This study aims to explore the effects and potential mechanisms of Modified Shuyu Pills in ameliorating depressive behaviors in the mouse model of vascular dementia(VaD). Seventy-two three-month-old male C57BL/6 mice were assigned into six groups: sham, model, low-, medium-, and high-dose Modified Shuyu Pills, and fluoxetine. The other five groups except the sham group underwent bilateral common carotid artery stenosis combined with chronic unpredictable stress. Depressive behaviors were assessed by the sucrose preference test and tail suspension test. Cerebral blood flow was measured by laser speckle imaging. Protein levels of low density lipoprotein receptor(LDLR), mitogen-activated protein kinase kinase(MEK), phosphorylated(p)-MEK, extracellular signal-regulated kinase(ERK), and p-ERK in the ventral tegmental area(VTA) and nucleus accumbens(NAc) were determined by Western blot. The fluorescence intensity of myelin basic protein(MBP) in the VTA and NAc were measured by immunofluorescence. Myelin sheath morphology in the VTA and NAc was observed by luxol fast blue staining, and the ultrastructure of myelin sheath in the VTA and NAc was examined by transmission electron microscopy. In the tail suspension test, the immobility time of the model group was longer than that of the sham group(P<0.01). In the sucrose preference test, the sucrose preference rate of the model group was lower than that of the sham group(P<0.01). After intervention with Modified Shuyu Pills, the immobility time in the tail suspension test was shortened(P<0.01), and the sucrose preference rate increased(P<0.01). Laser speckle imaging results showed that compared with the sham group, the model group showed reduced cerebral blood flow(P<0.01), and the reduction was reversed by medium-and high-dose Modified Shuyu Pills(P<0.01). Western blot results indicated that the relative expression levels of LDLR, p-MEK/MEK, and p-ERK/ERK in the VTA and NAc of the model group were lower than those in the sham group(P<0.01). Medium-and high-dose Modified Shuyu Pills reversed this trend(P<0.01). Immunofluorescence results showed that the fluorescence intensity of MBP in the VTA and NAc of the model group was lower than that of the sham group(P<0.01). The medium-and high-dose Modified Shuyu Pills groups showed increased fluorescence intensity of MBP in the VTA compared with the model group(P<0.01). In the NAc, the fluorescence intensity of MBP in all the groups of Modified Shuyu Pills increased to varying degrees compared with that in the model group(P<0.01). Luxol fast blue staining results showed that the model group presented lighter staining intensity and looser arrangement of myelin fibers than the sham group, indicating significant demyelination in the model group. However, after intervention with medium-and high-dose Modified Shuyu Pills, the staining intensity and myelin sheath structure in the VTA and NAc were improved. Transmission electron microscopy results revealed that the myelin sheath in the VTA and NAc of the sham group was intact and dense, while the model group exhibited extensive myelin loss, with myelin sheath degeneration and disintegration. After intervention with Modified Shuyu Pills, the myelin sheath loss in the VTA and NAc of mice was reduced, and the proportion of myelinated tissue increased. In summary, Modified Shuyu Pills may promote myelination via the VTA-NAc circuit by upregulating the LDLR/MEK/ERK signaling pathway, thereby ameliorating depressive-like behaviors in VaD mice.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Ventral Tegmental Area/metabolism* ; Mice, Inbred C57BL ; Disease Models, Animal ; Depression/genetics* ; Receptors, LDL/genetics* ; Dementia, Vascular/psychology* ; MAP Kinase Signaling System/drug effects* ; Nucleus Accumbens/metabolism* ; Behavior, Animal/drug effects* ; Humans ; Myelin Sheath/drug effects* ; Extracellular Signal-Regulated MAP Kinases/genetics*

Growth arrest DNA damage-inducible protein 45 β (GADD45B) has been reported to be a regulatory factor for active DNA demethylation and is implicated in the modulation of synaptic plasticity and chronic stress-related psychopathological processes. However, its precise role and mechanism of action in stress susceptibility remain elusive. In this study, we found a significant reduction in GADD45B expression specifically in the ventral, but not the dorsal hippocampal CA1 (dCA1) of stress-susceptible mice. Furthermore, we demonstrated that GADD45B negatively regulates susceptibility to social stress and NMDA receptor-dependent long-term potentiation (LTP) in the ventral hippocampal CA1 (vCA1). Importantly, through pharmacological inhibition using the NMDA receptor antagonist MK801, we provided further evidence supporting the hypothesis that GADD45B potentially modulates susceptibility to social stress by influencing NMDA receptor-mediated LTP. Collectively, these results suggested that modulation of NMDA receptor-mediated synaptic plasticity is a pivotal mechanism underlying the regulation of susceptibility to social stress by GADD45B.
Animals ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors* ; CA1 Region, Hippocampal/drug effects* ; Male ; Stress, Psychological/physiopathology* ; Mice ; Neuronal Plasticity/drug effects* ; Long-Term Potentiation/drug effects* ; Mice, Inbred C57BL ; Antigens, Differentiation/metabolism* ; Dizocilpine Maleate/pharmacology* ; Excitatory Amino Acid Antagonists/pharmacology* ; GADD45 Proteins

