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Search Results (204)

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Keywords = repeat-in-toxin

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20 pages, 1447 KB  
Review
Environmental and Regulatory Control of RTX Toxins in Gram-Negative Pathogens
by Hossein Jamali, Tylor Pereira and Charles M. Dozois
Toxins 2026, 18(1), 27; https://doi.org/10.3390/toxins18010027 - 6 Jan 2026
Viewed by 135
Abstract
Repeat-in-toxin (RTX) toxins are calcium-dependent exoproteins secreted by diverse Gram-negative bacteria and play central roles in cytotoxicity, immune modulation, and tissue colonization. While their structure and secretion mechanisms are well-characterized, the regulation of RTX toxin expression remains complex and species-specific. This review provides [...] Read more.
Repeat-in-toxin (RTX) toxins are calcium-dependent exoproteins secreted by diverse Gram-negative bacteria and play central roles in cytotoxicity, immune modulation, and tissue colonization. While their structure and secretion mechanisms are well-characterized, the regulation of RTX toxin expression remains complex and species-specific. This review provides a comprehensive overview of the regulatory networks governing RTX gene expression, highlighting both conserved mechanisms and niche-specific adaptations. RTX genes are controlled by multilayered regulatory systems that integrate global transcriptional control, metabolic regulation, and environmental sensing. Expression is further shaped by host-derived signals, physical contact with host cells, and population-dependent cues. Quorum sensing, post-transcriptional regulation by small RNAs, and post-translational activation mechanisms contribute additional layers of control to ensure precise regulation of toxin production. We also explore how RTX regulation varies across anatomical niches, including the gut, lung, bloodstream, and biofilms, and how it is co-regulated with broader bacterial virulence. Finally, we discuss emerging insights from omics-based approaches and the potential of anti-virulence strategies targeting RTX regulatory pathways. Together, these topics underscore RTX regulation as a model for adaptive virulence control in bacterial pathogens. Full article
(This article belongs to the Section Bacterial Toxins)
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19 pages, 7841 KB  
Review
Functional Coupling and Evolutionary Relationships Between Toxin–Antitoxin Systems and CRISPR-Cas Systems
by Yibo Meng, Jiyun Chen and Liang Liu
Toxins 2025, 17(12), 602; https://doi.org/10.3390/toxins17120602 - 16 Dec 2025
Viewed by 460
Abstract
Bacteria encode a broad range of survival and defence systems, including CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas systems, restriction-modification systems, and toxin–antitoxin (TA) systems, which are involved in bacterial regulation and immunity. The traditional view holds that CRISPR-Cas systems and TA systems [...] Read more.
Bacteria encode a broad range of survival and defence systems, including CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas systems, restriction-modification systems, and toxin–antitoxin (TA) systems, which are involved in bacterial regulation and immunity. The traditional view holds that CRISPR-Cas systems and TA systems are two independent defense lines in prokaryotes. However, groundbreaking studies in recent years have revealed multi-level functional coupling between them. This review systematically elaborates on this mechanism, focusing on three types of TA systems that mediate the core correlation of CRISPR-Cas systems: CreTA maintains the evolutionary stability of CRISPR-Cas systems through an addiction mechanism; CreR enables self-regulation of CRISPR-Cas expression; and CrePA provides herd immunity by triggering abortive infection after the CRISPR-Cas system has been destroyed by Anti-CRISPRS protein. Additionally, we discuss the evolutionary homology between the type III toxin AbiF and the type VI CRISPR effector Cas13, offering a new perspective for understanding the origin of CRISPR-Cas systems. These findings not only reveal the functional coupling of prokaryotic defense systems but also provide a powerful theoretical framework and practical solutions for addressing stability challenges in CRISPR technology applications. Full article
(This article belongs to the Section Bacterial Toxins)
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46 pages, 2441 KB  
Review
A State-of-the-Art Overview on (Epi)Genomics and Personalized Skin Rejuvenating Strategies
by Roxana-Georgiana Tauser, Ioana-Mirela Vasincu, Andreea-Teodora Iacob, Maria Apotrosoaei, Bianca-Ștefania Profire, Florentina-Geanina Lupascu, Oana-Maria Chirliu and Lenuta Profire
Pharmaceutics 2025, 17(12), 1585; https://doi.org/10.3390/pharmaceutics17121585 - 9 Dec 2025
Viewed by 990
Abstract
This article aims to point out new perspectives opened by genomics and epigenomics in skin rejuvenation strategies which target the main hallmarks of the ageing. In this respect, this article presents a concise overview on: the clinical relevance of the most important clocks [...] Read more.
