Search Results (1,407)

Alzheimer’s disease (AD) is a significant global health challenge, further exacerbated by the anticipated increase in prevalence in the coming years. The accumulation of β-amyloid peptide plays a critical role in the onset of AD; however, emerging evidence suggests that soluble oligomers of β-amyloid may primarily drive the neuronal impairments associated with this condition. Additionally, neurodegenerative diseases like AD are linked to oxidative stress and reduced antioxidant capacity in the brain. Natural products, particularly polysaccharides extracted from mushrooms, have garnered interest due to their neuroprotective properties and the potential to enhance the value of natural sources in addressing human diseases. This study examines the antioxidant and neuroprotective properties of polysaccharides derived from Cyttaria espinosae Lloyd (CePs), a relatively underexplored fungus native to Chile. Using Fourier Transform Infrared Spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS), we characterized CePs. We assessed their antioxidant capacity using DPPH and ABTS assays, yielding maximum inhibition rates of 32.14% and 19.10%, respectively, at a concentration of 10 mg mL⁻¹. CePs showed no toxicity in zebrafish embryos and maintained high cell viability in PC-12 cells exposed to amyloid β peptide (Aβ). Our findings suggest that CePs exhibit significant antioxidant and neuroprotective properties against Aβ peptide toxicity while remaining non-toxic to zebrafish embryos. This underscores the potential of the polysaccharides from this mushroom to serve as functional foods that mitigate oxidative stress and warrant further investigation into their mechanisms in the context of the physiopathology of Alzheimer’s disease. Full article

Liver fibrosis (LF) poses significant challenges in diagnosis and treatment. This study aimed to identify effective biomarkers for diagnosis and therapy, as well as to gain deeper insights into the immunological features associated with LF. LF-related datasets were retrieved from the Gene Expression Omnibus (GEO) database. Two datasets were merged to generate a metadata cohort for bioinformatics analysis and machine learning, while another dataset was reserved for external validation. Seventy-eight machine learning algorithms were employed to screen signature genes. The diagnostic performance of these genes was evaluated using receiver operating characteristic (ROC) curves, and their expression levels were validated via qRT-PCR experiments. The R language was utilized to delineate the immune landscape. Finally, correlation analysis was conducted to investigate the relationship between the signature genes and immune infiltration. Through the intersection of GEO datasets and Weighted Gene Co-expression Network Analysis (WGCNA), 42 genes were identified. Machine learning methods further narrowed down 13 signature genes (alpha-2-macroglobulin (A2M), ankyrin-3 (ANK3), complement component 7 (C7), cadherin 6 (CDH6), cysteine-rich motor neuron protein 1 (CRIM1), dihydropyrimidinase-like 3 (DPYSL3), F3, gamma-aminobutyric acid (GABA) receptor subunit epsilon (GABRE), membrane metalloendopeptidase (MME), solute carrier family 38 member 1 (SLC38A1), tropomyosin alpha-1 chain (TPM1), von Willebrand factor (VWF), and zinc finger protein 83 (ZNF83)), and qRT-PCR confirmed these genes’ expression patterns. Furthermore, these signature genes demonstrated strong correlations with multiple immune cell populations. In conclusion, the 13 genes (A2M, ANK3, C7, CDH6, CRIM1, DPYSL3, F3, GABRE, MME, SLC38A1, TPM1, VWF, and ZNF83) represent robust potential biomarkers for the diagnosis and treatment of LF. Among these genes, we first identified Gabre as related to LF and expressed in hepatocytes and cholangiocytes. The immune response mediated by these signature biomarkers plays a pivotal role in the pathogenesis and progression of LF through dynamic interactions between the biomarkers and immune-infiltrating cells. Full article

