Search Results (9,409)

Background/Objectives: Neurodegenerative diseases are driven by multiple interconnected pathological mechanisms involving both intrinsic and extrinsic molecular and cellular processes. Efficient bidirectional intracellular transport is essential for neuronal survival and function, enabling the movement of organelles, proteins, and vesicles between the neuronal soma and distal compartments. This process is primarily mediated by kinesin-dependent anterograde transport and dynein-dependent retrograde transport. Disruption of either motor protein compromises endosome–lysosome recycling, leading to cellular dysfunction and neurodegeneration. However, the mechanisms underlying motor protein impairment in Parkinson’s disease (PD) remain incompletely understood. Methods: We investigated the involvement of kinesin and dynein in intracellular transport dysfunction using both in vitro and in vivo models of PD. Cultured neuronal cells were exposed to MPP+ (1-methyl-4-phenylpyridinium) to model PD-associated neurotoxicity, and motor protein function, vesicular trafficking, and endosomal recycling were assessed. In parallel, an MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced mouse model of PD was used to evaluate dynein-positive fiber density in the spinal cord. The role of calpain-2 was examined by co-treatment with the selective calpain-2 inhibitor zLLYCH2F in both experimental systems. Results: MPP+ exposure disrupted kinesin- and dynein-mediated transport in neuronal cytoplasm, resulting in impaired vesicular trafficking and defective endosome–lysosome recycling. These alterations led to abnormal accumulation of vesicles in both perinuclear regions and at the cell periphery. Pharmacological inhibition of calpain-2 with zLLYCH2F restored motor protein function and normalized vesicle distribution in MPP+-treated cells. Consistent with in vitro findings, MPTP-treated mice exhibited a significant reduction in dynein-positive fiber density within the spinal cord, which was prevented by co-treatment with zLLYCH2F. Conclusions: Our findings demonstrate that calpain-2 activation contributes to kinesin and dynein dysfunction following MPP+/MPTP exposure, leading to impaired intracellular transport and vesicle recycling in PD models. Inhibition of calpain-2 preserves motor protein function, maintains cytoskeletal integrity, and supports normal intracellular trafficking. These results identify calpain-2 as a critical regulator of motor protein stability and suggest that targeting calpain-2 may represent a promising therapeutic strategy for mitigating intracellular transport defects in Parkinson’s disease. Full article

Hypoxic eye diseases represent a pivotal yet often underappreciated contributor to the onset and progression of many retinal disorders. When hypoxia persists or exceeds the tissue’s compensatory capacity, it triggers pathological retinal neovascularization, blood–retinal barrier disruption, and neuronal apoptosis, ultimately resulting in irreversible visual impairment. Connexins (Cxs) form gap junction channels and hemichannels and regulate retinal cell proliferation, differentiation, and survival, thereby playing a central regulatory role in the pathogenesis of hypoxic ocular diseases. In addition to gap junctions, Cx hemichannels promote transmission of molecules between intra- and extracellular environments, further influencing retinal homeostasis under hypoxic stress. This review synthesizes recent progress in understanding connexins in localized and systemic hypoxic eye diseases. We focus on the molecular mechanisms underlying the development and progression of hypoxia-induced ocular pathology, with particular emphasis on the emerging potential of Cxs as novel therapeutic targets for hypoxic ocular diseases. Following a systematic literature search, the electronic databases PubMed and EMBASE were consulted, with the search deadline set at December 2025. The search terms employed were as follows: hypoxia, connexin, gap junctions, hemichannels. Full article

Neurodegenerative disorders are characterized by progressive neuronal loss and dysfunction, yet increasing evidence indicates that glial cells are central mediators of both disease initiation and progression. Astrocytes, microglia, and oligodendrocyte lineage cells modulate neuronal survival by regulating neuroinflammation, metabolic support, synaptic maintenance, and proteostasis. However, dysregulated glial responses, including chronic microglial activation, impaired phagocytosis, altered cytokine production, and mitochondrial dysfunction, contribute to persistent inflammation and structural degeneration observed across Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease and multiple sclerosis. Recent advances in single-cell and spatial omics have revealed extensive glial heterogeneity and dynamic shifts between neuroprotective and neurotoxic phenotypes, emphasizing the context-dependent nature of glial activity. This review summarizes current knowledge regarding the multifaceted involvement of glial cells in neurodegenerative disorders. Full article

