RESUMEN
Purpose: Glaucoma, one of the leading causes of irreversible blindness, is a common progressive optic neuropathy characterised by visual field defects and structural changes to the optic nerve head (ONH). There is extracellular matrix (ECM) accumulation and fibrosis of the lamina cribrosa (LC) in the ONH, and consequently increased tissue stiffness of the LC connective tissue. Integrins are cell surface proteins that provide the key molecular link connecting cells to the ECM and serve as bidirectional sensors transmitting signals between cells and their environment to promote cell adhesion, proliferation, and remodelling of the ECM. Here, we investigated the expression of αVß3 integrin in glaucoma LC cell, and its effect on stiffness-induced ECM gene transcription and cellular proliferation rate in normal (NLC) and glaucoma (GLC) LC cells, by down-regulating αVß3 integrin expression using cilengitide (a known potent αVß3 and αVß5 inhibitor) and ß3 integrin siRNA knockdown. Methods: GLC cells were compared to age-matched controls NLC to determine differential expression levels of αVß3 integrin, ECM genes (Col1A1, α-SMA, fibronectin, vitronectin), and proliferation rates. The effects of αVß3 integrin blockade (with cilengitide) and silencing (with a pool of four predesigned αVß3 integrin siRNAs) on ECM gene expression and proliferation rates were evaluated using both reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting in the human NLC cells cultured on soft (4 kPa) and stiff (100 kPa) substrate and in GLC cells grown on standard plastic plates. Results: αVß3 integrin gene and protein expression were enhanced (p < 0.05) in GLC cells as compared to NLC. Both cilengitide and siRNA significantly reduced αVß3 expression in GLC. When NLC were grown in the stiff substrate, cilengitide and siRNA also significantly reduced the increased expression in αVß3, ECM components, and proliferation rate. Conclusions: Here, we provide evidence of cilengitide- and siRNA-mediated silencing of αVß3 integrin expression, and inhibition of ECM synthesis in LC cells. Therefore, αVß3 integrin may be a promising target for the development of novel anti-fibrotic therapies for treating the LC cupping of the ONH in glaucoma.
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Proliferación Celular , Glaucoma , Integrina alfaVbeta3 , Mecanotransducción Celular , Humanos , Integrina alfaVbeta3/metabolismo , Integrina alfaVbeta3/genética , Glaucoma/patología , Glaucoma/metabolismo , Glaucoma/genética , Matriz Extracelular/metabolismo , Disco Óptico/metabolismo , Disco Óptico/patología , Venenos de Serpiente , Persona de Mediana Edad , Masculino , Anciano , FemeninoRESUMEN
The variability in snake composition presents a significant challenge in accessing an effective broad-spectrum antivenom. These highly complex mixtures can result in numerous deleterious effects affecting thousands of individuals worldwide, particularly in Asia, sub-Saharan Africa, and Latin America. While the administration of antivenom remains a recommended treatment for snakebite envenomation and is the primary means to prevent systemic damage, there are limitations concerning specificity, reversal of local effects, and economic factors that hinder the availability of these antibodies. In this review, we have compiled information on the use of small molecule therapeutics in initial first-aid treatments before antivenom administration. These enzyme inhibitors have shown promise as viable candidates to broaden our treatment approaches, simplify procedures, reduce costs, and improve the clinical outcomes of affected patients.
