Search Results (2,563)

Cerebral ischemic-reperfusion injury (CIRI) involves mitochondrial dysfunction, with mitophagy playing a key role. Astragaloside IV (AS-IV) shows neuroprotective potential; however, its mechanisms related to mitochondrial function and apoptosis remain unclear. Methods: Using a rat MCAO/R model, we evaluated the AS-IV’s effects via neurological scores, TTC staining, and histopathology. Molecular assays and docking were used to analyze mitophagy (PINK1, Parkin, p62, ROS, Bcl-2, and BAX) and apoptosis markers. Results: AS-IV improved neurological function, reduced infarct volume, and alleviated neuronal/mitochondrial damage. It upregulated PINK1/Parkin, decreased p62, and modulated Bcl-2/Bax. Docking confirmed AS-IV binds PINK1/Parkin with high affinity. Conclusions: AS-IV protects against CIRI by regulating the PINK1/Parkin pathway, improving mitochondrial function, and inhibiting neuronal apoptosis, providing an experimental basis for the clinical use Full article

The C-terminus of the BoNT/A heavy chain (BoNT/AHC) mediates binding to its receptor, SV2, a critical step for toxicity. Antibody inhibition of this interaction enhances neuronal survival. We previously identified a functional anti-BoNT/AHC nanobody, HM. To extend its in vivo half-life, we designed and prepared two Fc-optimized nanoparticles, HM-Fc5 and HM-Fc6. Structural modeling (homology/docking) of the HM Fv-AHC complex predicted that HM engages key AHC residues (Tyr¹¹⁵⁵, Phe¹¹⁶⁰, Ile¹¹⁶¹, Val¹¹⁸⁴, Asn¹¹⁸⁸, Lys¹¹⁸⁹, Glu¹¹⁹⁰), which overlap with the SV2 binding site. This suggests HM’s protective mechanism involves blocking toxin-receptor binding and cellular entry. HM-Fc5 and HM-Fc6 retained the stability and function of the parental HM antibody while exhibiting prolonged in vivo half-life. These optimized nanobodies offer economical candidates potentially enabling longer dosing intervals, beneficial for prophylaxis or chronic disease treatment. Significance Statement: The purpose of the study is to design and prepare two Fc optimized nanoparticles, HM-Fc5 and HM-Fc6, and predict the key residues involved in the interaction between HMs and AHC. The experimental results showed that HM-Fc5 and HM-Fc6 have the same stability as the parent HM antibody but have a longer half-life in vivo. The key residues Tyr¹¹⁵⁵, Phe¹¹⁶⁰, Ile¹¹⁶¹, Val¹¹⁸⁴, Asn¹¹⁸⁸, Lys¹¹⁸⁹, and Glu¹¹⁹⁰ overlap with the SV2 binding site. Our experimental results indicate that these nanobody candidates are not only more economical and convenient, but may also have longer dosing intervals, providing strong evidence and reference for prolonging the in vivo half-life of nanomaterials. Full article

Mitochondrial dysfunction is a key contributor to neurodegeneration, particularly in Parkinson’s disease (PD), where dopaminergic neurons being highly metabolically active are vulnerable to oxidative stress and bioenergetic failure. In this study, we investigate the effects of rotenone, a Complex I inhibitor, and antimycin A, a Complex III inhibitor, on mitochondrial function in MN9D dopaminergic neuronal cells. Cells were treated with rotenone (1.5 µM) or antimycin A (10 µM) for one hour, and key biochemical parameters were assessed, including ATP levels, reactive oxygen species (ROS) production, dopamine metabolism, and neuromelanin formation. Our results indicate significant ATP depletion and ROS accumulation following treatment with both inhibitors, with antimycin A inducing a more pronounced oxidative stress response. Dysregulation of dopamine biosynthesis differed mechanistically from vesicular monoamine transporter (VMAT2) inhibition by tetrabenazine, suggesting alternative pathways of catecholamine disruption. Additionally, oxidative stress led to increased neuromelanin accumulation, indicating a possible adaptive response to mitochondrial dysfunction. These findings provide insights into the cellular mechanisms underlying dopaminergic neurotoxicity and highlight mitochondrial electron transport chain inhibition as a key driver of PD pathogenesis. Future research should explore therapeutic strategies aimed at enhancing mitochondrial function to mitigate neurodegenerative progression. Full article