This article aims to point out new perspectives opened by genomics and epigenomics in skin rejuvenation strategies which target the main hallmarks of the ageing. In this respect, this article presents a concise overview on: the clinical relevance of the most important clocks and biomarkers used in skin anti-ageing strategy evaluation, the fundamentals, the main illustrating examples preclinically and clinically tested, the critical insights on knowledge gaps and future research perspectives concerning the most relevant skin anti-ageing and rejuvenation strategies based on novel epigenomic and genomic acquisitions. Thus the review dedicates distinct sections to: senolytics and senomorphics targeting senescent skin cells and their senescent-associated phenotype; strategies targeting genomic instability and telomere attrition by stimulation of the deoxyribonucleic acid (DNA) repair enzymes and proteins essential for telomeres’ recovery and stability; regenerative medicine based on mesenchymal stem cells or cell-free products in order to restore skin-resided stem cells; genetically and chemically induced skin epigenetic partial reprogramming by using transcription factors or epigenetic small molecule agents, respectively; small molecule modulators of DNA methylases, histone deacetylases, telomerases, DNA repair enzymes or of sirtuins; modulators of micro ribonucleic acid (miRNA) and long-non-coding ribonucleic acid (HOTAIR’s modulators) assisted or not by CRISPR-gene editing technology (CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats); modulators of the most relevant altered nutrient-sensing pathways in skin ageing; as well as antioxidants and nanozymes to address mitochondrial dysfunctions and oxidative stress. In addition, some approaches targeting skin inflammageing, altered skin proteostasis, (macro)autophagy and intercellular connections, or skin microbiome, are very briefly discussed. The review also offers a comparative analysis among the newer genomic/epigenomic-based skin anti-ageing strategies vs. classical skin rejuvenation treatments from various perspectives: efficacy, safety, mechanism of action, evidence level in preclinical and clinical data and regulatory status, price range, current limitations. In these regards, a concise overview on senolytic/senomorphic agents, topical nutrigenomic pathways’ modulators and DNA repair enzymes, epigenetic small molecules agents, microRNAs and HOTAIRS’s modulators, is illustrated in comparison to classical approaches such as tretinoin and peptide-based cosmeceuticals, topical serum with growth factors, intense pulsed light, laser and microneedling combinations, chemical peels, botulinum toxin injections, dermal fillers. Finally, the review emphasizes the future research directions in order to accelerate the clinical translation of the (epi)genomic-advanced knowledge towards personalization of the skin anti-ageing strategies by integration of individual genomic and epigenomic profiles to customize/tailor skin rejuvenation therapies. Full article
(This article belongs to the Topic Challenges and Opportunities in Drug Delivery Research)
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12 pages, 795 KB  
Systematic Review
Intracavernosal Botulinum Toxin Injection for Erectile Dysfunction: A Comprehensive Systematic Review
by Vanessa Talavera Cobo, Carlos Andres Yanez Ruiz, Mario Daniel Tapia Tapia, Andres Calva Lopez, Carmina Alejandra Muñoz Bastidas, Francisco Guillen-Grima, Francisco Javier Ancizu Marckert, Luis Labairu Huerta, Marcos Torres Roca, Fernando Jose Diez-Caballero Alonso, Daniel Sanchez Zalabardo, Bernardino Miñana Lopez and Jose Enrique Robles Garcia
Life 2025, 15(12), 1826; https://doi.org/10.3390/life15121826 - 28 Nov 2025
Viewed by 1275
Abstract
Background: Erectile dysfunction (ED) affects approximately 20% of men worldwide, significantly affecting their quality of life. While phosphodiesterase type 5 inhibitors (PDE5-Is) are the standard first-line treatment, a substantial number of patients are non-responders. Second-line treatments, such as intracavernosal alprostadil, are effective but [...] Read more.
