Search Results (192)

Wnt/β-catenin signaling is hyper-activated in several cancer cells and cancer stem cells. Dishevelled/Dvl is a key adapter protein that acts as a bridge between the Wnt receptor Frizzled (Fzd) and other cytosolic factors. In detail, the C-terminal cytosolic region is the ligand of the PSD-95, disks large, and zonula occludens-1 (PDZ) domain of Dvl. Therefore, the PDZ domain (Dvl-PDZ) is thought to be a potential drug target. In this paper, we determined the first crystal structure of the PDZ domain of human Dvl1 (hDvl1-PDZ) at a 2.4 Å resolution. The domain was adapted into a unique trimeric form in which all the canonical ligand-binding clefts were occupied by the β2-β3 loop of the neighbor molecule, like an auto-inhibiting trimer. We used solution nuclear magnetic resonance (NMR) experiments to assess the presence of the self-associated oligomer of hDvl1-PDZ in the solution. Introducing the Ala substitution at Asp 272, the key residue of the β2-β3 loop, partly abolished the concentration-dependent chemical shift change, which suggests that this residue is one of the key residues for formation. Based on these observations, we propose an auto-inhibiting trimer formation of Dvl-PDZ in a Dvl-Axin hetero-oligomerization model of Wnt/β-catenin signal transduction. Full article

Multiple differentiation protocols have emerged in recent years, producing neurons with diverse morphologies, gene and protein expression profiles, and functionality. Many of these differentiation techniques require months of culture and the use of expensive growth factors. Most importantly, the derived neurons usually do not exhibit any electrical activity. This limits the value of the protocol as a tool for engineering and investigating neural networks. Here, we describe an efficacious method for differentiating mouse embryonic stem cells into functional neurons. CGR8 cells were neurally induced via the simultaneous application of retinoic acid and purmorphamine. The derived cells expressed neuronal (TUJ1 and NeuN) and synaptic (GAD2, PSD-95, Synaptophysin, and VGLUT1) markers. During whole-cell recordings, neurons exhibited inward and outward currents, likely caused by fast-inactivating voltage-gated potassium channels. Upon current injection, miniature action potentials were also recorded. The efficient generation of diverse subtypes of functional neurons can be a useful tool in fundamental investigations of neural network activity and translational studies. Full article

Neurodegeneration is increasingly recognized not as a linear trajectory of protein accumulation, but as a multidimensional collapse of biological organization—spanning intracellular signaling, transcriptional identity, proteostatic integrity, organelle communication, and network-level computation. This review intends to synthesize emerging frameworks that reposition neurodegenerative diseases (ND) as progressive breakdowns of interpretive cellular logic, rather than mere terminal consequences of protein aggregation or synaptic attrition. The discussion aims to provide a detailed mapping of how critical signaling pathways—including PI3K–AKT–mTOR, MAPK, Wnt/β-catenin, and integrated stress response cascades—undergo spatial and temporal disintegration. Special attention is directed toward the roles of RNA-binding proteins (e.g., TDP-43, FUS, ELAVL2), m6A epitranscriptomic modifiers (METTL3, YTHDF1, IGF2BP1), and non-canonical post-translational modifications (SUMOylation, crotonylation) in disrupting translation fidelity, proteostasis, and subcellular targeting. At the organelle level, the review seeks to highlight how the failure of ribosome-associated quality control (RQC), autophagosome–lysosome fusion machinery (STX17, SNAP29), and mitochondrial import/export systems (TIM/TOM complexes) generates cumulative stress and impairs neuronal triage. These dysfunctions are compounded by mitochondrial protease overload (LONP1, CLPP), UPR maladaptation, and phase-transitioned stress granules that sequester nucleocytoplasmic transport proteins and ribosomal subunits, especially in ALS and FTD contexts. Synaptic disassembly is treated not only as a downstream event, but as an early tipping point, driven by impaired PSD scaffolding, aberrant endosomal recycling (Rab5, Rab11), complement-mediated pruning (C1q/C3–CR3 axis), and excitatory–inhibitory imbalance linked to parvalbumin interneuron decay. Using insights from single-cell and spatial transcriptomics, the review illustrates how regional vulnerability to proteostatic and metabolic stress converges with signaling noise to produce entropic attractor collapse within core networks such as the DMN, SN, and FPCN. By framing neurodegeneration as an active loss of cellular and network “meaning-making”—a collapse of coordinated signal interpretation, triage prioritization, and adaptive response—the review aims to support a more integrative conceptual model. In this context, therapeutic direction may shift from damage containment toward restoring high-dimensional neuronal agency, via strategies that include the following elements: reprogrammable proteome-targeting agents (e.g., PROTACs), engineered autophagy adaptors, CRISPR-based BDNF enhancers, mitochondrial gatekeeping stabilizers, and glial-exosome neuroengineering. This synthesis intends to offer a translational scaffold for viewing neurodegeneration as not only a disorder of accumulation but as a systems-level failure of cellular reasoning—a perspective that may inform future efforts in resilience-based intervention and precision neurorestoration. Full article

