Humans ; Glioma/metabolism* ; Consensus ; China ; Brain Neoplasms/pathology* ; Pathology, Molecular

Objective:This study aims to investigate the mechanism and potential effects of two exposures to 100 dB sound pressure level（SPL） broadband white noise, with a 14-days interval, on the myelin sheath of the cochlear auditory nerve in mice. The research provides experimental evidence for understanding the pathophysiological processes of noise-induced hearing loss and hidden hearing loss. Methods:Fifteen 6-week-old male C57BL/6J mice with normal hearing thresholds were randomly divided into three groups: a control group（no noise exposure）, a single noise exposure group, and a double noise exposure group. The single noise exposure group was exposed to 100 dB SPL white noise for 2 hours, and ABR thresholds were measured 1 day（P1） and 14 days（P14） after the exposure. The double noise exposure group was exposed to the same conditions of 100 dB SPL white noise for 2 hours, followed by a second identical exposure 14 days later. ABR thresholds were measured 1 day（P15） and 14 days（P28） after the second exposure. The cochleae of all three groups were then collected for immunofluorescence observation of the basilar membrane and transmission electron microscopy to observe changes in the structure of the auditory nerve myelin sheath. Results:In the single noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P1. There were no significant changes in ABR thresholds at any frequency at P14. In the double noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P15 and P28（P<0.001）. After the first noise exposure, immunofluorescence observation revealed no significant weakening of the auditory nerve myelin sheath signal; transmission electron microscopy showed no significant changes in myelin sheath morphology. However, after the second noise exposure, immunofluorescence observation revealed a weakening of the myelin sheath signal, and transmission electron microscopy showed thinning of the myelin sheath, disruption of the lamellar structure, and separation from the axon, indicating demyelination. Conclusion:Two exposures to 100 dB SPL broadband white noise can lead to damage to the auditory nerve myelin sheath in mice, whereas a single exposure does not cause significant changes.
Animals ; Male ; Myelin Sheath/pathology* ; Mice ; Cochlear Nerve/pathology* ; Mice, Inbred C57BL ; Noise/adverse effects* ; Hearing Loss, Noise-Induced/physiopathology* ; Cochlea ; Evoked Potentials, Auditory, Brain Stem

OBJECTIVES: To investigate the mechanism by which circ_EPHB4 regulates temozolomide (TMZ) sensitivity of glioma cells through the miR-424-5p/Wnt3 signal axis. METHODS: We detected the expression levels of circ_EPHB4, miR-424-5p and Wnt3 mRNA in glioma specimens from 25 patients with primary glioma and 25 patients experiencing relapse following temozolomide-based chemotherapy and in TMZ-sensitive and -resistant glioma A172 and SHG44 cells with circ_EPHB4 knockdown using qRT-PCR, and Wnt3 protein expression level was detected with Western blotting. Cell viability, colony-forming ability, and apoptosis of the cells with circ_EPHB4 knockdown were assessed, and the targeted regulation relationship between circ_EPHB4, miR-424-5p, and Wnt3 was verified by dual luciferase reporter assay and RNA immunoprecipitation (RIP) experiments. The effect of circ_EPHB4 knockdown on tumorigenesis of glioma cells was evaluated in subcutaneous tumor-bearing nude mouse models. RESULTS: The expression of circ_EPHB4 was significantly increased in glioma tissues and cells as compared with normal neural tissues and astrocytes (P=0.014). In TMZ-resistant glioma cells, circ_EPHB4 knockdown resulted in an obvious reduction of IC50 value of TMZ, inhibited cell colony formation, and promoted cell apoptosis, and these effects were reversed by miR-424-5p knockdown. The expressions of miR-424-5p and circ_EPHB4 were negatively correlated in glioma tissues (P=0.011). MiR-424-5p knockdown also attenuated the effect of circ_EPHB4 knockdown on expressions of PCNA, P-gp, MRP1 and bax. CONCLUSIONS Circ_EPHB4 regulates Wnt3 expression through "sponge adsorption" of miR-424-5p, thereby modulating TMZ-resistant glioblastoma cell clonogenesis, apoptosis, and TMZ sensitivity, suggesting the potential of circ_EPHB4 as a therapeutic target for reversing drug resistance of gliomas.
MicroRNAs/genetics* ; Humans ; Temozolomide ; Glioma/genetics* ; Animals ; Mice, Nude ; Cell Line, Tumor ; Wnt3 Protein/metabolism* ; Mice ; Apoptosis ; RNA, Circular ; Drug Resistance, Neoplasm ; Brain Neoplasms/pathology* ; Signal Transduction

