Neurochemical Research最新文献

Perioperative neurocognitive disorders (PND) comprise a spectrum of cognitive disturbances after anesthesia and surgery, affecting learning, memory, and executive function. Although systemic inflammation, surgical trauma, anesthetic exposure, and patient vulnerability have been implicated in PND, the mechanisms linking perioperative stress to persistent cognitive changes remain incompletely understood. Microglia, as resident immune cells of the central nervous system, are important regulators of neuroimmune interactions and may contribute to PND through alterations in inflammatory signaling, synaptic regulation, vascular function, metabolism, and epigenetic programs. In this Overview, we summarize current evidence regarding microglial involvement in PND across five interconnected domains: neuroinflammation, blood–brain barrier dysfunction, microglia–neuron communication, mitochondrial and metabolic regulation, and epigenetic remodeling. We further discuss emerging single-cell transcriptomic and multi-omic studies indicating that microglial responses are heterogeneous, dynamic, and context dependent rather than adequately described by the traditional M1/M2 framework. We propose that PND involves complex interactions among peripheral immune activation, neurovascular dysfunction, microglial state transitions, and neuronal vulnerability. Finally, we highlight current challenges in translating microglial mechanisms into clinical applications and discuss future directions for identifying biomarkers and developing context-specific perioperative neuroprotective strategies.

This study investigated the therapeutic effects of acupuncture on post-stroke muscle hypertonia (PSMH) in rats, focusing on the WNK1-SPAK/OSR1-KCC2 pathway to elucidate its underlying mechanisms and support clinical translation. Behavioral, electrophysiological, TTC staining, AChE staining, and transmission electron microscope analyses were used to assess the efficacy of acupuncture. RT-qPCR, Western blot, and immunofluorescence were used to evaluate the expression of the medullary WNK1-SPAK/OSR1-KCC2 pathway. Pharmacological modulation using WNK463 and Gabazine suggested the involvement of WNK kinase activity. Acupuncture reduced neurological deficits and spasticity, enhanced motor recovery, suppressed spinal motor neuron hyperexcitability, and ameliorated neuromuscular dysfunction and muscular structural abnormality. Mechanistically, it downregulated WNK1, SPAK, and OSR1 and increased membrane KCC2 expression in the medulla oblongata. WNK463 partially mimicked acupuncture’s effects, while Gabazine partially reversed them. Acupuncture alleviates muscle hypertonia and enhances locomotor recovery in rats with PSMH, potentially by inhibiting the medullary WNK1-SPAK/OSR1 pathway and thereby upregulating KCC2 expression and membrane localization.

Spinorphin, an endogenous enkephalinase inhibitor, enhances physiological opioid signaling by preventing the degradation of endogenous enkephalins, however, its anticonvulsant potential has not previously been investigated. This study evaluated the effects of spinorphin on seizure activity and associated neurochemical alterations in two complementary acute experimental seizure models. The effects of spinorphin on seizure activity were investigated in pentylenetetrazole (PTZ)- and penicillin-induced acute seizure rat models. Behavioral seizure parameters, passive avoidance memory, electrocorticographic activity, cortical and hippocampal glutamate, GABA, c-Fos, calcitonin gene-related peptide (CGRP), inflammatory cytokines, and oxidative stress biomarkers were evaluated. Nalmefene was used to determine the contribution of opioid receptor signaling. Spinorphin significantly attenuated behavioral seizures, reduced cortical epileptiform spike frequency, and improved passive avoidance retention performance. It attenuated PTZ-induced alterations in cortical and hippocampal glutamate and GABA concentrations and reduced tissue levels of c-Fos and CGRP, together with changes in inflammatory and oxidative stress-related biomarkers in both the cortex and hippocampus. These effects were substantially attenuated by nalmefene, suggesting a possible contribution of endogenous opioid signaling, although the incomplete reversal indicates that additional opioid-independent mechanisms may also be involved. Spinorphin attenuates seizure activity and associated biochemical alterations in experimental seizure models. By enhancing the regional availability of endogenous enkephalins rather than directly activating opioid receptors, spinorphin may exert its anticonvulsant effects partly through endogenous opioid signaling, while additional opioid-independent mechanisms may also contribute. These findings provide a basis for further investigation of enkephalinase inhibition in experimental seizure models.