Background: Erectile dysfunction (ED) affects approximately 20% of men worldwide, significantly affecting their quality of life. While phosphodiesterase type 5 inhibitors (PDE5-Is) are the standard first-line treatment, a substantial number of patients are non-responders. Second-line treatments, such as intracavernosal alprostadil, are effective but often limited by their invasive nature and the need for frequent injections. Intracavernosal onabotulinumtoxinA (BoNT-A) offers a promising new option. By inhibiting acetylcholine release and norepinephrine, as well as other neurotransmitters involved in detumescence, it facilitates cavernosal smooth muscle relaxation and enhances penile blood flow. Its effects may persist for up to six months following a single injection, potentially reducing treatment burden and improving adherence among men with refractory ED. Methods: A systematic review was performed in accordance with the PRISMA guidelines. Literature searches were conducted in PubMed, Embase, Cochrane Library, Scopus, and Clinicaltrials.gov from inception until August 2025 using a combination of keywords and MeSH terms related to ‘erectile dysfunction’ and ‘botulinum toxin’. After screening, 51 studies met the inclusion criteria. Due to significant heterogeneity in interventions (e.g., BoNT-A dosage, co-therapies), patient populations, and reported outcomes, the data were not suitable for meta-analysis. Consequently, a narrative synthesis was performed to summarize the findings. Results: Among the included studies, intracavernosal BoNT-A was associated with improvements in validated erectile function scores. Reported response rates, variably defined across studies, ranged from 40% to 77.5%. Several studies suggested that efficacy was higher in patients with mild-to-moderate ED and with repeated administration of 100 U doses. The treatment exhibited a favorable safety profile. The most common adverse event was mild, transient penile pain (reported incidence 1.5–6%). No studies reported serious systemic adverse events. The overall strength of the evidence was limited by significant heterogeneity among the included studies and their generally small sample sizes. Conclusions: Based on this systematic review, intracavernosal onabotulinumtoxinA (BoNT-A) may be a beneficial therapeutic option for patients with refractory ED, offering potential improvements in sexual function while reducing the need for invasive therapies. Future large-scale, placebo-controlled studies are essential to confirm these benefits and standardize their clinical application. Full article
(This article belongs to the Section Medical Research)
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21 pages, 549 KB  
Article
Optimisation of a One-Step Reusable Immuno-Affinity Purification Method for the Analysis and Detection of Fumonisin Mycotoxins in Foods and Feeds
by Christian Kosisochukwu Anumudu
Toxins 2025, 17(11), 538; https://doi.org/10.3390/toxins17110538 - 30 Oct 2025
Viewed by 808
Abstract
Fumonisins are among the most prevalent mycotoxins in maize and maize-based products, posing significant food safety and public health risks due to their hepatotoxic, nephrotoxic, and potential carcinogenic effects. Given the strict regulatory limits set by the European Commission and Codex Alimentarius, the [...] Read more.
Fumonisins are among the most prevalent mycotoxins in maize and maize-based products, posing significant food safety and public health risks due to their hepatotoxic, nephrotoxic, and potential carcinogenic effects. Given the strict regulatory limits set by the European Commission and Codex Alimentarius, the development of reliable, sensitive, and matrix–robust analytical methods remain a priority for routine monitoring in both food and feed systems. In this study, a reusable immuno-affinity purification methodology for the quantitative determination of fumonisin mycotoxins (FB1, FB2 and FB3) in foods and feeds (maize matrix) was developed. A single extraction protocol using 2% formic acid in water was employed, followed by cleanup with an immuno-affinity purification column and toxin elution by methanol/PBS (1:1, v/v). Detection and quantification of the mycotoxins was achieved by a normal phase ultra-high performance liquid chromatography coupled with electrospray ionisation triple quadrupole mass spectrometry (UHPLC/ESI-MS/MS). The chromatographic mobile phase utilised was a linear gradient of methanol/water containing 0.1% formic acid. The developed method has a limit of detection of 2.5 ng/g and a limit of quantification of 5 ng/g, all well below the European commission’s guidance values of 1000 ng/g for corn destined for human consumption and 800 ng/g for maize-based breakfast cereals and snacks. While the recovery rates of the method in this study ranged from 65–70% for the three fumonisin analogues in solutions, when tested in maize matrix, recoveries were markedly lower (~30%) due to pronounced matrix suppression. Good repeatability (standard deviation <10%) was achieved for all the fumonisin analogues. The developed method, although quick and effective in solvent systems, suffered limitations to its practical usage due to matrix suppression of the extracts derived from the immuno-affinity purification column, thus significantly reducing the application of the method in measuring fumonisin mycotoxins in food and feed samples. Overall, the method was effective in quantification of fumonisin mycotoxins in solvent solutions but not in food and feed matrices, thus necessitating further optimisation for practical usage. The performance of the developed method was compared to a commercial lateral flow immunochromatographic assay which proved to be better than the developed method in the quantification of toxins in food matrices, as the commercial lateral flow immunochromatographic assay outperformed the developed method in maize matrices. These findings highlight the need for matrix-based validation and further refinement of antibody stability to ensure robust application in regulatory monitoring of fumonisins using immunoaffinity purification methods. Full article
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19 pages, 4754 KB  
Article
How Sodium and Calcium Ions Pass Through Batrachotoxin-Bound Sodium Channel
by Boris S. Zhorov
Toxins 2025, 17(10), 520; https://doi.org/10.3390/toxins17100520 - 21 Oct 2025
Viewed by 1025
Abstract
Steroidal sodium channel agonist batrachotoxin (BTX), one of the most potent animal toxins, dramatically increases calcium permeation and alters other channel characteristics. In a cryoEM structure of rat sodium channel Nav1.5 with two BTX-B molecules, one toxin binds between repeats III and IV [...] Read more.
