Journal of Molecular Neuroscience最新文献

The adult cerebellum retains a small Sox2/prominin-1 NSC pool whose fate is shaped by developmental cues and the glutamatergic milieu. We argue that glutamate excitotoxicity is the dominant negative regulator of this niche and Purkinje cell survival because it forms self-reinforcing loops. Spillover activates extrasynaptic GluN2B/2D-NMDARs, silencing CREB/PI3K–Akt and driving sustained (Ca^{2+}) influx; mitochondria translate this load into mPTP opening and ROS bursts, creating a (Ca^{2+})–ROS feedback that accelerates death. Oxidative stress and energy failure also depress EAAT1/2 clearance, elevating glutamate and re-activating eNMDARs. Loss of Purkinje cells withdraws Sonic Hedgehog support, shrinking the proliferative granule-precursor pool—another vicious cycle. A countervailing axis (synaptic GluN2A/2C and BDNF/TrkB) is muted by extrasynaptic drive. Cerebellar neurospheres model these gradients and readouts. We outline a triple strategy to break the loops: selective eNMDAR blockade, EAAT enhancement, and Sonic Hedgehog restoration.

Objectives

Depression is a widespread psychiatric condition marked by ongoing sadness, disinterest, insomnia, and thoughts of self-harm. Fluoxetine HCl (FH) is a frequently prescribed antidepressant; however, it has low oral bioavailability (28%) due to significant first-pass metabolism and has side effects such as low blood pressure, gastrointestinal discomfort, and blurred vision. This research aimed to create and assess a novel intranasal nanostructured lipid carrier (NLC) system for FH, utilizing saffron oil (SO) as a functional lipid to enhance brain delivery while minimizing systemic side effects.

Methods

FH-NLCs were prepared using the high-pressure homogenization and ultrasonication method and was optimized based on particle size, PDI, Drug loading and entrapment efficiency.

Results

The observed mean particle size of FH-NLCs is 117.3 nm, PDI 0.219, and ZP -44.76 mV which were ideal for nose-to-brain delivery. The optimized formulation showed high drug loading and entrapment efficiency. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed a uniform morphology, while X-ray diffraction (XRD) and differential scanning calorimetry (DSC) indicated partial amorphization of the drug within the lipid matrix. The in vitro drug release exhibited a sustained profile without burst release, adhering to Korsmeyer-Peppas kinetics, which showed non-fickian diffusion Super Case II Transport (n = 1.14). Ex vivo permeation studies on goat nasal mucosa revealed significantly enhanced nasal mucosal permeability compared to the FH solution, indicating the permeation-enhancing properties of SO. Histopathological assessments confirmed the formulation's safety for nasal application. The pharmacodynamic evaluations demonstrated a synergistic antidepressant effect between FH and SO, thereby supporting improved therapeutic efficacy.

Conclusion

The intranasal delivery of FH through SO-based NLCs offers a promising approach for direct brain targeting, potentially enhancing clinical outcomes in depression while reducing systemic side effects of FH.

Kadiyska et al. recently investigated the impact of a histamine-reducing diet in children with autism spectrum disorder (ASD), with attention to potential modifying effects of AOC1 and HNMT gene variants. Although the study poses an important question, several design limitations may affect the certainty of its conclusions. The dietary intervention removed not only foods high in histamine but also gluten, dairy, sugar, and other items. Such broad restrictions can influence health and behavior on their own. This makes it difficult to determine whether the reported improvements were specifically the result of reduced histamine. The histamine cut-off chosen for participant selection was not explained or tied to clinical standards, which makes reproducibility less clear. In addition, some of the genetic results rested on very small numbers, at times a single child, reducing confidence in their reliability. Finally, histamine levels were not re-measured after the intervention, and the developmental outcomes were not fully explained in terms of clinical significance. Stronger evidence will require controlled diets, standardized thresholds, larger cohorts, and outcomes relevant to daily life.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized by progressive loss of motor neurons. Due to heterogeneity in both cause and clinical phenotype, accuracy of diagnosis and efficacy of treatment remain challenging. An evolving body of evidence point to the importance of the “gene-time-environment” hypothesis in ALS onset and progression. Despite extensive research, understanding of the complex environmental risk factors remains fragmented. In this study, we comprehensively analyzed the associations between trace elements, biochemical signatures, and modifiable risk factors among ALS patients stratified by age, sex, type of onset, disease severity, and progression. Specifically, we investigated blood concentrations of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), and iron (Fe) levels in 121 participants. Moreover, we examined the associations between trace metals, biochemical indicators including serum ferritin (SF), blood glucose, cholesterol (CHOL), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), cerebrospinal fluid (CSF) cell count, CSF total protein, as well as history of hypertension, hazardous chemical exposure, drinking, and smoking in ALS patients. Specifically, we report that high Fe levels were found in male and spinal-onset patients. Moreover, high serum ferritin was positively associated with age of onset, blood iron and glucose, as well as high disease severity. Results from this study highlight the complex characteristics of ALS and provide new insight for understanding the intricate relationship between disease phenotype, metal homeostasis, and modifiable risk factors.