Background: The vast majority of GBMs recur within 2 years following standard treatment, including radiotherapy. Seizures and epilepsy are common in GBM patients, suggesting tumor-cell-induced neuron toxicity. Additionally, the tumor cells and neurons interact during tumor development; however, the effects of tumor cells on the neurons remain unclear. Methods: Orthotopic xenografts initiated from GSCs expressing GFP implanted into the right striatum of nude mice were irradiated (10 Gy) 35 days after implantation, followed by immunohistochemistry (IHC) to investigate the tumor cell–neuron interactions. Moreover, we established a direct coculture of human GSCs and neurons differentiated from human iPSC-derived neural progenitor cells (NPCs) to investigate the impact of the tumor cells on the neurons. Neuronal cell counts were monitored to assess neurotoxicity. Culture CM were analyzed through cytokine profiling. Results: In untreated mice, tumors invaded across the right hemisphere (RH), with increased cell contact with the mouse neurons. In irradiated mice, the tumor regrowth was less invasive and had fewer neurons. In vitro, the GSCs induced neuronal death in the direct coculture. Similarly, the CM from the direct cocultures caused significant neuronal death. The cytokine analysis revealed that the cocultures uniquely secreted IL-8 into the CM. Furthermore, treatment with recombinant (r) human IL-8 caused significant neuron death, while IL-8 blocking antibodies prevented this neurotoxicity in the coculture. Conclusions: This study demonstrates that GBM tumors regrown after radiation lack neurons, and direct interaction between GSCs and the neurons is necessary for GSC-mediated neurotoxicity, likely involving IL-8 in neuronal death. 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

Catalase, a pivotal antioxidant enzyme, plays a central role in converting hydrogen peroxide (H₂O₂) into oxygen and water, thereby safeguarding cells from oxidative damage. In patients with diabetes, obesity, Alzheimer’s disease (AD), and Parkinson’s disease (PD), catalase becomes increasingly susceptible to non-enzymatic glycation, resulting in enzyme inactivation, oxidative stress, and defective mitochondrial function. This review uniquely emphasizes catalase glycation as a converging pathological mechanism that bridges metabolic and neurodegenerative disorders, underscoring its translational significance beyond prior general reviews on catalase function. In patients with metabolic diseases, glycation impairs β-cell function and insulin signaling, while in patients with neurodegeneration, it accelerates protein aggregation, mitochondrial dysfunction, and neuroinflammation. Notably, the colocalization of glycated catalase with amyloid-β and α-synuclein highlights its potential role in protein aggregation and neuronal toxicity, a mechanism not previously addressed. Therapeutically, targeting catalase glycation opens up new avenues for intervention. Natural and synthetic agents can be used to protect catalase activity by modulating glyoxalase activity, heme integrity, or carbonyl stress. Vitamins C and E, along with agents like sulforaphane and resveratrol, exert protection through complementary mechanisms, beyond ROS scavenging. Moreover, novel strategies, including Nrf2 activation and receptor for advanced glycation end products (RAGE) inhibition, are showing promise in restoring catalase activity and halting disease progression. By focusing on glycation-specific mechanisms and proposing targeted therapeutic approaches, this review positions catalase glycation as a novel and clinically relevant molecular target in patients with chronic diseases and a viable candidate for translational research aimed at improving clinical outcomes. Full article

The neuropeptide oxytocin (OXT) is involved in social bonding, reproduction, and childbirth. Its activity is mediated by the oxytocin receptor (OXTR), also expressed in the skin. OXT alleviates dermal fibroblast senescence, and OXT levels correlate with visible skin aging. OXT inhibits nociceptive signaling and promotes neuronal plasticity. Here, we demonstrate OXT-like benefits of OXTR activation for skin touch sensoriality and nociception, as well as visible skin health and beauty indicators, using an aqueous extract of Hyacinthus orientalis bulbs. OXTR activation was evaluated in a Chinese hamster ovary (CHO) cell model. Nociception and innervation benefits were investigated in keratinocyte/sensory neuron coculture models. A placebo-controlled clinical study evaluated gentle touch receptivity, nociception, skin tone, elasticity, and wrinkling. The extract activated OXTR and enhanced dermal fibroblast proliferation in vitro. In the keratinocyte-neuron coculture, the HO extract lowered nociceptive CGRP release below that of the unstimulated and OXT controls and promoted neuronal survival and dendricity. An organ-on-a-chip coculture showed decreased electrical activity and increased neuronal peripherin. Clinically, we observed selective left-side frontal alpha-wave activation, indicating pleasant sensation, reduced nociception, enhanced skin glow, improved elasticity, and reduced wrinkling. This extract thus shows high value for holistic wellbeing solutions, enhancing the skin’s receptivity to pleasant sensations and promoting well-aging. Full article