Background: Botulinum toxin type A (BoNT/A) is widely used in both clinical and aesthetic settings to induce temporary neuromuscular paralysis by inhibiting acetylcholine release. Although generally regarded as safe and effective, complications such as iatrogenic ptosis or facial asymmetry may occur and persist for several weeks or even months, with no standardized method currently available to accelerate recovery. Objective: This article explores the hypothesis that photobiomodulation (PBM)—a non-invasive modality recognized for its neuroregenerative potential—may facilitate the reversal of BoNT/A-induced neuromuscular blockade. Discussion: PBM enhances mitochondrial activity by stimulating cytochrome c oxidase in nerve and muscle tissues, thereby increasing ATP production and modulating intracellular signaling pathways associated with neuroplasticity, cell survival, and synaptogenesis. Preclinical studies have demonstrated that PBM can upregulate neurotrophic factors (e.g., BDNF, NGF), enhance SNAP-25 expression, and promote structural remodeling of neurons in both young and aged brains. These mechanisms are biologically consistent with the regenerative processes required for recovery from BoNT/A-induced effects. While controlled clinical trials for this specific application are currently lacking, anecdotal clinical reports suggest that PBM may accelerate functional recovery in cases of BoNT/A-related complications. Conclusions: Although this approach has not yet been tested in clinical trials, we propose that photobiomodulation may hypothetically serve as a supportive strategy to promote neuromuscular recovery in patients experiencing adverse effects from BoNT/A. This hypothesis is grounded in robust preclinical evidence but requires validation through translational and clinical research. Full article

Developmental exposure to polybrominated diphenyl ethers (PBDEs), which are commonly used as flame retardants, results in irreversible cognitive impairments. Postnatal hippocampal neurogenesis, which occurs in the subgranular zone (SGZ) of the dentate gyrus, is critical for neuronal circuits and plasticity. Wnt7a-Frizzled5 (FZD5) is essential for both neurogenesis and synapse formation; moreover, Wnt signaling participates in PBDE neurotoxicity and also contributes to the neuroprotective effects of melatonin. Therefore, we investigated the impacts of perinatal decabromodiphenyl ether (BDE-209) exposure on hippocampal neurogenesis and synaptogenesis in juvenile rats through BrdU injection and Golgi staining, as well as the alleviation of melatonin pretreatment. Additionally, we identified the structural basis of Wnt7a and two compounds via molecular docking. The hippocampal neural progenitor pool (Sox2+BrdU+ and Sox2+GFAP+cells), immature neurons (DCX+) differentiated from neuroblasts, and the survival of mature neurons (NeuN+) in the dentate gyrus were inhibited. Moreover, in BDE-209-exposed offspring rats, it was observed that dendritic branching and spine density were reduced, alongside the long-lasting suppression of the Wnt7a-FZD5/β-catenin pathway and targeted genes (Prox1, Neurod1, Neurogin2, Dlg4, and Netrin1) expression. Melatonin alleviated BDE-209-disrupted memory, along with hippocampal neurogenesis and dendritogenesis, for which the restoration of Wnt7a-FZD5 signaling may be beneficial. This study suggested that melatonin could represent a potential intervention for the cognitive deficits induced by PBDEs. Full article

Parishin C (PaC) is an active ingredient in Gastrodia elata Bl. that has neuroprotective effects. However, research on its role in oxidative stress and neuroinflammation is still limited. This study used LPS–stimulated HT22 cells to investigate the antioxidant properties of PaC. Through the co–culture system of HT22 and BV2 cells, the effect of PaC on neuroinflammation was explored. The current results indicated that PaC can inhibit the levels of reactive oxygen species and peroxides in LPS–stimulated HT22 cells and increase the levels of antioxidant factors. Meanwhile, PaC can also inhibit neuronal ferroptosis and the levels of pro–inflammatory cytokines in BV2 cells. Importantly, the antioxidant and anti–inflammatory effects of PaC are achieved by activating the Nrf2 signaling pathway. The WB and IF results indicated that PaC can promote nuclear translocation of Nrf2, activate downstream antioxidant factors, and thereby regulate inflammatory responses. Inhibition of Nrf2 can significantly inhibit the regulation of PaC on the Nrf2 signaling pathway. These results indicated that PaC can activate the Nrf2 signaling pathway to inhibit oxidative stress and inflammation. Full article

