Neurochemical Research最新文献

Familial hypercholesterolemia (FH), caused by mutations in the low-density lipoprotein receptor (LDLr) gene, has been increasingly associated with neurodegenerative and mood disorders. Studies with LDLR knockout mice (LDLr^−/−) showed that neuroinflammation is a key event in FH-related brain dysfunction. Because mTOR inhibition has been shown to mitigate brain alterations in this model, we hypothesized that metformin, a drug reported to influence cellular energy metabolism, could attenuate FH-associated brain changes. To test this, adult LDLr^−/− mice received daily oral doses of metformin (200 mg/Kg) or vehicle for 30 days. During the final week, behavioral assessments were conducted, including the open-field test, novel object recognition and object reallocation tasks, and the tail suspension test (depressive-like behavior). Body weight, total cholesterol and glucose plasma levels were analyzed. Hippocampal astrocyte and microglial density, as well as the expression of genes related to neuroinflammation and synaptic plasticity, were evaluated. Metformin did not alter total cholesterol levels but significantly improved cognitive performance and reduced depressive-like behavior. The treatment also attenuated hippocampal astrogliosis without affecting microglial reactivity. Molecular analysis revealed reduced hippocampal TGF-β gene expression and increased PSD-95 gene expression and protein content in metformin-treated LDLr^−/− mice. Although a slight, non-significant reduction in the phosphorylated-to-total mTOR ratio was detected, no clear evidence of AMPK/mTOR pathway modulation was observed. Overall, metformin improved memory function and astrocyte reactivity in LDLr^−/− mice independently of cholesterol reduction and without demonstrable involvement of the AMPK/mTOR pathway, suggesting its potential as a therapeutic strategy for FH-associated brain dysfunction.

Demyelinating diseases are heterogeneous in their etiology, clinical course, and manifestations. In the long run, however, they lead to irreversible dysfunction of the nervous system. Although myelin regeneration occurs in response to myelin damage in both animal models of demyelination and human patients, the outcome is usually less favorable in humans. This explains the interest in treatments that could improve the effectiveness of myelin regeneration. Among these, treatment with the monoclonal antibody rHIgM22 has been shown to effectively enhance myelin regeneration in both immune and non-immune mouse models of demyelination. Its administration to patients with multiple sclerosis was well tolerated, and it was detected in the cerebrospinal fluid, suggesting penetration of the central nervous system. Previously, we demonstrated that administering rHIgM22 to rat mixed glial cultures alters the balance between ceramide and sphingosine 1-phosphate (S1P), thereby inducing S1P release and astrocyte and oligodendrocyte precursor cell (OPC) proliferation. In this paper, we studied the effects of rHIgM22 treatment on the lipid composition of purified glial cultures from the rat brain, including astrocytes, OPC, and oligodendrocytes (OL) at various stages of in vitro differentiation. rHIgM22 did not affect the phospholipid composition of any of the analyzed cell types. A steady-state metabolic labeling procedure revealed that sphingolipid patterns were unaffected by rHIgM22 treatment in astrocytes. However, rHIgM22 treatment significantly increased the levels of GM3 and GD3 gangliosides in oligodendroglial cells. The increase in GM3 and GD3 versus controls was highest in fully differentiated OL. We also detected a slight but significant reduction in cholesterol levels and in vitro acid sphingomyelinase activity in these cells. Acid sphingomyelinase is a key enzyme in sphingolipid metabolism. Thus, the effect of rHIgM22 on lipid metabolism is cell-specific among different glial populations. We hypothesize that the myelin regeneration effects of rHIgM22 could result from alterations in lipid-dependent membrane organization in oligodendroglial cells.

Focused ultrasound stimulation (FUS) is a promising non-invasive neuromodulation technique that can influence neuronal activity through mechanical stimulation. In this study, primary cortical neurons were isolated from embryonic rat brains and cultured for 14 days in vitro before being divided into Control, FUS 5 V, and FUS 10 V groups. Cells were exposed to low-intensity pulsed FUS (300 kHz, 10 min) using a vertically mounted transducer positioned 5 mm above the culture dish. Post-exposure analyses included cell viability using the MTS assay, total protein quantification by the Bradford method, morphological assessment by Trypan Blue staining, and Fluo-3 AM–based confocal calcium imaging. FUS treatment produced no significant differences in viability or total protein concentration compared with the Control group. Morphological observations confirmed healthy neuronal somata and intact neuritic networks across all groups, with no evidence of cell death or structural damage compared with controls. In contrast, calcium imaging revealed a robust transient elevation in intracellular Ca²⁺ responsiveness when assessed 24 h after FUS exposure, with a significantly higher integrated area under the curve relative to Control. These findings demonstrate that low-intensity FUS safely enhances intracellular calcium signalling while preserving neuronal viability, protein integrity, and morphology, defining a safe acoustic window for non-destructive neuromodulation and providing a framework for mechanistic studies in neurodegenerative disease models.

