Search Results (393)

Insulin is an anabolic hormone involved in the regulation of several processes, such as the storage of glucose into glycogen, decrease of glucose output, stimulation of glucose transport into cells, etc. The hormone binds to its receptor, thereby activating an intracellular signaling cascade. Once activated, the insulin receptor (INSR) phosphorylates multiple intracellular substrates, which initiate the downstream signaling pathway. The nature of insulin signaling pathways may vary depending on the organ or tissue. In the central nervous system (CNS), INSRs are expressed in all cell types. This observation may suggest that insulin signaling is involved in important and diverse processes. It regulates glucose metabolism, supports cognitive functions, enhances the outgrowth of neurons, as well as plays a role in the modulation of release and uptake of catecholamine, among other roles. Importantly, insulin can freely cross the blood–brain barrier (BBB) from the circulation and is also synthesized locally within the brain. Insulin resistance (IR) impairs insulin signaling, which may accelerate brain aging, affect plasticity, and potentially contribute to neurodegeneration. Dysregulation of insulin signaling has been implicated in several diseases, including diabetes mellitus, metabolic syndrome, certain cancers, and neurodegenerative diseases, such as Alzheimer’s disease. There are two principal insulin signaling pathways: the PI3K/AKT pathway, primarily associated with metabolic effects, and the MAPK pathway, which is involved in cell growth, survival, and gene expression. Our review describes the role of insulin in the human brain, as well as the disturbances in insulin signaling resulting from brain insulin resistance, with a particular focus on its association with Alzheimer’s disease. Full article

Avobenzone (AVO) and ethylhexyl salicylate (EHS) are widely used organic UV filters with distinct photochemical properties and reported biological effects. Experimental and predictive evidence suggests that some lipophilic UV filters may reach systemic circulation and potentially cross the blood–brain barrier (BBB), raising concerns about possible central nervous system effects, although direct evidence for AVO and EHS remains limited. This study evaluated the effects of subcytotoxic concentrations (0.01–1 µM) of AVO and EHS on differentiated SH-SY5Y human neuroblastoma cells, focusing on early stress-related molecular responses. Cell viability and reactive oxygen species production were not significantly affected at any tested concentration. Integrated analyses of microRNA, gene, and protein expression revealed modest and variable modulation of miR-200a-3p and miR-29b-3p. Western blot analysis showed increased phosphorylation of AKT and ERK, no significant changes in mTOR activation, and an increased Bax/Bcl-2 ratio. Overall, these findings indicate that AVO and EHS trigger an early stress-adaptive response involving PI3K/AKT and MAPK/ERK signaling and modulation of apoptosis-related pathways. Such responses reflect a dynamic balance between cellular adaptation and pro-apoptotic signaling, which may become relevant under prolonged or higher-intensity exposure conditions. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by persistent memory impairment and complex molecular and cellular pathological changes in the brain. Current treatments, including acetylcholinesterase inhibitors and memantine, only help with symptoms for a short time and do not stop the disease from getting worse. This is mainly because these drugs do not reach the brain well and are quickly removed from the body. The blood–brain barrier (BBB) restricts the entry of most drugs into the central nervous system; therefore, new methods of drug delivery are needed. Nanotechnology-based drug delivery systems (NTDDS) are widely studied as a potential approach to address existing therapeutic limitations. Smart biosensing nanoparticles composed of polymers, lipids, and metals can be engineered to enhance drug stability, improve drug availability, and target specific brain regions. These smart nanoparticles can cross the BBB via receptor-mediated transcytosis and other transport routes, making them a promising option for treating AD. Additionally, multifunctional nanocarriers enable controlled drug release and offer theranostic capabilities, supporting real-time tracking of AD treatment responses to facilitate more precise and personalized interventions. Despite these advantages, challenges related to long-term safety, manufacturing scalability, and regulatory approval remain. This review discusses current AD therapies, drug-delivery strategies, recent advances in nanoparticle platforms, and prospects for translating nanomedicine into effective, disease-modifying treatments for AD. Full article

