5XFAD mice. RESULTS:EA treatment significantly improved working memory and synaptic plasticity, alleviated neuroinflammation, and reduced ultrastructural degradation of synapses via upregulation of synaptophysin and postsynaptic density-95 protein in 5XFAD mice. Furthermore, microglia-mediated A? deposition was reduced after EA treatment and coincided with a reduction in amyloid precursor protein. CONCLUSIONS:Our findings demonstrate that EA treatment ameliorates cognitive impairment via inhibition of synaptic degeneration and neuroinflammation in a mouse model of AD.
| S-EPMC6909515 | biostudies-literature
Project description:Demyelination is characterized by the loss of the myelin sheath that surrounds nerve fibers and myelin-supporting cells in the nervous system. This leads to increased vulnerability of axons to damage, resulting in significant atrophy and neuro-axonal degeneration. Demyelination is a common pathological feature in a wide range of diseases of the central nervous system (CNS). Multiple pathomolecular processes contribute to brain damage, including demyelination, neuroinflammation, oligodendrocyte (OLs) cell death, and progressive neuronal dysfunction. In this study, we used the cuprizone (CPZ) mouse model to investigate long-term non-invasive gamma entrainment using sensory stimulation (GENUS) as a potential therapeutic intervention for promoting myelination and reducing neuroinflammation. Our results demonstrate that GENUS effectively mitigated demyelination, stimulated oligodendrogenesis in the corpus callosum (CC), and preserved functional integrity and synaptic plasticity. Additionally, GENUS attenuated OLs ferroptosis-induced cell death. Furthermore, chronic GENUS exhibited a marked reduction in brain inflammation, decreasing both microgliosis and astrogliosis and proinflammatory molecules, such as high mobility group box 1 (HMGB1), complement component 1q (C1q) and complement C3 (C3). Considering the pro-remyelination and anti-neuroinflammatory effects observed with GENUS, these findings suggest its potential as a therapeutic approach for demyelinating disorders.
2024-06-07 | GSE240815 | GEO
Project description:Cystatin F attentuates neuroinflammation and demyelination following murine coronavirus infection of the central nervous system
| PRJNA1023970 | ENA
Project description:White matter hyperintensity (WMH) is a pressing global medical issue linked to cognitive decline and stroke risk. Despite its significance, the underlying mechanisms remain unclear. Here, we directly demonstrated in humans that high WMH burden correlated with delayed glymphatic pathway drainage. Additionally, a longitudinal cohort study revealed that glymphatic dysfunction predicted WMH progression. Next, in a rat model of WMH, we confirmed the presence of impaired lymphangiogenesis and glymphatic drainage, followed by elevated microglial activation and white matter demyelination. Notably, enhancing meningeal lymphangiogenesis and glymphatic drainage through adenoviral delivery of Vascular Endothelial Growth Factor-C (VEGF-C) mitigated microglial gliosis and white matter demyelination. Conversely, blocking the growth of meningeal lymphatics with a VEGF-C trap strategy exacerbated these changes. Our findings highlight the role of meningeal lymphatics and glymphatic pathway dysfunction in aggravating brain white matter injury and advancing WMH, providing a potential novel strategy for WMH prevention and treatment.
2024-07-17 | GSE240229 | GEO