OBJECTIVES: To investigate whether mesenchymal stem cell-derived exosomes (MSC-Exo) alleviate white matter damage (WMD) in neonatal rats by targeting the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3). METHODS: Three-day-old Sprague-Dawley rats were randomly assigned to four groups: Sham, hypoxia-ischemia (HI), MSC-Exo, and MCC950 (NLRP3 inhibitor) (n=24 per group). The WMD model was established by unilateral common carotid artery ligation combined with hypoxia. Exosomes (1×10⁸ particles/μL) were transplanted into the lateral ventricle using stereotaxic guidance. Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in brain tissue, and transmission electron microscopy was used to assess myelinated axons. Western blotting was performed to detect the expression of myelin basic protein (MBP), NLRP3, caspase-1, and interleukin-1β (IL-1β). Immunohistochemistry was used to measure NLRP3, caspase-1, and IL-1β expression. Twenty-eight days post-modeling, behavioral changes were evaluated using the Morris water maze. RESULTS: In the HI group, marked inflammatory cell infiltration, extensive vacuolation, and decreased numbers of myelinated axons were observed compared to the Sham group. The MSC-Exo group showed reduced inflammatory infiltration, fewer vacuoles, and increased myelinated axons compared to the HI group, while the MCC950 group showed nearly normal cell morphology. Compared to the Sham group, the HI group exhibited decreased MBP expression, fewer platform crossings, shorter time in the target quadrant, increased expression of NLRP3, caspase-1, and IL-1β, and longer escape latency (all P<0.05). Compared to the HI group, the MSC-Exo and MCC950 groups showed increased MBP expression, more platform crossings, longer target quadrant stay, and reduced NLRP3, caspase-1, and IL-1β expression, as well as shorter escape latency (all P<0.05). CONCLUSIONS MSC-Exo may attenuate white matter damage in neonatal rats by targeting the NLRP3 inflammasome and promoting oligodendrocyte maturation.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors* ; Rats, Sprague-Dawley ; White Matter/pathology* ; Inflammasomes/physiology* ; Rats ; Animals, Newborn ; Mesenchymal Stem Cells ; Interleukin-1beta/analysis* ; Male ; Caspase 1/analysis* ; Hypoxia-Ischemia, Brain/therapy* ; Myelin Basic Protein/analysis*

OBJECTIVES: To investigate whether human umbilical cord mesenchymal stem cells (HUC-MSCs) play protective effects against white matter injury (WMI) in neonatal rats via activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)/heme oxygenase-1 (HO-1) signaling pathway. METHODS: A neonatal WMI model was established in 3-day-old Sprague-Dawley rats by unilateral common carotid artery ligation combined with hypoxia. The study comprised two parts. (1) Rats were randomized into sham, hypoxia-ischemia (HI), and HUC-MSC groups (n=36 per group); brain tissues were collected at 7, 14, and 21 days after modeling. (2) Rats were randomized into sham, HI, HUC-MSC, and HUC-MSC+ML385 (Nrf2 inhibitor) groups (n=12 per group); tissues were collected 14 days after modeling. Hematoxylin-eosin staining assessed histopathology, and Luxol fast blue staining evaluated myelination. Immunohistochemistry examined the localization and expression of Nrf2, myelin basic protein (MBP), and proteolipid protein (PLP). Immunofluorescence assessed synaptophysin (SYP) and postsynaptic density-95 (PSD-95). Western blotting quantified Nrf2, Keap1, HO-1, SYP, PSD-95, MBP, and PLP. Spatial learning and memory were evaluated by the Morris water maze. RESULTS: At 7, 14, and 21 days after modeling, the sham group showed intact white matter, whereas the HI group exhibited white matter disruption, cellular vacuolation, and disorganized nerve fibers. These pathological changes were attenuated in the HUC-MSC group. Compared with the HI group, the HUC-MSC group showed increased Nrf2 immunopositivity and protein levels, increased HO-1 protein levels, and decreased Keap1 protein levels (P<0.05). Compared with the HI group, the HUC-MSC group had higher SYP and PSD-95 immunofluorescence intensities and protein levels, higher MBP and PLP positivity and protein levels, increased mean optical density of myelin, more platform crossings, and longer time in the target quadrant (all P<0.05). These improvements were reduced in the HUC-MSC+ML385 group compared with the HUC-MSC group (P<0.05). CONCLUSIONS HUC-MSCs may promote oligodendrocyte maturation and synaptogenesis after neonatal WMI by activating the Nrf2/Keap1/HO-1 pathway, thereby improving spatial cognitive function.
NF-E2-Related Factor 2/physiology* ; Animals ; Rats, Sprague-Dawley ; Signal Transduction/physiology* ; Humans ; Rats ; White Matter/pathology* ; Kelch-Like ECH-Associated Protein 1/physiology* ; Umbilical Cord/cytology* ; Heme Oxygenase-1/physiology* ; Animals, Newborn ; Male ; Mesenchymal Stem Cell Transplantation ; Heme Oxygenase (Decyclizing)/physiology* ; Mesenchymal Stem Cells/physiology* ; Female ; Hypoxia-Ischemia, Brain