The gut microbiome produces thousands of metabolites with potential to modulate central nervous system function through peripheral or direct neural mechanisms. Tourette syndrome, attention-deficit/hyperactivity disorder, and autism spectrum disorder exhibit shared neurotransmitter dysregulation and microbiome alterations, yet mechanistic links between microbial metabolites and receptor-mediated neuromodulation remain unclear. We screened 27,642 microbiome SMILES metabolites for blood–brain barrier permeability using rule-based SwissADME classification and a PyTorch 2.0 neural network trained on 7807 experimental compounds (test accuracy 86.2%, AUC 0.912). SwissADME identified 1696 BBB-crossing metabolites following Lipinski’s criteria, while PyTorch classified 2484 metabolites with expanded physicochemical diversity. Following 3D conformational optimization (from SMILES) and curation based on ≤32 rotatable bonds, molecular docking was performed against five neurotransmitter receptors representing ionotropic (GABRA2, GRIA2, GRIN2B) and metabotropic (DRD4, HTR1A) receptor classes. The top 50 ligands across five receptors demonstrated method-specific BBB classification (44% SwissADME-only, 44% PyTorch-only, 12% overlap), validating complementary prediction approaches. Fungal metabolites from Ascomycota dominated high-affinity top ligands (66%) and menaquinone MK-7 showed broad phylogenetic conservation (71.4% of phylum). Our results establish detailed receptor–metabolite interaction maps, with fungal metabolites dominating high-affinity ligands, challenging the prevailing bacterial focus of the microbiome and providing a foundation for precision medicine and a framework for developing microbiome-targeted therapeutics to address clinical needs in neurodevelopmental disorders. Full article

The blood–brain barrier (BBB) restricts therapeutic delivery to the central nervous system (CNS), hindering the treatment of neurological disorders, such as Alzheimer’s disease, Parkinson’s disease, brain cancers, and stroke. Aptamers, short single-stranded DNA or RNA oligonucleotides that can fold into unique 3D shapes and bind to specific target molecules, offer high affinity and specificity, low immunogenicity, and promising BBB penetration via receptor-mediated transcytosis targeting receptors such as the transferrin receptor (TfR) and low-density lipoprotein receptor-related protein 1 (LRP1). This review examines aptamer design through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) and its variants, mechanisms of BBB crossing, and applications in CNS disorders. Recent advances, including in silico optimization, in vivo SELEX, BBB chip-based MPS-SELEX, and nanoparticle–aptamer hybrids, have identified brain-penetrating aptamers and enhanced the brain delivery efficiency. This review highlights the potential of aptamers to transform CNS-targeted therapies. Full article

Alzheimer’s disease (AD) remains an unmet medical challenge, as there are no effective therapies that alter the disease’s progression. While approaches have targeted molecules like acetylcholine (ACh) and glutamate, these strategies have provided only limited benefits and do not address the complex molecular mechanisms underlying AD development. This review suggests that β-alanine (3-aminopropanoic acid) is an underexplored neurotransmitter that could serve as a potential AD drug target. Existing evidence indicates that β-alanine modulates GABAergic and glutamatergic neurotransmission, thereby affecting neuronal hyperexcitability. Additionally, studies suggest that β-alanine has antioxidant effects, reducing oxidative stress caused by reactive oxygen species (ROS). We propose that β-alanine might bind to Aβ/tau proteins, possibly targeting the six-amino acid sequences EVHHQK/DDKKAK, which are involved in protein aggregation. β-Alanine may also influence the release of pro-inflammatory cytokines from microglia, potentially reducing neuroinflammation. We also hypothesize that β-alanine may help regulate metal dyshomeostasis, which leads to ROS production. Taurine, structurally like β-alanine, appears to influence comparable mechanisms. Although structural similarity doesn’t ensure therapeutic effectiveness, this evidence supports considering β-alanine as a treatment for AD. Furthermore, β-alanine and its analogues face challenges, including crossing the blood–brain barrier (BBB) and optimizing structure–activity relationships (SAR). This review includes articles through September 2025, sourced from four databases. Full article

