Molecular Neurobiology最新文献

Spinal cord injuries (SCI) are associated with significant physical and economic burdens on individuals and healthcare systems. Research has shown that several molecular and cellular interactions significantly contribute to SCI progression. The initiation and development of SCI are strongly linked to cellular stress mechanisms, notably those associated with the endoplasmic reticulum (ER), which gives rise to the unfolded protein response (UPR). This systematic review discusses the molecular pathways involved in ER stress, particularly the role of the activating transcription factor 6 (ATF6)-mediated apoptosis pathway and the role of CCAAT/enhancer-binding homologous protein (CHOP) in SCI pathogenesis. Prolonged ER stress exacerbates neuronal degeneration and apoptosis, making it a key factor in SCI. Efforts to inhibit this pathway via genetic or pharmacological interventions have shown potential in addressing cellular dysfunction and preventing SCI-related degeneration. Moreover, pharmacological approaches that mitigate ER stress, for example, by promoting protein folding, are promising for enhancing neuronal survival and reducing damage after SCI. Complementary strategies, such as maintaining metabolic health and engaging in physical activity, could also help fortify the spinal cord against ER stress-related damage. These preventive and therapeutic approaches underscore the importance of targeting ER stress to minimize SCI onset and progression, offering valuable insights for improved care and recovery.

Ferroptosis contributes significantly to neuronal loss and functional decline after spinal cord injury (SCI). Emerging evidence links the vitamin K (VK) cycle to ferroptosis regulation, but its status and role in SCI remain unknown. Therefore, this study aims to elucidate the role and underlying mechanism of the VK cycle in neuronal ferroptosis post-SCI, thereby providing insights for developing novel therapeutic strategies. We quantified VK₂ levels and examined VK cycle enzyme expression in injured spinal cords after SCI to identify mechanisms of VK₂ reduction. The role of VKORC1L1 in neuronal ferroptosis and motor recovery was assessed via overexpression and inhibition both in vivo and in vitro. Finally, VK₂ supplementation was tested for its effects on ferroptosis, tissue damage, electrophysiological outcomes, and motor function after SCI. VK₂ levels were significantly reduced at the injury site following SCI. Expression of VKORC1L1, a pivotal enzyme in the VK cycle, was found to decrease at the injury site after SCI. Enhancing VKORC1L1 expression reduced neuronal ferroptosis, protected spinal cord tissue, and promoted functional recovery. Conversely, inhibiting VKORC1L1 activity heightened neuronal vulnerability and exacerbated ferroptosis. Additionally, supplementation with VK₂ alleviated neuronal ferroptosis, alleviated spinal cord damage, and improved motor function following SCI. The downregulation of VKORC1L1 disrupts the VK cycle, thereby exacerbating neuronal ferroptosis after SCI. Therapeutic strategies targeting VKORC1L1 upregulation or VK₂ supplementation represent promising avenues for SCI treatment.

Mesenchymal stem cells (MSCs)-based therapy has received considerable research attention for its anti-inflammatory properties in depressive-like behavior, but poor MSC survival and immunogenicity after transplantation limit their therapeutic effectiveness. This study evaluated pretreated bone marrow-derived MSCs (BM-MSCs) with Lactobacillus plantarum supernatant (L.PS) in an animal model of chronic restraint stress (CRS)-induced depressive-like behavior. BM-MSCs were pretreated with 15 μM of fluoxetine (Flx) or 10 µl/ml of L.PS for 24 h. Thirty-six adult male Wistar rats were divided into six groups: CTRL, CRS, CRS + PBS (Phosphate-Buffered Saline), CRS + MSCs, CRS + MSCs(Flx) (Flx-preconditioned MSCs), and CRS + MSCs(L.PS) groups. The open field test, Morris water maze, forced swimming test, body weight, and blood glucose levels were measured. After sacrifice, the hippocampal tissues underwent histopathological analysis. Additionally, hippocampal mRNA levels of NF-κB and pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α) were measured using real-time PCR, while ELISA was used to measure protein levels of these cytokines and serum corticosterone. A bioinformatic analysis, including protein-protein interaction network, enrichment, and correlation analysis related to depression, was performed. Pre-treatment of MSCs with L.PS significantly improved depressive-like behavior (p < 0.05) by enhancing MSCs neuroprotection through the downregulation of NF-κB and pro-inflammatory cytokines. An in silico analysis also supported the importance of evaluating and targeting this pathway. In conclusion, we found that L.PS pretreated MSCs significantly improves CRS-induced depressive-like behavior, which can be partly attributed to the inhibition of NLRP3-mediated neuroinflammation.