Temporal lobe epilepsy (TLE) is a common drug-resistant form of epilepsy, often accompanied by cognitive and emotional disturbances, highlighting the urgent need for novel therapies. Scorpion Venom Heat-Resistant Synthetic Peptide (SVHRSP), isolated and synthetically derived from scorpion venom, has shown anti-epileptic and neuroprotective potential. This study evaluated the anti-epileptic effects of SVHRSP in a kainic acid (KA)-induced TLE rat model. Our results demonstrated that SVHRSP (0.81 mg/kg/day) reduced the frequency and severity of spontaneous seizures. Behavioral tests showed improved cognitive performance in the novel object recognition, object location, and T-maze tasks, as well as reduced anxiety-like behavior in the open-field test. Moreover, SVHRSP mitigated hippocampal neuronal loss and glial activation. Transcriptomic analysis indicated that SVHRSP upregulates genes involved in adhesion molecule-triggered and axon guidance pathways. Western blotting and immunofluorescence further confirmed that SVHRSP restored dendritic (MAP2), axonal (NFL), and synaptic (PSD95) marker expression, elevated the functionally important L1CAM fragment (L1-70), and increased myelin basic protein-induced serine protease activity responsible for L1-70 generation. Blockade of L1CAM expression diminished the neuroprotective effects of SVHRSP, suggesting a critical role for L1CAM-mediated synapse functions. This study is the first to reveal the therapeutic potential of SVHRSP in TLE via L1CAM-associated mechanisms. Full article

Background/Objective: The Rs1 exon-1-del rat (Rs1KO) XLRS model shows normal retinal development until postnatal day 12 (P12) when small cystic spaces start to form in the inner nuclear layer. These enlarge rapidly, peak at P15, and then collapse by P19. These events overlap with eye opening at P12–P15. We investigated whether new light-driven retinal activity could contribute to the appearance and progression of schisis cavities in this rat model of XLRS disease. Methods: For dark rearing (D/D), mating pairs of Rs1KO strain were raised in total darkness in a special vivarium at UC Davis. When pups were born, they were maintained in total darkness, and eyes were collected at P12, P15, and P30 (n = 3/group) for each of the D/D and cyclic light-reared 12 h light–12 h dark (L/D) Rs1KO and wild-type (WT) littermates. Eyes were fixed, paraffin-embedded, and sectioned. Tissue morphology was examined by H&E and marker expression of retinoschisin1 (Rs1), rhodopsin (Rho), and postsynaptic protein 95 (Psd95) by fluorescent immunohistochemistry. H&E-stained images were analyzed with ImageJ version 1.54h to quantify cavity size using the “Analyze Particles” function. Results: Small intra-retinal schisis cavities begin to form by P12 in the inner retina of both D/D and L/D animals. Cavity formation was equivalent or more pronounced in D/D animals than in L/D animals. We compared Iba1 (activation marker of immune cells) distribution and found that by P12, when schisis appeared, Iba1⁺ cells had accumulated in regions of schisis. Iba1⁺ cells were more abundant in Rs1KO animals than WT animals and appeared slightly more prevalent in D/D- than L/D-reared Rs1KO animals. We compared photoreceptor development using Rho, Rs1, and Psd95 expression, and these were similar; however, the outer segments (OSs) of D/D animals with Rho labeling at P12 were longer than L/D animals. Conclusions: The results showed that cavities formed at the same time in D/D and L/D XLRS rat pups, indicating that the timing of schisis formation is not light stimulus-driven but rather appears to be a result of developmental events. Cavity size tended to be larger under dark-rearing conditions in D/D animals, which could be due to the decreased rate of phagocytosis by the RPE in the dark, allowing for continued growth of the OSs without the usual shedding of the distal tip, a key mechanism behind dark adaptation in the retina. These results highlight the complexity of XLRS pathology; however, we found no evidence that light-driven metabolic activity accounted for schisis cavity formation. Full article