Regulatory T cells (Tregs) have anti-inflammatory immunomodulatory activity and hold therapeutic potential for chronic neuroinflammatory neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS). We are developing engineered human Tregs with enhanced disease-modifying activity for treating ALS. A combination of a disease-specific chimeric antigen receptor (CAR) recognizing misfolded human superoxide dismutase-1 (hSOD1) and constitutive expression of brain-derived neurotrophic factor (BDNF) was tested. The scFv region of CAR demonstrated binding to anterior horn tissues of ALS patients with and without familial ALS mutations in SOD1. Tregs transduced to express BDNF showed the ability to secrete BDNF and protect co-cultured neuronal cells from peroxidase toxicity. Co-expression of BDNF did not inhibit CAR Treg expansion, Treg markers, or CAR-mediated anti-inflammatory cytokine production. Human Tregs co-expressing CAR and BDNF were tested for activity in G93A hSOD1-NSG transgenic mice, which develop an early-onset and aggressive ALS-like disease and do not reject human cells. Human Tregs expressing CAR and BDNF delayed the onset of disease development, extended survival, and decreased spinal cord neuroinflammation. The engineered Tregs showed enhanced disease-modifying activity and hold promise as a therapy for ALS. Full article

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra (SN), leading to motor impairments and numerous non-motor manifestations, including anxiety. Notably, anxiety has been shown to exacerbate disease progression and hinder treatment outcomes in PD. Botulinum neurotoxin (BoNT), recognized for its ability to block excessive release of acetylcholine (ACh), has been shown to provide clinical effectiveness in managing motor symptoms. BoNT appears to enhance neuroregenerative plasticity and mitigate neuroinflammation through mechanisms speculated to extend beyond its classical mode of action. Nevertheless, reports on its potential anxiolytic and neuroprotective effects in PD remain limited. Aim: This study investigated the effect of BoNT on motor and anxiety-like behaviors in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. Methods: The experimental animals were assessed for behavioral changes using the open field test (OFT), rotarod, pole test, light-dark box test (LDBT), and elevated plus maze (EPM). Immunohistochemistry was employed to enumerate tyrosine hydroxylase (TH)-positive dopaminergic neurons and ionized calcium-binding adapter molecule (Iba)-1 expressing microglia in SN. Results: BoNT treatment markedly alleviated motor deficits and anxiety. Quantification of TH- and Iba-1-positive cells revealed that BoNT promotes neuroprotection and minimizes microglial burden in the SN of the PD model. Conclusions: The outcome of the study represents the anxiolytic, neuroprotective, and microglial modulatory potentials of BoNT in PD, supporting its therapeutic promise beyond the management of motor symptoms. Given its multifaceted properties, BoNT can be considered a potential therapeutic candidate for PD and other neurological disorders. Full article

Voltage-gated Na⁺ channels (Nav) are the molecular determinants of action potential initiation and propagation. Among the nine voltage-gated Na⁺ channel isoforms (Nav1.1–Nav1.9), Nav1.2 and Nav1.6 are of particular interest because of their developmental expression profile throughout the central nervous system (CNS) and their association with channelopathies. Although the α-subunit coded by each of the nine isoforms can sufficiently confer transient Na⁺ currents (I_Na), in vivo these channels are modulated by auxiliary proteins like intracellular fibroblast growth factor (iFGFs) through protein–protein interaction (PPI), and probes developed from iFGF/Nav PPI complexes have been shown to precisely modulate Nav channels. Previous studies identified ZL0177, a peptidomimetic derived from a short peptide sequence at the FGF14/Nav1.6 PPI interface, as a functional modulator of Nav1.6-mediated I_Na⁺. However, the isoform specificity, binding sites, and putative physiological impact of ZL0177 on neuronal excitability remain unexplored. Here, we used automated planar patch-clamp electrophysiology to assess ZL0177’s functional activity in cells stably expressing Nav1.2 or Nav1.6. While ZL0177 was found to suppress I_Na in both Nav1.2- and Nav1.6-expressing cells, ZL0177 elicited functionally divergent effects on channel kinetics that were isoform-specific and supported by differential docking of the compound to AlphaFold structures of the two channel isoforms. Computational modeling predicts that ZL0177 modulates Nav1.2 and Nav1.6 in an isoform-specific manner, eliciting phenotypically divergent effects on action potential discharge. Taken together, these results highlight the potential of PPI derivatives for isoform-specific regulation of Nav channels and the development of therapeutics for channelopathies. Full article

