RESUMO
Camelid single-domain antibodies (VHH) represent a promising class of immunobiologicals for therapeutic applications due to their remarkable stability, specificity, and therapeutic potential. To enhance the effectiveness of antivenoms for snakebites, various methods have been explored to address limitations associated with serum therapy, particularly focusing on mitigating local damage and ensuring sustainable production. Our study aimed to characterize the pharmacological profile and neutralization capacity of anti-Phospholipase A2 (PLA2) monomeric VHH (Genbank accessions: KC329718). Using a post-envenoming mouse model, we used intravital microscopy to assess leukocyte influx, measured CK and LDH levels, and conducted a histopathology analysis to evaluate VHH KC329718's ability to neutralize myotoxic activity. Our findings demonstrated that VHH KC329718 exhibited heterogeneous distribution in muscle tissue. Treatment with VHH KC329718 reduced leukocyte influx caused by BthTX-I (a Lys-49 PLA2) by 28 %, as observed through intravital microscopy. When administered at a 1:10 ratio [venom or toxin:VHH (w/w)], VHH KC329718 significantly decreased myotoxicity, resulting in a 35-40 % reduction in CK levels from BthTX-I and BthTX-II (an Asp-49 PLA2) and a 60 % decrease in CK levels from B. jararacussu venom. LDH levels also showed reductions of 60%, 80%, and 60% induced by BthTX-I, BthTX-II, and B. jararacussu venom, respectively. Histological analysis confirmed the neutralization potential, displaying a significant reduction in tissue damage and inflammatory cell count in mice treated with VHH KC329718 post B. jararacussu venom inoculation. This study underscores the potential of monomeric anti-PLA2 VHH in mitigating myotoxic effects, suggesting a promising avenue for the development of new generation antivenoms to address current therapeutic limitations.
Assuntos
Antivenenos , Bothrops , Fosfolipases A2 , Anticorpos de Domínio Único , Mordeduras de Serpentes , Animais , Anticorpos de Domínio Único/imunologia , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/imunologia , Antivenenos/farmacologia , Antivenenos/uso terapêutico , Camundongos , Fosfolipases A2/metabolismo , Venenos de Crotalídeos/imunologia , Venenos de Crotalídeos/toxicidade , Masculino , Modelos Animais de Doenças , Músculo Esquelético/patologia , Músculo Esquelético/efeitos dos fármacos , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Humanos , Creatina Quinase/sangueRESUMO
Snakebites are an important Public Health issue, so much so that they are classified as Neglected Tropical Diseases (NTDs) in category A, by the World Health Organization (WHO). The biggest victims are young people, mainly rural workers, who often, due to temporary or even permanent disability, end up affecting not only their family, but their entire community. Annually in Brazil, 90% of reported cases are caused by the Bothrops genus. Bothrops jararacussu is probably one of the most fearsome and imposing of this genus. Its bite is painful, and the main local effect is myonecrosis, which can result in deficient muscle regeneration. Its venom is mainly composed of phospholipases A2, which is why it has an important myotoxic effect. These phospholipases are myotoxic components that directly destabilize the plasma membrane of muscle cells, causing the influx of calcium ions and so hypercontraction and the early appearance of cells with delta lesions. Understanding the pathogenesis of poisoning is of fundamental importance for studies of better therapies.
O ofidismo é uma questão importante de Saúde Pública, tanto que está classificado como Doenças Tropicais Negligenciadas (DTN) na categoria A, pela Organização Mundial da Saúde (OMS). As maiores vítimas são jovens, principalmente trabalhadores rurais, que muitas vezes pela incapacidade temporária ou até permanente, acabam afetando não só sua família, mas toda a sua comunidade. Anualmente no Brasil, 90% dos casos notificados são causados pelo gênero Bothrops. A Bothrops jararacussu é provavelmente uma das mais temíveis e imponentes deste gênero. Sua picada é dolorosa e como principal efeito local temos a mionecrose, que pode ter como sequela uma regeneração muscular deficiente. Seu veneno é composto principalmente por fosfolipases A2, o motivo de ter um efeito miotóxico importante. Essas fosfolipases são componentes miotóxicos que desestabilizam diretamente a membrana plasmática das células musculares, causando o influxo de íons cálcio e consequentemente uma hipercontração e o aparecimento precoce de células com lesões delta. A compreensão da patogênese dos envenenamentos é de fundamental importância para estudos de melhores terapias.