Background/Objectives: Contextual memory associated with methamphetamine (METH) use contributes to relapse and persistence of addiction. Angiotensin II type 1 receptor (AT1R) signaling has been implicated in drug reinforcement. LCZ696, a clinically used combination of sacubitril (a neprilysin inhibitor) and valsartan (an AT1R antagonist), may interfere with METH-associated memory through the modulation of dopaminergic pathways. Methods: Male C57BL/6J mice were tested in a conditioned place preference (CPP) paradigm to assess the effects of LCZ696, sacubitril (AHU377), and valsartan on METH-induced memory expression and reinstatement. Synaptic plasticity in the nucleus accumbens (NAc) was examined by assessing the levels of synaptophysin (Syp) and postsynaptic density protein 95 (Psd95), as well as dendritic spine density. Dopaminergic signaling in the ventral tegmental area (VTA) was evaluated via ELISA, Western blotting, and chromatin immunoprecipitation (ChIP), targeting cAMP response element-binding protein (Creb) binding to the tyrosine hydroxylase (Th) promoter. To further assess the role of Th, an adeno-associated virus (AAV9) carrying a CRISPR-Cas9-based sgRNA targeting Th (AAV9-Th-sgRNA) was microinjected into the VTA. Results: LCZ696 and valsartan significantly reduced METH-induced CPP and reinstatement. LCZ696 reversed METH-induced synaptic and dopaminergic alterations and suppressed Creb-mediated Th transcription. Th knockdown attenuated both CPP acquisition and relapse. Conclusions: LCZ696 disrupts METH-associated contextual memory by modulating dopaminergic signaling and Creb-dependent Th expression, supporting its potential as a treatment for METH use disorder. Full article

Neuropathic pain is a persistent and exhausting condition which results from damage to the nervous system and is often accompanied by emotional and cognitive impairments. In this study, we investigated dynamic changes in pain-related behaviors over 8 weeks using a spared nerve injury (SNI) model in male C57Bl/6 mice. We examined behavioral outcomes in conjunction with glial activation, neurogenesis, and glutamatergic signaling in the hippocampus to elucidate the mechanisms underlying cognitive and affective alterations associated with chronic pain. Our findings demonstrate that SNI-induced neuropathic pain progressively increases anxiety-like behavior and impairs both working and long-term memory. These behavioral deficits are accompanied by significant activation of microglia and astrocytes, a reduction in hippocampal neurogenesis, and a decrease in the expression of NMDA and AMPA glutamate receptor subunits and the scaffolding protein PSD-95. Taken together, our results suggest that hippocampal neuroinflammation and associated synaptic dysfunction contribute to the affective and cognitive disturbances observed in chronic pain, providing insight into potential molecular targets for therapeutic intervention. Full article

Previous studies have demonstrated neuronal and microglial Fyn, a Src family kinase (SFK), and how its interactions with tau contribute to epileptogenesis. Saracatinib, a Fyn/SFK inhibitor, modifies disease progression in rat kainate (KA) epilepsy models. In this study, we investigated neuronal-specific fyn knockdown effects on Fyn–tau signaling, neurodegeneration, and gliosis using a calcium/calmodulin-dependent protein kinase II (CaMKII)-promoter-driven adeno-associated viral vector (AAV9)-mediated fyn-shRNA injection in the rat hippocampus. Eight days following AAV administration, rats received repeated low-dose KA injections intraperitoneally to induce status epilepticus (SE). Both fyn-shRNA and control groups showed comparable SE severity, indicating inadequate neuronal fyn knockdown at this timepoint. Two weeks post fyn-shRNA injection, hippocampal Fyn significantly decreased, alongside reductions in NR2B, pNR2B^Y1472, PSD95, and total tau. There was also a compensatory activation of SFK (pSFK^Y416:Fyn) and tau hyperphosphorylation (AT8:total tau), negatively correlating with NeuN expression. Proximity ligation assay indicated unchanged Fyn–tau interactions, suggesting tau interactions with alternative SH3 domain proteins. Persistent neuronal loss, astrogliosis, and microgliosis suggested limited effectiveness of neuronal-specific fyn knockdown at this timepoint. An extended-duration fyn knockdown study, or using broad SFK inhibitors such as saracatinib or tau-SH3 blocking peptides, may effectively prevent SE-induced epileptogenesis. Full article