Graphical Abstract

Rett syndrome (RTT) is a severe neurodevelopmental disorder primarily caused by missense variants in the MECP2 gene. However, the presence of variants of uncertain significance (VUS) poses major challenges for clinical diagnosis and genetic counseling. In this study, we systematically evaluated the performance of 33 in silico prediction tools using a curated ClinVar dataset of MECP2 missense variants. Performance metrics included accuracy, sensitivity, specificity, area under the curve (AUC), and Matthews correlation coefficient (MCC), incorporating gene-specific pathogenicity thresholds to enhance predictive precision. Evolutionary conservation was assessed using ConSurf, while structural consequences were examined using UniProt, HOPE, DUET, PyMOL, and RING. Nine top-performing tools—MutPred, MetaRNN, REVEL, MutScore, SNPred, BayesDel, ClinPred, AlphaMissense, and DeepSAV—achieved accuracies exceeding 91% and correctly classified all 19 functionally validated pathogenic variants. These tools consistently predicted 15 VUS as pathogenic, with 14 located within the methyl-CpG-binding domain (MBD) and one within the NCOR2/SMRT interaction region; all occurred at highly conserved residues (ConSurf score: 9). Structural analyses revealed destabilizing effects through altered hydrophobicity, electrostatic charge, and residue interactions, implicating impaired DNA binding or disrupted co-repressor interactions. This integrative framework, combining high-performance computational prediction with structural modeling, offers a robust approach to reclassifying MECP2 VUS and supports improved diagnostic accuracy and personalized care in RTT.

One of the well-studied epigenetic regulators is miRNA (miRNA) which plays critical roles in gene regulation and has been implicated in autism spectrum disorder (ASD) pathology, particularly through their involvement in neuroinflammation and neuronal regulation. MiR-146A and miR-146B are of special interest due to their dysregulation in ASD. Epigenetic modifications, such as promoter methylation, and genetic variations in miRNAs can influence their expression and function, yet their roles in ASD remain unclear. This study aimed to investigate promoter methylation patterns and sequence variations in miR-146A and miR-146B to evaluate their potential contributions to ASD. The study included Egyptian patients with ASD (ages 5–16 years) diagnosed using DSM-V criteria and assessed for severity using the Childhood Autism Rating Scale (CARS). DNA was extracted from peripheral blood samples of 93 autistic patients and 44 age-matched controls. Methylation-specific PCR (MSP) was used to analyze promoter methylation of miR-146A and miR-146B, while Sanger sequencing was employed to detect sequence variations in these genes and their flanking regions. Statistical analyses included independent t-tests, ANOVA, ROC curve, and Pearson correlation. No significant differences in promoter methylation levels of miR-146A and miR-146B were observed between ASD cases and controls or among severity subgroups (P > 0.05). Sequence variation analysis identified no significant differences in the distribution of common SNPs (rs2910164 and rs2224374). However, a novel miR-146A upstream variant (C/A at 5:160,485,254) was discovered in one case with autism. Methylation and common genetic variations in miR-146A and miR-146B are unlikely to play significant roles in ASD in this population. The discovery of a novel upstream variant highlights the potential importance of regulatory regions in miRNA function. Further studies with larger cohorts and functional validation are recommended.

Multiple sclerosis (MS) is the most common chronic inflammatory disease affecting the brain and spinal cord, with approximately 2.8 million cases globally. This study analyzed high-throughput MS datasets to identify dysregulated RNAs and visualized novel RNA regulatory networks to uncover non-coding interactions in MS-related signaling pathways. High-throughput gene expression datasets were analyzed in R Studio to identify dysregulated mRNAs in MS patients. miRNA, lncRNA, and protein interactions were explored using miRWalk and lncRRIsearch. Pathway enrichment analysis was performed via Enrichr and KEGG, and qRT-PCR validated the gene expression results. RGS2 was found to be significantly upregulated in both microarray (logFC: 1.7667, adj.P. Value: 0.0079) and qRT-PCR analyses (logFC: 4.547, p-value < 0.0001). Similarly, the lncRNAs NCK1-DT (logFC: 2.155, p-value: 0.0132) and ASH1L-AS1 (logFC: 3.345, p-value < 0.0001) exhibited elevated expression in MS samples, suggesting a regulatory impact on RGS2 expression levels. The marked changes in the expression of RGS2, NCK1-DT, and ASH1L-AS1 in MS patients compared to normal samples position them as promising diagnostic biomarkers. Additionally, RGS2 and its associated proteins have been implicated in modulating the NF-Kappa B signaling pathway. MiR-4638-3p was identified to directly downregulate RGS2 expression, while miR-4525 influences the expression of RGS2 and ASH1L-AS1 within a competing endogenous RNA (ceRNA) network. NCK1-DT and ASH1L-AS1 are the two novel diagnostic biomarkers of MS. Mentioned lncRNAs might affect the normal regulatory mechanisms of “NF-Kappa B signaling pathway” through direct and indirect interaction with mRNA RGS2.