Neurodegenerative diseases (NDDs), defined by the progressive loss of neurons, present a major challenge to global health. Oxidative stress and lysosomal dysfunction are both key pathogenic factors in NDDs, and they do not operate in isolation; instead, the vicious cycle they form, often mediated through organellar crosstalk, serves as the core driver of the pathological progression of NDDs, collectively worsening disease outcomes. Specifically, excessive reactive oxygen species (ROS) can disrupt lysosomal membrane integrity through lipid peroxidation and inhibit the activity of vacuolar ATPase (V-ATPase), ultimately leading to impaired lysosomal acidification. Meanwhile, lysosomal dysfunction hinders the clearance of damaged mitochondria (the primary endogenous source of ROS), toxic protein aggregates, and free iron ions. This further exacerbates ROS accumulation and accelerates neuronal degeneration. Conventional therapeutic approaches have limited efficacy, primarily due to the challenges in crossing the blood–brain barrier (BBB), insufficient targeting ability, and an inability to effectively intervene in this pathological loop. Nanotherapeutics, leveraging their tunable physicochemical properties and modular functional design, represent a transformative strategy to address these limitations. This review systematically elaborates on the reciprocal interplay between oxidative stress and lysosomal dysfunction in NDDs, with a particular focus on the central role of lysosome-mitochondria axis dysfunction, critically appraises recent advances in nanotechnology-based targeted therapies, and thereby provides a comprehensive theoretical framework to guide the development of novel NDD therapeutics. Full article

Profiling the blood–brain barrier (BBB) permeability of bioactive molecules during early drug development is critical for optimizing their pharmacokinetic profile. The in vivo ability of a compound to cross the BBB is measured by the log BB parameter; however, its determination requires costly and time-consuming animal experiments. This study aimed to develop a novel in vitro method for high-throughput prediction of log BB values. The approach combines experimental data from open-tubular capillary electrochromatography (CEC) and automated potentiometric titrations, including the CEC retention factor (k′), electropherograms, and physicochemical parameters pK_a and log D_7.4. The k′ parameter reflects BBB permeability using a capillary internally coated with liposomes that mimic a biological membrane. Preliminary CEC analyses were conducted for 25 neutral drugs at pH 7.4, revealing a promising correlation between the permeability parameters log k and log BB. The validation was extended to 57 ionized drugs, with additional determination of pK_a and log D_7.4. A regression model was developed: log BB = −2.45 + 0.1k′ + 0.3logD_7.4 + 0.27pK_a (R² = 0.64). Furthermore, the analysis of CEC electropherograms enabled the machine learning-based rapid classification of compounds using Dynamic Time Warping, k-Nearest Neighbors, and the Bag-of-SFA-Symbols in Vector Space model, yielding an accuracy of 0.81 and an F1_weighted score of 0.8. Full article

p17, the human immunodeficiency virus type 1 (HIV-1) matrix protein traditionally associated with viral assembly, has been recently investigated for its extracellular functions linked to vascular damage. This review examines the molecular and pathogenic signatures by which p17 and its variants (vp17s) contribute to endothelial activation, aberrant angiogenesis, and vascular inflammation, highlighting their relevance even under effective antiretroviral therapy (ART). Specifically, p17 exerts chemokine-like activities by binding to chemokine (C-X-C motif) receptor-1 and 2 (CXCR-1/2) on endothelial cells (ECs). This interaction triggers key signaling cascades, including the protein kinase B (Akt)-dependent extracellular signal-regulated kinase (ERK) pathway and endothelin-1/endothelin receptor B axis, driving EC motility, capillary formation, and lymphangiogenesis. Variants such as S75X demonstrate enhanced lymphangiogenic potency, associating them with tumorigenic processes involved in non-Hodgkin lymphoma (NHL) pathogenesis. Importantly, p17 promotes endothelial von Willebrand factor (vWF) storage and secretion, implicating a pro-coagulant state that may trigger the increased thromboembolic risks observed in HIV-positive patients. Furthermore, p17 crosses the blood–brain barrier (BBB) via CXCR-2-mediated pathways, contributing to neuroinflammation by activating microglia and astrocytes and amplifying monocyte chemoattractant protein-1 (MCP-1) levels, therefore playing a critical role in the development of HIV-associated neurocognitive disorders. Hence, the elaboration of potential therapeutic strategies finalized at inhibiting p17/vp17s’ interaction with their receptors could complement ART by addressing HIV-related neurovascular morbidity. Full article

