Molecular Neurobiology最新文献

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.

Background: Chemotherapy is a crucial part of cancer treatment, but it has been linked to a set of cognitive impairments. 5-Fluorouracil, a chemotherapeutic drug causing mitochondrial dysfunction and neurodegeneration. This study primarily aimed to evaluate the effect of Plumbagin on mitochondrial dynamics, neuroinflammation and oxidative stress in adult zebrafish subjected to 5-Fluorouracil-induced cognitive impairment.

Material and methods: In this study, initially in-silico studies were conducted for lead compound identification. For the in-vivo studies, adult zebrafish (~ 6-8 months old; 470-530 mg; 126 animals are used) were randomly assigned to 7 groups and treated with 5-Fluorouracil (25 mg/kg; i.p.) for 1 day followed by post-treated with Plumbagin (10 and 20 mg/kg; i.p.) and Donepezil (5 mg/kg; i.p.) for 6 days. Behavioral, biochemical, molecular, mitochondrial, and histopathological analyses were performed after completion of the study.

Result: In-silico analyses revealed that Plumbagin exhibits stronger binding affinity as compared to 5-Fluorouracil. In vivo findings further demonstrated that post-treatment with Plumbagin significantly mitigates oxidative stress markers, reduces neuroinflammatory cytokines, and enhances mitochondrial functioning (mitochondrial enzyme complexes, caspases-3, and cellular viability) relative to zebrafish treated with 5-Flurouracil alone. Additionally, Plumbagin treatment led to marked reduction in GSK-3β expression, improvements in mitochondrial structure (as observed through Transmission electron microscopy analysis. Further, post-treatment with Plumbagin significantly improved mitochondrial morphology (as observed through TEM analysis) and neuronal morphology (assessed via Hematoxylin and Eosin staining and Nissl staining) as compared to 5-Fluorouracil -treated zebrafish.

Conclusion: Our findings provide strong evidence that Plumbagin significantly reduced neuroinflammation, provided neuroprotective support, and alleviates cognitive impairment, as demonstrated through in-silico and in-vivo analyses.

While epidemiological studies have linked cardiovascular disease (CVD) and amyotrophic lateral sclerosis (ALS), the causal pathways remain unclear. This study aims to clarify the causal relationship between CVD and ALS, with a focus on lipid metabolism as a potential mediator. We conducted a bidirectional two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between CVD and ALS. Furthermore, we utilized mediation MR, summary-data-based MR analysis (SMR), the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) pathway analysis, miRNA interaction prediction analysis, and protein-protein interaction (PPI) studies to validate the mediating effect of lipid metabolism on the risk of CVD and ALS onset, as well as to predict potential signaling pathways and mechanisms. The MR analysis revealed a significant association between CVD, particularly IHD, and an increased risk of ALS. Mediation analysis indicated that the level of sphingomyelin (d34:0) in serum may mediate the effect of IHD on ALS, along with the identification of seven additional types of plasma metabolites. Furthermore, KEGG and GO analyses highlighted lipid metabolism pathways, including "cholesterol metabolism" and the "phospholipid metabolic process." Additionally, miRNA interaction prediction analysis identified MFGE8 as a potential therapeutic target. Our study identifies IHD as a vascular risk factor for ALS, driven by lipid metabolic dysregulation. The identification of sphingomyelin (d34:0) and MFGE8 as key mediators in lipid metabolic dysregulation offers potential preventive and therapeutic strategies for CVD patients at elevated risk of ALS.

Cadmium (Cd) is a toxic heavy metal found in the environment from natural (volcanic eruptions) and industrial sources, including mining, smelting, batteries, and fuel combustion. Studies have shown that oxidative stress, inflammation, and abnormal immune response are associated with Cd-induced hypothalamic-pituitary-testicular (HPT) toxicity. The dietary trace element zinc (Zn) prevents oxidative and inflammatory effects in diverse experimental models. The literature has reported that Zn inhibits Cd-mediated HPT toxicity. Our objective is to investigate the mechanisms by which Zn inhibits the Cd-induced HPT toxicity in rats. A 42-day waterborne exposure of Cd and Zn was administered to rats individually at 200 μg/L or in a co-exposure. Treatment with Zn significantly (p < 0.05) reduced inflammatory and oxidative imbalance, as well as indoleamine 2,3-dioxygenase (IDO) activity and expression in both the hypothalamus and testes of rats. Furthermore, a Zn-induced reduction (p < 0.05) in cadmium (Cd) concentration led to fewer degenerating neurons in the hypothalamus and lower testicular injury scores observed in the Sertoli and Leydig cells on histological examination. Exposure to Zn also resulted in an increased (p < 0.05) sperm count, motility, viability, and lowered morphological alterations due to its antagonistic effect on Cd-induced decrease in reproductive/pituitary hormones and steroidogenic enzyme activities. Zn displayed high binding affinity (-9.2 kcal/mol) when docked with IDO, thus counteracting Cd-induced increase in IDO activity/expression by modulating redox imbalance.

Neurodegenerative disorders, particularly Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), represent a significant and growing global health concern in recent decades due to their complex pathology and lack of curative treatments. The fundamental cause of the evolution of these disorders is the dysfunction of cholinergic neurotransmission; those are mostly regulated by cholinesterase enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Conventional synthetic cholinesterase inhibitors like donepezil, rivastigmine, and galantamine are proposed for symptomatic relief but are often associated with adverse effects, limited bioavailability, and decreased long-term efficacy. Here, green-synthesized silver nanoparticles (AgNPs), which are derived from plant extracts and other biological systems, give an extraordinary alternative. These nanoparticles offer a biocompatible, eco-friendly, and cost-effective alternative to conventional synthetic methods. Greener AgNPs inhibit them by binding to the enzymes AChE and BChE and prevents them from breaking down neurotransmitters ACh and BCh. As a result, the count of neurotransmitters remains high in the synapse and can provide an effective synaptic transmission. Green-synthesized AgNPs can provide targeted drug delivery, enhance solubility, enhance bioavailability, improve absorption, and also be able to overcome the blood-brain barrier (BBB); all these characteristics give better therapeutic action than all conventional methods. This study evaluates the efficacy of green-synthesized silver nanoparticles in combination with several medicinal plants for treating neurodegenerative diseases, encouraging further research to upgrade these formulations for improved patient outcomes and increased clinical applicability.