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Antivenenos , Mordeduras de Serpientes , Mordeduras de Serpientes/tratamiento farmacológico , Antivenenos/uso terapéutico , Humanos , Animales , Venenos de Serpiente/antagonistas & inhibidores , Inhibidores Enzimáticos/uso terapéuticoRESUMEN
Despite the wide range of institutions that maintain venomous snakes in captivity in Brazil there are no comprehensive data on the occurrence of snakebites and envenomations in these places. We examined the range of native and exotic species of venomous snakes kept by Brazilian zoos and serpentaria (scientific and commercial) and assessed the frequency of snakebites in workers handling these snakes during a 10-year period (2012-2021). Twenty-two (73.3%) of 30 institutions returned a standard questionnaire, including 15 serpentaria and 7 zoos that together kept 10,607 venomous snakes in 2022/2023. Commercial and scientific serpentaria had many more snakes (n = 10,550, consisting of 10,499 native specimens and 51 exotic specimens) than zoos (n = 57 native specimens), with two genera accounting for the majority of native species (Bothrops spp. = 84.5% and Crotalus durissus ssp. = 13.5%). Thirty-seven snakebites were reported and involved primarily the hands (33), seven of which occurred during venom extraction and 30 in other circumstances, most of them while handling/manipulating the cages or snake boxes (10) and restraining (9) or feeding (5) the snake. In addition, there were two cases of venom accidently sprayed on the face, including the eyes. Most bites were caused by Bothrops spp. (31), followed by C. durissus ssp. (4), Lachesis muta (1) and Micrurus corallinus (1). Thirty-three bites (89.2%) were treated with antivenom, with four bites to the fingers by Bothrops spp. resulting in local functional sequelae. There were 366,918 venom extractions with a ratio of 1.9 bites/100,000 extractions; no bites were recorded in the six institutions that sedated the snakes prior to venom extraction, which accounted for 22.7% of all extractions. These findings show that although snakebites are rare in Brazilian zoos and serpentaria, severe envenomation may occur. The occurrence of snakebites could be reduced by measures such as sedation of the snakes before venom extraction.
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Animales de Zoológico , Mordeduras de Serpientes , Mordeduras de Serpientes/epidemiología , Animales , Brasil/epidemiología , Humanos , Venenos de Serpiente , Bothrops , Crotalus , Serpientes , Serpientes VenenosasRESUMEN
HER2-positive breast cancer, representing 15-20% of all breast cancer cases, often develops resistance to the HER2-targeted therapy trastuzumab. Unfortunately, effective treatments for advanced HER2-positive breast cancer remain scarce. This study aims to investigate the roles of ITGß3, and Hedgehog signaling in trastuzumab resistance and explore the potential of combining trastuzumab with cilengitide as a therapeutic strategy. Quantitative gene expression analysis was performed to assess the transcription of EMT (epithelial-mesenchymal transition) markers Slug, Snail, Twist2, and Zeb1 in trastuzumab-resistant HER2-positive breast cancer cells. The effects of ITGß3 and Hedgehog signaling were investigated. Additionally, the combination therapy of trastuzumab and cilengitide was evaluated. Acquired trastuzumab resistance induced the transcription of Slug, Snail, Twist2, and Zeb1, indicating increased EMT. This increased EMT was mediated by ITGB3 and Hedgehog signaling. ITGß3 regulated both the Hedgehog pathway and EMT, with the latter being independent of the Hedgehog pathway. The combination of trastuzumab and cilengitide showed a synergistic effect, reducing both EMT and Hedgehog pathway activity. Targeting ITGß3 with cilengitide, combined with trastuzumab, effectively suppresses the Hedgehog pathway and EMT, offering a potential strategy to overcome trastuzumab resistance and improve outcomes for HER2-positive breast cancer patients.
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Neoplasias de la Mama , Resistencia a Antineoplásicos , Transición Epitelial-Mesenquimal , Integrina beta3 , Receptor ErbB-2 , Trastuzumab , Humanos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Transición Epitelial-Mesenquimal/genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Trastuzumab/farmacología , Trastuzumab/uso terapéutico , Integrina beta3/metabolismo , Integrina beta3/genética , Receptor ErbB-2/metabolismo , Receptor ErbB-2/genética , Línea Celular Tumoral , Transducción de Señal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas Hedgehog/metabolismo , Venenos de SerpienteRESUMEN
Background: Snakebite is a global environmental and occupational hazard and a significant public health threat. In rural areas, snakebite cases often go unreported and undocumented due to the lack of access to well-structured healthcare facilities/infrastructure. In some cases, the need for antisnake venom (ASV) far outstrips supply, negatively affecting treatment outcomes. This study, therefore, assessed the epidemiological characteristics of snakebite cases, their management, and how antivenoms are utilised at the selected hospital in the Jasikan District Hospital. Methods: A 6-year retrospective study using secondary data from antivenom return forms (pharmacy records), clinical records (patient folders), the District Health Information Management System-2 (DHIMS-2) database, and consulting room registers was carried out in selected hospitals in the Jasikan District, Oti, Ghana. Results: The predominant symptom of snakebite was localised pain (71.4%). The snakebite commonly occurred at home (19%) and on farms (18%). Of the 98 snakebite cases, ASV was administered to 73 (74.5%) cases. Supportive treatment applied included prophylactic antitetanus immunoglobulin (ATS) (80.6%), prophylactic antibiotics (63%), corticosteroids (80.6%), and analgesics (63%). 95% (n = 94) of complete recoveries were recorded; three were discharged against medical advice, and one was mortality. The supply and use of antivenom were erratic throughout the months of high incidence, partly due to inconsistent availability at the Regional Medical Stores. The average ASV vials and hospital stay duration were 1.23 ± 0.86 vials and 2.67 ± 1.97 days, respectively. Although the peak of snakebites occurs in April, May, and June, the demand for antivenom in April and May exceeded supply. Conclusion: The outcome of most snakebite case management was appropriate, irrespective of inadequate ASV supply in certain months. The erratic antivenom supply should be aligned with seasonal and facility-use patterns to enhance regional snakebite management.
