Central nervous system oxygen toxicity (CNS-OT) is a toxic reaction induced by inhalation of gases with excessively high partial pressure of oxygen, for which effective proactive preventive and therapeutic measures are currently lacking. Building on our previous work implicating adenosine A2A receptor (A2AR) signaling, we examined the prophylactic effects of istradefylline (KW-6002), an approved A2AR antagonist, in male mice. We found that pretreatment oral administration of istradefylline (0.5–20 mg/kg) in mice significantly prolonged the latency to seizure onset and markedly reduced both the intensity and frequency of seizures during a 30-min exposure to 100% oxygen at 5 ATA. Cortical targeted metabolomics showed that HBO exposure decreased GABA and increased glutamate; istradefylline increased cortical GABA without significantly reducing cortical glutamate. Separate ELISA measurements showed lower hippocampal glutamate in istradefylline-treated mice than in HBO-exposed vehicle controls, whereas reductions in the other regions examined were not statistically significant. In the striatum, istradefylline was associated with lower cAMP, immunoreactive PKA protein concentration, and phosphorylated CREB, together with reduced GluA1 Ser845 phosphorylation and increased GABA_A receptor β3 Ser408/409 phosphorylation. In the cortex, malondialdehyde levels decreased and catalase activity increased, whereas glutathione peroxidase activity decreased further. Striatal IL-1β, IL-6, and TNF-α mRNA levels were also reduced. These findings support a prophylactic effect of istradefylline against HBO-induced seizures in male mice and identify associated changes in neurotransmitter levels, receptor phosphorylation, signaling markers, oxidative-stress measures, and inflammatory-gene expression. These results provide a theoretical basis for the development of proactive preventive and therapeutic strategies for CNS-OT with potential clinical application.
BackgroundMajor depressive disorder (MDD) is associated with impaired neural plasticity, while extracellular matrix (ECM) and perineuronal nets (PNNs) are important regulators of synaptic stability and extracellular homeostasis. However, the cellular states and molecular signatures associated with ECM/PNN alterations in MDD remain poorly understood.MethodsWe integrated bulk and single-cell transcriptomic datasets to characterize ECM/PNN-associated cellular states in MDD. Astrocyte populations were evaluated using multiple ECM/PNN scoring approaches, and disease-associated transcriptional changes were integrated with astrocyte co-expression networks to identify candidate molecular signatures. Functional enrichment, cell–cell communication, pseudotime, and in silico perturbation analyses were further used to investigate their biological context. Finally, corticosterone (CORT)-treated HT22 cells were used as a glucocorticoid-induced neuronal stress paradigm to assess stress-responsive expression of the identified genes.ResultsAmong astrocyte clusters, Cluster2 exhibited overall high ECM and PNN signature scores. Integration of Cluster2-associated co-expression modules with MDD-related differentially expressed genes identified 28 overlapping genes, from which ACSL6, FIP1L1, and ZNF709 were prioritized as cross-tissue candidate signatures showing consistent expression trends in brain and peripheral blood datasets. ACSL6 and ZNF709 were downregulated, whereas FIP1L1 was upregulated in MDD. Functional analyses implicated the three genes in metabolic and amino-acid-related processes, while FIP1L1 showed additional associations with cell adhesion, cytoskeletal organization, and synaptic signaling. Cell communication and pseudotime analyses further suggested altered intercellular signaling and increasing ECM/PNN activity across inferred astrocyte state transitions. In CORT-treated HT22 cells, ACSL6 and ZNF709 were significantly decreased, whereas FIP1L1 was increased, consistent with the transcriptomic observations.ConclusionThese findings identify an ECM/PNN-high astrocyte state and three associated cross-tissue molecular signatures in MDD. Among them, FIP1L1 emerged as a functionally prioritized candidate linked to adhesion- and synaptic-plasticity-related programs. The stress-responsive expression of these genes provides additional experimental support for their relevance to glucocorticoid-associated neuronal stress and supports an astrocyte-centered ECM/PNN working model for further mechanistic investigation.
ObjectiveCerebral ischemia–reperfusion (I/R) injury is a major contributor to neuronal damage and long-term neurological dysfunction after stroke. Our previous studies demonstrated that miR-140-5p expression is markedly upregulated following cerebral ischemia and that in vivo overexpression of miR-140-5p exacerbates cognitive impairment, suppresses neurogenesis, and promotes neuronal death in ischemic mouse models; however, its molecular mechanisms remain unclear. This study aimed to investigate the downstream molecular targets of miR-140-5p and to elucidate the mechanisms by which miR-140-5p regulates neuronal injury after I/R.MethodsWe established an oxygen–glucose deprivation/reoxygenation (OGD/R) model in primary cortical neurons and assessed viability via Cell Counting Kit-8 (CCK-8). miR-140-5p expression after OGD/R was examined, and loss-of-function experiments evaluated the effects of miR-140-5p inhibition. Synaptic integrity was assessed by immunofluorescence, and inflammatory cytokines by enzyme-linked immunosorbent assay (ELISA). Proteomic analysis identified potential downstream targets, which were validated via Western blotting and dual-luciferase reporter assays.ResultsWe found that miR-140-5p expression was significantly upregulated in mouse cortical neurons after OGD/R. Functional inhibition of miR-140-5p markedly enhanced neuronal survival, promoted synaptic remodeling, and attenuated inflammatory responses following OGD/R injury. Mechanistically, miR-140-5p was shown to directly target Il1rapl1 and modulate downstream c-Jun N-terminal kinase (JNK) signaling, thereby regulating neuronal viability, inflammation, and synaptic plasticity under ischemia–reperfusion conditions.ConclusionThis study reveals a novel miR-140-5p–mediated regulatory mechanism in neuronal injury following cerebral ischemia–reperfusion and suggests a potential therapeutic target for ischemic brain injury.
Kallmann syndrome (KS) arises from impaired development of the olfactory–GnRH neuronal system, yet the molecular consequences of individual gene defects remain poorly defined. In particular, the link between primary genetic variants and downstream transcriptional changes affecting neurodevelopmental pathways remains poorly understood. In the present study, we analyzed a Polish family with X-linked KS. We identified a hemizygous ANOS1 variant (c.452G > C; p.Cys151Ser) in two affected brothers presenting with hypogonadotropic hypogonadism and olfactory impairment. The identified ANOS1 variant remains classified as a variant of uncertain significance (VUS); however, its segregation with the KS phenotype and substitution of a highly conserved cysteine residue within the WAP domain supports its potential functional relevance and further investigation. The minigene assay did not reveal detectable effects on ANOS1 pre-mRNA splicing, while direct transcript analysis was limited by very low ANOS1 expression in peripheral blood. Whole-blood RNA sequencing revealed significant upregulation of PROK2 in the affected individuals, and qRT-PCR showed concordant upregulation in both patients. No coding or splice-site variants or detectable exon-usage alterations were identified in PROK2. Given the complementary roles of ANOS1 and PROK2 in olfactory system development and GnRH neuron migration, and previous evidence linking anosmin-1 to PK2/PROKR2 signaling, these findings suggest that ANOS1-associated dysfunction may be accompanied by secondary changes in functionally related molecular pathways, although this interpretation requires validation in appropriate experimental models.