Steroidal sodium channel agonist batrachotoxin (BTX), one of the most potent animal toxins, dramatically increases calcium permeation and alters other channel characteristics. In a cryoEM structure of rat sodium channel Nav1.5 with two BTX-B molecules, one toxin binds between repeats III and IV and exposes to the pore lumen two oxygen atoms and protonatable nitrogen. The mechanism of ion permeation and selectivity in BTX-bound channel is unclear. Here Monte Carlo energy-minimized profiles of sodium and calcium ions pulled through the pore were computed in models with various protonated states of the DEKA lysine and BTX-B. The only model where the ions readily passed by the DEKA lysine and BTX-B involved their deprotonated nitrogens. In this model, electronegative atoms of BTX-B attracted a permeant cation that stabilized the “dunked” lysine through electrostatic interactions and nearby water molecules. This would retard reprotonation of the lysine and its “uplifting” to the DEKA carboxylates, which otherwise attracts calcium. The results suggest how sodium and calcium ions pass through BTX-bound sodium channel and why BTX increases calcium permeation. The study supports an earlier hypothesis that during the sodium ion permeation cycle, the DEKA lysine alternates between uplifted and dunked conformations in the protonated and deprotonated states, respectively, while the sodium-displaced proton and the sodium ion nullify the net electrical charge at the DEKA region. Full article
(This article belongs to the Section Animal Venoms)
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14 pages, 786 KB  
Article
Typing of Yersinia pestis in Challenging Forensic Samples Through Targeted Next-Generation Sequencing of Multilocus Variable Number Tandem Repeat Regions
by Hyeongseok Yun, Seung-Ho Lee, Se Hun Gu, Seung Hyun Lim and Dong Hyun Song
Microorganisms 2025, 13(10), 2320; https://doi.org/10.3390/microorganisms13102320 - 7 Oct 2025
Viewed by 713
Abstract
Microbial forensics involves analyzing biological evidence to evaluate weaponized microorganisms or their toxins. This study aimed to detect and type Yersinia pestis from four simulated forensic samples—human plasma diluted in phosphate-buffered saline (#24-2), tomato juice (#24-5), grape juice (#24-8), and a surgical mask [...] Read more.
Microbial forensics involves analyzing biological evidence to evaluate weaponized microorganisms or their toxins. This study aimed to detect and type Yersinia pestis from four simulated forensic samples—human plasma diluted in phosphate-buffered saline (#24-2), tomato juice (#24-5), grape juice (#24-8), and a surgical mask (#24-10). Notably, samples #24-10 may have contained live bacteria other than Y. pestis. A real-time polymerase chain reaction confirmed the presence of Y. pestis in all samples; however, whole-genome sequencing (WGS) coverage of the Y. pestis chromosome ranged from 0.46% to 97.1%, largely due to host DNA interference and low abundance. To address these limitations and enable strain-level identification, we designed a hybridization-based target enrichment approach focused on multilocus variable number tandem repeat analysis (MLVA). Next-generation sequencing (NGS) using whole-genome amplification revealed that the accuracy of the 25 MLVA profiles of Y. pestis for samples #24-2, #24-5, #24-8, and #24-10 was 4%, 100%, 52%, and 0%, respectively. However, all samples showed 100% accuracy with target-enriched NGS, confirming they all belong to the same strain. These findings demonstrate that a targeted enrichment strategy for MLVA loci can overcome common obstacles in microbial forensics, particularly when working with trace or degraded samples where conventional WGS proves challenging. Full article
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21 pages, 1643 KB  
Review
The Autistic Toe Walking: A Narrative Review for Interventions and Comparison with Idiopathic Toe Walking
by Luiz Renato Agrizzi de Angeli, Bárbara Lívia Corrêa Serafim and Julio Javier Masquijo
Children 2025, 12(9), 1198; https://doi.org/10.3390/children12091198 - 8 Sep 2025
Viewed by 3617
Abstract
Background/Objectives: Idiopathic toe walking (ITW) is a diagnosis of exclusion in children who demonstrate a persistent toe-walking gait without an identifiable underlying neuromuscular or orthopedic pathology. The classification of toe-walking behavior (TWB) in children with Autism Spectrum Disorder (ASD) remains an area of [...] Read more.