Although cisplatin is a widely used chemotherapeutic agent, it is severely toxic and causes irreversible hearing loss, restricting its application in clinical settings. This study aimed to determine the molecular mechanism underlying cisplatin-induced ototoxicity. Here, we established in vitro and in vivo ototoxicity models of cisplatin-induced hair cell loss, and our results showed that reducing STING levels decreased inflammatory factor expression and hair cell death. In addition, we found that cisplatin-induced mitochondrial dysfunction was accompanied by cytosolic DNA, which may act as a critical linker between the cyclic GMP-AMP synthesis-stimulator of interferon genes (cGAS-STING) pathway and the pathogenesis of cisplatin-induced hearing loss. H-151, a specific inhibitor of STING, reduced hair cell damage and ameliorated the hearing loss caused by cisplatin in vivo. This study underscores the role of cGAS-STING in cisplatin ototoxicity and presents H-151 as a promising therapeutic for hearing loss.
Cisplatin/toxicity* ; Animals ; Nucleotidyltransferases/antagonists & inhibitors* ; Membrane Proteins/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Mice ; Hair Cells, Auditory, Inner/pathology* ; Antineoplastic Agents/toxicity* ; Mice, Inbred C57BL ; Hearing Loss/metabolism* ; Male ; Ototoxicity/metabolism*

Autism Spectrum Disorder (ASD) is marked by early-onset neurodevelopmental anomalies, yet the temporal dynamics of genetic contributions to these processes remain insufficiently understood. This study aimed to elucidate the role of the Shank3 gene, known to be associated with monogenic causes of autism, in early developmental processes to inform the timing and mechanisms for potential interventions for ASD. Utilizing the Shank3B knockout (KO) mouse model, we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex (ACC) across different postnatal stages. Our longitudinal analysis revealed that, while Shank3B KO mice displayed normal neuronal morphology at one week postnatal, significant impairments in dendritic growth and synaptic activity emerged by two to three weeks. These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.
Animals ; Nerve Tissue Proteins/metabolism* ; Mice, Knockout ; Dendrites/metabolism* ; Mice ; Synapses/metabolism* ; Gyrus Cinguli/metabolism* ; Male ; Mice, Inbred C57BL ; Autism Spectrum Disorder/genetics* ; Microfilament Proteins

Alzheimer's disease (AD), a neurodegenerative disorder with complex etiologies, manifests through a cascade of pathological changes before clinical symptoms become apparent. Among these early changes, alterations in the expression of non-coding RNAs (ncRNAs) have emerged as pivotal events. In this study, we focused on the aberrant expression of ncRNAs and revealed that Lamr1-ps1, a pseudogene of the laminin receptor, significantly exacerbates early spatial learning and memory deficits in APP/PS1 mice. Through a combination of bioinformatics prediction and experimental validation, we identified the miR-29c/Bace1 pathway as a potential regulatory mechanism by which Lamr1-ps1 influences AD pathology. Importantly, augmenting the miR-29c-3p levels in mice ameliorated memory deficits, underscoring the therapeutic potential of targeting miR-29c-3p in early AD intervention. This study not only provides new insights into the role of pseudogenes in AD but also consolidates a foundational basis for considering miR-29c as a viable therapeutic target, offering a novel avenue for AD research and treatment strategies.
Animals ; Alzheimer Disease/pathology* ; Pseudogenes/genetics* ; Mice ; Memory Disorders/metabolism* ; MicroRNAs/genetics* ; Disease Models, Animal ; Spatial Learning/physiology* ; Mice, Transgenic ; Presenilin-1/genetics* ; Male ; Amyloid Precursor Protein Secretases/metabolism* ; Mice, Inbred C57BL ; Aspartic Acid Endopeptidases/metabolism*

During the hyperacute phase of intracerebral hemorrhage (ICH), the mass effect and blood components mechanically lead to brain damage and neurotoxicity. Our findings revealed that the mass effect and transferrin precipitate neuronal oxidative stress and iron uptake, culminating in ferroptosis in neurons. M6A (N6-methyladenosine) modification, the most prevalent mRNA modification, plays a critical role in various cell death pathways. The Fto (fat mass and obesity-associated protein) demethylase has been implicated in numerous signaling pathways of neurological diseases by modulating m6A mRNA levels. Regulation of Fto protein levels in neurons effectively mitigated mass effect-induced neuronal ferroptosis. Applying nanopore direct RNA sequencing, we identified voltage-dependent anion channel 3 (Vdac3) as a potential target associated with ferroptosis. Fto influenced neuronal ferroptosis by regulating the m6A methylation of Vdac3 mRNA. These findings elucidate the intricate interplay between Fto, Vdac3, m6A methylation, and ferroptosis in neurons during the hyperacute phase post-ICH and suggest novel therapeutic strategies for ICH.
Ferroptosis/physiology* ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics* ; Animals ; Neurons/metabolism* ; Transferrin/pharmacology* ; Mice ; Methylation ; Mice, Inbred C57BL ; Adenosine/metabolism* ; RNA, Messenger/metabolism* ; Male ; Oxidative Stress/physiology*