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Antivenenos , Mordeduras de Serpientes , Mordeduras de Serpientes/epidemiología , Mordeduras de Serpientes/tratamiento farmacológico , Humanos , Ghana/epidemiología , Antivenenos/uso terapéutico , Masculino , Estudios Retrospectivos , Femenino , Adulto , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Anciano , Preescolar , Venenos de SerpienteRESUMEN
Several species during evolution suffered random mutations in response to various environmental factors, which resulted in the formation of venom in phylogenetically distant species. The composition of the venom of most species is poorly known. Snake venom is well characterized while most species have poorly known composition. In contrast, snake venoms are well characterized which proteins and peptides are the main active and most abundant constituents. 42 protein families have been identified, including metalloproteins known as metalloproteinases. These macromolecules are enzymes with zinc in their active site derived from the disintegrin A and metalloproteinase (ADAM) cellular family and are categorized into three classes (PI, PII and PIII) according to their domain organization. The snake venom metalloproteinases (SVMP) are cytotoxic, neurotoxic, myotoxic and/or hematotoxic with a crucial role in the defense and restraint of prey. In this scenario envenoming represents a danger to human health and has been considered a neglected disease worldwide, particularly in tropical and subtropical countries. Nevertheless, recently advances in "omics" technologies have demonstrated interesting biological activities of SVMPs such as antimicrobial, anticancer, against cardiovascular diseases and nervous system disorders. Metalloproteins have the therapeutic potential to be converted into drugs as other components of the venom have undergone this process (e.g., captopril, tirefiban and eptifibatide). So, this chapter is focused on the metalloproteins found in the secretions of venomous species, highlight some aspects such as structure, biological activity, pharmacological therapeutic potential and on.
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Metaloproteínas , Venenos de Serpiente , Animales , Humanos , Venenos de Serpiente/metabolismo , Venenos de Serpiente/química , Venenos de Serpiente/enzimología , Metaloproteínas/metabolismo , Metaloproteínas/química , Metaloproteínas/antagonistas & inhibidoresRESUMEN
Metastatic melanoma, a deadly form of skin cancer, often develops resistance to the BRAF inhibitor drug vemurafenib, highlighting the need for understanding the underlying mechanisms of resistance and exploring potential therapeutic strategies targeting integrins and TGF-ß signalling. In this study, the role of integrins and TGF-ß signalling in vemurafenib resistance in melanoma was investigated, and the potential of combining vemurafenib with cilengitide as a therapeutic strategy was investigated. In this study, it was found that the transcription of PAI1 and p21 was induced by acquired vemurafenib resistance, and ITGA5 levels were increased as a result of this resistance. The transcription of ITGA5 was mediated by the TGF-ß pathway in the development of vemurafenib resistance. A synergistic effect on the proliferation of vemurafenib-resistant melanoma cells was observed with the combination therapy of vemurafenib and cilengitide. Additionally, this combination therapy significantly decreased invasion and colony formation in these resistant cells. In conclusion, it is suggested that targeting integrins and TGF-ß signalling, specifically ITGA5, ITGB3, PAI1, and p21, may offer promising approaches to overcoming vemurafenib resistance, thereby improving outcomes for metastatic melanoma patients.