Background/Objectives: Idiopathic toe walking (ITW) is a diagnosis of exclusion in children who demonstrate a persistent toe-walking gait without an identifiable underlying neuromuscular or orthopedic pathology. The classification of toe-walking behavior (TWB) in children with Autism Spectrum Disorder (ASD) remains an area of debate, with some considering it a part of the broader ITW spectrum, while others view it as a distinct entity. Children with TWB associated with ASD (Autistic Toe Walking—ATW) present unique clinical challenges. This subgroup exhibits a higher prevalence of toe walking, and their gait patterns are often associated with underlying neurodevelopmental differences, frequently leading to increased resistance to conventional treatment approaches and higher rates of persistence and recurrence. This narrative review aims to summarize the available evidence on interventions for ATW, highlight differences compared to ITW and discuss implications for clinical practice. Methods: A literature search was performed, including articles that addressed interventions for toe walking in children with ASD. Results: The literature is limited and heterogeneous. Identified interventions include physiotherapy, orthoses, botulinum toxin injections, serial casting, and surgical procedures. Evidence of effectiveness is scarce, with most studies consisting of small case series. ATW differs from classic ITW in some aspects of pathophysiology and clinical presentation. Treatment decisions should balance potential benefits with risks, particularly regarding repeated anesthesia exposure during casting versus earlier surgical options. Conclusions: Evidence for managing ATW is limited. While comparisons to ITW may be useful, clinicians must recognize that they present distinct characteristics. Future research should focus on standardized definitions and controlled trials to guide management. Full article
(This article belongs to the Special Issue Children with Autism Spectrum Disorder: Diagnosis and Treatment)
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26 pages, 3012 KB  
Article
Cytoprotective Effects of Gymnema inodorum Against Oxidative Stress-Induced Human Dermal Fibroblasts Injury: A Potential Candidate for Anti-Aging Applications
by Wattanased Jarisarapurin, Thanchanok Puksasook, Sarawut Kumphune, Nattanicha Chaiya, Pawinee Pongwan, Rawisada Pholsin, Issara Sramala and Satita Tapaneeyakorn
Antioxidants 2025, 14(9), 1043; https://doi.org/10.3390/antiox14091043 - 24 Aug 2025
Viewed by 1432
Abstract
Repeated UV exposure, air pollution, and toxins promote skin oxidative stress. ROS destroy macromolecules, changing cellular mechanisms and signaling cascades. Inflammation and injury to skin cells degrade function and accelerate aging, causing wrinkles, firmness loss, and dermatological disorders. Gymnema inodorum (GI) contains phytochemical [...] Read more.
Repeated UV exposure, air pollution, and toxins promote skin oxidative stress. ROS destroy macromolecules, changing cellular mechanisms and signaling cascades. Inflammation and injury to skin cells degrade function and accelerate aging, causing wrinkles, firmness loss, and dermatological disorders. Gymnema inodorum (GI) contains phytochemical antioxidants such polyphenols and triterpenoids that lower ROS and strengthen skin. GI extracts (GIEs) have never been examined for their effects on dermal skin fibroblasts’ oxidative stress and intracellular cytoprotective mechanisms. In this study, GIEs were prepared as a water extract (GIE0) and ethanol extracts with concentrations ranging from 20% to 95% v/v (GIE20, GIE40, GIE60, GIE80, and GIE95). These extracts were assessed for phytochemical content, antioxidant capacity, and free radical scavenging efficacy. The results were compared to a commercially available native Gymnema extract (NGE) obtained from Gymnema sylvestre. During principal component analysis (PCA), the most effective extracts were identified and subsequently evaluated for their ability to mitigate oxidative stress in fibroblasts. Cytoprotective effects of GIE and NGE against H2O2-induced human dermal fibroblast injury were investigated by cell viability, intracellular ROS production, and signaling pathways. GIE0, GIE80, GIE95, and NGE were the best antioxidants. By preserving ROS balance and redox homeostasis, GIE and NGE reduce fibroblast inflammation and oxidative stress-induced damage. Decreased ROS levels reduce MAPK/AP-1/NF-κB and PI3K/AKT/NF-κB signaling pathways, diminishing inflammatory cytokines. In conclusion, GIE and NGE have antioxidant and anti-inflammatory capabilities that can reduce H2O2-induced fibroblast oxidative stress and damage, thereby preventing skin aging and targeting cancer-associated fibroblasts. Full article
(This article belongs to the Section Natural and Synthetic Antioxidants)
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18 pages, 6269 KB  
Article
Investigating the Relationship Between Microcystin Concentrations and Water Quality Parameters in Three Agricultural Irrigation Ponds Using Random Forest
by Jaclyn E. Smith, James A. Widmer, Matthew D. Stocker, Jennifer L. Wolny, Robert L. Hill and Yakov Pachepsky
Water 2025, 17(16), 2361; https://doi.org/10.3390/w17162361 - 8 Aug 2025
Viewed by 1518
Abstract
Cyanotoxins in agricultural waters pose a human and animal health risk. These toxins can be transported to nearby crops and soil during irrigation practices; they can remain in the soil for extended periods and be adsorbed by root systems. Additionally, in livestock watering [...] Read more.