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

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*

Listeria brainstem encephalitis with myelitis is extremely rare in clinical practice.Since the clinical manifestations are non-specific,MRI is helpful for diagnosis.Positive cerebrospinal fluid culture is considered the gold standard for diagnosis.This article reports a case of an immunocompetent individual with listeria brainstem encephalitis with myelitis,aiming to enhance the awareness of this condition.
Humans ; Brain Stem/pathology* ; Diagnostic Errors ; Encephalitis/complications* ; Encephalomyelitis, Acute Disseminated/diagnosis* ; Listeriosis/complications* ; Myelitis/complications*

Understanding the fundamental processes of human brain development and diseases is of great importance for our health. However, existing research models such as non-human primate and mouse models remain limited due to their developmental discrepancies compared with humans. Over the past years, an emerging model, the "brain organoid" integrated from human pluripotent stem cells, has been developed to mimic developmental processes of the human brain and disease-associated phenotypes to some extent, making it possible to better understand the complex structures and functions of the human brain. In this review, we summarize recent advances in brain organoid technologies and their applications in brain development and diseases, including neurodevelopmental, neurodegenerative, psychiatric diseases, and brain tumors. Finally, we also discuss current limitations and the potential of brain organoids.
Animals ; Mice ; Humans ; Induced Pluripotent Stem Cells ; Brain/pathology* ; Disease Models, Animal ; Neurodegenerative Diseases/pathology* ; Organoids/pathology*

Detailed characterizations of genomic alterations have not identified subtype-specific vulnerabilities in adult gliomas. Mapping gliomas into developmental programs may uncover new vulnerabilities that are not strictly related to genomic alterations. After identifying conserved gene modules co-expressed with EGFR or PDGFRA (EM or PM), we recently proposed an EM/PM classification scheme for adult gliomas in a histological subtype- and grade-independent manner. By using cohorts of bulk samples, paired primary and recurrent samples, multi-region samples from the same glioma, single-cell RNA-seq samples, and clinical samples, we here demonstrate the temporal and spatial stability of the EM and PM subtypes. The EM and PM subtypes, which progress in a subtype-specific mode, are robustly maintained in paired longitudinal samples. Elevated activities of cell proliferation, genomic instability and microenvironment, rather than subtype switching, mark recurrent gliomas. Within individual gliomas, the EM/PM subtype was preserved across regions and single cells. Malignant cells in the EM and PM gliomas were correlated to neural stem cell and oligodendrocyte progenitor cell compartment, respectively. Thus, while genetic makeup may change during progression and/or within different tumor areas, adult gliomas evolve within a neurodevelopmental framework of the EM and PM molecular subtypes. The dysregulated developmental pathways embedded in these molecular subtypes may contain subtype-specific vulnerabilities.
Humans ; Brain Neoplasms/pathology* ; Neoplasm Recurrence, Local/metabolism* ; Glioma/pathology* ; Neural Stem Cells/pathology* ; Oligodendrocyte Precursor Cells/pathology* ; Tumor Microenvironment