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Post-traumatic stress disorder (PTSD) is a severe psychiatric condition for which effective preventive strategies are lacking. Innate immune preconditioning has shown promise for the prevention of PTSD, yet the transient nature of such protection when induced in adulthood poses a substantial limitation. Using male C57BL/6J mice, we tested whether administration of macrophage colony-stimulating factor (M-CSF, 100 µg/kg, intraperitoneally) during adolescence, a developmental period characterized by heightened microglial plasticity, could establish enduring resilience against trauma-induced PTSD-like behaviors. Mice received a single M-CSF injection at postnatal day 28 (PND28) and were subsequently subjected to single prolonged stress (SPS/FS) at 4, 16, or 32 weeks thereafter, with behavioral and molecular assessments conducted at PND70, PND154, and PND266, respectively. Our results showed that adolescent M-CSF exposure substantially prevented SPS/FS-induced anxiety-like behaviors assessed by the elevated plus maze and open field test, and SPS/FS-induced fear-like behaviors evaluated by contextual and cued fear conditioning tests, at all three post-administration intervals. Concurrently, M-CSF pretreatment prevented SPS/FS-induced interleukin-1β (Il-1β), Il-6, and tumor necrosis factor-α (Tnf-α) mRNA expression within the hippocampus and medial prefrontal cortex across all time points examined. These protective phenotypes were eliminated when microglial function was pharmacologically inhibited or when microglia were depleted before M-CSF administration, establishing that microglial integrity at the time of adolescent immune challenge is required for the establishment of long-term resilience. Taken together, these findings demonstrate that a single developmental immune intervention confers lifelong protection against SPS/FS-induced PTSD-like behaviors through microglia-dependent mechanisms, introducing a vaccine-like paradigm for the prevention of PTSD.

Cerebral ischemic diseases, such as ischemic stroke (IS) and vascular dementia (VaD), are major causes of neurological disability and mortality. Neuroinflammation acts as a pivotal driver of secondary brain injury, mediated by intricate bidirectional interactions between peripheral T cells and central nervous system (CNS)-resident microglia. This review delineates the molecular mechanisms underlying T cell-microglia crosstalk in cerebral ischemia, emphasizing their dual roles in exacerbating neurotoxicity and promoting repair. Direct interactions involve antigen presentation via MHC-TCR engagement and co-stimulatory checkpoints (e.g., CD80/CD86-CD28, PD-L1-PD-1), which regulate T cell activation and microglial polarization. Direct signaling through cytokines (IFN-γ, IL-4, IL-17, IL-10) further modulates microglial phenotypes: Th1/Th17 cells drive pro-inflammatory M1 polarization via STAT1/NF-κB pathways, while Tregs/Th2 cells induce anti-inflammatory M2 states through STAT6/SMAD signaling. Spatial transcriptomics and single-cell omics reveal spatiotemporal dynamics of these interactions, identifying STAT1/STAT6 imbalance as a critical determinant of neuroinflammatory outcomes. Advanced methodologies, including two-photon intravital microscopy and microfluidic blood-brain barrier (BBB) models, enable real-time visualization of immune cell trafficking and synaptic communication. Therapeutically, targeting immune checkpoints (CTLA-4, PD-1) or cytokine pathways (e.g., IL-4 mimetics) shows promise in recalibrating neuroimmune responses. However, challenges such as blood-brain barrier impermeability to biologics and interspecies immune heterogeneity necessitate innovative delivery strategies. This review integrates molecular, cellular, and technological insights to propose a framework for precision immunomodulation. By elucidating context-dependent signaling nodes and leveraging emerging tools, the study underscores the potential of harnessing T cell-microglia crosstalk to mitigate neuroinflammation and enhance neural repair, offering transformative avenues for stroke and dementia therapy.