Cyanotoxins in agricultural waters pose a human and animal health risk. These toxins can be transported to nearby crops and soil during irrigation practices; they can remain in the soil for extended periods and be adsorbed by root systems. Additionally, in livestock watering ponds, cyanotoxins pose a direct ingestion risk. This work evaluated the performance of the random forest algorithm in estimating microcystin concentrations using eight in situ water quality measurements at one active livestock water pond and two working irrigation ponds in Georgia and Maryland, USA. Measurements of microcystin along with eight in situ-sensed water quality parameters were used to train and test the machine learning model. The models performed better at the Georgia ponds compared to the Maryland pond, and interior models performed better than nearshore or whole-pond models. The most important variables for microcystin prediction were water temperature and phytoplankton pigments. Overall, the random forest algorithm(RF), augmented with a ‘trainControl’ function to perform repeated cross validations, was able to explain 40% to 70% of the microcystin concentration variation in the three agricultural ponds. Water quality measurements showed potential to aid water monitoring/sampling design by predicting the microcystin concentrations in the studied ponds by using readily available and easy to collect in situ data. Full article
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20 pages, 1773 KB  
Article
Make Acetylcholine Great Again! Australian Skinks Evolved Multiple Neurotoxin-Proof Nicotinic Acetylcholine Receptors in Defiance of Snake Venom
by Uthpala Chandrasekara, Marco Mancuso, Glenn Shea, Lee Jones, Jacek Kwiatkowski, Dane Trembath, Abhinandan Chowdhury, Terry Bertozzi, Michael G. Gardner, Conrad J. Hoskin, Christina N. Zdenek and Bryan G. Fry
Int. J. Mol. Sci. 2025, 26(15), 7510; https://doi.org/10.3390/ijms26157510 - 4 Aug 2025
Viewed by 6048
Abstract
Many vertebrates have evolved resistance to snake venom as a result of coevolutionary chemical arms races. In Australian skinks (family Scincidae), who often encounter venomous elapid snakes, the frequency, diversity, and molecular basis of venom resistance have been unexplored. This study investigated the [...] Read more.
Many vertebrates have evolved resistance to snake venom as a result of coevolutionary chemical arms races. In Australian skinks (family Scincidae), who often encounter venomous elapid snakes, the frequency, diversity, and molecular basis of venom resistance have been unexplored. This study investigated the evolution of neurotoxin resistance in Australian skinks, focusing on mutations in the muscle nicotinic acetylcholine receptor (nAChR) α1 subunit’s orthosteric site that prevent pathophysiological binding by α-neurotoxins. We sampled a broad taxonomic range of Australian skinks and sequenced the nAChR α1 subunit gene. Key resistance-conferring mutations at the toxin-binding site (N-glycosylation motifs, proline substitutions, arginine insertions, changes in the electrochemical state of the receptor, and novel cysteines) were identified and mapped onto the skink organismal phylogeny. Comparisons with other venom-resistant taxa (amphibians, mammals, and reptiles) were performed, and structural modelling and binding assays were used to evaluate the impact of these mutations. Multiple independent origins of α-neurotoxin resistance were found across diverse skink lineages. Thirteen lineages evolved at least one resistance motif and twelve additional motifs evolved within these lineages, for a total of twenty-five times of α-neurotoxic venoms resistance. These changes sterically or electrostatically inhibit neurotoxin binding. Convergent mutations at the orthosteric site include the introduction of N-linked glycosylation sites previously known from animals as diverse as cobras and mongooses. However, an arginine (R) substitution at position 187 was also shown to have evolved on multiple occasions in Australian skinks, a modification previously shown to be responsible for the Honey Badger’s iconic resistance to cobra venom. Functional testing confirmed this mode of resistance in skinks. Our findings reveal that venom resistance has evolved extensively and convergently in Australian skinks through repeated molecular adaptations of the nAChR in response to the enormous selection pressure exerted by elapid snakes subsequent to their arrival and continent-wide dispersal in Australia. These toxicological findings highlight a remarkable example of convergent evolution across vertebrates and provide insight into the adaptive significance of toxin resistance in snake–lizard ecological interactions. Full article
(This article belongs to the Section Biochemistry)
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20 pages, 2293 KB  
Article
An Evaluation of the Safety, Immunogenicity, and Protective Efficacy of a Combined Diphtheria–Tetanus–Acellular Pertussis, Haemophilus influenzae Type b, and ACYW135 Meningococcal Conjugate Vaccine in Murine and Rat Models
by Xiuwen Sui, Zhujun Shao, Yuanyuan Ji, Hairui Wang, Qingfu Xu, Bochao Wei, Zhuojun Duan, Chang Wang, Ying Yang, Jiayu Zhao and Tao Zhu
Vaccines 2025, 13(7), 724; https://doi.org/10.3390/vaccines13070724 - 3 Jul 2025
Cited by 1 | Viewed by 1799
Abstract
Background: The combined diphtheria–tetanus–acellular pertussis (three-component), Haemophilus influenzae type b (Hib, conjugate), and ACYW135 meningococcal (conjugate) vaccine (DTaP-Hib-MCV4) offers a promising alternative to single-component vaccines, potentially simplifying immunization schedules and improving vaccination coverage. Methods: We evaluated the safety, immunogenicity, and protective [...] Read more.