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Resistencia a Antineoplásicos , Melanoma , Venenos de Serpiente , Vemurafenib , Vemurafenib/farmacología , Vemurafenib/uso terapéutico , Humanos , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Melanoma/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Línea Celular Tumoral , Venenos de Serpiente/farmacología , Integrina beta3/metabolismo , Integrina beta3/genética , Factor de Crecimiento Transformador beta/metabolismo , Transducción de Señal/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Integrinas/metabolismo , Integrinas/antagonistas & inhibidores , Integrina alfa5/metabolismo , Integrina alfa5/genética , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Indoles/farmacología , Indoles/uso terapéutico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Antineoplásicos/farmacología , Antineoplásicos/uso terapéuticoRESUMEN
Over a century has passed since Alois Alzheimer first described Alzheimer's disease (AD), and since then, researchers have made significant strides in understanding its pathology. One key feature of AD is the presence of amyloid-ß (Aß) peptides, which form amyloid plaques, and therefore, it is a primary target for treatment studies. Naturally occurring peptides have garnered attention for their potential pharmacological benefits, particularly in the central nervous system. In this study, nine peptide derivatives of Crotamine, a polypeptide from Crotalus durissus terrificus Rattlesnake venom, as well as one d-enantiomer, were evaluated for their ability to modulate Aß42 aggregation through various assays such as ThT, QIAD, SPR, and sFIDA. All tested peptides were able to decrease Aß42 aggregation and eliminate Aß42 aggregates. Additionally, all of the peptides showed an affinity for Aß42. This study is the first to describe the potential of crotamine derivative peptides against Aß42 aggregation and to identify a promising d-peptide that could be used as an effective pharmacological tool against AD in the future.
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Péptidos beta-Amiloides , Venenos de Crotálidos , Fragmentos de Péptidos , Péptidos beta-Amiloides/metabolismo , Humanos , Animales , Agregado de Proteínas/efectos de los fármacos , Venenos de Serpiente/química , Péptidos/farmacología , Péptidos/química , CrotalusRESUMEN
Snakebite envenomation has been a long-standing global issue that is difficult to treat, largely owing to the flawed nature of current immunoglobulin-based antivenom therapy and the complexity of snake venoms as sophisticated mixtures of bioactive proteins and peptides. Comprehensive characterisation of venom compositions is essential to better understanding snake venom toxicity and inform effective and rationally designed antivenoms. Additionally, a greater understanding of snake venom composition will likely unearth novel biologically active proteins and peptides that have promising therapeutic or biotechnological applications. While a bottom-up proteomic workflow has been the main approach for cataloguing snake venom compositions at the toxin family level, it is unable to capture snake venom heterogeneity in the form of protein isoforms and higher-order protein interactions that are important in driving venom toxicity but remain underexplored. This review aims to highlight the importance of understanding snake venom heterogeneity beyond the primary sequence, in the form of post-translational modifications that give rise to different proteoforms and the myriad of higher-order protein complexes in snake venoms. We focus on current top-down proteomic workflows to identify snake venom proteoforms and further discuss alternative or novel separation, instrumentation, and data processing strategies that may improve proteoform identification. The current higher-order structural characterisation techniques implemented for snake venom proteins are also discussed; we emphasise the need for complementary and higher resolution structural bioanalytical techniques such as mass spectrometry-based approaches, X-ray crystallography and cryogenic electron microscopy, to elucidate poorly characterised tertiary and quaternary protein structures. We envisage that the expansion of the snake venom characterisation "toolbox" with top-down proteomics and high-resolution protein structure determination techniques will be pivotal in advancing structural understanding of snake venoms towards the development of improved therapeutic and biotechnology applications.
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Proteómica , Venenos de Serpiente , Venenos de Serpiente/química , Animales , Procesamiento Proteico-Postraduccional , Isoformas de ProteínasRESUMEN
Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical manifestations, local and systemic haemorrhage are of particular relevance, as this may result in ischemia, organ failure and even cardiovascular shock. Thus far, in vitro studies have failed to recapitulate the haemorrhagic effects observed in vivo. Here, we present an organ-on-a-chip approach to investigate the effects of four different snake venoms on a perfused microfluidic blood vessel model. We assess the effect of the venoms of four snake species on epithelial barrier function, cell viability, and contraction/delamination. Our findings reveal two different mechanisms by which the microvasculature is being affected, either by disruption of the endothelial cell membrane or by delamination of the endothelial cell monolayer from its matrix. The use of our blood vessel model may shed light on the key mechanisms by which tissue-damaging venoms exert their effects on the capillary vessels, which could be helpful for the development of effective treatments against snakebites.
