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Frontiers in Aging Neuroscience 2024As the global population ages, the incidence of elderly patients with dementia, represented by Alzheimer's disease (AD), will continue to increase. Previous studies have... (Review)
Review
As the global population ages, the incidence of elderly patients with dementia, represented by Alzheimer's disease (AD), will continue to increase. Previous studies have suggested that β-amyloid protein (Aβ) deposition is a key factor leading to AD. However, the clinical efficacy of treating AD with anti-Aβ protein antibodies is not satisfactory, suggesting that Aβ amyloidosis may be a pathological change rather than a key factor leading to AD. Identification of the causes of AD and development of corresponding prevention and treatment strategies is an important goal of current research. Following the discovery of soluble oligomeric forms of Aβ (AβO) in 1998, scientists began to focus on the neurotoxicity of AβOs. As an endogenous neurotoxin, the active growth of AβOs can lead to neuronal death, which is believed to occur before plaque formation, suggesting that AβOs are the key factors leading to AD. PANoptosis, a newly proposed concept of cell death that includes known modes of pyroptosis, apoptosis, and necroptosis, is a form of cell death regulated by the PANoptosome complex. Neuronal survival depends on proper mitochondrial function. Under conditions of AβO interference, mitochondrial dysfunction occurs, releasing lethal contents as potential upstream effectors of the PANoptosome. Considering the critical role of neurons in cognitive function and the development of AD as well as the regulatory role of mitochondrial function in neuronal survival, investigation of the potential mechanisms leading to neuronal PANoptosis is crucial. This review describes the disruption of neuronal mitochondrial function by AβOs and elucidates how AβOs may activate neuronal PANoptosis by causing mitochondrial dysfunction during the development of AD, providing guidance for the development of targeted neuronal treatment strategies.
PubMed: 38808033
DOI: 10.3389/fnagi.2024.1400544 -
Nature Communications May 2024
PubMed: 38806512
DOI: 10.1038/s41467-024-48904-y -
Nature Communications May 2024Mercury (Hg), a potent neurotoxin posing risks to human health, is cycled through vegetation uptake, which is susceptible to climate change impacts. However, the extent...
Mercury (Hg), a potent neurotoxin posing risks to human health, is cycled through vegetation uptake, which is susceptible to climate change impacts. However, the extent and pattern of these impacts are largely unknown, obstructing predictions of Hg's fate in terrestrial ecosystems. Here, we evaluate the effects of climate change on vegetation elemental Hg [Hg(0)] uptake using a state-of-the-art global terrestrial Hg model (CLM5-Hg) that incorporates plant physiology. In a business-as-usual scenario, the terrestrial Hg(0) sink is predicted to decrease by 1870 Mg yr in 2100, that is ~60% lower than the present-day condition. We find a potential decoupling between the trends of CO assimilation and Hg(0) uptake process by vegetation in the 21st century, caused by the decreased stomatal conductance with increasing CO. This implies a substantial influx of Hg into aquatic ecosystems, posing an elevated threat that warrants consideration during the evaluation of the effectiveness of the Minamata Convention.
Topics: Carbon Dioxide; Mercury; Climate Change; Ecosystem; Plants
PubMed: 38802424
DOI: 10.1038/s41467-024-48849-2 -
Nutrition and Metabolic Insights 20246-Hydroxydopamine (6-OHDA) is a classic neurotoxin that has been widely used in Parkinson's disease research. 6-OHDA can increase intracellular reactive oxygen species...
6-Hydroxydopamine (6-OHDA) is a classic neurotoxin that has been widely used in Parkinson's disease research. 6-OHDA can increase intracellular reactive oxygen species (ROS) and can cause cell damage, which can be attenuated with (-)-Epigallocatechin-3-gallate (EGCG) treatment. However, the mechanism by which EGCG alters the 6-OHDA toxicity remains unclear; In this study, we found 6-OHDA (25 μM) alone increased intracellular ROS concentration in N27 cells, which was attenuated by pretreating with EGCG (100 μM). We evaluated the intracellular oxidative damage by determining the level of thiobarbituric acid reactive substances (TBARS) and protein carbonyl content. 6-OHDA significantly increased TBARS by 82.7% ( < .05) and protein carbonyl content by 47.8 ( < .05), compared to the control. Pretreatment of EGCG decreased TBARS and protein carbonyls by 36.4% ( < .001) and 27.7% ( < .05), respectively, compared to 6-OHDA alone treatment. Antioxidant effect was tested with E2-related factor 2 (Nrf2), heme oxygenase-1(HO-1) and peroxisome-proliferator activator receptor γ (PPARγ) expression. 6-OHDA increased Nrf2 expression by 69.6% ( < .001), HO-1 by 173.3% ( < .001), and PPARγ by 122.7% ( < .001), compared with untreatment. EGCG pretreatment stabilized these alterations induced by 6-OHDA. Our results suggested that the neurotoxicity of 6-OHDA in N27 cells was associated with ROS pathway, whereas pretreatment of EGCG suppressed the ROS generation and deactivated the Nrf2/HO-1 and PPARγ expression.