Perioperative neurocognitive disorders (PND) are prevalent complications in elderly patients following surgery, characterized by cognitive decline and memory impairment. This study investigates the contribution of plasma-derived exosomal microRNA hsa-miR-3677-3p to PND pathogenesis via ABCB8 regulation and subsequent induction of neuronal ferroptosis. Exosomes were isolated from plasma of patients with delayed neurocognitive recovery (dNCR) and non-dNCR patients. Characterization confirmed successful exosome isolation, revealing distinct microRNA profiles between the two groups. MicroRNA sequencing identified 69 differentially expressed microRNAs, with hsa-miR-3677-3p significantly upregulated in dNCR patients. Functional enrichment analysis implicated these microRNAs in mitochondrial function and nervous system development. In vitro overexpression of hsa-miR-3677-3p mimicked the pathological phenotype, leading to downregulation of ABCB8, which resulted in iron dyshomeostasis and oxidative stress, marked by reduced antioxidant capacity, intracellular iron accumulation, elevated malondialdehyde (MDA), a decreased glutathione/glutathione disulfide (GSH/GSSG) ratio, and increased mitochondrial lipid peroxidation (MitoPerOx). Treatment with the ferroptosis inhibitor Ferrostatin-1 (Fer-1) attenuated these alterations, restoring mitochondrial function and reducing oxidative damage. Taken together, our findings indicate that exosomal hsa-miR-3677-3p modulates ABCB8-mediated ferroptosis in neurons, highlighting a novel insight into PND pathogenesis and potential therapeutic strategies.

Spinal cord injury (SCI), a serious neurological condition caused by trauma, inflammation, infection, or vascular diseases, potentially causing partial or complete loss of sensory and motor function, and in severe cases, may lead to paralysis. The global incidence of SCI is rising annually, with a significant increase observed in China. The ependymal region of the spinal cord, containing endogenous neural stem cells (ENSCs), is recognized for its potential in neural regeneration and functional recovery after SCI. Cells lining the central canal of the spinal cord can develop into neurons, astrocytes, and oligodendrocytes, which are essential for repairing SCI. The present manuscript delves into the cellular origins, distribution, heterogeneity, and the potential therapeutic applications of ENSCs, offering insights into novel clinical interventions for SCI based on endogenous regenerative capabilities.

Aluminum (Al), a pervasive environmental neurotoxicant, has been strongly implicated in the onset and progression of Alzheimer’s disease (AD)-like pathology. Chronic and sub-chronic exposure to aluminum chloride (AlCl₃) induces cognitive deficits, oxidative stress, cholinergic dysfunction, neuroinflammation, and neuronal damage, making it a widely used agent for modeling AD in preclinical research. This study aimed to evaluate the neuroprotective efficacy of TKM01, a novel 4-anilinoquinazoline derivative, in an AlCl₃-induced AD-like zebrafish model. Adult zebrafish were exposed to AlCl₃ (11 mg/L for 15 days) and pre-treated with TKM01 at two concentrations (240 and 480 µg/mL). Behavioral assessments, including the T-maze, novel object recognition (NOR), and open field test (OFT), demonstrated significant improvements in spatial learning, recognition memory, and reduced anxiety-like behavior in TKM01-treated groups. Biochemical analyses revealed decreased acetylcholinesterase (AChE) activity and lipid peroxidation (LPO), alongside elevated antioxidant enzyme activities, including superoxide dismutase (SOD) and catalase (CAT). ELISA showed a reduction in pro-inflammatory cytokines (TNF-α and IL-1β), and RT-PCR analysis confirmed downregulation of NLRP3, ASC, and caspase A gene expression. Furthermore, histopathological examination revealed that TKM01 mitigated AlCl₃-induced neuronal degeneration, edema, and cellular disorganization in brain telencephalon. Additionally, molecular docking and 200 ns molecular dynamics simulations supported stable and favorable binding interactions between TKM01 and IL-1β/ASC. Collectively, these findings suggest that TKM01 attenuates AlCl₃-induced neurotoxicity via antioxidant, anti-inflammatory, anticholinesterase, and neuroprotective mechanisms. TKM01 emerges as a promising multifunctional therapeutic candidate for AD, warranting further investigation in mammalian models.

Nuclear Mouse ID Associated 1 (MIDA1), also known as Hsp40/DNAJC2 and ZRF1, plays a key role in the establishment of neural progenitors in the brain. In the cytoplasm, MIDA1 ensures proper protein folding, which, if disrupted, can lead to protein misfolding and ultimately neurodegeneration. Thus, MIDA1 is crucial for maintaining brain cell homeostasis. However, it remains unclear whether neurons and astrocytes express MIDA1 equally, whether the distribution of MIDA1 between the nucleus and cytoplasm differs, and if this difference changes with age. Therefore, we evaluated MIDA1 content and distribution in neurons and astrocytes of the CA1, CA3, and dentate gyrus (DG) in 3- and 12-month-old mice. The results indicated that, relative to the nucleus, cytoplasmic MIDA1 content is higher in neurons and astrocytes at both ages. An overall reduction of MIDA1 in the nucleus of neurons was noted with age, while the three-month-old mice displayed increased cytoplasmic MIDA1. In contrast, astrocytes exhibited similar levels of MIDA1 in the nucleus across the hippocampal regions analyzed. However, astrocytes from the CA1 and CA3 regions in the 12-month-old group showed increased cytoplasmic MIDA1 content. Lastly, a comparison of MIDA1 immunofluorescence between neurons and astrocytes revealed that astrocytes exhibit lower nuclear MIDA1 levels at both ages. Notably, at 12 months, cytoplasmic MIDA1 levels were higher in astrocytes than in neurons. Given that MIDA1 function depends on its subcellular location, our results suggest that MIDA1 undergoes more dynamic changes in the cytoplasm across different hippocampal areas, becoming more pronounced in astrocytes at 12 months. Thus, the chaperone role of MIDA1 may be particularly crucial as astrocytes and neurons age, coinciding with the appearance of age-related cognitive deficits detected in the novel object recognition test.