RESUMO
Envenomation by Bothrops snakes and Apis mellifera bee may imply systemic disorders which affect well-perfused organs such as kidneys, a process that can lead to acute renal failure. Nevertheless, there is scarce information regarding a direct renal cell effect and the putative antagonism by antivenoms. Here the cytotoxic effect of B. jararacussu and A. mellifera venoms was evaluated in the renal proximal tubule cell line LLC-PK1, as well as the antagonism of this effect by heparin. B. jararacussu venom showed significant cytotoxicity as assessed by LDH release and MTT reduction, with a sharp decline of the cell number after 180 min (>90% at 50 µg/mL). A. mellifera venom produced a much faster and potent cytotoxic activity, conferring almost no viable cells after 15 min at 25 µg/mL. Phase contrast microscopy revealed that while B. jararacussu venom induced a progressive loss of cell adhesion and detachment, A. mellifera venom promoted a rapid plasma membrane disruption and nuclear condensation suggestive of necrotic cell death. Pre-incubation of both venoms with heparin for 30 min significantly reduced cytotoxicity. Our results demonstrate direct toxicity of B. jararacussu and A. mellifera venoms toward renal cells but with distinct kinetics and cell pattern, suggesting different mechanisms of action. In addition, the antagonistic, cytoprotective effect of heparin ascribes such compound as a promising drug for preventing renal failure from envenomation.
Assuntos
Antineoplásicos , Bothrops , Venenos de Crotalídeos , Abelhas , Animais , Heparina/farmacologia , Antivenenos/farmacologia , Venenos de Crotalídeos/toxicidade , RimRESUMO
Objetivo: Avaliar se a fotobiomodulação isolada e em associação com a soroterapia, modula fatores pró- e anti-inflamatórios, bem como o reparo e a função motora de músculos de camundongos injetados com veneno de Bothrops jararacussu. Métodos: Camundongos (Swiss, machos, 45 dias, 18-22g) foram submetidos experimentalmente a modelo de mionecrose causada por reações locais desencadeadas pelo envenenamento botrópico (injeção intra-muscular na pata posterior direita), soroterapia (uma única vez, pela via intra-venosa, 45 minutos após o envenenamento) e fotobiomodulação (LASER de baixa intensidade - 660nm, potência média de 100mW e dose de 3,0J de energia). Em seguida, foram distribuídos nos seguintes grupos: veneno (V), antiveneno (A), LASER (L), antiveneno+LBI (AL) e controle (C). A fotobiomodulação ocorreu no músculo envenenado e a cada 24h, por até 14. Incilamente foi testada a ação miotóxica do modelo de lesão proposto e após estes procedimentos, foram coletadas amostras de tecido muscular: 4 horas, 1, 7, 14 e 21 dias pós-envenenamento; para realização de análises histológicas, dosagem de mieloperoxidase (MPO) e N-acetil-β-D-glicosaminidase (NAG), níveis de CK-residual, citocinas (método de ELISA): IL-1β, TNF-⍺, IL-6 e IL-10 e (método de Western Blotting) CD68, CD206, VEGF, TGF-βMyoD, além da realização de teste funcionais: rotarod e análise da marcha. Resultados: As análises dos desfechos propostos e as comparações intergrupos, demonstraram que o protocolo de fotobiomodulação associado à soroterapia promoveu a presença de áreas de maior concentração de características de regeneração muscular, detectadas nas análises histológicas e mediante o aumento dos níveis de CK-residual. Além disso, apresentou aspectos de proteção do tecido muscular, uma vez que conteve os níveis de infiltrado inflamatório neutrofílico nos tempos mais precoces do presente estudo. Foram identificados melhores índices funcionais e detectadas características anti-inflamatórias e reparadoras da lesão, mediante os aumentos dos níveis de CD206, IL-10, TGF-β e MyoD. Conclusões: O protocolo de fotobiomodulação, principalmente quando associado à soroterapia; se mostrou efetivo para modular os fatores anti-inflamatórios, regenerativos e as características funcionais.