PubMed: 38800717
DOI: 10.1177/11786388241253436 -
Research Square May 2024Snakebite envenoming remains a devastating and neglected tropical disease, claiming over 100,000 lives annually and causing severe complications and long-lasting...
Snakebite envenoming remains a devastating and neglected tropical disease, claiming over 100,000 lives annually and causing severe complications and long-lasting disabilities for many more . Three-finger toxins (3FTx) are highly toxic components of elapid snake venoms that can cause diverse pathologies, including severe tissue damage and inhibition of nicotinic acetylcholine receptors (nAChRs) resulting in life-threatening neurotoxicity . Currently, the only available treatments for snakebite consist of polyclonal antibodies derived from the plasma of immunized animals, which have high cost and limited efficacy against 3FTxs . Here, we use deep learning methods to de novo design proteins to bind short- and long-chain α-neurotoxins and cytotoxins from the 3FTx family. With limited experimental screening, we obtain protein designs with remarkable thermal stability, high binding affinity, and near-atomic level agreement with the computational models. The designed proteins effectively neutralize all three 3FTx sub-families and protect mice from a lethal neurotoxin challenge. Such potent, stable, and readily manufacturable toxin-neutralizing proteins could provide the basis for safer, cost-effective, and widely accessible next-generation antivenom therapeutics. Beyond snakebite, our computational design methodology should help democratize therapeutic discovery, particularly in resource-limited settings, by substantially reducing costs and resource requirements for development of therapies to neglected tropical diseases.
PubMed: 38798548
DOI: 10.21203/rs.3.rs-4402792/v1 -
Journal, Genetic Engineering &... Jun 2024Venomous marine cone snails produce unique neurotoxins called conopeptides or conotoxins, which are valuable for research and drug discovery. Characterizing Conus venom...
BACKGROUND
Venomous marine cone snails produce unique neurotoxins called conopeptides or conotoxins, which are valuable for research and drug discovery. Characterizing Conus venom is important, especially for poorly studied species, as these tiny and steady molecules have considerable potential as research tools for detecting new pharmacological applications. In this study, a worm-hunting cone snail, Conus flavidus inhabiting the Red Sea coast were collected, dissected and the venom gland extraction was subjected to proteomic analysis to define the venom composition, and confirm the functional structure of conopeptides.
RESULTS
Analysis of C. flavidus venom identified 117 peptide fragments and assorted them to conotoxin precursors and non-conotoxin proteins. In this procedure, 65 conotoxin precursors were classified and identified to 16 conotoxin precursors and hormone superfamilies. In the venom of C. flavidus, the four conotoxin superfamilies T, A, O2, and M were the most abundant peptides, accounting for 75.8% of the total conotoxin diversity. Additionally, 19 non-conotoxin proteins were specified in the venom, as well as several potentially biologically active peptides with putative applications.
CONCLUSION
Our research displayed that the structure of the C. flavidus-derived proteome is similar to other Conus species and includes toxins, ionic channel inhibitors, insulin-like peptides, and hyaluronidase. This study provides a foundation for discovering new conopeptides from C. flavidus venom for pharmaceutical use.
PubMed: 38797555
DOI: 10.1016/j.jgeb.2024.100375 -
Journal of Clinical Medicine May 2024Graves' ophthalmopathy (GO) is characterized by upper eyelid retraction (UER), the most prevalent clinical sign. We aimed to assess the clinical efficacy of a...