Vascular damage plays a significant role in the onset and progression of Alzheimer's disease (AD). However, the precise molecular mechanisms underlying the induction of neuronal injury by vascular damage remain unclear. The present study aimed to examine the impact of fibrinogen (Fg) on tau pathology. The results showed that Fg deposits in the brains of tau P301S transgenic mice interact with tau, enhancing the cytotoxicity of pathological tau aggregates and promoting tau phosphorylation and aggregation. Notably, Fg-modified tau fibrils caused enhanced neuronal apoptosis and synaptic damage compared to unmodified fibrils. Furthermore, intrahippocampal injection of Fg-modified tau fibrils worsened the tau pathology, neuroinflammation, synaptic damage, neuronal apoptosis, and cognitive dysfunction in tau P301S mice compared to controls. The present study provides compelling evidence linking Fg and tau, thereby connecting cerebrovascular damage to tau pathology in AD. Consequently, inhibiting Fg-mediated tau pathology could potentially impede the progression of AD.
Animals ; tau Proteins/metabolism* ; Alzheimer Disease/metabolism* ; Fibrinogen/metabolism* ; Mice, Transgenic ; Mice ; Disease Models, Animal ; Memory Disorders/metabolism* ; Male ; Mice, Inbred C57BL ; Brain/metabolism* ; Hippocampus/metabolism* ; Protein Aggregation, Pathological/metabolism* ; Apoptosis ; Phosphorylation

High mobility group box 1 (HMGB1), when released extracellularly, plays a pivotal role in the development of spinal cord synapses and exacerbates autoimmune diseases within the central nervous system. In experimental autoimmune encephalomyelitis (EAE), a condition that models multiple sclerosis, the levels of extracellular HMGB1 and interleukin-33 (IL-33) have been found to be inversely correlated. However, the mechanism by which IL-33 deficiency enhances HMGB1 release during EAE remains elusive. Our study elucidates a potential signaling pathway whereby the absence of IL-33 leads to increased binding of P300/CBP-associated factor with HMGB1 in the nuclei of astrocytes, upregulating HMGB1 acetylation and promoting its release from astrocyte nuclei in the spinal cord of EAE mice. Conversely, the addition of IL-33 counteracts the TNF-α-induced increase in HMGB1 and acetylated HMGB1 levels in primary astrocytes. These findings underscore the potential of IL-33-associated signaling pathways as a therapeutic target for EAE treatment.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Astrocytes/metabolism* ; Interleukin-33/metabolism* ; HMGB1 Protein/metabolism* ; Acetylation ; Mice, Knockout ; Mice, Inbred C57BL ; p300-CBP Transcription Factors/metabolism* ; Mice ; Spinal Cord/metabolism* ; Cells, Cultured ; Female ; Signal Transduction

Neuropathic pain, often featuring allodynia, imposes significant physical and psychological burdens on patients, with limited treatments due to unclear central mechanisms. Addressing this challenge remains a crucial unsolved issue in pain medicine. Our previous study, using protein kinase C gamma (PKCγ)-tdTomato mice, highlights the spinal feedforward inhibitory circuit involving PKCγ neurons in gating neuropathic allodynia. However, the regulatory mechanisms governing this circuit necessitate further elucidation. We used diverse transgenic mice and advanced techniques to uncover the regulatory role of the descending serotonin (5-HT) facilitation system on spinal PKCγ neurons. Our findings revealed that 5-HT neurons from the rostral ventromedial medulla hyperpolarize spinal inhibitory interneurons via 5-HT_2C receptors, disinhibiting the feedforward inhibitory circuit involving PKCγ neurons and exacerbating allodynia. Inhibiting spinal 5-HT_2C receptors restored the feedforward inhibitory circuit, effectively preventing neuropathic allodynia. These insights offer promising therapeutic targets for neuropathic allodynia management, emphasizing the potential of spinal 5-HT_2C receptors as a novel avenue for intervention.
Animals ; Neuralgia/physiopathology* ; Protein Kinase C/metabolism* ; Receptor, Serotonin, 5-HT2C/metabolism* ; Hyperalgesia/physiopathology* ; Mice, Transgenic ; Mice ; Spinal Cord/metabolism* ; Serotonin/metabolism* ; Male ; Neurons/metabolism* ; Mice, Inbred C57BL

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