RESUMO
Around 70% of the ophidian accidents reported in Brazil (2021) are from Bothrops genus snakebites. Intense inflammatory reaction in the local tissue with, in severe cases of bothropic envenomation, dysfunction of affected organ. Bothropstoxin-I (BthTX-I), isolated from Bothrops jararacussu venom, is a phospholipase A2 (PLA2) involved in inflammatory process and tissue damage. Cooperation between tissue components and immune cells, such as the macrophage, is critical for the repair of the injured site. The inflammatory response is initiated by detecting signs of acute tissue damage due the disturbance in the homeostasis (DAMPs) and/or by recognition of pathogen-associated molecular patterns (PAMPs). Several receptors are involved in the detection of PAMPs and DAMPs, and among them are the inflammasome. Therefore, it has been reported that the inflammasome participates in the induction and resolution of inflammatory response induced by different microbial antigens and/or those. Mice genetically selected for maximum (AIRmax) and minimum (AIRmin) acute inflammatory response to the Biogel, have been useful for the studies of the mechanisms involved in the inflammatory response. Therefore, our focus is to evaluate the inflammatory process induced by BthTX-I in AIRmax and AIRmin mice. Therefore, the BthTX-I was obtained from the B.jararacussu venom in quantity and purity for the next experiments. Furthermore, the BthTX-I was able to induce myotoxicity in AIRMax and AIRMin mice, which will allow the development of next experiments and studies to contribute for the understanding the mechanisms involved in the inflammatory process.
Cerca de 70 % dos acidentes ofídicos relatados no Brasil, em 2021, são resultantes de picadas de serpentes do gênero Bothrops. Intensa reação inflamatória é observada na lesão tecidual com relatos de disfunção do órgão afetado em casos graves de envenenamento botrópico. Bothropstoxina-I (BthTX-I), isolada do veneno de Bothrops jararacussu, é uma fosfolipase A2 (FLA2) envolvida no processo inflamatório e lesão local. A cooperação entre componentes teciduais e células imunes, como o macrófago, é fundamental para o reparo do local lesionado. A resposta inflamatória é iniciada por meio da detecção de sinais resultantes do dano tecidual devido à quebra da homeostasia (DAMPs) e/ou por reconhecimento de padrões moleculares associados aos patógenos (PAMPs). Diversos receptores estão envolvidos na detecção de PAMPs e DAMPs e, dentre eles estão os inflamassomas. Portanto, têm sido demonstrada a participação do inflamassoma na indução e regulação da resposta inflamatória induzida por antígenos microbianos e/sinais de danos teciduais. Camundongos geneticamente selecionados para máxima (AIRmax) e mínima (AIRmin) resposta inflamatória aguda ao Biogel, têm sido utilizados como modelo experimental para o estudo dos mecanismos envolvidos na resposta inflamatória. Isto posto, temos como foco avaliar a ação da BthTX-I sobre o processo inflamatório em camundongos AIRmax e AIRmin. Portanto, a BthTX-I foi obtida a partir do veneno de B. jararacussu em quantidade e pureza para a realização dos experimentos. Além disso, a BthTX-I purificada foi capaz de induzir atividade miotóxica em camundongos AIRMax e AIRMin, o que permitirá o desenvolvimento de novos estudos e experimentos sobre os fatores/mecanismos que medeiam a resposta inflamatória.
RESUMO
The worrisome emergence of pathogens resistant to conventional drugs has stimulated the search for new classes of antimicrobial and antiparasitic agents from natural sources. Antimicrobial peptides (AMPs), acting through mechanisms that do not rely on the interaction with a specific receptor, provide new possibilities for the development of drugs against resistant organisms. This study sought to purify and proteomically characterize the antimicrobial and antiparasitic peptidomes of B. atrox and B. jararacussu snake venoms against Gram-positive (Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus-MRSA), Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria, and the protozoan parasites Leishmania amazonensis and Plasmodium falciparum (clone W2, resistant to chloroquine). To this end, B. atrox and B. jararacussu venom peptides were purified by combination of 3 kDa cut-off Amicon® ultracentrifugal filters and reverse-phase high-performance liquid chromatography, and then identified by electrospray-ionization Ion-Trap/Time-of-Flight mass spectrometry. Fourteen distinct peptides, with masses ranging from 443.17 to 1383.73 Da and primary structure between 3 and 13 amino acid residues, were sequenced. Among them, 13 contained unique sequences, including 4 novel bradykinin-potentiating-like peptides (BPPs), and a snake venom metalloproteinase tripeptide inhibitor (SVMPi). Although commonly found in Viperidae venoms, except for Bax-12, the BPPs and SVMPi here reported had not been described in B. atrox and B. jararacussu venoms. Among the novel peptides, some exhibited bactericidal activity towards P. aeruginosa and S. aureus, had low hemolytic effect, and were devoid of antiparasitic activity. The identified novel antimicrobial peptides may be relevant in the development of new drugs for the management of multidrug-resistant Gram-negative and Gram-positive bacteria.
Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Venenos de Crotalídeos/química , Peptídeos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antimaláricos/química , Antimaláricos/farmacologia , Bothrops , Venenos de Crotalídeos/isolamento & purificação , Hemolíticos/química , Hemolíticos/farmacologia , Humanos , Leishmania/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/isolamento & purificação , Plasmodium falciparum/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Staphylococcus aureus/efeitos dos fármacosRESUMO
Photobiomodulation using light-emitting diode (LED) treatment has analgesic and anti-inflammatory effects which can be an effective therapeutic associated with serum therapy for local treatment of snakebites. Here we explored the effects of LED treatment on isolated macrophage under Bothrops jararacussu venom. Results showed that LED induced IL-6 and TNF-α genes down-regulation and, TGF and ARG1 genes up-regulation which indicates a polarization of macrophages to an M2 phenotype contributing to both tissue repair and resolution of inflammation.
Assuntos
Bothrops , Venenos de Crotalídeos , Terapia com Luz de Baixa Intensidade , Animais , Macrófagos , Camundongos , FenótipoRESUMO
Envenoming caused by snakebites is a very important neglected tropical disease worldwide. The myotoxic phospholipases present in the bothropic venom disrupt the sarcolemma and compromise the mechanisms of energy production, leading to myonecrosis. Photobiomodulation therapy (PBMT) has been used as an effective tool to treat diverse cases of injuries, such as snake venom-induced myonecrosis. Based on that, the aim of this study was to analyze the effects of PBMT through low-level laser irradiation (904 nm) on the muscle regeneration after the myonecrosis induced by Bothrops jararacussu snake venom (Bjssu) injection, focusing on myogenic regulatory factors expression, such as Pax7, MyoD, and Myogenin (MyoG). Male Swiss mice (Mus musculus), 6-8-week-old, weighing 22 ± 3 g were used. Single sub-lethal Bjssu dose or saline was injected into the right mice gastrocnemius muscle. At 3, 24, 48, and 72 h after injections, mice were submitted to PBMT treatment. When finished the periods of 48 and 72 h, mice were euthanized and the right gastrocnemius were collected for analyses. We observed extensive inflammatory infiltrate in all the groups submitted to Bjssu injections. PBMT was able to reduce the myonecrotic area at 48 and 72 h after envenomation. There was a significant increase of MyoG mRNA expression at 72 h after venom injection. The data suggest that beyond the protective effect promoted by PBMT against Bjssu-induced myonecrosis, the low-level laser irradiation was able to stimulate the satellite cells, thus enhancing the muscle repair by improving myogenic differentiation.
Assuntos
Bothrops , Venenos de Crotalídeos/toxicidade , Regulação da Expressão Gênica/efeitos da radiação , Terapia a Laser , Miogenina/metabolismo , Necrose/terapia , Animais , Diferenciação Celular , Terapia com Luz de Baixa Intensidade , Masculino , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/efeitos da radiação , Miogenina/genéticaRESUMO
Several reports have suggested that photobiomodulation, owing to its analgesic, anti-inflammatory, and healing effects, may be an effective therapeutic option for local effects of snakebites when the availability and accessibility of conventional serum therapy are inefficient and far from medical care centers. Although there have been studies that demonstrate the application of photobiomodulation in the treatment of local adverse events due to snakebites from snakes of the genus Bothrops, its role in the activation of leukocytes, particularly macrophages, has not been evaluated. Here, we assessed the effect of light-emitting diode (LED) treatment on macrophage activation induced by B. jararacussu venom (BjV). LED treatment caused an increase in the viability of macrophages incubated with BjV. This treatment reduced reactive oxygen species (ROS) and nitric oxide (NO) production by macrophages after incubation with BjV. However, LED treatment did not interfere with IL-1ß and IL-10 production by macrophages after incubation with BjV. In conclusion, this study showed that LED treatment has the potential to be used in combination with conventional serum therapy to prevent or minimize the progression of local to severe symptoms after Bothrops envenomation.