Graves' ophthalmopathy (GO) is characterized by upper eyelid retraction (UER), the most prevalent clinical sign. We aimed to assess the clinical efficacy of a multimodal combination of steroids, 5-fluorouracil (5-FU), and botulinum neurotoxin A (BoNT-A) injections in managing UER with GO and analyze the clinical factors in relation to the injection response. A total of 37 eyes from 23 patients were enrolled for UER with GO. At the endocrinology clinic, the patients were referred to the ophthalmology clinic after taking antithyroid medication for an average of 5.76 months (13 patients), while 10 patients were initially diagnosed with GO and referred to the endocrinology clinic for management of the thyroid hormone function. They performed an orbital computed tomography (CT) scan and measured the cross-sectional area of the orbit, orbital fat, and each extra ocular muscle (EOM) except for the inferior oblique muscle 4 mm behind the eyeball. Each of the EOMs and orbital fat were calculated as a ratio to the total orbit area. A total of 0.1 cc of triamcinolone (40 mg/mL), dexamethasone (5 mg/mL), 5-FU, and BoNT-A (2.5 units) was injected transconjunctivally. Medical records were examined and photographs were utilized to assess MRD1, inferior palpebral fissure (IPF), and lid lag during down gaze before and after the injection. The patients were divided into two groups: responders (more than 1 mm decrease in MRD1 after injection) and non-responders. During the follow-up period (11.0 ± 11.6 months), any potential adverse effects were monitored. CAS decreased from 3.0 ± 0.8 to 1.4 ± 0.5 after the injection, and MRD1 decreased from 5.0 ± 0.9 mm to 4.5 ± 1.3 mm. Sixty percent of the patients were responders. Before and after the injection, the difference between IPF and MRD1 in responders was 0.60 ± 1.10 mm and 0.90 ± 0.90 mm, respectively, whereas, in non-responders, it was -0.57 ± 0.88 mm and -0.15 ± 0.75 mm, respectively. In the responders, pre-injection IPF and FT4 were significantly higher ( < 0.05). Responders had a larger EOM cross-sectional area (153.5 ± 18.0 mm), including a larger lateral rectus muscle cross-sectional area (37.6 ± 9.7 mm) than non-responders (132.0 ± 27.9 mm; 29.1 ± 8.1 mm). In responders, the treatment effect on IPF and MRD1 remained consistent at 1.2 ± 3.4 mm and 1.2 ± 1.6 mm, respectively, during the latest follow-up assessment. The combination injection of corticosteroids, 5-FU, and BoNT-A would be effective, especially, in patients with hyperthyroidism and an elongated IPF. Additionally, an increase in EOM cross-sectional area on CT, up to 150 mm, may serve as an additional positive indicator for the use of multimodal injections in UER with GO.
PubMed: 38792551
DOI: 10.3390/jcm13103012 -
PloS One 2024Differential white blood cell counts are frequently used in diagnosis, patient stratification, and treatment selection to optimize therapy responses. Referral... (Comparative Study)
Comparative Study
Differential white blood cell counts are frequently used in diagnosis, patient stratification, and treatment selection to optimize therapy responses. Referral laboratories are often used but challenged with use of different hematology platforms, variable blood shipping times and storage conditions, and the different sensitivities of specific cell types. To extend the scientific literature and knowledge on the temporal commutability of blood samples between hematology analyzers, we performed a comparative ex-vivo study using four of the most utilized commercial platforms, focusing on the assessment of eosinophils given its importance in asthma management. Whole blood from healthy volunteers with and without atopy (n = 6+6) and participants with eosinophilic asthma (n = 6) were stored under different conditions (at 4, 20, 30, and 37°C, with or without agitation) and analyzed at different time points (3, 6, 24, 48 and 72h post-sampling) in parallel on the Abbott CELL-DYN Sapphire, Beckman Coulter DxH900, Siemens ADVIA 2120i and Sysmex XN-1000V. In the same blood samples, eosinophil-derived neurotoxin (EDN), eosinophil activation and death markers were analyzed. All platforms gave comparable measurements of cell differentials on fresh blood within the same day of sampling. However, by 24 hours, significant temporal and temperature-dependent differences were observed, most markedly for eosinophils. None of the platforms performed perfectly across all temperatures tested during the 72 hours, showing that handling conditions should be optimized depending on the cell type of interest and the hematology analyzer. Neither disease status (healthy vs. asthma) nor agitation of the sample affected the cell quantification result or EDN release. The eosinophil activation markers measured by flow cytometry increased with time, were influenced by temperature, and were higher in those with asthma versus healthy participants. In conclusion, hematology analyzer, time window from sampling until analysis, and temperature conditions must be considered when analyzing blood cell differentials, particularly for eosinophils, via central labs to obtain counts comparable to the values obtained in freshly sampled blood.