CD44, a structurally diverse cell-surface glycoprotein, plays a multifaceted and indispensable role in neural tissue across both physiological and pathological conditions. It orchestrates complex cell–extracellular matrix interactions and intracellular signaling through its variant isoforms and post-translational modifications and is broadly expressed in neural stem/progenitor cells, microglia, astrocytes, and selected neuronal populations. The interactions of CD44 with ligands such as hyaluronan and osteopontin regulate critical cellular functions, including migration, differentiation, inflammation, and synaptic plasticity. In microglia and macrophages, CD44 mediates immune signaling and phagocytic activity, and it is dynamically upregulated in neuroinflammatory diseases, particularly through pathways involving Toll-like receptor 4. CD44 expression in astrocytes is abundant during central nervous system development and in diseases, contributing to glial differentiation, reactive astrogliosis, and scar formation. Though its expression is less prominent in mature neurons, CD44 supports neural plasticity, circuit organization, and injury-induced repair mechanisms. Additionally, its expression at nervous system barriers, such as the blood–brain barrier, underscores its role in regulating vascular permeability during inflammation and ischemia. Collectively, CD44 emerges as a critical integrator of neural cell function and intercellular communication. Although the roles of CD44 in glial cells appear to be similar to those explored in other tissues, the expression of this molecule and its variants on neurons reveals peculiar functions. Elucidating the cell-type-specific roles and regulation of CD44 variants may offer novel therapeutic strategies for diverse neurological disorders. Full article

Parkinson’s disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, and key pathways such as neuroinflammation, oxidative stress, and autophagy are believed to significantly contribute to the mechanisms of neurodegeneration. Calpain activation plays a critical role in neuroinflammation and neurodegeneration, as demonstrated by its impact on microglial activation, reactive oxygen species (ROS) production, and neuronal survival. In this study, we investigated the effects of calpain inhibition using calpeptin (CP) and calpain-2-specific inhibitors in cellular and murine models of neuroinflammation and PD. In BV2 microglial cells, LPS-induced production of pro-inflammatory cytokines (TNF-α, IL-6) and chemokines (MCP-1, IP-10) were significantly reduced by CP treatment with a concomitant decrease in ROS generation. Similarly, in VSC-4.1 motoneuron cells, calpain inhibition attenuated IFN-γ-induced ROS production and improved cell viability, demonstrating its neuroprotective effects. Moreover, in a murine MPTP model of PD, calpain inhibition reduced astrogliosis, ROCK2 expression, and levels of inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-7, and IL12p70) and chemokines (MCP-1 and IP-10) in the dorsal striatum and plasma. The specific role of calpain-2 in immune modulation was further highlighted in human microglia, SV-40 cells. With respect to immune modulation in these cells, siRNA-mediated knockdown of calpain-2, but not calpain-1, significantly reduced antigen presentation to CD4+ T cells. Thus, calpain-2 is likely involved in regulating antigen presentation and activation of inflammatory CD4+ T cells. These findings underscore the therapeutic potential of calpain-2 inhibition in mitigating neuroinflammation and neurodegeneration, particularly in PD, by targeting microglial activation, ROS production, and neuronal survival pathways. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia, with current therapies offering only limited symptomatic relief and lacking disease-modifying efficacy. Addressing this critical therapeutic gap, natural multi-target compounds like mulberroside A (MsA)—a bioactive glycoside from Morus alba L.—present promising alternatives. This study investigated MsA’s neuroprotective potential using scopolamine-induced AD-like mice and N2a/APP695swe cells. In vivo, MsA significantly ameliorated cognitive deficits and neuronal loss, concurrently enhancing cholinergic neurotransmission through increased acetylcholine levels and inhibited acetylcholinesterase (AChE)/butyrylcholinesterase (BChE) activities. MsA also upregulated neurotrophic factors (BDNF, CREB) in critical brain regions. In vitro, MsA restored cholinergic function, mitigated oxidative stress, and crucially reduced amyloid-β (Aβ) production by dual regulation of APP processing: promoting the non-amyloidogenic pathway via ADAM10 upregulation and inhibiting the amyloidogenic pathway via suppression of BACE1 and γ-secretase components. Mechanistically, these multi-target benefits were mediated by MsA’s activation of the PI3K/AKT pathway, which triggered downstream inhibitory phosphorylation of GSK3β—directly reduced tau hyperphosphorylation—and activation of CREB/BDNF signaling. Collectively, our findings demonstrate that MsA confers comprehensive neuroprotection against AD pathology by simultaneously targeting cholinergic dysfunction, oxidative stress, Aβ accumulation, tau phosphorylation, and impaired neurotrophic signaling, highlighting its strong therapeutic candidacy. Full article

