Molecular Brain最新文献

Voltage-gated K⁺ (Kv) channels are tetrameric complexes of proteins encoded by KCN genes. Gain-of-function (GoF) mutations in KCNH1 (Kv10.1, hEAG1) and KCNH5 (Kv10.2, hEAG2) give rise to developmental disorders, intellectual disability, and epilepsy. Currently, clinical symptoms are not straightforwardly associated with functional properties of mutated channels. Here we investigated how members of the KCNH subfamily are affected by heteromerization with mutant Kv10.1 or Kv10.2 protein subunits. The de novo variant Kv10.1-G496E, which leads to impaired neurodevelopment and epilepsy, was expressed alone or with other wild-type subunits in HEK293T cells and characterized using whole-cell patch clamp. While Kv10.1-G496E alone did not yield functional K⁺ channels, coexpression with Kv10.1 or Kv10.2 shifted the half-maximum voltage of activation in the hyperpolarizing direction. Likewise, the homologous mutation Kv10.2-G465E did not yield functional channels but also induced GoF upon coexpression with wild-type Kv10.1 or Kv10.2. By contrast, the mutants did not affect the function of Kv11.1 (KCNH2, hERG1) channels. To infer the relevance of Kv10 GoF mutations under physiological conditions, we used the fluorescent genetically encoded voltage indicator mK2-rEstus and found that both, Kv10.1 and Kv10.2, hyperpolarized HEK293T cells, and that coexpression of the GoF mutants augmented this hyperpolarization. Our findings imply that interpretation of clinical symptoms related to Kv10 GoF mutations requires considering the functional crosstalk with Kv10.1 and Kv10.2 subunits, which are both expressed in glutamatergic neurons in cortical Layers III and IV.

Psychological distress and chronic stress were suggested to contribute to the pathophysiology of idiopathic pain conditions such as provoked vulvodynia (PV). The comorbidity of PV and mood disorder is quite common. Thus, vulvar pain can trigger anxiety, and mood disruption, whereas elevated anxiety and mood disruption play a critical role in pain maintenance. Yet, whether chronic stress can facilitate the development of chronic vulvar pain remains unclear. Here, we aimed to assess the effects of chronic stress on anxiety, depression-like behaviors, and the development of chronic vulvar pain after vulvar inflammation, which combines acute inflammation with chronic unpredictable stress (CUS) in female rats. Current result indicates that CUS leads to a reduction in vulvar mechanical thresholds and an increase in anxiety-like behavior, including reduced entries and time spent in the open arms of the EPM, reduced time in the center, increased distance moved in the OF, and reduced sucrose intake compared to the non-CUS group. Blood corticosterone levels and gene expression related to neuronal activation (cFOS) and GABA-synthesis (GAD67) were significantly increased in the amygdala and PAG in the CUS group compared to the non-CUS group. Following vulvar injection (saline/zymosan), there was a significant reduction in vulvar mechanical threshold in all groups: non-CUS/Saline, non-CUS/Zymosan, CUS/Saline, and CUS/Zymosan. However, mechanical thresholds returned to baseline in all groups except the CUS/Zymosan group, which exhibited prolonged vulvar hypersensitivity with no sign of recovery. Long-term behavioral assessments revealed reduced open-arm entries, altered locomotion, and decreased sucrose intake of the CUS groups compared to non-CUS groups. In conclusion, chronic stress enhances vulnerability to chronic vulvar pain following acute inflammation, alongside persistent anxiety and depression-like behaviors. These findings support a biopsychosocial model of PV, emphasizing the interplay between stress and inflammation in vulvar pain chronification.

Septin-5 is a GTP-binding protein implicated in synaptic vesicle exocytosis and 22q11.2 deletion-related neuropsychiatric disorders. We recently showed that Septin5-deficient (Septin5^-/-) mice display intact hippocampal spine ultrastructure, but marked deficits in both recent and remote contextual fear memory, whereas cued fear memory is preserved. Building on these findings, we asked whether Septin-5 is required for baseline forms of hippocampus-dependent spatial and object recognition memories, or more selectively for novelty-dependent memory stabilization. Using congenic Septin5^-/- mice, we performed a behavioural test battery including hippocampus-dependent spatial and object recognition tasks. Septin5^-/- mice showed normal performance in T-maze (spontaneous and forced alternation), Barnes maze (acquisition and recent/remote spatial reference memory), and object location memory. After 5-min training in the novel object recognition task, short-term recognition memory was indistinguishable between genotypes. Together with our previous report that long-term object recognition after 15-min training is intact in Septin5^-/- mice, these results indicate that Septin-5 is dispensable for a broad set of hippocampus-dependent spatial and object recognition memories despite contextual fear deficits. In contrast, Septin5^-/- mice exhibited a selective deficit in behavioural tagging: in wild-type mice, novelty exploration 30 min after 5-min object training converted an otherwise labile trace into a 24-h memory, whereas this novelty-induced stabilization was absent in Septin5^-/- mice. Thus, Septin-5 is not required for baseline performance in hippocampus-dependent spatial and object recognition tasks, but is implicated in novelty-dependent stabilization of weak hippocampal memories under the established 10-min novelty exposure condition, consistent with a contribution to synaptic tagging-like processes.