Cinchonidine (CD), a metabolite derived from gut microbiota, shows promise in protecting against traumatic brain injury (TBI), where mitochondrial dysfunction is a key driver of secondary damage. Using a mouse model of controlled cortical impact (CCI) and an in vitro primary neuron injury model, CD administration resulted in improved physiological status (weight recovery, stabilized heart rate) and behavioral outcomes (increased travel distance and speed) in TBI mice. Histological analysis showed reduced hippocampal neuronal damage, decreased pro-inflammatory cytokines (interleukin‑1β, interleukin‑6, and tumor necrosis factor‑α), and upregulated blood-brain barrier tight-junction proteins (Claudin-5, Occludin, zonula occludens‑1). Mitochondrial function was improved, evidenced by increased mitochondrial DNA copy number, elevated expression of translocase of outer mitochondrial membrane 20 and cytochrome c oxidase subunit IV, and restoration of mitochondrial membrane potential. In addition, CD attenuated TBI-induced changes in mitochondrial dynamics and biogenesis, restoring the phosphorylated dynamin-related protein 1 (p-DRP1)/DRP1 ratio and the expression of mitofusin 1/2 (MFN-1/2) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), while reducing mitochondrial DRP1. Network pharmacology identified proto‑oncogene tyrosine‑protein kinase Src (SRC) as a key target, validated by stable binding in molecular docking and drug affinity responsive target stability assays. Furthermore, cellular thermal shift assays demonstrated a direct interaction between CD and SRC. CD treatment suppressed the activation of the SRC/RAF proto-oncogene serine/threonine-protein kinase (RAF1)/nuclear factor kappa B (NF-κB) signaling axis, as evidenced by reduced phosphorylation of SRC and p65, along with decreased expression of RAF1 and cleaved Caspase-3. Crucially, SRC knockdown mimicked CD’s protection, while SRC overexpression abolished its benefits. These findings suggest that CD ameliorates post-TBI mitochondrial dysfunction, neuroinflammation, and neuronal damage by inhibiting SRC kinase activity and its downstream RAF1/NF-κB signaling pathway. Thus, CD may represent a promising SRC-targeted neuroprotective strategy for TBI.

Opioids are widely used in clinical sedation and anesthesia, but the downstream phosphorylation events associated with opioid-induced reductions in arousal remain incompletely understood. Here, we investigated whether thalamic phosphoproteomic remodeling and the pyruvate dehydrogenase kinase (PDK)–pyruvate dehydrogenase E1 alpha subunit (PDHA1) pathway are associated with opioid-induced loss of righting reflex (LORR) in rats. Phosphoproteomic profiling of rat thalamic tissues after treatment with fentanyl, FENT-001 (a synthetic fentanyl analog), and other sedative and anesthetic agents revealed broad changes in thalamic phosphopeptide abundance.Differentially phosphorylated proteins were enriched in neuronal projections, synapses, cytoskeletal organization and synaptic transmission. PDHA1 was identified as a significantly differentially phosphorylated protein and was further examined by Western blotting. Fentanyl and 3-methylfentanyl altered phosphorylation at multiple PDHA1 sites. Pharmacological inhibition of PDKs with dichloroacetate reduced PDHA1 Ser293 phosphorylation in cultured cortical neurons and produced numerical increases in the estimated ED₅₀ values for fentanyl- and 3-methylfentanyl-induced LORR. These changes were consistent with a trend toward reduced LORR sensitivity. Conversely, CM-targeted overexpression of PDK2 or PDK4 shifted the fitted fentanyl-induced LORR dose–response curves to the left relative to the Vector control, with a larger numerical reduction in ED₅₀ following PDK2 overexpression.These findings suggest that opioid treatment remodels the thalamic phosphoproteome and that the PDK–PDHA1 phosphorylation pathway is functionally associated with opioid-induced LORR sensitivity.