This cross-sectional study explored the potential utility of salivary circadian gene expression as a non-invasive biomarker for early cognitive impairment in shift workers. Three hundred participants aged 25 to 55 were categorized into cognitively impaired shift workers (MoCA < 26, n = 100), cognitively intact shift workers (n = 100), and non-shift working controls (n = 100). Saliva samples collected at 07:00 and 19:00 were analyzed for mRNA expression of PER1, BMAL1, and CLOCK using qRT-PCR. Shift workers with cognitive impairment showed significantly attenuated diurnal variation in gene expression, with reduced evening levels of BMAL1 and PER1 compared to both control groups (p < 0.001). Evening BMAL1 expression was independently associated with cognitive status (OR 2.14, 95% CI 1.62–2.85), achieving an AUC of 0.876 (81.3% sensitivity, 78.0% specificity). A combined three-gene panel modestly improved diagnostic accuracy (AUC 0.913). These preliminary findings suggest that alterations in salivary circadian gene expression, particularly in BMAL1, may hold promise as a molecular indicator of early neurocognitive changes in shift-working populations.

AD is a neurodegenerative disorder and is associated with the presence of amyloid-β plaques and neurofibrillary tangles leading to net loss of neurons, which demonstrates an urgent unmet need to develop new human health therapies based on the fundamental mechanisms of oxidative stress and neuroinflammation. This work is a computational assessment of the potential use of neolupenol, a triterpenoid produced in Pluchea lanceolata, as a pharmacologically active compound that exerted its beneficial effect through the modulation of the Keap1-Nrf2 axis, one of the central regulators of the antioxidant response. Using an integrated approach that combined network pharmacology, molecular docking, and molecular dynamics (MD) simulations, we identified neolupenol as a high-affinity Keap1-binding molecule capable of activating the Nrf2-mediated neuroprotective pathway. Virtual screening of 25 phytochemicals from Pluchea lanceolata (retrieved from the PubChem database) with customized filters revealed neolupenol as the top candidate, showing strong binding affinity (− 8.22 kcal/mol; Ki = 1.45 µM) toward the Keap1 Kelch domain (PDB ID: 2FLU). The docked complex demonstrated hydrogen bonds with VAL463 (2.17 Å), THR560, and ILE559, along with hydrophobic interactions involving CYS513, ALA366, and VAL514, which collectively stabilized the ligand at the Neh2-binding interface. Network pharmacology yielded 30 of such common targets of AD-neolupenol (e.g., GSK3B, CASP3, TNF, and BACE1), enriched in pathways such as amyloid processing, tau phosphorylation, oxidative stress response, and lipid metabolism (FDR-adjusted p < 0.0001). Complex stability was verified by MD simulations (100 ns): RMSD of the backbone 2.34–3.84 = 2.34 Å, unchanged radius of gyration (17.8–18.0 Å), and stable inter-hydrogen bonding. Residues VAL561, PHE577, and SER602 were found to have an interaction occupancy of > 70%, providing a basis of dynamic stability. The triterpenoid cavity appeared in neolupenol contributing to pleasant PK, the ability to herald the blood–brain barrier, and suboptimal toxicity. These results position neolupenol as a potent, multi-target neuroprotective agent that disrupts Keap1–Nrf2 interaction, promoting Nrf2 nuclear translocation and antioxidant gene activation. Future work warrants in vivo validation of its efficacy in mitigating AD pathology and clinical translation.

Graphical Abstract

The polarization of microglia/macrophages is crucial for maintaining the neuroinflammatory response during cerebral ischemia/reperfusion (I/R) injury. Integrin CD11b is implicated in the processes of neuroinflammation, immune regulation, and nerve injury repair. However, its role in microglia- and macrophage-mediated neuroinflammation during cerebral I/R injury remains poorly understood. Wild-type (WT), CD11b knockout (KO), or neutralizing antibody-treated mice were subjected to a transient cerebral artery I/R injury (tMCAO) model. CD11b expression was detected by qPCR, immunofluorescence, and western blotting. Histopathological features were evaluated by H&E and Nissl staining, ROS production was detected by DHE staining, neuronal apoptosis was detected by TUNEL assays, and microglia polarization was evaluated by immunofluorescence staining. We discovered that CD11b was significantly increased in the ischemic penumbra following tMCAO. CD11b KO significantly alleviated tMCAO-induced infarct, neurological deficits, oxidative stress, and neuronal apoptosis in the ischemic penumbra. Moreover, CD11b KO significantly enhanced the anti-inflammatory phenotype transition of microglia/macrophages, leading to accelerated inflammation resolution. Furthermore, pharmacological blockade of CD11b demonstrated a protective effect similar to that of CD11b KO. Meanwhile, CD11b deficiency significantly inhibited the activation of p-p65/p-STAT1 signaling pathway and upregulated p-STAT6 expression. In conclusion, CD11b protects against cerebral I/R injury by modulating microglial and macrophage polarization, thereby reducing subsequent neuroinflammation and neuronal death. Our findings suggest that CD11b intervention could be a potential therapeutic strategy for acute cerebral ischemic stroke.