Background: The combined diphtheria–tetanus–acellular pertussis (three-component), Haemophilus influenzae type b (Hib, conjugate), and ACYW135 meningococcal (conjugate) vaccine (DTaP-Hib-MCV4) offers a promising alternative to single-component vaccines, potentially simplifying immunization schedules and improving vaccination coverage. Methods: We evaluated the safety, immunogenicity, and protective efficacy of DTaP-Hib-MCV4 in animal models. Acute and long-term toxicity studies were conducted in Sprague-Dawley (SD) rats with equal numbers of male and female animals. Immunogenicity was assessed in female NIH mice and SD rats using a three-dose regimen at 14-day intervals. Orbital blood was collected 14 days post-immunization to measure IgG titers against pertussis, diphtheria, tetanus, Hib, and meningococcal antigens. The protective efficacy was determined using potency tests for the pertussis, diphtheria, and tetanus components; passive protection studies for Hib; and serum bactericidal antibody (SBA) titers against A/C/Y/W135 meningococcal serogroups. Results: Acute and repeated-dose toxicity studies in SD rats showed no signs of abnormal toxicity or irritation at either high (three doses/rat) or low (one dose/rat) doses levels. The no-observed-adverse-effect level (NOAEL) for DTaP-Hib-MCV4 was established at three doses/rat after 8 weeks of repeated intramuscular administration and a 4-week recovery period. Specific IgG antibodies against all the vaccine components were detected in animal sera at both one and three doses/rat, with no evidence of immunotoxicity. Following two-dose primary immunization in murine models, the combined vaccine elicited robust antigen-specific antibody responses, with geometric mean titers (GMTs) as follows: 1,280,000 for pertussis toxin (PT); 761,093 for filamentous hemagglutinin (FHA); 1,159,326 for pertactin (PRN); 1,659,955 for diphtheria toxoid (DT); 1,522,185 for tetanus toxoid (TT); 99 for Haemophilus influenzae type b (Hib); and 25,600, 33,199, 8300, and 9051 for serogroups A, C, Y, and W135 of Neisseria meningitidis, respectively. In the rat models, three-dose primary immunization also elicited robust antigen-specific antibody responses. Protection studies demonstrated efficacy against pertussis, tetanus toxin, and diphtheria toxin challenges. In the Hib challenge study, none of the 10 animals given anti-DTaP-Hib-MCV4 antiserum developed bacteremia after the live Hib challenge (vs. 5814/0.1 mL in the negative control, p < 0.001). In addition, the SBA titers against meningococcal serogroups exceeded the protective threshold (≥1:8) in 92.2% of the immunized mice and 100% of the immunized rats. Crucially, the combined vaccine induced potent immune responses and protective efficacy, with antibody levels and protection against each component antigen comparable to or greater than those of the individual components: DTaP, Hib, and MCV4. Conclusions: These findings demonstrate that the DTaP-Hib-MCV4 combined vaccine is both safe and immunogenic, supporting its potential as a viable alternative to individual vaccines. This combined vaccine may streamline immunization programs and enhance vaccination coverage. Full article
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7 pages, 606 KB  
Communication
Identification of Two Distinct Stem Cell Clusters, Lrig1-Derived and Wnt/CD44-Dependent, in Corneal Epithelium
by Laurent Barnes, Evangelia Konstantinou, Jean-Hilaire Saurat, Alexandre Moulin and Gürkan Kaya
Int. J. Mol. Sci. 2025, 26(13), 6383; https://doi.org/10.3390/ijms26136383 - 2 Jul 2025
Viewed by 720
Abstract
We previously showed that selective suppression of CD44 in the corneal epithelium leads to structural abnormalities in the mouse cornea. Our comparative studies of young and aged ocular biopsies revealed that CD44 expression is downregulated in aged corneas, while leucine-rich repeats and immunoglobulin-like [...] Read more.