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Dispositivos Laboratorio en un Chip , Venenos de Serpiente , Animales , Humanos , Células Endoteliales/efectos de los fármacos , Hemorragia , Supervivencia Celular/efectos de los fármacos , Mordeduras de Serpientes/tratamiento farmacológico , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Sistemas MicrofisiológicosRESUMEN
The analysis and detection of snake venom toxins are a matter of great importance in clinical diagnosis for fast treatment and the discovery of new pharmaceutical products. Current detection methods have high associated costs and require the use of sophisticated bioreceptors, which in some cases are difficult to obtain. Herein, we report the synthesis of template-based molecularly imprinted micromotors for dynamic detection of α-bungarotoxin as a model toxin present in the venom of many-banded krait (Bungarus multicinctus). The specific recognition sites are built-in in the micromotors by incubation of the membrane template with the target toxin, followed by a controlled electrodeposition of a poly(3,4-ethylenedioxythiophene)/poly(sodium 4-styrenesulfonate) polymeric layer, a magnetic Ni layer to promote magnetic guidance and facilitate washing steps, and a Pt layer for autonomous propulsion in the presence of hydrogen peroxide. The enhanced fluid mixing and autonomous propulsion increase the likelihood of interactions with the target analyte as compared with static counterparts, retaining the tetramethylrhodamine-labeled α-bungarotoxin on the micromotor surface with extremely fast dynamic sensor response (after just 20 s navigation) in only 3 µL of water, urine, or serum samples. The sensitivity achieved meets the clinically relevant concentration postsnakebite (from 0.1 to 100 µg/mL), illustrating the feasibility of the approach for practical applications. The selectivity of the protocol is very high, as illustrated by the absence of fluorescence in the micromotor surface in the presence of α-cobratoxin as a representative toxin with a size and structure similar to those of α-bungarotoxin. Recoveries higher than 95% are obtained in the analysis of urine- and serum-fortified samples. The new strategy holds considerable promise for fast, inexpensive, and even onsite detection of several toxins using multiple molecularly imprinted micromotors with tailored recognition abilities.
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Bungarotoxinas , Bungarotoxinas/química , Bungarotoxinas/orina , Animales , Polímeros/química , Venenos de Serpiente/química , Bungarus , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Impresión Molecular , Ácidos SulfónicosRESUMEN
Phagocytosis, an essential process for host defense, requires the coordination of a variety of signaling reactions. MT-II, an enzymatically inactive Lys49 phospholipase A2 (PLA2) homolog, and MT-III, a catalytically-active Asp49 PLA2, are known to activate phagocytosis in macrophages. In this study, the signaling pathways mediating phagocytosis, focusing on protein kinases, were investigated. Macrophages from male Swiss mice peritoneum were obtained 96 h after intraperitoneal thioglycolate injection. Phagocytosis was evaluated using non-opsonized zymosan particles in the presence or absence of specific inhibitors, as well as PKC and PKC-α localization by confocal microscopy. Moreover, protein kinase C (PKC) activity was assessed by γP32 ATP in macrophages stimulated by both PLA2s. Data showed that both sPLA2s increased phagocytosis. Cytochalasin D, staurosporine/H7, wortmannin, and herbimycin, inhibitors of actin polymerization, PKC, phosphoinositide 3-kinase (PI3K), and protein tyrosine kinase (PTK), respectively, significantly reduced phagocytosis induced by both PLA2s. PKC activity was increased in macrophages stimulated by both PLA2s. Actin polymerization and talin were evidenced by immunofluorescence and talin was recruited 5 min after both PLA2s stimulation. PKC and PKC-α localization within the cell were increased after 60 min of MT-II and MT-III stimulation. These data suggest that the effect of both PLA2s depends on actin cytoskeleton rearrangements and the activation of PKC, PI3K, and PTK signaling events required for phagocytosis.