Topics: Humans; Asthma; Eosinophils; Female; Male; Adult; Blood Cell Count; Leukocyte Count; Middle Aged; Hematology
PubMed: 38787860
DOI: 10.1371/journal.pone.0301845 -
Toxins May 2024Axial postural abnormalities (APAs), characterized by their frequency, disabling nature, and resistance to pharmacological treatments, significantly impact Parkinson's... (Review)
Review
Axial postural abnormalities (APAs), characterized by their frequency, disabling nature, and resistance to pharmacological treatments, significantly impact Parkinson's disease and atypical Parkinsonism patients. Despite advancements in diagnosing, assessing, and understanding their pathophysiology, managing these complications remains a significant challenge. Often underestimated by healthcare professionals, these disturbances can exacerbate disability. This systematic review assesses botulinum toxin treatments' effectiveness, alone and with rehabilitation, in addressing APAs in Parkinson's disease, utilizing MEDLINE (PubMed), Web of Science, and SCOPUS databases for source material. Of the 1087 records retrieved, 16 met the selection criteria. Most research has focused on botulinum toxin (BoNT) as the primary treatment for camptocormia and Pisa syndrome, utilizing mostly observational methods. Despite dose and injection site variations, a common strategy was using electromyography-guided injections, occasionally enhanced with ultrasound. Patients with Pisa syndrome notably saw consistent improvements in APAs and pain. However, studies on the combined effects of botulinum toxin and rehabilitation are limited, and antecollis is significantly under-researched. These findings recommend precise BoNT injections into hyperactive muscles in well-selected patients by skilled clinicians, avoiding compensatory muscles, and underscore the necessity of early rehabilitation. Rehabilitation is crucial in a multidisciplinary approach to managing APAs, highlighting the importance of a multidisciplinary team of experts.
Topics: Humans; Parkinson Disease; Botulinum Toxins; Neuromuscular Agents; Spinal Curvatures; Posture
PubMed: 38787080
DOI: 10.3390/toxins16050228 -
Toxins May 2024Botulinum neurotoxins E (BoNT/E) and A (BoNT/A) act by cleaving Synaptosome-Associated Protein 25 (SNAP25) at two different C-terminal sites, but they display very...
Intramuscular Botulinum Neurotoxin Serotypes E and A Elicit Distinct Effects on SNAP25 Protein Fragments, Muscular Histology, Spread and Neuronal Transport: An Integrated Histology-Based Study in the Rat.
Botulinum neurotoxins E (BoNT/E) and A (BoNT/A) act by cleaving Synaptosome-Associated Protein 25 (SNAP25) at two different C-terminal sites, but they display very distinct durations of action, BoNT/E being short acting and BoNT/A long acting. We investigated the duration of action, spread and neuronal transport of BoNT/E (6.5 ng/kg) and BoNT/A (125 pg/kg) after single intramuscular administrations of high equivalent efficacious doses, in rats, over a 30- or 75-day periods, respectively. To achieve this, we used (i) digit abduction score assay, (ii) immunohistochemistry for SNAP25 (N-ter part; SNAP25 and C-ter part; SNAP25) and its cleavage sites (cleaved SNAP25; c-SNAP25 and c-SNAP25) and (iii) muscular changes in histopathology evaluation. Combined in vivo observation and immunohistochemistry analysis revealed that, compared to BoNT/A, BoNT/E induces minimal muscular changes, possesses a lower duration of action, a reduced ability to spread and a decreased capacity to be transported to the lumbar spinal cord. Interestingly, SNAP25 completely disappeared for both toxins during the peak of efficacy, suggesting that the persistence of toxin effects is driven by the persistence of proteases in tissues. These data unveil some new molecular mechanisms of action of the short-acting BoNT/E and long-acting BoNT/A, and reinforce their overall safety profiles.
Topics: Animals; Synaptosomal-Associated Protein 25; Botulinum Toxins; Botulinum Toxins, Type A; Injections, Intramuscular; Male; Rats; Muscle, Skeletal; Rats, Sprague-Dawley; Neurons
PubMed: 38787077
DOI: 10.3390/toxins16050225