Stroke, a result of acute cerebrovascular disease that causes cerebral dysfunction, often coexists with depression or even major depressive disorder (MDD). Despite the recognized significance of lipid metabolism disorders in both stroke and depression, their interwoven role in the pathogenesis of these conditions remains largely uncharted. This study sourced transcriptomic data linked to stroke and depression from the GEO database. Hub genes were identified through weighted gene coexpression network analysis (WGCNA) and machine learning algorithms. The diagnostic efficacy of the model featuring hub genes was evaluated using receiver operating characteristic (ROC) curve analyses and nomogram plots. Enrichment analysis and immune infiltration were examined while potential therapeutic agents were predicted using the drug profile database. The expression levels of the hub genes were verified on peripheral blood samples using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). 6 differentially expressed genes (DEGs) related to lipid metabolism were identified showing significant enrichment in metabolic and immune pathways. The diagnostic model constructed based on these genes demonstrated robust performance across multiple datasets. Gene set enrichment analysis (GSEA) suggested the involvement of nucleic acid metabolism and olfactory transduction in both diseases. Immune infiltration analysis revealed significant differences among various immune cells, such as monocytes and neutrophils. 11 potential drugs targeting at least two hub genes were identified. The exploration of lipid metabolism-related diagnostic genes offers valuable insights into the potential interplay between stroke and depression.

Schizophrenia is a heterogeneous psychiatric disorder that remains inadequately treated with current therapies. Developing appropriate animal models that reflect the broad spectrum of schizophrenia symptoms is crucial for advancing our understanding of the disease and identifying effective treatments. However, existing animal models often have limitations in fully recapitulating the diverse symptomatology observed in humans. Previously, we reported that mice with conditional ablation of TMEM16A (ANO1) in cholinergic neurons of the medial habenula (ANO1 cKO) exhibit behavioral patterns indicative of anxiety, reduced social motivation, and anhedonia. In the present study, we found that these mice display schizophrenia-like phenotypes, including impaired prepulse inhibition (PPI), enhanced cocaine sensitivity, and reduced c-Fos expression in the medial prefrontal cortex (mPFC), a feature also observed in patients with schizophrenia. Moreover, ANO1 cKO mice exhibited elevated Drd2 expression in the ventral medial geniculate nucleus (MGv) and transcriptomic alterations overlapping with schizophrenia-associated genes. Importantly, these phenotypes emerged only when ANO1 deletion occurred during development, whereas adult-stage manipulation failed to reproduce them, underscoring a critical developmental window for habenular-thalamocortical circuit maturation. This developmental specificity represents a central novelty of the model and provides new insight into how early-life dysregulation of habenular cholinergic signaling contributes to schizophrenia-related pathophysiology.

Microglia, the resident immune cells in the central nervous system, play important roles not only in immune response but also in neurogenesis, synaptogenesis, and neural circuit formation. Microglia also surveil the brain environment via elongation and retraction of their processes. Previously, we found that the purine salvage pathway is involved in the regulation of morphology and dynamics of the microglial cell line BV2. Here, we show that intraperitoneal administration of mycophenolate mofetil (MMF), an inosine monophosphate dehydrogenase (IMPDH) inhibitor, reduces microglial branching during postnatal development. Imaging mass spectrometry analysis revealed that MMF administration decreases guanosine nucleotides in the brain. Interestingly, despite the essential role of guanosine nucleotides in cellular proliferation, MMF administration did not significantly affect microglial proliferation. On the other hand, MMF administration attenuated the level of GTP-bound forms of RhoA and Rac1 small GTPases. Notably, MMF administration decreased the number of branches, while process length remained unaffected. Since microglial branching affects microglial complexity and diversity, our findings suggest that guanosine nucleotide production is essential for generating proper microglial diversity.