Cerebral injury following cardiac arrest (CA) is a primary contributor to patients’ mortality and poor neurological outcome. However, there are currently no definitive and effective therapeutic approaches. Emerging evidence has indicated that mesenchymal stem cell (MSC) pretreatment exerted protective effects against cardiac and cerebral injuries in the porcine model of CA. However, given the unpredictable nature of CA, we administered immunity-and-matrix-regulatory cells (IMRCs) derived from human embryonic stem cells (hESCs) following CA to investigate whether IMRCs could alleviate cerebral injury following CA in swine. In vivo, a porcine CA model was established using male domestic white swine. In vitro, CA-induced injury was simulated by subjecting HT22 cells and primary cultures of hippocampal neurons to hypoxia/reoxygenation (H/R). SAT1 overexpression was achieved in HT22 cells via lentiviral transduction and in primary cultures of hippocampal neurons via adeno‑associated virus (AAV) transduction. Following IMRC administration, neurological function, cerebral injury, cell viability, lactate dehydrogenase (LDH) release, and ferroptosis-related indicators were systematically evaluated using a series of experimental assays. IMRC administration significantly decreased ferroptosis-related ferrous iron (Fe²⁺), lipid reactive oxygen species (ROS), malondialdehyde (MDA), and 4‑hydroxynonenal (4‑HNE) at 24, 48, and 72 h following CA, while concomitantly elevating glutathione (GSH) levels and mitigating cerebral injury. Further in vitro studies demonstrated that SAT1 overexpression promoted ALOX15 activation and suppressed GPX4 expression, thereby exacerbating H/R-induced neuronal ferroptosis. Moreover, SAT1 overexpression was found to partially attenuate the protective effects of IMRCs against H/R-induced ferroptosis. In vivo, IMRC administration downregulated the expression of SAT1 and ALOX15, while concurrently upregulating GPX4 levels. Early post-resuscitation administration of IMRCs attenuated cerebral injury following cardiac arrest, and this protective effect was possibly related to the suppression of ferroptosis via regulation of the SAT1/ALOX15/GPX4 signaling pathway.

Neonatal bacterial meningitis (NBM) is a severe neonatal infectious disease associated with a high incidence of neurological sequelae. Lipopolysaccharide (LPS) and inflammatory cytokines aggravate cerebral injury, whereas the mechanism of ferroptosis in the pathogenesis of NBM remains unclear. Melatonin (MT), an endogenous neurohormone, provides anti-ferroptotic neuroprotection in models of cerebral injury; however, its mechanism of action against NBM-related injury through ferroptosis has not been clarified. This study investigated the protective effects mediated by MT in vivo and in vitro. Rat models of LPS-induced inflammatory brain injury were established through intracerebroventricular (i.c.v.) injection, and Escherichia coli (E. coli)-infected cell models were developed to investigate the neuroprotective effects of MT against TFRC-related ferroptosis. CCK-8 assays, Western blotting, transmission electron microscopy (TEM), iron detection, and immunofluorescence, BODIPY staining were used to assess cell viability, inflammatory factors, mitochondrial ultrastructure, iron accumulation, and GPX4 expression. E. coli infection induced typical ferroptotic mitochondrial damage. MT alleviated neuroinflammation and reduced the expression of ferroptosis-related proteins both in vitro and in vivo. MT treatment increased mitochondrial GPX4 expression. The ferroptosis agonist RSL3 reversed the neuroprotective effects of MT. MT inhibited TFRC-related ferroptosis and alleviated neuronal damage. MT protects against E. coli/Lipopolysaccharide induced neuronal injury by regulating TFRC-related ferroptosis, indicating that MT may be a promising therapeutic agent for NBM.