Depression is associated with bidirectional interactions between inflammatory responses and behavioral dysfunction. Paeoniflorin (PF), a monoterpene glycoside derived from Paeonia lactiflora, exhibits potent anti-inflammatory properties. This study investigates the therapeutic effects of PF on lipopolysaccharide (LPS)-induced depression-like behaviors in mice and neuroinflammation in BV2 microglial cells. Mice were co-administered PF (20, 40, or 80 mg/kg/day) and LPS (2 mg/kg) for 7 days. Behavioral tests; Nissl staining; and Golgi, Iba1, DLG4, and cytokine assays were conducted. Additionally, hippocampal NF-κB, Nrf2, and BDNF signaling pathways were analyzed using Western blots. In BV2 cells, oxidative stress and the Nrf2/HO-1 pathway were assessed using CCK-8, flow cytometry, and Western blotting after 24 h of LPS and PF treatment. PF significantly alleviated LPS-induced depression-like behaviors, increased hippocampal neuron and dendritic spine density, and upregulated synaptic proteins (PSD95, SNAP25, and BDNF). Mechanistically, PF suppressed NLRP3 inflammasome activation via the Akt/GSK3β pathway, reduced pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and enhanced the Nrf2/HO-1 antioxidant axis. In BV2 cells, PF restored mitochondrial membrane potential, inhibited apoptosis, and decreased cytokine levels (TNF-α, IL-1β, and IL-6) by inhibiting TLR4/NF-κB signaling. In conclusion, PF significantly improved LPS-induced depression-like behaviors and attenuated neuroinflammation in BV2 microglial cells, highlighting its potential as a therapeutic agent for inflammation-associated depression. Full article

IQSEC2 is a guanine nucleotide exchange factor that modulates synaptic transmission, the excitatory/inhibitor balance and memory consolidation. Pathogenic mutations in the IQSEC2 gene result in epilepsy, cognitive dysfunction and autism spectrum disorder. The most common de novo IQSEC2 mutation in the IQSEC2 gene, associated with a particularly severe phenotype in males as compared to other IQSEC2 mutations, is due to a frameshift mutation near the C terminus, resulting in an extension of the open reading frame [IQSEC2 S1474Qfs*133]. The objective of this study was to understand the pathophysiology of this specific IQSEC2 mutation using molecular modeling protein–protein interaction assays and a conditional transgenic mouse model of the mutation. Molecular modeling studies showed that the mutation results in the generation of a new domain that may bind ATP. The mutant IQSEC2 protein failed to interact with proteins that normally interact with IQSEC2, most notably with PSD-95. Finally, mice expressing the human mutation displayed marked developmental delays and abnormal social behavior. We conclude that diseases associated with the IQSEC2 S1474Qfs*133 may be due not only to the loss of function of IQSEC2 but also to the appearance of new detrimental activity. The conditional mouse model will allow for the identification of brain regions that are critical for IQSEC2 expression and will serve as a platform for the development of personalized therapies for this disease. Full article