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Fagocitosis , Proteína Quinasa C-alfa , Transducción de Señal , Animales , Fagocitosis/efectos de los fármacos , Ratones , Transducción de Señal/efectos de los fármacos , Masculino , Proteína Quinasa C-alfa/metabolismo , Macrófagos/efectos de los fármacos , Fosfolipasas A2 Secretoras/metabolismo , Venenos de Serpiente/toxicidad , Rifabutina/análogos & derivados , Rifabutina/farmacologíaRESUMEN
Snakebite envenomation often induces acute kidney injury (AKI) and acute liver injury (ALI), leading to augmented injuries and poor rehabilitation. Phospholipase A2 (PLA2) and metalloproteinase (SVMP) present in venom are responsible for the envenomation-associated events. In this study, mice envenomed with Deinagkistrodon acutus, Naja atra, or Agkistrodon halys pallas venom exhibited typical AKI and ALI symptoms, including significantly increased plasma levels of myoglobin, free hemoglobin, uric acid, aspartate aminotransferase, and alanine aminotransferase and upregulated expression of kidney NGAL and KIM-1. These effects were significantly inhibited when the mice were pretreated with natural inhibitors of PLA2 and SVMP isolated from Sinonatrix annularis (SaPLIγ and SaMPI). The inhibitors protected the physiological structural integrity of the renal tubules and glomeruli, alleviating inflammatory infiltration and diffuse hemorrhage in the liver. Furthermore, the dual therapy alleviated oxidative stress and apoptosis in the kidneys and liver by mitigating mitochondrial damage, thereby effectively reducing the lethal effect of snake venom in the inhibitor-treated mouse model. This study showed that dual therapy with inhibitors of metalloproteinase and phospholipase can effectively prevent ALI and AKI caused by snake bites. Our findings suggest that intrinsic inhibitors present in snakes are prospective therapeutic agents for multi-organ injuries caused by snake envenoming.
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Lesión Renal Aguda , Metaloproteasas , Mordeduras de Serpientes , Animales , Lesión Renal Aguda/tratamiento farmacológico , Lesión Renal Aguda/patología , Ratones , Masculino , Metaloproteasas/antagonistas & inhibidores , Metaloproteasas/metabolismo , Mordeduras de Serpientes/tratamiento farmacológico , Mordeduras de Serpientes/complicaciones , Inhibidores de Fosfolipasa A2/farmacología , Fosfolipasas A2/metabolismo , Hígado/efectos de los fármacos , Hígado/patología , Hígado/metabolismo , Crotalinae , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Estrés Oxidativo/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/patología , Venenos de Crotálidos/toxicidad , Venenos de Serpiente , Apoptosis/efectos de los fármacos , Venenos ElapídicosRESUMEN
Establishing humane endpoints to minimize animal suffering in studies on snake venom toxicity and antivenom potency tests is crucial. Our findings reveal that Swiss mice exhibit early temperature drop following exposure to different snake venoms and combinations of venoms and antivenoms, predicting later mortality. Evaluating temperature we can identify within 3 h post-inoculation, the animals that will not survive in a period of 48 h. Implementing temperature as a criterion would significantly reduce animal suffering in these studies without compromising the outcomes.
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Antivenenos , Venenos de Serpiente , Animales , Ratones , Antivenenos/farmacología , Venenos de Serpiente/toxicidad , Temperatura Corporal/efectos de los fármacos , Temperatura , MasculinoRESUMEN
On the 26 th January 2023, a free to attend, 'improving in vivo snake venom research: a community discussion' meeting was held virtually. This webinar brought together researchers from around the world to discuss current neutralisation of venom lethality mouse assays that are used globally to assess the efficacy of therapies for snakebite envenoming. The assay's strengths and weaknesses were highlighted, and we discussed what improvements could be made to refine and reduce animal testing, whilst supporting preclinical antivenom and drug discovery for snakebite envenoming. This report summarises the issues highlighted, the discussions held, with additional commentary on key perspectives provided by the authors.