The intranasal delivery of exogenous mitochondria is a potential therapy for Parkinson’s disease (PD). The regulatory mechanisms and effectiveness in genetic models remains uncertain, as well as the impact of modulating the mitochondrial permeability transition pore (mPTP) in grafts. Utilizing UQCRC1 (p.Tyr314Ser) knock-in mice, and a cellular model, this study validated the transplantation of mitochondria with or without cyclosporin A (CsA) preloading as a method to treat mitochondrial dysfunction and improve disease progression through intranasal delivery. Liver-derived mitochondria were labeled with bromodeoxyuridine (BrdU), incubated with CsA to inhibit mPTP opening, and were administered weekly via the nasal route to 6-month-old mice for six months. Both treatment groups showed significant locomotor improvements in open-field tests. PET imaging showed increased striatal tracer uptake, indicating enhanced dopamine synthesis capacity. The immunohistochemical analysis revealed increased neuron survival in the dentate gyrus, a higher number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) and striatum (ST), and a thicker granule cell layer. In SN neurons, the function of mitochondrial complex III was reinstated. Additionally, the CsA-accumulated mitochondria reduced more proinflammatory cytokine levels, yet their therapeutic effectiveness was similar to that of unmodified mitochondria. External mitochondria were detected in multiple brain areas through BrdU tracking, showing a 3.6-fold increase in the ST compared to the SN. In the ST, about 47% of TH-positive neurons incorporated exogenous mitochondria compared to 8% in the SN. Notably, GFAP-labeled striatal astrocytes (ASTs) also displayed external mitochondria, while MBP-labeled striatal oligodendrocytes (OLs) did not. On the other hand, fewer ASTs and increased OLs were noted, along with lower S100β levels, indicating reduced reactive gliosis and a more supportive environment for OLs. Intranasally, mitochondrial transplantation showed neuroprotective effects in genetic PD, validating a noninvasive therapeutic approach. This supports mitochondrial recovery and is linked to anti-inflammatory responses and glial modulation. Full article

Background: Parkinson’s disease (PD) involves progressive dopaminergic neuron degeneration and motor deficits. Oligodendrocyte dysfunction contributes to PD pathogenesis through impaired myelination. Methods: Single-nucleus RNA sequencing (snRNA-seq) of PD mice revealed compromised oligodendrocyte differentiation and STAT5B downregulation. Pseudotemporal trajectory analysis via Monocle2 demonstrated impaired oligodendrocyte maturation in PD oligodendrocytes, correlating with reduced myelin-related gene expression (Sox10, Plp1, Mbp, Mog, Mag, Mobp). DoRothEA-predicted regulon activity identified STAT5B as a key transcriptional regulator. Results: Oligodendrocyte-specific STAT5B activation improved myelin integrity, as validated by Luxol Fast Blue staining and transmission electron microscopy; attenuated dopaminergic neuron loss; and improved motor function. Mechanistically, STAT5B binds the MBP promoter to drive transcription, a finding confirmed by the luciferase assay, while the DNMT3A-mediated hypermethylation of the STAT5B promoter epigenetically silences its expression, as verified by MethylTarget sequencing and methylation-specific PCR. Conclusions: DNMT3A inhibited the expression of STAT5B by affecting its methylation, which reduced the transcription of MBP, caused oligodendrocyte myelin damage, and eventually led to dopamine neuron damage and motor dysfunction in an MPTP-induced mouse model. This DNMT3A-STAT5B-MBP axis underlies PD-associated myelin damage, connecting epigenetic dysregulation with oligodendrocyte dysfunction and subsequent PD pathogenesis. Full article

Bruton Tyrosine Kinase (BTK) has emerged as a critical mediator in the pathophysiology of neuroinflammation associated with neurodegenerative diseases. BTK, a non-receptor tyrosine kinase predominantly expressed in cells of the hematopoietic lineage, modulates B-cell receptor signaling and innate immune responses, including microglial activation. Recent evidence implicates aberrant BTK signaling in the exacerbation of neuroinflammatory cascades contributing to neuronal damage in disorders such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, ischemic stroke, and Huntington’s disease. Pharmacological inhibition of BTK has shown promise in attenuating microglial-mediated neurotoxicity, reducing pro-inflammatory cytokine release, and promoting neuroprotection in preclinical models. BTK inhibitors, originally developed for hematological malignancies, demonstrate favorable blood–brain barrier penetration and immunomodulatory effects relevant to central nervous system pathology. This therapeutic approach may counteract detrimental neuroimmune interactions without broadly suppressing systemic immunity, thus preserving host defense. Ongoing clinical trials are evaluating the safety and efficacy of BTK inhibitors in patients with neurodegenerative conditions, with preliminary results indicating potential benefits in slowing disease progression and improving neurological outcomes. This review consolidates current knowledge on BTK signaling in neurodegeneration and highlights the rationale for BTK inhibition as a novel, targeted therapeutic strategy to modulate neuroinflammation and mitigate neurodegenerative processes. Full article