Neuronal synapses are the functional units of communication in the central nervous system. This review describes the molecular mechanisms regulating synaptic transmission, plasticity, and circuit refinement. At the presynaptic active zone, scaffolding proteins including bassoon, piccolo, RIMs, and munc13 organize vesicle priming and the localization of voltage-gated calcium channels. Neurotransmitter release is mediated by the SNARE complex, comprising syntaxin-1, SNAP25, and synaptobrevin, and triggered by the calcium sensor synaptotagmin-1. Following exocytosis, synaptic vesicles are recovered through clathrin-mediated, ultrafast, bulk, or kiss-and-run endocytic pathways. Postsynaptically, the postsynaptic density (PSD) serves as a protein hub where scaffolds such as PSD-95, shank, homer, and gephyrin anchor excitatory (AMPA, NMDA) and inhibitory (GABA-A, Glycine) receptors are observed. Synaptic strength is modified during long-term potentiation (LTP) and depression (LTD) through signaling cascades involving kinases like CaMKII, PKA, and PKC, or phosphatases such as PP1 and calcineurin. These pathways regulate receptor trafficking, Arc-mediated endocytosis, and actin-dependent remodeling of dendritic spines. Additionally, synapse formation and elimination are guided by cell adhesion molecules, including neurexins and neuroligins, and by microglial pruning via the complement cascade (C1q, C3) and “don’t eat me” signals like CD47. Molecular diversity is further expanded by alternative splicing and post-translational modifications. A unified model of synaptic homeostasis is required to understand the basis of neuropsychiatric and neurological disorders. Full article

Simultaneously inhibiting beta-amyloid protein (Aβ) aggregation and reducing metal ion overload in the brain is a promising strategy for treating Alzheimer’s disease (AD). Aloe emodin (AE) is one of the major components of the traditional Chinese medicine rhubarb. Based on its reported pharmacological effects and its structural affinity for metal ions, this study aims to explore the potential of AE in improving AD pathology. Through the injection of Aβ or copper-Aβ complex in the bilateral hippocampus of rats, we constructed two kinds of nontransgenic animal models. Behavioral tests were used to evaluate cognitive impairment, and the effects of AE on neuronal damage and Aβ deposition were measured via Nissl staining and immunohistochemistry. Furthermore, we detected copper content in the serum and brain tissues as well as some biochemical indexes of Aβ cascade pathology in the brain tissues of model rats to explore the mechanism of action. AE treatment decreased copper accumulation and regulated Aβ metabolism in the brain of model rats, thereby improving Aβ deposition, memory impairment, hippocampal nerve cell damage, and related biochemical indicators. AE ameliorated the AD pathology of the model rats by targeting copper-induced Aβ toxicity, revealing a mechanism of action by which AE may exhibit good clinical efficacy in treating AD. Full article

Traumatic brain injury (TBI) often leads to long-lasting motor deficits, but the underlying cellular mechanisms still remain poorly understood. In this study, we examined glial and neuronal responses after focal cortical aspiration injury of the right hindlimb sensorimotor cortex in adult male rats. This is a model we have previously shown induces persistent gait asymmetry and postural deficits. Immunohistochemical analysis of activated microglia/macrophages (CD11b, IBA-1), astrocytes (GFAP), and neurons (NeuN) was performed bilaterally in the peri-lesional cortex at 3, 7, 14, 21, and 28 days post-injury (n = 3–6 per time point). The injury induced an early, sharply localized increase in CD11b-positive myeloid cells in the injured hemisphere, suggesting an activation of both resident microglia and infiltrating monocyte-derived cell. This was followed by a more sustained IBA-1-positive microglial activation that gradually extended contralaterally. Astrocytic activation showed a delayed but prolonged profile, rising ipsilaterally within the first week, peaking around two weeks, and becoming bilaterally elevated by four weeks. Sham-operated animals showed only basal glial immunoreactivity without signs of hypertrophy or reactive morphology at any time point. NeuN immunoreactivity remained stable across timepoints, suggesting preservation of neuronal soma labeling without evidence of overt secondary neuronal loss. These findings reveal a staged and spatially distinct glial response to focal cortical injury, with early myeloid activation, prolonged microglial reactivity, and delayed bilateral astrogliosis. Together, these findings are consistent with the possibility that persistent motor deficits after focal TBI arise from both primary tissue loss within the lesion core and peri-lesional glial remodeling, highlighting glial–neuronal interactions as a potential therapeutic target. Full article