Background: Sleep deprivation (SD) is a common condition affecting many people in modern life. Edaravone (Eda) is a neuroprotective drug, but whether it can improve cognitive impairment caused by SD remains unclear. Methods: Animals received oral gavage doses of Eda (10, 20, and 40 mg/kg) for 8 and 5 days before and during SD. Starting from the 6th day, a modified multiple platform model was used to produce SD in mice for 72 h. The Lashley III maze was used for evaluating spatial learning and memory. Malondialdehyde (MDA) in the hippocampus and serum corticosterone were assessed. Total antioxidant capacity (TAC) and the activity of the enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured. Growth-associated protein 43 (GAP-43), synapsin 1 (SYN-1), post-synaptic density-95 (PSD-95), synaptophysin (SYP), and signs of inflammation were detected using Western blotting. Results: SD caused cognitive impairment, whereas Eda pretreatment warded off such an effect. While serum corticosterone levels rose with SD as well, they decreased in SD mice that received Eda (p < 0.05). Moreover, Eda normalized the SD-induced decline in hippocampal activity of SOD and GPx, lowered MDA levels, and elevated TAC (p < 0.01). Additionally, the hippocampal levels of GAP-34, SYP, SYN-I, and PSD-95 were elevated, while IL-1β and tumor necrosis factor α (TNF-α) were lowered following Eda pretreatment (p < 0.05). Conclusions: SD caused memory impairment; however, pretreatment with Eda improved memory by upregulating synaptic proteins in the hippocampus and having anti-inflammatory and antioxidant effects. Full article

Frmpd3 (FERM and PDZ Domain Containing 3), a scaffold protein potentially involved in excitatory synaptic function, has not been thoroughly characterized in terms of its expression and functional role in vivo. Here, we investigated the distribution of Frmpd3 in the central nervous system and its potential regulatory role in epilepsy, a neurological disorder characterized by disrupted excitatory–inhibitory balance. The distribution of Frmpd3 throughout the mouse brain was investigated by immunofluorescence. Western blotting was conducted to examine potential alterations in Frmpd3 protein expression in the hippocampus of a pentylenetetrazol (PTZ)-induced chronic epilepsy model. Using stereotaxic techniques, we delivered Frmpd3 siRNA-AAV9 into the hippocampal CA1 region to achieve targeted protein knockdown. Then, the functional consequences of Frmpd3 depletion were assessed through behavioral observations and electrophysiological recordings in PTZ-treated mice. Finally, protein–protein interactions were investigated using immunoprecipitation and Western blot analysis. Immunofluorescence analysis revealed Frmpd3 expression in cortical, hypothalamic, cerebellar, and hippocampal neurons of adult mice. Subcellular localization studies demonstrated predominant distribution of Frmpd3 in the excitatory postsynaptic density (PSD) of hippocampal CA1 neurons, with additional expression in inhibitory neurons. Quantitative analysis showed significantly elevated Frmpd3 protein levels in the hippocampus of PTZ-induced epileptic mice compared to controls. Frmpd3 knockdown in the CA1 region resulted in the following: (1) reduced seizure frequency, (2) prolonged seizure latency, and (3) decreased incidence of PTZ-induced generalized seizures. Local field potential (LFP) recordings demonstrated that seizure amplitude tended to be reduced, and epileptic discharge durations tended to be shorter in Frmpd3-depleted mice compared to controls. Furthermore, we observed decreased membrane expression of the AMPA receptor GluA2 subunit in the hippocampus of Frmpd3 knockdown mice. Molecular interaction studies revealed that Frmpd3 forms complexes with glutamate receptor-interacting protein (GRIP) and GluA2. Our findings identify Frmpd3 as a novel regulatory scaffold protein that modulates epileptic susceptibility through molecular interactions with GRIP and GluA2. The underlying mechanism appears to involve Frmpd3-mediated regulation of GluA2 trafficking from the cytoplasm to the membrane, ultimately enhancing neuronal excitability through increased membrane expression of GluA2-containing AMPA receptors. Full article