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Antivenenos , Mordeduras de Serpientes , Venenos de Serpiente , Antivenenos/uso terapéutico , Animales , Venenos de Serpiente/antagonistas & inhibidores , Ratones , Mordeduras de Serpientes/tratamiento farmacológico , HumanosRESUMEN
BACKGROUND: Snakebite envenomation inflicts a high burden of mortality and morbidity in sub-Saharan Africa. Antivenoms are the mainstay in the therapy of envenomation, and there is an urgent need to develop antivenoms of broad neutralizing efficacy for this region. The venoms used as immunogens to manufacture snake antivenoms are normally selected considering their medical importance and availability. Additionally, their ability to induce antibody responses with high neutralizing capability should be considered, an issue that involves the immunization scheme and the animal species being immunized. METHODOLOGY/PRINCIPAL FINDINGS: Using the lethality neutralization assay in mice, we compared the intrageneric neutralization scope of antisera generated by immunization of horses with monospecific, bispecific/monogeneric, and polyspecific/monogeneric immunogens formulated with venoms of Bitis spp., Echis spp., Dendroaspis spp., spitting Naja spp. or non-spitting Naja spp. It was found that the antisera raised by all the immunogens were able to neutralize the homologous venoms and, with a single exception, the heterologous congeneric venoms (considering spitting and non-spitting Naja separately). In general, the polyspecific antisera of Bitis spp, Echis spp, and Dendroaspis spp gave the best neutralization profile against venoms of these genera. For spitting Naja venoms, there were no significant differences in the neutralizing ability between monospecific, bispecific and polyspecific antisera. A similar result was obtained in the case of non-spitting Naja venoms, except that polyspecific antiserum was more effective against the venoms of N. melanoleuca and N. nivea as compared to the monospecific antiserum. CONCLUSIONS/SIGNIFICANCE: The use of polyspecific immunogens is the best alternative to produce monogeneric antivenoms with wide neutralizing coverage against venoms of sub-Saharan African snakes of the Bitis, Echis, Naja (non-spitting) and Dendroaspis genera. On the other hand, a monospecific immunogen composed of venom of Naja nigricollis is suitable to produce a monogeneric antivenom with wide neutralizing coverage against venoms of spitting Naja spp. These findings can be used in the design of antivenoms of wide neutralizing scope for sub-Saharan Africa.
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Antivenenos , Pruebas de Neutralización , Animales , Caballos/inmunología , Antivenenos/inmunología , Antivenenos/administración & dosificación , Ratones , África del Sur del Sahara , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Venenos de Serpiente/inmunología , Sueros Inmunes/inmunología , Venenos Elapídicos/inmunología , Mordeduras de Serpientes/inmunologíaRESUMEN
Animal-derived venom, like snake venom, has been proven to be valuable natural resources for the drug development. Previously, snake venom was mainly investigated in its pharmacological activities in regulating coagulation, vasodilation, and cardiovascular function, and several marketed cardiovascular drugs were successfully developed from snake venom. In recent years, snake venom fractions have been demonstrated with anticancer properties of inducing apoptotic and autophagic cell death, restraining proliferation, suppressing angiogenesis, inhibiting cell adhesion and migration, improving immunity, and so on. A number of active anticancer enzymes and peptides have been identified from snake venom toxins, such as L-amino acid oxidases (LAAOs), phospholipase A2 (PLA2), metalloproteinases (MPs), three-finger toxins (3FTxs), serine proteinases (SPs), disintegrins, C-type lectin-like proteins (CTLPs), cell-penetrating peptides, cysteine-rich secretory proteins (CRISPs). In this review, we focus on summarizing these snake venom-derived anticancer components on their anticancer activities and underlying mechanisms. We will also discuss their potential to be developed as anticancer drugs in the future.