We previously showed that selective suppression of CD44 in the corneal epithelium leads to structural abnormalities in the mouse cornea. Our comparative studies of young and aged ocular biopsies revealed that CD44 expression is downregulated in aged corneas, while leucine-rich repeats and immunoglobulin-like domain 1 (Lrig1+) stem cells remain preserved in the peripheral limbus. These findings suggest an age-related shift in the corneal stem cell compartmentalization, characterized by impaired CD44 expression in the central cornea and preservation of Lrig1+ stem cells in the limbus, which become the main stem cells in the senescent cornea. To investigate this further, we performed topical tamoxifen-inducible, diphtheria toxin-mediated ablation of Lrig1+ stem cells in mouse corneas. We then assessed both activated and non-activated beta-catenin expression in wild-type (WT) and CD44 knockout (CD44KO) mice, given that CD44 modulates the Wingless-related integration site (Wnt) pathway. Our results indicate that two distinct stem cell populations operate in the mouse cornea: Lrig1-derived stem cells and Wnt-activity/CD44-dependent stem cells. The Lrig1-derived cells act as a reservoir of quiescent stem cells that regenerate the cornea upon injury, whereas under homeostatic conditions, the Wnt-activity/CD44-dependent stem cells are primarily responsible for corneal renewal. In the aged cornea, the loss of CD44 expression leads to reduced Wnt signaling, making the tissue increasingly dependent on Lrig1+ stem cells for regeneration. In mice, Lrig1+ stem cells are capable of sustaining permanent corneal renewal, even in the absence of CD44. Full article
(This article belongs to the Special Issue Molecular Research Progress of Skin and Skin Diseases: 2nd Edition)
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14 pages, 368 KB  
Article
Long-Term Effectiveness of Onabotulinum Toxin-A in a Combined Total Endoscopic Management of Pediatric Vesicoureteral Reflux in Neurogenic Bladder Dysfunction
by Claudio Paratore, Chiara Pellegrino, Noemi Deanesi, Rebecca Pulvirenti, Maria Luisa Capitanucci and Giovanni Mosiello
Toxins 2025, 17(7), 330; https://doi.org/10.3390/toxins17070330 - 29 Jun 2025
Viewed by 1035
Abstract
Vesicoureteral reflux (VUR) management in children with neurogenic bladder dysfunction (NBD) remains a clinical challenge. Total endoscopic management (TEM), combining intradetrusor Onabotulinum Toxin-A (BTX-A) and subureteric dextranomer/hyaluronic acid (Deflux(R)) injection, offers a minimally invasive alternative. The aim of this retrospective study [...] Read more.
Vesicoureteral reflux (VUR) management in children with neurogenic bladder dysfunction (NBD) remains a clinical challenge. Total endoscopic management (TEM), combining intradetrusor Onabotulinum Toxin-A (BTX-A) and subureteric dextranomer/hyaluronic acid (Deflux(R)) injection, offers a minimally invasive alternative. The aim of this retrospective study is to evaluate the long-term effectiveness of TEM. Inclusion criteria: symptomatic II–V grade VUR (also I in bilateral VUR) in NBD children with follow-up ≥12 months. Nineteen patients were enrolled, 24 ureters (grade I–II: 2, grade III–V: 22); 5 patients (20.8%) had bilateral VUR. Mean age at surgery: 7.6 years (1.3–17). No complications were reported. TEM was effective in 11 patients (57.9%), 3/11 requiring a second TEM treatment. VUR resolution appeared in 14 ureters (58.3%), downgrading in 6 (42.9%), persistence in 4 (28.6%). Among non-responders’ patients (8/19, 42.1%), five (26.3%) required bladder augmentation (one combined with ureteral reimplantation), one (5.3%) underwent reimplantation, and two (10.5%) continued conservative management. At bladder biopsy, 11 patients (57.9%) had chronic inflammation, 8 (42.1%) showed fibrosis; no difference in success rate was recorded. All responders required repeated BTX-A injections. Mean follow-up: 3.2 years (range 1–4.7). In selected patients, TEM appears to be a safe and effective strategy, potentially delaying or avoiding major reconstructive surgery. Full article
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13 pages, 521 KB  
Article
Between Anxiety and Adaptation: Children’s and Parents’ Experiences with Botulinum Toxin Treatment in Cerebral Palsy
by Rannei Sæther, Siri Merete Brændvik and Ann-Kristin Gunnes Elvrum
J. Clin. Med. 2025, 14(9), 3164; https://doi.org/10.3390/jcm14093164 - 2 May 2025
Viewed by 1231
Abstract
Background/Objectives: This study explores how children with cerebral palsy (CP) and their parents experience botulinum toxin type A (BoNT-A) treatment, focusing on emotional and procedural challenges and communication within the triad of children, parents, and healthcare providers. Methods: This qualitative sub-study [...] Read more.
Background/Objectives: This study explores how children with cerebral palsy (CP) and their parents experience botulinum toxin type A (BoNT-A) treatment, focusing on emotional and procedural challenges and communication within the triad of children, parents, and healthcare providers. Methods: This qualitative sub-study was conducted within the WE-study, a randomized controlled trial on BoNT-A effects in children with CP. Semi-structured interviews with 20 parents and 18 children (aged 4–15 years, GMFCS I–II) were thematically analyzed. Results: Three themes were identified: Preparing for the treatment, Being in the moment, and Adapting after treatment. Pre-procedural anxiety was common, with children describing nervousness or physical discomfort in the days before the treatment. During the procedure, pain management and sedation choices influenced children’s experiences, with healthcare providers being the primary source of information. After treatment, some children experienced temporary walking instability, but most quickly resumed daily activities. Communication primarily occurred between healthcare providers and each party individually, rather than through a triadic interaction. Conclusions: BoNT-A treatment involves both emotional distress and adaptation. Strengthening child-inclusive communication, structured preparation, and collaboration within the triad may improve treatment experiences and better align care with child-centered principles. Future research should explore strategies to enhance child involvement in repeated treatments. Full article
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