Calcium-phosphate (CaP) is a ubiquitous inorganic compound that plays an important structural role in healthy bone and teeth formation, but its pathologic buildup can occur in dyshomeostatic calcium disorders like Alzheimer's disease and Leigh syndrome. The nexus of pathologic extracellular CaP in the nervous system is not well understood, but prior evidence suggests mitochondria could be a source. We have observed mitochondria-sized sheet-like CaP aggregates within functional wild type cortical neuron cultures at 1 and 20 days in vitro. Neurons were extracted from embryonic day 18 (E18) rat embryos following standard protocols to study neuronal structure and function. We have used a combination of cryo-ET, cryo-CLEM, and LDSAED to demonstrate that these aggregates are octacalcium phosphate-like, are associated with mitochondria, and that at least a portion are extruded via migrasomes. Visually similar aggregates were previously observed in Huntington's disease model neurons, but in that study they were not observed in WT controls. These findings show that this CaP aggregation process occurs routinely in WT neurons and may reveal an important link for how mitochondria may participate in calcification, highlighting them as potential therapeutic targets in neurological disorders characterized by pathological calcification, such as Alzheimer's disease.

Autophagy is a conserved catabolic pathway that preserves cellular homeostasis through lysosomal degradation. Beyond its general role in proteostasis, selective autophagy mediates the clearance of selective cellular targets such as persistent stress granules (SGs), in a process termed granulophagy. SGs are dynamic cytoplasmic assemblies that normally disassemble after stress relief; however, their aberrant persistence has arisen as a pathological feature of neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). However, the molecular regulation of granulophagy remains incompletely understood. Here, we established a tandem fluorescent SG reporter system with mCherry-pHluorin-FUS^P525L, enabling live-cell visualization of granulophagic flux. Using this system, we screened a chemical library and identified VR23, a proteasome inhibitor, as a potent inducer of granulophagy. VR23 promoted SG clearance through autophagic mechanisms, as evidenced by enhanced LC3 colocalization, lysosome-dependent degradation, and Bafilomycin A1-sensitive flux. Notably, disruption of SG assembly via G3BP1 inhibition abolished VR23-induced clearance, confirming its SG selectivity. These findings suggest a link between proteasome inhibition and granulophagy, highlighting VR23 as a valuable tool compound to dissect the mechanisms of SG turnover, and provide a platform for discovering modulators of pathological SG clearance in protein aggregation.

Adeno-associated virus (AAV) is a promising vector for neurological gene therapy, yet engineered serotypes are restricted to targeting either the central or peripheral nervous system (CNS or PNS). To overcome this limitation, we generated AAV with mosaic capsid, AAV-PHP.(S + eB), by co-packaging the AAV with two engineered capsid variants: AAV-PHP.eB and AAV-PHP.S, which exhibits strong CNS tropism and PNS tropism, respectively. Systemic administration of AAV-PHP.(S + eB) in adult mice mediated widespread transgene expression throughout the CNS, comparable to AAV-PHP.eB, while simultaneously achieving robust transduction of dorsal root ganglia neurons, similar to AAV-PHP.S. Notably, the mosaic vector demonstrated significantly reduced off-target transduction in the liver compared to both parental vectors, suggesting an improved safety. These results indicate that mosaic capsid assembly is a potent strategy for designing dual-tropic AAV vectors without increasing viral dose. This approach holds significant promise for treating complex neurological disorders that involve both nervous system compartments.

Autism Spectrum Disorder (ASD) presents as a complicated neurodevelopmental disorder which leads to social communication challenges and repetitive behavioral patterns. Early identification of ASD is crucial to facilitate early intervention that can make a large positive impact on long-term developmental outcomes. With the advent of artificial intelligence (AI) and data-driven diagnoses, there is increased interest in combining machine learning methods with biological and behavioral signatures to detect early ASD. This review provides an overview of broad classes of biomarkers-behavioral, neuroimaging, genetic, and eye gaze-and their respective methodologies, clinical applications, and diagnostic accuracy. For each of these biomarker domains, the research gap has been identified as existing for instance limited interpretability in neuroimaging models, genomics-related ethical and data accessibility issues, and innovation saturation for behavioral measurement. A comparative analysis highlights eye gaze analysis as a promising but under-explored option, providing a balance of cost-effectiveness, non-invasiveness, and potential for real-time, objective measurement. In addition, the application of Explainable AI (XAI) methodologies across these biomarker fields is discussed in order to meet the pressing need for transparency, clinical confidence, and decision-making support. This review makes a final call for further exploration of eye gaze-based models enriched by XAI methods as a future research direction towards filling the gap between algorithmic innovation and real-world, interpretable diagnostics in the context of ASD research.