Oligodendrocyte lineage cells, including oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), are essential in establishing and maintaining brain circuits. Autophagy is a conserved process that keeps the quality of organelles and proteostasis. The role of autophagy in oligodendrocyte lineage cells remains unclear. The present study shows that autophagy is required to maintain the number of OPCs/OLs and myelin integrity during brain aging. Inactivation of autophagy in oligodendrocyte lineage cells increases the number of OPCs/OLs in the developing brain while exaggerating the loss of OPCs/OLs with brain aging. Inactivation of autophagy in oligodendrocyte lineage cells impairs the turnover of myelin basic protein (MBP). It causes MBP to accumulate in the cytoplasm as multimeric aggregates and fails to be incorporated into integral myelin, which is associated with attenuated endocytic recycling. Inactivation of autophagy in oligodendrocyte lineage cells impairs myelin integrity and causes demyelination. Thus, this study shows autophagy is required to maintain myelin quality during aging by controlling the turnover of myelin components.
Animals ; Autophagy/physiology* ; Oligodendroglia/metabolism* ; Myelin Sheath/physiology* ; Aging/pathology* ; Myelin Basic Protein/metabolism* ; Cell Lineage/physiology* ; Mice ; Oligodendrocyte Precursor Cells ; Mice, Inbred C57BL ; Brain/cytology* ; Cells, Cultured ; Cell Count

Neurodegeneration involves a wide range of neuropathological alterations affecting the integrity, physiology, and architecture of neural cells. Many studies have demonstrated neurodegeneration in different animals. In the case of Alzheimer's disease (AD), spontaneous animal models should display two neurohistopathological hallmarks: the deposition of β-amyloid and the arrangement of neurofibrillary tangles. However, no natural animal models that fulfill these conditions have been reported and most research into AD has been performed using transgenic rodents. Recent studies have also demonstrated that toothed whales - homeothermic, long-lived, top predatory marine mammals - show neuropathological signs of AD-like pathology. The neuropathological hallmarks in these cetaceans could help to better understand their endangered health as well as neurodegenerative diseases in humans. This systematic review analyzes all the literature published to date on this trending topic and the proposed causes for neurodegeneration in these iconic marine mammals are approached in the context of One Health/Planetary Health and translational medicine.
Animals ; Neurodegenerative Diseases/pathology* ; Whales ; Disease Models, Animal ; Humans ; Brain/pathology*

Noise-induced hearing loss is a worldwide public health issue that is characterized by temporary or permanent changes in hearing sensitivity. This condition is closely linked to inflammatory responses, and interventions targeting the inflammatory gene tumor necrosis factor-alpha (TNFα) are known to mitigate cochlear noise damage. TNFα-induced proteins (TNFAIPs) are a family of translucent acidic proteins, and TNFAIP6 has a notable association with inflammatory responses. To date, there have been few reports on TNFAIP6 levels in the inner ear. To elucidate the precise mechanism, we generated transgenic mouse models with conditional knockout of Tnfaip6 (Tnfaip6 cKO). Evaluation of hair cell morphology and function revealed no significant differences in hair cell numbers or ribbon synapses between Tnfaip6 cKO and wild-type mice. Moreover, there were no notable variations in hair cell numbers or hearing function in noisy environments. Our results indicate that Tnfaip6 does not have a substantial impact on the auditory system.
Animals ; Mice, Knockout ; Hair Cells, Auditory, Inner/pathology* ; Mice ; Mice, Transgenic ; Hearing Loss, Noise-Induced ; Evoked Potentials, Auditory, Brain Stem/physiology*