Domoic acid (DA) is a neurotoxic terpenoid compound produced by certain marine algae. It accumulates through the food web and poses a significant threat to humans and animals by selectively targeting hippocampal neurons, leading to neuronal degeneration, necrosis, and subsequent memory impairment. The primary mechanism involves its potent agonism at glutamate receptors, which induces excessive calcium influx, resulting in excitotoxic cell swelling and death. Recent studies have further elucidated the critical role of downstream oxidative stress and other pathogenic factors in DA-induced neurotoxicity. These insights into its multifaceted mechanism have paved the way for novel therapeutic strategies, highlighting promising directions for future treatment development. Full article

Parkinson’s disease (PD) is a progressive neurodegenerative disorder marked by the degeneration of dopaminergic neurons in the substantia nigra, resulting in cardinal motor symptoms such as tremor, rigidity, and bradykinesia. Neuroinflammation is increasingly recognized as a central driver of PD onset and progression in which oligodendrocytes, astrocytes, and microglia engage in complex bidirectional crosstalk that shapes the inflammatory milieu of the central nervous system. Pathological activation of glial cells triggers the release of pro-inflammatory cytokines, chemokines, and reactive oxygen species, thereby exacerbating neuronal injury and contributing to sustained disease progression. Modulating maladaptive glial activation states and their intercellular communication represents a promising therapeutic avenue aimed at mitigating neuroinflammation and slowing PD pathology. This review synthesizes current knowledge on neuroinflammation in PD, focusing on the distinct roles of microglia, astrocytes, and oligodendrocytes, their interaction networks, and emerging therapeutic strategies. Full article

Background/Objectives: Cancer pain affects 55–95% of patients with advanced malignancy, representing a complex syndrome involving nociceptive, neuropathic and nociplastic mechanisms. Despite therapeutic advances, two-thirds of patients with metastatic cancer experience inadequate pain control. This scoping review synthesizes recent advances in cancer pain pathophysiology and management, focusing on molecular and cellular mechanisms, emerging pharmacological, interventional and technological therapies and key evidence gaps to inform future precision-based pain management strategies. Methods: Following PRISMA-ScR methodology, we searched PubMed, Embase, Scopus, and Web of Science for studies published between January 2022 and September 2025. After screening 3412 records, 278 studies were included and analyzed across different domains: biological mechanisms, pharmacological management, interventional and neuromodulatory approaches, radiotherapy developments, and digital health innovations. Results: Recent mechanistic research reveals cancer pain arises from tumor–neuron–immune crosstalk, with malignant cells secreting neurotrophic factors that promote axonal sprouting and nociceptor sensitization. Genetic polymorphisms and epigenetic modifications contribute to inter-individual pain variability. Management strategies are evolving toward multimodal precision medicine: NSAIDs and opioids remain foundational, complemented by adjuvant agents and interventional procedures including nerve blocks, intrathecal delivery, and neuromodulation (spinal cord and dorsal root ganglion stimulation). Stereotactic body radiotherapy demonstrates superior analgesic durability versus conventional approaches. Digital health innovations, such as mobile applications, remote monitoring, wearables, and AI-enabled predictive models, enable continuous assessment and personalized treatment optimization. Conclusions: Cancer pain management is transitioning toward mechanism-based precision medicine integrating biological insights, advanced interventional techniques, and digital technologies. However, implementation challenges persist, including limited randomized trials for interventional approaches, the incomplete external validation of AI tools, and digital health equity concerns. Future research must prioritize prospective controlled studies and equitable integration into routine care. Full article