The mineralocorticoid receptor (MR), traditionally associated with renal function, has also been identified in various extrarenal tissues, including the heart, brain, and dorsal root ganglion (DRG) neurons in rodents. Previous studies suggest a role for the MR in modulating peripheral nociception, with MR activation in rat DRG neurons by its endogenous ligand, aldosterone. This study aimed to determine whether MR, its protective enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), its endogenous ligand aldosterone, and the aldosterone-synthesizing enzyme CYP11B2 are expressed in human DRG neurons and whether they colocalize with key pain-associated signaling molecules as potential targets for genomic regulation. To this end, we performed mRNA transcript profiling and immunofluorescence confocal microscopy on human and rat DRG tissues. We detected mRNA transcripts for MR, 11β-HSD2, and CYP11B2 in human DRG, alongside transcripts for key thermosensitive and nociceptive markers such as TRPV1, the TTX-resistant sodium channel Nav1.8, and the neuropeptides CGRP and substance P (Tac1). Immunofluorescence analysis revealed substantial colocalization of MR with 11β-HSD2 and CGRP, a marker of unmyelinated C-fibers and thinly myelinated Aδ-fibers, in human DRG. MR immunoreactivity was primarily restricted to small- and medium-diameter neurons, with lower expression in large neurons (>70 µm). Similarly, aldosterone colocalized with CYP11B2 and MR with nociceptive markers including TRPV1, Nav1.8, and TrkA in human DRG. Importantly, functional studies demonstrated that prolonged intrathecal inhibition of aldosterone synthesis within rat DRG neurons, using an aldosterone synthase inhibitor significantly downregulated pain-associated molecules and led to sustained attenuation of inflammation-induced hyperalgesia. Together, these findings identify a conserved peripheral MR signaling axis in humans and highlight its potential as a novel target for pain modulation therapies. Full article

Background/Objectives: The bidirectional selection of the Roman low- (RLA) and Roman high-avoidance (RHA) rat strains for extremely slow vs. very rapid acquisition of the two-way (shuttle-box) avoidance response has generated two divergent phenotypic profiles: RHA rats exhibit a behavioural pattern and gene expression profile in the frontal cortex and hippocampus (HPC) that are relevant to social and attentional/cognitive schizophrenia-linked symptoms; on the other hand, RLA rats display phenotypic traits linked to increased anxiety and sensitivity to stress-induced depression-like behaviours. The present studies aimed to evaluate the enduring and potentially positive effects of neonatal handling-stimulation (NH) on the traits differentiating these two strains of rats. Methods: We evaluated the effects of NH on anxious behaviour, prepulse inhibition of startle (PPI), spatial working memory, and hormone responses to stress in adult rats of both strains. Furthermore, given the proposed involvement of neuronal/synaptic plasticity and neurotrophic factors in the development of anxiety, stress, depression, and schizophrenia-related symptoms, using Western blot (WB) we assessed the effects of NH on the content of brain-derived neurotrophic factor (BDNF), its trkB receptor and Polysialilated-Neural Cell Adhesion Molecule (PSA-NCAM), in the prefrontal cortex (PFC), anterior cingulate cortex (ACg), ventral (vHPC), and dorsal (dHPC) hippocampus of adult rats from both strains. Results: NH increased novelty-induced exploration and reduced anxiety, particularly in RLA rats, attenuated the stress-induced increment in corticosterone and prolactin plasma levels, and improved PPI and spatial working memory in RHA rats. These effects correlated to long-lasting increases of BDNF and PSA-NCAM content in PFC, ACg, and vHPC. Conclusions: Collectively, these findings show enduring and distinct NH effects on neuroendocrine and behavioural and cognitive processes in both rat strains, which may be linked to neuroplastic and synaptic changes in the frontal cortex and/or hippocampus. Full article

Cholinergic neuron impairment is a significant cause of cognitive decline in Alzheimer’s disease (AD), making acetylcholinesterase (AChE) a key therapeutic target. AChE inhibitors are principal drugs prescribed to alleviate symptoms in AD patients, while up to 50% of these individuals also suffer from depression, frequently treated with selective serotonin reuptake inhibitors (SSRIs). Due to the multisymptomatic nature of AD, there is a growing interest in developing multitargeted ligands that simultaneously enhance cholinergic and serotonergic tone. This study presents the synthesis of novel ligands based on functionalized piperidines, evaluated through radioligand binding assays at the serotonin transporter (SERT) and AChE and butyrylcholinesterase (BuChE) inhibition. The pharmacological results showed that some compounds exhibited moderate inhibitory activity against AChE, with one compound 19 standing out as the most potent, also displaying a moderate BuChE inhibitory activity, while showing low affinity for SERT. On the other hand, compound 21 displayed an interesting polypharmacological profile, with good and selective activity against BuChE and SERT. The results underscore the difficulty of designing promiscuous ligands for these targets and suggest that future structural modifications could optimize their therapeutic potential in AD. Full article