Background: Every year, over 40 million people sustain mild traumatic brain injury (mTBI) which affects the glucocorticoid stress pathway and synaptic plasticity. Ketamine, a multimodal dissociative anesthetic, modulates the stress pathway and synaptic plasticity. However, the effects of post-mTBI ketamine administration on plasma stress hormones and brain synaptic plasticity are largely unknown. Methods: Adult male Sprague-Dawley rats with indwelling jugular venous catheters sustained mTBI with the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) in a single session (3 impacts × 1.5 J). One hour later, rats received intravenous (IV) ketamine (0, 10, or 20 mg/kg, 2 h). Catheter blood samples were collected for plasma corticosterone and progesterone assays. Brain tissue sections were double-labeled for presynaptic synapsin-1 and postsynaptic density protein 95 (PSD-95). Utilizing the Synaptic Evaluation and Quantification by Imaging Nanostructure (SEQUIN) workflow, super-resolution confocal images were generated, and synapsin-1, PSD-95, and synaptic density were quantified in the CA1 of the hippocampus and medial prefrontal cortex (mPFC). Results: IV ketamine infusion produced biphasic effects on corticosterone levels: a robust elevation during the infusion followed by a reduction after the infusion. CHIMERA injury elevated progesterone levels at post-injury day (PID)-1 and reduced synaptic density in the CA1 at PID-4, regardless of ketamine infusion. Ketamine infusion increased synaptic density in the mPFC at PID-4. Conclusions: Mild TBI and IV ketamine modulate the stress pathway and synaptic plasticity in the brain. Further research is warranted to investigate the functional outcomes of subanesthetic doses of ketamine on stress pathways and neuroplasticity following mTBI. Full article

This study underscores the critical role of tillage methods in optimizing soybean yield and quality. Plowed tillage + strip-drill sowing (PSD) offers a balance between crop productivity and quality by maintaining soil structure while enhancing nutrient availability. Reduced tillage methods such as zero tillage + strip-drill (ZSD) and no-plowed tillage + strip-drill (NSD) can improve leaf greenness by about 10–15% and pod numbers by 6.7% and 3.5%, respectively. However, such methods may reduce seed quality and germination capacity, impacting the overall yield. In contrast, plowed tillage + conventional row sowing (PCR) promotes balanced nutrient composition and carbohydrate production under optimal soil conditions. Tillage practices significantly influence nutrient components such as ash content, which ranges from 55.8 g kg⁻¹,(PCR) to 57.4 g kg⁻¹ (ZSD). ZSD was found to enhance protein levels by 3% at the expense of carbohydrates, likely due to improved nutrient retention. The present analysis highlights ZSD as an effective method for stabilizing protein yield (mean value 843.8 kg ha⁻¹) and fat yield (mean value 449.3 kg ha⁻¹) across variable environments, supporting the use of ZSD in conservation agriculture. Future studies should explore how tillage practices affect soil health, economic sustainability, and yield stability over time, especially under changing climatic conditions. Optimizing plant density, enhancing seed traits, and improving germination can collectively drive significant improvements in soybean productivity across diverse agro-ecological zones. Full article

Precisely localizing the spatial distribution of proteins within various brain cell types and subcellular compartments, such as the synapses, is essential for generating and testing hypotheses to elucidate their roles in brain function. While the fms-like tyrosine kinase-3 (Flt3) has been extensively studied in the context of blood cell development and leukemia pathogenesis, its role in the brain remains poorly understood. Previous efforts to address this issue were hindered by the low expression levels of Flt3 and the limited sensitivity of the standard immunolabeling method, which were insufficient to reliably detect Flt3 protein in brain tissue. In this study, we systematically characterized Flt3 protein localization during brain development using a highly sensitive immunolabeling method based on alkaline phosphatase (AP) polymer biochemistry. This approach revealed a previously unrecognized neuron-selective Flt3 expression pattern in both mouse and human cerebella, with a developmental increase in total protein levels accompanied by a shift from a cytosolic to a dendritic subcellular distribution. Combining AP-polymer-based immunohistochemistry (AP-IHC) for Flt3 with conventional immunostaining of cell type marker proteins revealed parvalbumin- and calbindin-positive Purkinje cells to be the main cell type expressing Flt3 in the cerebellum. To validate the versatility of the AP-IHC method for detecting low-abundance neuronal proteins, we demonstrated robust labeling of Kir2.1, a potassium channel protein, in brain tissue sections from mouse, pig, and human samples. We further applied the AP-IHC method to human stem cell-derived neurons, effectively visualizing the postsynaptic density scaffold protein PSD95 within synapses. To our knowledge, this is the first study to employ an AP-IHC method combined with other standard immunofluorescent staining to co-detect weakly expressed neuronal proteins and other cellular markers in brain tissue and cultured neurons. Additionally, our findings uncover a previously unrecognized neuron-specific pattern of Flt3 expression in the cerebellum, laying the foundation for future mechanistic studies on its role in normal brain development and neurological disorders. Full article