Hepatocellular carcinoma (HCC) is the main type of liver cancer and one of the malignancies with the highest mortality rates worldwide. HCC is associated with diverse etiological factors including alcohol use, viral infections, fatty liver disease, and liver cirrhosis (a major risk factor for HCC). Unfortunately, many patients are diagnosed at advanced stages of the disease and receive palliative treatment only. Therefore, early markers of HCC and novel therapeutic approaches are urgently needed. The endocannabinoid system is involved in various physiological processes such as motor coordination, emotional control, learning and memory, neuronal development, antinociception, and immunological processes. Interestingly, endocannabinoids modulate signaling pathways involved in cell survival, proliferation, apoptosis, autophagy, and immune response. Consistently, several cannabinoids have demonstrated potential antitumor properties in experimental models. The participation of metabotropic and ionotropic cannabinoid receptors in the biological effects of cannabinoids has been extensively described. In addition, cannabinoids interact with other targets, including several ion channels. Notably, several ion channels targeted by cannabinoids are involved in inflammation, proliferation, and apoptosis in liver diseases, including HCC. In this literature review, we describe and discuss both the endocannabinoid system and exogenous phytocannabinoids, such as cannabidiol and Δ⁹-tetrahydrocannabinol, along with their canonical receptors, as well as the cannabidiol-targeted ion channels and their role in liver cancer and its preceding liver diseases. The cannabidiol-ion channel association is an extraordinary opportunity in liver cancer prevention and therapy, with potential implications for several environments that are for the benefit of cancer patients, including sociocultural, public health, and economic systems. Full article

Late-onset sporadic Alzheimer’s disease (LOAD) is the most common form of dementia. The disease is characterized by progressive loss of memory and behavioral changes followed by neurodegeneration of all cortical areas. While the contribution of genetic and environmental factors is important, advanced aging remains the most important disease risk factor. Because LOAD does not naturally occur in most animal species, except humans, studies have traditionally relied on the use of transgenic mouse models recapitulating early-onset familial Alzheimer’s disease (EOAD). Hence, the development of more representative LOAD models through reprograming of patient-derived cells into neuronal, glial, and immune cells became a necessity to better understand the disease’s origin and pathophysiology. Herein, and focusing on neurons, we review current work in the field and compare results obtained with two different reprograming methods to generate LOAD patient’s neuronal cells: the induced pluripotent stem cell and induced neuron technologies. We also evaluate if these models can faithfully mimic cellular and molecular pathologies observed in LOAD patients’ brains. Full article

Paraneoplastic neurological syndromes (PNSs) are immune-mediated disorders caused by an antitumor response that cross-reacts with the nervous system, leading to severe and often irreversible neurological disability. Once considered exceedingly rare, PNSs are now increasingly recognized owing to the identification of novel neural autoantibodies, wider use of commercial testing, and the emergence of immune checkpoint inhibitor (ICI)-related neurotoxicity that phenotypically overlaps with classic PNS. In this narrative review, we performed a structured search of PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar, without date restrictions, to summarize contemporary advances in the epidemiology, pathogenesis, diagnosis, and management of PNS. Population-based data show rising incidence, largely reflecting improved ascertainment and expanding indications for ICIs. Pathogenetically, we distinguish T-cell-mediated syndromes associated with intracellular antigens from antibody-mediated disorders targeting neuronal surface proteins, integrating emerging concepts of molecular mimicry, tumor genetics, and HLA-linked susceptibility. The 2021 PNS-Care criteria are also reviewed, which replace earlier “classical/non-classical” definitions with risk-stratified phenotypes and antibodies, and demonstrate superior diagnostic performance while underscoring that “probable” and “definite” PNS should be managed with equal urgency. Newly described antibodies and methodological innovations such as PhIP-Seq, neurofilament light chain, and liquid biopsy are highlighted, which refine tumor search strategies and longitudinal monitoring. Management principles emphasize early tumor control, prompt immunotherapy, and a growing repertoire of targeted agents, alongside specific considerations for ICI-associated neurological syndromes. Remaining challenges include diagnostic delays, limited high-level evidence, and the paucity of validated biomarkers of disease activity. Future work should prioritize prospective, biomarker-driven trials and multidisciplinary pathways to shorten time to diagnosis and improve long-term outcomes in patients with PNS. Full article