Epilepsy affects over 50 million people worldwide. Drug-resistant epilepsy (DRE) accounts for up to a third of these cases, and neuro-inflammation is thought to play a role in such cases. Despite being a long-debated issue in the field of DRE, the mechanisms underlying neuroinflammation have yet to be fully elucidated. The pro-inflammatory microenvironment within the brain tissue of people with DRE has been probed using single-cell multimodal transcriptomics. Evidence suggests that inflammatory cells and pro-inflammatory cytokines in the nervous system can lead to extensive biochemical changes, such as connexin hemichannel excitability and disruption of neurotransmitter homeostasis. The presence of inflammation may give rise to neuronal network abnormalities that suppress endogenous antiepileptic systems. We focus on the role of neuroinflammation and brain network anomalies in DRE from multiple perspectives to identify critical points for clinical application. We hope to provide an insightful overview to advance the quest for better DRE treatments.
Humans ; Drug Resistant Epilepsy/metabolism* ; Neuroinflammatory Diseases/immunology* ; Animals ; Brain/pathology* ; Nerve Net/pathology*

Previous studies have found associations between color discrimination deficits and cognitive impairments besides aging. However, investigations into the microstructural pathology of brain white matter (WM) associated with these deficits remain limited. This study aimed to examine the microstructural characteristics of WM in the non-demented population with abnormal color discrimination, utilizing Neurite Orientation Dispersion and Density Imaging (NODDI), and to explore their correlations with cognitive functions and cognition-related plasma biomarkers. The tract-based spatial statistic analysis revealed significant differences in specific brain regions between the abnormal color discrimination group and the healthy controls, characterized by increased isotropic volume fraction and decreased neurite density index and orientation dispersion index. Further analysis of region-of-interest parameters revealed that the isotropic volume fraction in the bilateral anterior thalamic radiation, superior longitudinal fasciculus, cingulum, and forceps minor was significantly correlated with poorer performance on neuropsychological assessments and to varying degrees various cognition-related plasma biomarkers. These findings provide neuroimaging evidence that WM microstructural abnormalities in non-demented individuals with abnormal color discrimination are associated with cognitive dysfunction, potentially serving as early markers for cognitive decline.
Humans ; White Matter/pathology* ; Male ; Female ; Cognitive Dysfunction/physiopathology* ; Middle Aged ; Aged ; Color Perception/physiology* ; Brain/pathology* ; Neuropsychological Tests ; Diffusion Tensor Imaging

Schizophrenia (SZ) stands as a severe psychiatric disorder. This study applied diffusion tensor imaging (DTI) data in conjunction with graph neural networks to distinguish SZ patients from normal controls (NCs) and showcases the superior performance of a graph neural network integrating combined fractional anisotropy and fiber number brain network features, achieving an accuracy of 73.79% in distinguishing SZ patients from NCs. Beyond mere discrimination, our study delved deeper into the advantages of utilizing white matter brain network features for identifying SZ patients through interpretable model analysis and gene expression analysis. These analyses uncovered intricate interrelationships between brain imaging markers and genetic biomarkers, providing novel insights into the neuropathological basis of SZ. In summary, our findings underscore the potential of graph neural networks applied to multimodal DTI data for enhancing SZ detection through an integrated analysis of neuroimaging and genetic features.
Humans ; Schizophrenia/pathology* ; Diffusion Tensor Imaging/methods* ; Male ; Female ; Adult ; Brain/metabolism* ; Young Adult ; Middle Aged ; White Matter/pathology* ; Gene Expression ; Nerve Net/diagnostic imaging* ; Graph Neural Networks

Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model, experimental autoimmune encephalomyelitis (EAE). This study investigates the role of high mobility group box 1 (HMGB1) in oligodendrocyte precursor cells (OPCs) in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier (BBB) by using OPC-specific HMGB1 knockout (KO) mice. We found that HMGB1 released from OPCs promotes BBB disruption, subsequently allowing increased immune cell infiltration. The migration of CD4+ T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes (OLs). OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS, leading to less damage to the myelin sheath and mitigated EAE progression. CD4+ T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs. Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; HMGB1 Protein/deficiency* ; Mice, Knockout ; Oligodendrocyte Precursor Cells/immunology* ; Mice, Inbred C57BL ; CD4-Positive T-Lymphocytes/immunology* ; Cell Movement ; Blood-Brain Barrier/immunology* ; Mice ; Myelin Sheath/pathology* ; Disease Models, Animal ; Coculture Techniques ; Oligodendroglia/metabolism* ; Female ; Cells, Cultured