For 40 years, Intron Retention (IR) was dismissed as splicing noise and is now recognized as a dynamic and evolutionarily conserved mechanism of post-transcriptional gene regulation. Unlike canonical splicing, which excises all introns from pre-mRNAs, IR selectively retains intronic sequences, albeit at seemingly random places; however, current research now reveals that this process is strategic in its retention. IR influences mRNA stability, localization, and translational potential. Retained introns can lead to nonsense-mediated decay, promote nuclear retention, or give rise to novel protein isoforms that contribute to expanding proteomic and transcriptomic profiles. IR is finely regulated by splice site strength, splicing regulatory elements, chromatin structure, methylation patterns, RNA polymerase II elongation rates, and the availability of co-transcriptional splicing factors. IR plays critical roles in cell-type and tissue-specific gene expression with observed patterns, particularly during neuronal, cardiac, hematopoietic, and immune development. It also functions as a molecular switch during cellular responses to environmental and physiological stressors such as hypoxia, heat shock, and infection. Dysregulated IR is increasingly associated with cancer, neurodegeneration, aging, and immune dysfunction, where it may alter protein function, suppress tumor suppressor genes, or generate immunogenic neoepitopes. Experimental and computational tools like RNA-seq, RT-PCR, IRFinder, and IntEREst have enabled transcriptome-wide detection and validation of IR events, uncovering their widespread functional roles. This review will examine current knowledge on the function, regulation, and detection of IR, and also summarize recent advances in understanding its role in both normal and pathophysiological settings. Full article

Acute human alpha-herpesvirus 1 (HSV-1) infection culminates in a latent infection of neurons in trigeminal ganglia (TG) and the central nervous system. Following infection of mucosal epithelial cells, certain neurons survive infection and life-long latency is established. Periodically, stressful stimuli trigger reactivation from latency, which result in virus shedding, transmission to other people, and, occasionally, recurrent disease. The glucocorticoid receptor (GR) and Krüppel-like factor 15 (KLF15) comprise a feed-forward transcriptional loop that cooperatively transactivate key HSV-1 promoters that drive expression of infected cell protein 0 (ICP0), ICP4, and ICP27. Silencing KLF15 significantly reduces HSV-1 replication in cultured mouse neuroblastoma cells. Consequently, we hypothesized that KLF15 mediates certain aspects of reactivation from latency. To test this hypothesis, we compared HSV-1 replication in KLF15^−/− mice versus wild-type (wt) parental C57BL/6 mice. Virus shedding during acute infection was reduced in KLF15^−/− mice. Male KLF15^−/− mice shed higher titers of virus during late stages of reactivation from latency compared to KLF15^−/− females and wt mice regardless of sex. At 15 d after explant-induced reactivation, virus shedding was higher in male KLF15^−/− mice relative to wt mice and female KLF15^−/− mice. These studies confirm KLF15 expression enhances viral replication during acute infection and reactivation from latency. Full article

Background/Objectives: Endozepines known as the endogenous ligands of benzodiazepine-binding sites, include the diazepam binding inhibitor (DBI) and its processing products, the triakontatetraneuropeptide (TTN) and the octadecaneuropeptide (ODN). Despite indisputable evidence of the binding of ODN on GABA_AR-BZ-binding sites, their action on this receptor lacks compelling electrophysiological observations, with some studies reporting that ODN acts as a negative allosteric modulator (NAM) of GABA_AR while others suggest the opposite (positive allosteric modulation, PAM effect). All these studies were carried out in vitro with various neuronal cell types. To further elucidate the role of ODN in neuronal excitability, we tested its effect in vivo in the cerebral cortex of the anesthetized mouse. Methods: Spontaneous neuronal spikes were recorded by means of an extracellular pipette, in the vicinity of which ODN was micro-infused, either at a high dose (10⁻⁵ M) or low dose (10⁻¹¹ M). Results: ODN at a high dose induced a significant increase in neuronal spiking. This effect could be antagonized by the GABA_AR-BZ-binding site blocker flumazenil. In sharp contrast, at low concentrations, ODN reduced neuronal spiking with a magnitude similar to GABA itself. Interestingly, this decrease in neuronal activity by low dose of ODN was not flumazenil-dependent, suggesting that this effect is mediated by another receptor. Finally, we show that astrocytes in culture, known to be stimulated by picomolar doses of ODN via a GPCR, increased their export of GABA when stimulated by low dose of ODN. Conclusion: Our results confirm the versatility of ODN in the control of GABA transmission, but suggest that its PAM-like effect is, at least in part, mediated via an astrocytic non-GABA_AR ODN receptor release of GABA. Full article