Per- and polyfluoroalkyl substances are persistent environmental contaminants increasingly implicated in neurotoxicity. Establishing causality and mechanisms relevant to Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis requires human-relevant systems that capture exposure, barrier function, and brain circuitry. We review advanced cellular platforms—iPSC-derived neuronal and glial cultures, cerebral and midbrain organoids, and chip-based microphysiological systems—that model disease-relevant phenotypes (Aβ/tau pathology, dopaminergic vulnerability, myelination defects) under controlled PFAS exposures and defined genetic risk backgrounds. Modular, fluidically coupled BBB-on-chip → brain-organoid microphysiological systems have been reported, enabling chronic, low-dose PFAS perfusion under physiological shear, real-time barrier integrity readouts such as transepithelial/transendothelial electrical resistance (TEER), quantification of PFAS partitioning and translocation, and downstream neuronal–glial responses assessed by electrophysiology and multi-omics. Across platforms, convergent PFAS-responsive processes emerge—mitochondrial dysfunction and oxidative stress, lipid/ceramide dysregulation, neuroinflammatory signaling, and synaptic/network impairments—providing a mechanistic scaffold for biomarker discovery and gene–environment interrogation with isogenic lines. We outline principles for exposure design (environmentally relevant ranges, longitudinal paradigms), multimodal endpoints (omics, electrophysiology, imaging), and cross-lab standardization to improve comparability. Together, these models advance the quantitative evaluation of PFAS neurotoxicity and support translation into risk assessment and therapeutic strategies. Full article

3′-sialyl-N-acetyllactosamine (3′-SLN) and 6′-sialyl-N-acetyllactosamine (6′-SLN) are two important human milk oligosaccharides (HMOs) which play significant functions in brain development and antiviral potential. However, their metabolism is still unknown. In this study, chemoenzymatically synthesized 3′-SLN and 6′-SLN were labeled with cyanine-7 (Cy7) via formation triazole (Tz) derivatives to investigate their metabolism and organ distribution in a mouse model. The fluorescence signals were detected in the brains of mice after 0.5 h of gavage with 3′-SLN-Tz-Cy7 and 6′-SLN-Tz-Cy7. It was found for the first time that both of them can cross the blood–brain barrier (BBB) as a whole and reach the brain in a sex-specific manner. And the results show that, whether in the in vivo imaging results or the brain fluorescence signal results, the male mice absorbed 3′-SLN-Tz-Cy7 more than 6′-SLN-Tz-Cy7; meanwhile, in the female mice, the results were exactly the opposite. Both 3′-SLN-Tz-Cy7 and 6′-SLN-Tz-Cy7 exhibited the highest fluorescence intensity in pulmonary tissues, followed by substantial hepatic deposition. This study would offer preliminary evidence for the hypothesis that the oral administration of 3′-SLN and 6′-SLN may promote brain development and provide a foundation for the further exploration of their functions in brain cognition. Full article

Alzheimer’s disease is characterized by the accumulation of neurotoxic forms of amyloid-beta (Aβ) in the brain, leading to synaptic dysfunction, neuroinflammation, and neuronal death. The tetrapeptide HAEE crosses the blood–brain barrier (BBB), inhibits the formation of toxic Aβ oligomers, and reduces amyloid burden in vivo. However, the mechanisms of HAEE’s anti-amyloidogenic effect remained incompletely understood. In this study, we investigated the mechanism of HAEE-dependent Aβ clearance both in vitro and in vivo. Using ELISA, we assessed the HAEE effect on the levels of Aβ, IL-6, and TNFα in mouse brain tissue following intracerebroventricular administration. The mechanism of the anti-Aβ effect of HAEE was studied using primary brain cell cultures and a BBB transwell model through ELISA, flow cytometry, and microscopy. We showed that HAEE reduced Aβ level by 35% and IL-6 level by 40% in mouse brain tissue. HAEE enhanced Aβ clearance via LRP1- and PgP-dependent Aβ transport through the BBB and doubled the rate of Aβ degradation by microglia. In addition to inhibition of Aβ aggregation, HAEE dissolved already formed Aβ oligomers. The HAEE-induced decrease in IL-6 levels in the mouse brain was associated with reduced pro-inflammatory activation of microglia. Thus, HAEE’s effect against Aβ-related neuropathologies is realized through a decrease in the level of toxic Aβ oligomer and inhibition of neuroinflammation. Full article