Asunto(s)
Antineoplásicos , Venenos de Serpiente , Humanos , Venenos de Serpiente/química , Antineoplásicos/farmacología , Antineoplásicos/química , Animales , Neoplasias/tratamiento farmacológico , L-Aminoácido Oxidasa/química , L-Aminoácido Oxidasa/farmacología , Apoptosis/efectos de los fármacos , Fosfolipasas A2/metabolismo , Fosfolipasas A2/química , Toxinas Biológicas/química , Toxinas Biológicas/farmacologíaRESUMEN
Although non-front fanged snakes account for almost two-thirds of snake diversity, most studies on venom composition and evolution focus exclusively on front-fanged species, which comprise most of the clinically relevant accidents. Comprehensive reports on venom composition of non-front fanged snakes are still scarce for several groups. In this study, we address such shortage of knowledge by providing new insights about the venom composition among species of Phalotris, a poorly studied Neotropical dipsadid genus. Phalotris are known for their specialized venom delivery system and toxic venoms, which can cause life-threatening accidents in humans. We evaluate the venom-gland transcriptome of Phalotris, comparing the following three South American species: P. reticulatus for the Araucaria Pine forests, P. lemniscatus for the Pampa grasslands, and P. mertensi for the Brazilian Cerrado. Our results indicate similar venom profiles, in which they share a high expression level of Kunitz-type inhibitors (KUNZ). On the other hand, comparative analyses revealed substantial differences in the expression levels of C-type lectins (CTL) and snake venom metalloproteinases (SVMP). The diverse set of SVMP and CTL isoforms shows signals of positive selection, and we also identified truncated forms of type III SVMPs, which resemble type II and type I SVMPs of viperids. Additionally, we identified a CNP precursor hosting a proline-rich region containing a BPP motif resembling those commonly detected in viperid venoms with hypotensive activity. Altogether, our results suggest an evolutionary history favoring high expression levels of few KUNZ isoforms in Phalotris venoms, contrasting with a highly diverse set of SVMP and CTL isoforms. Such diversity can be comparable with the venom variability observed in some viperids. Our findings highlight the extreme phenotypic diversity of non-front fanged snakes and the importance to allocate greater effort to study neglected groups of Colubroidea.
Asunto(s)
Transcriptoma , Animales , Venenos de Serpiente/genética , Lectinas Tipo C/genética , Brasil , Metaloproteasas/genéticaRESUMEN
Investigating snake venom is necessary for developing new treatments for envenoming and harnessing the therapeutic potential that lies within venom toxins. Despite considerable efforts in previous research, several technical challenges remain for characterizing the individual components within such complex mixtures. Here, we present native and top-down mass spectrometry (MS) workflows that enable the analysis of individual venom proteins within complex mixtures and showcase the utility of these methodologies on King cobra (Ophiophagus hannah) venom. First, we coupled ion mobility spectrometry for separation and electron capture dissociation for charge reduction to resolve highly convoluted mass spectra containing multiple proteins with masses ranging from 55 to 127 kDa. Next, we performed a top-down glycomic analysis of a 25.5 kDa toxin, showing that this protein contains a fucosylated complex glycan. Finally, temperature-controlled nanoelectrospray mass spectrometry facilitated the top-down sequence analysis of a ß-cardiotoxin, which cannot be fragmented by collisional energy due to its disulfide bond pattern. The work presented here demonstrates the applicability of new and promising MS methods for snake venom analysis.
Asunto(s)
Venenos Elapídicos , Animales , Venenos Elapídicos/química , Elapidae , Venenos de Serpiente/química , Espectrometría de Movilidad Iónica/métodos , Espectrometría de Masas/métodos , Proteómica/métodos , Secuencia de AminoácidosRESUMEN
INTRODUCTION: Antivenom is widely accepted as an effective treatment for snake envenomation. This is despite very limited evidence supporting clinical effectiveness for major envenomation syndromes, and is mainly based on pre-clinical studies and observational studies without control groups. EFFECTIVENESS OF EARLY ANTIVENOM: Although antivenom exhibits efficacy by binding to snake toxins and preventing toxic injury in animals if pre-mixed with venom, this efficacy does not always translate to clinical effectiveness. There are many irreversible venom mediated effects that antivenom cannot neutralise or reverse, such as pre-synaptic neurotoxicity and myotoxicity. Fortunately, early antivenom appears to prevent some of these. PRACTICALITIES OF ADMINISTERING ANTIVENOM EARLY: With good evidence that early antivenom prevents some envenomation syndromes, the time between bite and antivenom administration must be reduced. This requires improving the initial assessment of snakebite patients, and improving early decision making based on clinical effects. CONCLUSION: Until there are improved, simplified, easy to use, rapid and inexpensive tests, whether available in the laboratory or preferably at the bedside that identify systemic envenomation, the key to early antivenom administration is early assessment and decision making based on systemic symptoms, including nausea, vomiting, headache and abdominal pain.