Glioma is the most common and lethal intrinsic primary tumor of the brain. Its controversial origins may contribute to its heterogeneity, creating challenges and difficulties in the development of therapies. Among the components constituting tumors, glioma stem cells are highly plastic subpopulations that are thought to be the site of tumor initiation. Neural stem cells/progenitor cells and oligodendrocyte progenitor cells are possible lineage groups populating the bulk of the tumor, in which gene mutations related to cell-cycle or metabolic enzymes dramatically affect this transformation. Novel approaches have revealed the tumor-promoting properties of distinct tumor cell states, glial, neural, and immune cell populations in the tumor microenvironment. Communication between tumor cells and other normal cells manipulate tumor progression and influence sensitivity to therapy. Here, we discuss the heterogeneity and relevant functions of tumor cell state, microglia, monocyte-derived macrophages, and neurons in glioma, highlighting their bilateral effects on tumors. Finally, we describe potential therapeutic approaches and targets beyond standard treatments.
Humans ; Glioma/metabolism* ; Neuroglia/metabolism* ; Carcinogenesis/pathology* ; Neural Stem Cells/metabolism* ; Microglia/metabolism* ; Brain Neoplasms/metabolism* ; Tumor Microenvironment

Diffuse intrinsic pontine glioma (DIPG) is the main cause of brain tumor-related death among children. Until now, there is still a lack of effective therapy with prolonged overall survival for this disease. A typical strategy for preclinical cancer research is to find out the molecular differences between tumor tissue and para-tumor normal tissue, in order to identify potential therapeutic targets. Unfortunately, it is impossible to obtain normal tissue for DIPG because of the vital functions of the pons. Here we report the human fetal hindbrain-derived neural progenitor cells (pontine progenitor cells, PPCs) as normal control cells for DIPG. The PPCs not only harbored similar cell biological and molecular signatures as DIPG glioma stem cells, but also had the potential to be immortalized by the DIPG-specific mutation H3K27M in vitro. These findings provide researchers with a candidate normal control and a potential medicine carrier for preclinical research on DIPG.
Animals ; Brain Stem Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cellular Senescence ; Female ; Glioma ; genetics ; metabolism ; pathology ; Histones ; genetics ; Humans ; Mice, Inbred NOD ; Mice, SCID ; Neoplasm Transplantation ; Neoplastic Stem Cells ; drug effects ; metabolism ; pathology ; Neural Stem Cells ; drug effects ; metabolism ; pathology ; Pons ; embryology ; metabolism ; pathology ; Primary Cell Culture

BACKGROUND AND OBJECTIVES: Auditory brainstem response (ABR) can be utilized to verify the hearing threshold and determine the existence of retrocochlear pathology in sudden deafness. However, little is known about the significance of ABR characteristics as a prognostic factor in sudden deafness. The purpose of this study is to evaluate which characteristics of ABR is associated with the prognosis of sudden deafness. SUBJECTS AND METHOD: We studied patients who were diagnosed with unilateral sudden deafness from January 2017 to May 2018. ABR results of click stimuli at 90 dB nHL were analyzed by the latency of wave I, III, and V. RESULTS: A total of 113 patients (55 men and 58 women) participated in the study. Hearing recovery was observed in 94 cases (83.2%). The absolute latency of wave I, III, and V was prolonged in the affected ears when compared with the unaffected ears. Hearing improvement was only correlated to the interaural latency delay of wave I (Pearson's r=−0.278, p<0.05). Prolonged interaural latency delay was noted from complete toward slight hearing recovery group. When the hearing outcome was evaluated by the interaural latency delay of wave I at 0.2 ms, the result of under 0.2 ms was significantly better than that over 0.2 ms and no visible wave I. CONCLUSION: Prolonged interaural delay of wave I over 0.2 ms and no visible wave I in ABR showed worse hearing outcome in sudden deafness. This finding may provide ABR as a potential prognostic indicator in sudden deafness.
Ear ; Evoked Potentials ; Evoked Potentials, Auditory, Brain Stem ; Hearing Loss, Sudden ; Hearing ; Humans ; Male ; Methods ; Pathology ; Prognosis