Serotonergic signaling is traditionally conceived as a transient, vesicle-mediated process restricted to the synaptic cleft. Here, we propose an expanded model in which serotonin can also be inserted into the plasma membrane of neurons and glial cells, forming a stable, membrane-associated reservoir that prolongs its availability beyond classical synaptic timescales. In this framework, the synapse emerges not as a simple neurotransmitter–receptor interface but as a dynamic, multiscale medium where membrane order, hydration, and quantum-level processes jointly govern information flow. Two temporal “tunnels” appear to regulate serotonin bioavailability: its aggregation in synaptic vesicles during exocytosis, and its cholesterol-dependent insertion into neuronal and glial membranes at the tripartite synapse. Lipid raft microdomains enriched in cholesterol and gangliosides thus act as active regulators of a continuum between transient and constitutive serotonin signaling. This extended serotonergic persistence prompts a reconsideration of current pharmacological models and the action of antidepressants such as fluoxetine, which not only inhibits the serotonin transporter (SERT) but also accumulates in lipid rafts, perturbs raft organization, and alters serotonin–cholesterol equilibria, contributing to SERT-independent effects. Grounded in the recently established fundamental parameters of biological systems, this model invites a broader, quantum-informed rethinking of synaptic transmission. Full article

Introduction: Multiple sclerosis (MS) is a chronic autoimmune inflammatory disorder of the central nervous system (CNS) that leads to demyelination of CNS neurons and is influenced by genetic, environmental, and lifestyle factors, including diet and obesity. Methods: This review aims to analyze at the molecular level the relationship between obesity, as a chronic inflammatory condition, and the pathophysiology of MS, as a chronic autoimmune inflammatory disease, in order to understand the complex links between obesity and MS through a search of the PubMed and Google Scholar databases. Discussion: Chronic inflammation and OS are interconnected processes, causing a toxic state, which contributes to the development of CNS neuroinflammation and neuronal damage, resulting in neuronal demyelination and the onset of MS. Adipose tissue is a complex endocrine organ; in addition to being a lipid storage organ, it secretes cytokines and adipokines, which are involved in the regulation of hormones, metabolism, inflammation, and whole-body homeostasis. Obesity triggers chronic low-grade inflammation, disruption of the blood–brain barrier (BBB) and brain metabolism, infiltration of the CNS by immune cells, production of ROS, and generation of oxidative stress (OS). Anti-inflammatory and pro-inflammatory adipokines are also implicated in MS and obesity. Conclusions: Obesity affects MS through common underlying mechanisms and seems to be a modifiable risk factor. Antioxidant and anti-inflammatory compounds with multi-functional characteristics could be additional tools to slow the progression of MS and its promotion through obesity while also offering potential treatment options for both conditions via their multi-targeting characteristics. Full article

Glycolysis-derived pyruvate is the almost exclusive source of acetyl-CoA for energy production in mitochondrial compartments of all types of neuronal and glial cells. Neurons utilize several times more glucose than glial cells due to their neurotransmitter functions. Cholinergic neurons that are responsible for cognitive functions require additional amounts of acetyl-CoA for acetylcholine-transmitter synthesis in their cytoplasmic compartment. It may be assured by preferential localization of ATP-citrate lyase (ACLY) in the cytoplasm of cholinergic neurons’ perikaryons and axonal terminals. This thesis is supported by the existence of strong regional and developmental correlations of ATP-citrate lyase and choline acetyltransferase (ChAT) activities and ACh levels in the brain. Electrolytic or chemical lesions of cholinergic nuclei cause proportional loss of the above parameters in the respective cortical target areas. On the other hand, the regional activity of mitochondrial pyruvate dehydrogenase complex (PDHC), which synthesizes nearly the whole pool of neuronal acetyl-CoA, displays no correlation with cholinergic innervation. It makes cholinergic neurons highly susceptible to brain pathologies impairing energy metabolism. Therefore, the ACLY pathway, which provides acetyl units directly to the site of acetylcholine synthesis in cholinergic nerve terminals, plays a key role in the maintenance of cholinergic neurotransmission. On the other hand, in cholinergic motor neurons, various ACLY–protein complexes are involved not only in neurotransmission but also in axonal transport of cholinergic elements from the perikaryon to cholinergic neuro-muscular junctions. This review presents findings supporting this thesis. Full article