Serum miRNA-155 and TREM2 levels were investigated as potential non-invasive indicators. In this case-control study, serum miRNA-155 and TREM2 levels were evaluated in 80 patients with multiple sclerosis (MS) and 80 age- and sex-matched healthy controls. Levels were measured using qPCR and ELISA, with correlations assessed against Expanded Disability Status Scale (EDSS) scores, MRI lesion burden, and cerebrospinal fluid (CSF) markers (oligoclonal bands and immunoglobulin G index). Participants were followed for 24 months to evaluate biomarker dynamics during relapses and treatment. Patients with MS showed significantly elevated miRNA-155 and TREM2 levels compared to controls. Compared to healthy controls, the combined panel demonstrated good discriminatory performance (AUC = 0.924), with 89.0% sensitivity and 87.5% specificity. However, these metrics represent differentiation from health rather than disease specificity, as the study lacked disease control groups with inflammatory or non-inflammatory neurological disorders-a critical limitation for assessing actual diagnostic utility, performing better than the individual markers. Both biomarkers correlated moderately with EDSS (miRNA-155 r = 0.62, 95% CI 0.49-0.73; TREM2 r = 0.59, 95% CI 0.45-0.71), MRI abnormalities, and CSF parameters (r = 0.48-0.60, p < 0.001). Longitudinally, elevations tracked relapse activity, while therapy responders showed reductions (miRNA-155: -18.7%; TREM2: -15.3%), underscoring utility in monitoring treatment efficacy. These results indicate that serum miRNA-155 and TREM2 effectively capture MS neuroinflammation, structural damage, and therapeutic responses. This dual-biomarker approach provides clinicians with a practical, noninvasive tool for tracking disease progression and optimizing the management of MS.

Neuropathic pain (NP) and depression frequently co-occur, creating a complex clinical challenge with limited therapeutic options due to poorly understood shared mechanisms. Our preliminary screening identified the mitochondrial deacetylase SIRT3 as a potential key regulator of this comorbidity. Building on this finding, we hypothesized that Gastrodin, a natural compound with documented neuroprotective properties, exerts its therapeutic effects by targeting SIRT3. This study was therefore designed to investigate whether Gastrodin alleviates NP-depression comorbidity through a SIRT3-dependent mechanism. A rat model of NP-depression comorbidity was established by combining spared sciatic nerve injury (SNI) with chronic unpredictable mild stress (CUMS). Behavioral tests were conducted to assess mechanical allodynia, thermal hyperalgesia, and depression-like behaviors. Molecular mechanisms were evaluated using Western blot, ELISA, qPCR, and transmission electron microscopy. The specific role of SIRT3 was confirmed using the inhibitor 3-TYP in vivo and siRNA in vitro. Gastrodin administration (200/300 mg/kg) significantly ameliorated both pain hypersensitivity and depression-like behaviors in the comorbidity model. Mechanistically, Gastrodin upregulated SIRT3 expression and enhanced its deacetylase activity in the hippocampus, as evidenced by reduced acetylation of SOD2. This led to attenuated neuroinflammation (TNF-α, IL-1β, IL-6) and oxidative stress (MDA, ROS). Furthermore, Gastrodin improved mitochondrial ultrastructure and promoted mitochondrial biogenesis via the PGC-1α/TFAM pathway in astrocytes. Critically, all therapeutic benefits of Gastrodin were abolished upon SIRT3 inhibition. Gastrodin exerts dual therapeutic effects on NP-depression comorbidity by activating the SIRT3 pathway, thereby rescuing mitochondrial function in hippocampal astrocytes. These findings identify Gastrodin as a promising candidate for treating pain-depression comorbidity and underscore SIRT3 as a critical therapeutic target.

Upregulation of tumor necrosis factor-like weak apoptosis-inducing factor (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) was observed in stroke patients and murine models, contributing to neuronal apoptosis and blood-brain barrier (BBB) disruption. This study aimed to investigate the TWEAK/Fn14 signaling axis in cerebral ischemia and reperfusion using different in vitro oxygen-glucose deprivation (OGD) durations and cellular models. Western blot and RT-qPCR were used to evaluate TWEAK/Fn14 expression in monocultures, co-cultures, and triple-cultures of human immortalized endothelial cells, pericytes, and astrocytes. Six OGD conditions were tested: 4, 8, and 16 h, with or without 24 h reoxygenation. BBB model integrity was evaluated by analyzing occludin, zonula occludens-1, and VE-cadherin. A significant, duration-dependent downregulation of Fn14 was observed in monocultures after OGD (up to 85%, p < 0.05-p < 0.001), with partial recovery after 24 h reoxygenation (p < 0.05). TWEAK levels remained stable with minor fluctuations. Similar Fn14 reductions were seen in co- and triple-cultures (p < 0.01), followed by recovery. Endothelial biomarkers exhibited an initial stress response post-OGD, followed by recovery during reoxygenation. In conclusion, TWEAK remains stable during ischemia without immune cells, while Fn14 is downregulated during OGD and recovers after reoxygenation, indicating time-dependent roles in ischemic response and repair. The findings indicate a time-dependent regulation of Fn14 under ischemic conditions in vitro, highlighting its role in BBB stress and recovery. Nevertheless, further preclinical studies are needed to establish its therapeutic potential.