Epilepsy is increasingly recognized as a disorder with prominent metabolic disturbances, but how defined epilepsy-causing mutations reshape metabolism under controlled genetic and environmental conditions remains poorly understood. Here, we used the Drosophila melanogaster gain-of-function voltage-gated sodium channel (VGSC) mutant para^Shu, a well-established model of neuronal and behavioral hyperexcitability, to characterize whole-body metabolic alterations and their modulation by dietary supplementation with the ω-3 polyunsaturated fatty acid α-linolenic acid (ALA), which strongly and specifically suppresses para^Shu seizure phenotypes. Adult wild-type and para^Shu females were reared on control or ALA-supplemented diets, and 172 metabolites were quantified using GC-MS and LC-MS. The para^Shu mutation induced broad metabolic alterations, including enhanced glycolysis, reduced tricarboxylic acid cycle and pentose phosphate pathway intermediates, and depletion of nicotinamide riboside and nicotinic acid adenine dinucleotide, suggesting metabolic stress, mitochondrial dysfunction, and impaired redox balance. Amino acid and nucleotide metabolism were extensively reorganized, with prominent changes in tryptophan pathways, as well as imbalances in purine and pyrimidine nucleotides and cyclic nucleotides (cAMP, cGMP). Levels of microbially derived short-chain fatty acids and indole derivatives were elevated, implicating altered gut–brain metabolic interactions. Dietary ALA partially normalized key metabolites, including succinate, 6-phosphogluconate, glycine, proline, and short-chain fatty acids, and increased N-methylnicotinamide, consistent with improved redox homeostasis and attenuated inflammation. These findings demonstrate that VGSC–driven hyperexcitability elicits coordinated metabolic and microbiota-related changes, and that ALA can mitigate these disturbances, highlighting testable metabolic targets for mechanism-based interventions in epilepsy.

Neonatal hypoxic-ischemic brain damage (HIBD) is a leading cause of neurological dysfunction and long-term disability in newborns. Lactate accumulation and metabolic disturbances after brain injury inhibit neurogenesis, while the restorative capacity of endogenous neural stem cells (NSCs) is essential for neural reconstruction. Melatonin (Mel) alleviates neonatal brain injury, but its effects on NSCs proliferation and migration remain unclear, and the visualization methods for dynamic monitoring of metabolic changes are inadequate. In this study, a neonatal rat model of HIBD was established, and multimodal MRI combined with histological techniques was employed to evaluate the effects of Mel on NSCs regeneration and metabolic conditions in the hippocampal dentate gyrus. Using these techniques, the potential neuroprotective effects of Mel via the JAK2/STAT3 pathway were investigated. Multimodal MRI revealed that Mel increased cerebral blood flow and oxygen saturation, reduced lactate levels, improved brain metabolic microenvironment, and alleviated brain damage caused by HIBD. EdU/Nestin and EdU/DCX staining revealed that Mel promoted the proliferation and migration of endogenous NSCs, thereby enhancing neurogenesis. In addition, the use of a JAK2 inhibitor (WP1066) and agonist (C-A1) verified that Mel exerted its protective effects by down-regulating the JAK2/STAT3 pathway. Morris water maze further confirmed that Mel improved spatial learning and memory function in neonatal rats with HIBD. Multimodal MRI offers a visual basis for monitoring metabolic changes and therapeutic effects, while Mel enhances neurogenesis and mitigates brain injury through inhibition of the JAK2/STAT3 pathway, thus providing a theoretical basis for the clinical application of Mel in HIBD in neonates.

Perinatal hypoxic–ischemic injury (HI) upregulated an endogenous retrovirus–derived lncRNA, EVADR, via HIF-1α/NF-κB. EVADR bound and repressed miR-145, thereby activating WNT/β-catenin signaling. Binding specificity was confirmed by biotin–miRNA pull-down and mutant-seed luciferase reporters. Genetic (si-CTNNB1/si-WNT3A) and pharmacologic (XAV939/CHIR99021) cross-validation demonstrated pathway necessity and rescue. EVADR gain-of-function reduced neuronal death and inflammation and improved behavioral outcomes following HI. Circulating EVADR levels in plasma/CSF correlated with injury severity; ROC analyses indicated diagnostic potential alone and combined with S100B/NSE. These data support EVADR–miR-145→WNT/β-catenin as a mechanistic axis with translational relevance.

Graphical Abstract