α-Latrotoxin stimulates neurotransmitter release by binding to a presynaptic receptor and then forming ion-permeable membrane pores and/or stimulating the receptor, latrophilin-1, or Adhesion G-protein-coupled receptor type L1 (ADGRL1). To avoid pore formation, we use the mutant α-latrotoxin (LTX^N4C), which does not form pores and only acts through ADGRL1. ADGRL1 is cleaved into an N-terminal fragment (NTF) and a C-terminal fragment (CTF), which behave as independent cell-surface proteins, reassociating upon binding LTX^N4C. We investigated the role of the NTF-CTF association in LTX^N4C action, using perfluorooctanoic acid (PFOA). We demonstrate that at low concentrations (≤100 μM) PFOA does not adversely affect ADGRL1-expressing neuroblastoma cells or inhibit LTX^N4C binding. However, it causes the dissociation of the NTF-CTF complexes, independent redistribution of the fragments on the cell surface, and their separate internalization. PFOA also promotes the dissociation of NTF-CTF complexes induced by LTX^N4C binding. When applied to mouse neuromuscular junctions, PFOA inhibits LTX^N4C-induced neurotransmitter release in a concentration-dependent manner. Our results indicate that ADGRL1 can mediate LTX^N4C signaling only while its fragments remain associated. These findings explain some aspects of receptor-dependent toxin action and contribute to a mechanistic understanding of ADGRL1 functions in neurons. Full article

The 2016 Zika virus (ZIKV) epidemic has largely subsided, but a key question remains. How did ZIKV evolve to become a virulent human pathogen compared to the virus of its original discovery? What specific virologic and pathologic changes contributed to increased pathogenicity in humans? Phylogenetic studies have identified two genetically distinct ZIKV, the African and Asian lineages, which differ in their pathogenicity. Previous studies including ours suggest that the envelope (E) protein plays a key role in viral entry, immune activation, and neuropathogenesis. This study aimed to further elucidate virologic and pathogenic differences between these lineages by assessing their ability to bind and replicate in host cells, induce apoptotic cell death, trigger inflammatory responses, and influence human neural progenitor cell (hNPC)-derived neurosphere formation. We compared a historic African ZIKV strain (MR766) with an epidemic Brazilian strain (BR15) and evaluated the effects of the E protein inhibitor quercetin-3-β-O-D-glucoside (Q3G) and an E protein-neutralizing antibody (AbII). Our results revealed distinct virologic properties and that MR766 exhibited stronger inhibition of neurosphere formation due to enhanced viral binding to neuronal SH-SY5Y cells, while BR15 infection triggered a heightened pro-inflammatory cytokine response with reduced viral binding. Chimeric virus studies suggested that the E protein likely influences viral binding, replication efficiency, immune activation, and neuropathogenesis. Notably, Q3G exhibited antiviral activities against both MR766 and BR15, whereas AbII preferentially inhibited MR766. These findings highlight the virological differences between ancestral and epidemic viral strains, as well as the critical role of E protein in viral permissiveness, immune response, and neuropathogenesis, providing insights for developing targeted antiviral strategies. Full article

Migraine is a neurovascular paroxysmal disorder characterized by neurogenic inflammation and has a remarkable impact on the quality of life. The Food and Drug Administration (FDA) approved onabotulinumtoxin A in 2010 for the prophylactic treatment of chronic migraine. Today, in its 4th decade, it is approved in 100 countries for 15 main indications. Its mechanism of action, based on the inhibition of neurotransmitter release from primary sensory neurons, is very complex: it affords antinociception, but it also has an analgesic effect on neuropathic pain conditions and reduces the need for rescue medications. Genetic variants have been investigated for their potential role in the pathogenesis and clinical expression of migraine and of the response to treatments. These studies primarily involved genes associated with vascular regulation and cardiovascular pathology, including those encoding angiotensin-converting enzyme (ACE) and methylenetetrahydrofolate reductase (MTHFR). However, epigenetics and, particularly, genetic and epigenetic modifications are still poorly studied in terms of understanding the mechanisms implicated in susceptibility to migraine, aura, chronification and response to symptomatic and preventive treatments. In particular, the aim of the present study is to gather evidence on the genetic variants and epigenetic modifications affecting the pathway of the calcitonin gene-related peptide (CGRP), the target of onabotulinumtoxin A and of all the novel monoclonal antibodies. Full article