Secondary damage in remote brain regions following ischemic stroke significantly worsens patient outcomes, yet its underlying mechanisms remain poorly understood. Microglial activation is a central pathological feature of secondary damage, with the P2X7 receptor (P2X7R) emerging as a key regulator of neuroinflammatory processes. In this study, we employed a distal middle cerebral artery occlusion (dMCAO) model in rats to investigate the role of P2X7R in secondary damage in the ventral posterolateral nucleus (VPN) of the ipsilateral thalamus. We observed a spatiotemporal pattern of microglial activation and elevated P2X7R expression in the VPN, coinciding with delayed neuronal loss and gliosis. P2X7R activation drove the NLRP3 inflammasome cascade, leading to the release of interleukin-1β (IL-1β). Inhibition of P2X7R using Brilliant Blue G (BBG) significantly attenuated microglial activation, suppressed the NLRP3/IL-1β axis, and reduced neuronal loss and gliosis in the VPN. Molecular dynamics simulations confirmed BBG's high-affinity binding to P2X7R, while behavioral tests demonstrated improved neurological function. Transcriptome sequencing revealed that P2X7R inhibition by BBG induces profound reprogramming of calcium signaling pathways, suppressing calcium-regulated exocytosis and neuroactive ligand-receptor interactions, while enriching the cAMP pathway. This correlates with BBG's efficacy in attenuating microglial activation, NLRP3/IL-1β axis activation, and neuronal loss. Our findings establish P2X7R as a central driver of neuroinflammation in delayed neurodegeneration after ischemic stroke,and inhibition with P2X7R offers a promising strategy to mitigate secondary damage.

Alzheimer's disease (AD) is characterized by an insidious onset and complex pathophysiology, necessitating the development of effective strategies for early detection and intervention. This exploratory study aimed to identify differentially expressed genes (DEGs) and disrupted molecular pathways in AD by analyzing blood samples from participants recruited in Valle del Cauca, Colombia, a region with high genetic admixture and persistent underrepresentation in genomic research. A total of 41 individuals (AD, n = 14; cognitively healthy controls (CHC), n = 27) were included. Groups did not differ significantly in age, education, sex distribution, or vascular comorbidities. Peripheral blood RNA was sequenced using 150-bp paired-end reads, and transcriptomic profiling revealed 399 DEGs, with 378 upregulated and 21 downregulated in the AD group. Key genes such as APOE, MMP2, PPARG, and TUBB3 were enriched in the Metabolism of Proteins pathway. At the same time, TUBB3, CACNA2D1, and GABBR2 were implicated in transmission across chemical synapses, suggesting synaptic signaling and protein metabolism dysregulation. Multiple factor analysis (MFA), integrating gene expression with neurocognitive and functional outcomes, revealed distinct molecular signatures associated with cognitive decline and functional impairment. These findings highlight the role of systemic metabolic dysfunction and synaptic dysregulation in AD pathogenesis. By focusing on an ancestrally diverse cohort, this study underscores the critical need to expand the molecular characterization of AD beyond European-ancestry populations, informing the development of inclusive biomarkers and precision strategies for early diagnosis and intervention.

The long-term effects of non-convulsive status epilepticus (NCSE) and their mechanisms in the brain remain largely unknown. Such insight is needed to better shape the clinical approach to this condition. Here, we investigated long-term alterations in hippocampal transcriptomic profiles following an episode of limbic NCSE in periadolescent rats. Cortical and hippocampal mRNA expressions were measured 2 months following intrahippocampal kainic acid (NCSE group, n = 3) or saline injections (controls, n = 4). Compared to controls, NCSE-treated rodents exhibited a significant twofold downregulation in 126 genes in the CA1 hippocampal subfield, 11 in the CA2-3 region, and 21 in the dentate/hilar areas. Most of the identified genes are known to play an essential role in learning and hippocampal plasticity. Additional roles include modulation of inflammatory responses. Twenty altered genes are known to contribute to human intellectual and mental disease pathology, and nine out of these are direct causes of cognitive and neurodevelopmental brain disorders. Spatial deconvolution analyses revealed NCSE-related increases in CA2-3 microglia and hilar astrocytes coupled with increases in dentate GABAergic neurons. These long-term region-specific cellular and molecular hippocampal alterations may contribute to both inflammatory states and disturbances in neuronal function. Taken together, these gene expression changes are suggestive of neuroinflammation-driven synaptic dysfunction following NCSE.

Perioperative neurocognitive disorders (PND) are common complications in elderly surgical patients; their mechanisms remain unclear and no effective therapeutic targets exist. This study aims to determine whether copper dyshomeostasis contributes to PND via 18 kDa translocator protein (TSPO)-mediated pathways and to evaluate the therapeutic potential of a TSPO inhibitor. An aged-mouse model of PND was established by right carotid exposure, and BV-2 microglia were stimulated with lipopolysaccharide (LPS) to mimic neuroinflammation. Copper ions, TSPO expression, and mitochondrial function were assessed in the hippocampus, serum, and cultured cells. Postoperative mice exhibited elevated copper levels in both the hippocampus and serum, accompanied by a significant increase in hippocampal TSPO expression. In vitro, LPS-induced TSPO over-expression in BV-2 cells led to copper accumulation and mitochondrial dysfunction, both of which were reversed by the TSPO inhibitor PK11195. TSPO-mediated disruption of copper homeostasis is a critical mechanism in PND, and targeting TSPO offers a novel strategy for PND prevention and treatment.