Background: Antibodies that cross the blood–brain barrier (BBB) by targeting receptor-mediated transport (RMT) systems can allow efficient drug delivery to the central nervous system (CNS). In order to improve brain uptake of antibodies, their binding properties have been engineered, but it is not always clear what antibody properties dictate BBB transport efficiency. In this study, we therefore developed and employed an in vitro phenotypic screen and a quantitative transcytosis assay in an attempt to identify improved variants of a previously identified BBB transcytosing antibody known as 46.1. Methods: First, a random mutagenic 46.1 antibody phage display library was screened for improved transcytosis through a human induced pluripotent stem cell (iPSC)-derived BBB model. These screens yielded antibody variants that enriched over multiple screening rounds; however, when produced as soluble antibodies, the variants did not display improved in vitro transcytosis over the wild-type (WT) 46.1 antibody. As a second strategy, we performed a targeted histidine point mutation of a solvent-exposed residue in each complementarity-determining region (CDR) and evaluated the in vitro transcytosis capacity of the variants. Results and Conclusions: In this way, we identified a 46.1 variant, R162H, with modestly improved in vitro transcytosis properties. These results show that the iPSC-derived BBB screening insights and evaluation strategies presented here could facilitate the engineering and optimization of lead antibodies for CNS delivery. Full article

Multiple sclerosis (MS) is a chronic neuroinflammatory and demyelinating disease that causes disability in patients. Cladribine is an oral treatment that is used in relapsing–remitting and active secondary progressive MS. T and B lymphocytes are especially sensitive to cladribine, which are transiently depleted upon short treatment courses. However, cladribine crosses the blood–brain barrier (BBB), supporting the hypothesis that cladribine may affect central nervous system (CNS)-resident cells. In this study, we used human primary cells and human cell lines to test the effect of cladribine, at therapeutic concentrations, on cells of the CNS. In these conditions, cladribine did not affect survival, proliferation and the capacity of producing cytokines of human microglial cells (HMC3 cell line) or primary human astrocytes but enhanced the production of oxygen reactive species in both cell types. The initial differentiation of primary human neuronal progenitor cells was impaired when continuously exposed to the maximum therapeutic concentration of cladribine, but not when lower concentrations were used. However, cladribine protected differentiated SH-SY5Y human neuroblastoma cell line from oxidative stress-related cell death. In conclusion, using different in vitro cell models, we demonstrate that cladribine maintains the normal function of CNS glia and protects neuronal cells from oxidative stress damage. Full article

Neurological damage, a debilitating condition closely associated with chronic neuroinflammation, currently lacks disease-modifying treatments, with management limited to symptomatic relief. Vitamins B6 (VB6), B12 (VB12), and proteolipid protein 1 (PLP-1) exhibit multimodal neuroprotective and anti-inflammatory effects; however, their therapeutic potential is limited by low bioavailability and inadequate ability to cross the blood–brain barrier (BBB). To address these limitations, we developed an ursolic acid-based nanoparticle system for the intranasal co-delivery of VB6, VB12, and recombinant PLP-1. The PLP-1 model predicted by AlphaFold3 was used for molecular docking. The docking results confirmed high-affinity binding interactions with VB6 and VB12, elucidating the mechanistic basis of their synergy. In vitro studies using a glucose-deprived PC12 cell injury model identified an optimal synergistic molar ratio of 10:1:2 (VB6: VB12: PLP-1). This combination significantly upregulated neuroprotective markers (PLP-1 and PGC-1α) and downregulated the pro-inflammatory cytokine TNF-α. In a mouse model of neural damage, the nano-encapsulated combination therapy demonstrated improved pharmacokinetics and significantly attenuated neuroinflammation and oxidative stress in brain tissue. This was evidenced by lower TNF-α and IL-1β levels and elevated GSH and SOD concentrations compared to free drug controls. The treatment regimen showed no detectable hepatorenal toxicity. Our findings demonstrate that this nanoformulation represents a safe, effective, and promising disease-modifying strategy to treat vestibular dysfunction by synergistically targeting its underlying neuroimmunological mechanisms. Full article