RESUMO
Monoamine insufficiency is suggested to be associated with depressive features such as sadness, anhedonia, insomnia, and cognitive dysfunction, but the mechanisms that cause it are unclear. We found that the acute-phase protein lipopolysaccharide-binding protein (LBP) inhibits monoamine biosynthesis by acting as an endogenous inhibitor of dopamine-ß-hydroxylase (DBH) and aromatic-L-amino-acid-decarboxylase (DDC). LBP expression was increased in individuals with depression and by diverse stress challenges in mice. LBP antibodies and LBP knockdown inhibited monoamine insufficiency and depression-like features in mice, which worsened with LBP overexpression or administration. Monoamine insufficiency and depression-like symptoms were not induced by stressful stimuli in LBP-deficient mice, further highlighting a role for LBP in stress-induced depression, and a peptide we designed that blocks LBP-DBH and LBP-DDC interactions showed anti-depression effects in mice. This study reveals an important role for LBP in regulating monoamine biosynthesis and suggests that targeting LBP may have potential as a treatment for some individuals with depression.
Assuntos
Proteínas de Transporte , Depressão , Camundongos , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/metabolismo , Glicoproteínas de Membrana/metabolismo , AminasRESUMO
SignificanceAn immunosuppressant protein (MTX), which facilitates virus infection by inhibiting leukotriene A4 hydrolase (LTA4H) to produce the lipid chemoattractant leukotriene B4 (LTB4), was identified and characterized from the submandibular salivary glands of the bat Myotis pilosus. To the best of our knowledge, this is a report of an endogenous LTA4H inhibitor in animals. MTX was highly concentrated in the bat salivary glands, suggesting a mechanism for the generation of immunological privilege and immune tolerance and providing evidence of viral shedding through oral secretions. Moreover, given that the immunosuppressant MTX selectively inhibited the proinflammatory activity of LTA4H, without affecting its antiinflammatory activity, MTX might be a potential candidate for the development of antiinflammatory drugs by targeting the LTA4-LTA4H-LTB4 inflammatory axis.
Assuntos
Inibidores Enzimáticos/metabolismo , Epóxido Hidrolases , Vírus da Influenza A Subtipo H1N1/metabolismo , Leucotrieno A4/metabolismo , Infecções por Orthomyxoviridae/enzimologia , Glândulas Salivares , Proteínas e Peptídeos Salivares/metabolismo , Viroses , Animais , Quirópteros , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Camundongos , Glândulas Salivares/enzimologia , Glândulas Salivares/virologiaRESUMO
Studies have shown significantly increased thromboembolic events at high altitude. We recently reported that transferrin could potentiate blood coagulation, but the underlying mechanism for high altitude-related thromboembolism is still poorly understood. Here, we examined the activity and concentration of plasma coagulation factors and transferrin in plasma collected from long-term human residents and short-stay mice exposed to varying altitudes. We found that the activities of thrombin and factor XIIa (FXIIa) along with the concentrations of transferrin were significantly increased in the plasma of humans and mice at high altitudes. Furthermore, both hypoxia (6% O2) and low temperature (0°C), 2 critical high-altitude factors, enhanced hypoxia-inducible factor 1α (HIF-1α) levels to promote the expression of the transferrin gene, whose enhancer region contains HIF-1α binding site, and consequently, to induce hypercoagulability by potentiating thrombin and FXIIa. Importantly, thromboembolic disorders and pathological insults in mouse models induced by both hypoxia and low temperature were ameliorated by transferrin interferences, including transferrin antibody treatment, transferrin downregulation, and the administration of our designed peptides that inhibit the potentiation of transferrin on thrombin and FXIIa. Thus, low temperature and hypoxia upregulated transferrin expression-promoted hypercoagulability. Our data suggest that targeting the transferrin-coagulation pathway is a novel and potentially powerful strategy against thromboembolic events caused by harmful environmental factors under high-altitude conditions.
Assuntos
Altitude , Trombofilia , Camundongos , Humanos , Animais , Transferrina/genética , Trombina/metabolismo , Temperatura , Hipóxia/metabolismo , Trombofilia/etiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismoRESUMO
Atherosclerosis is a chronic inflammatory disease of arterial wall. Mitochondrial DNA (mtDNA) and human antimicrobial peptide LL-37 (Cramp in mice) are involved in atherosclerosis. Recently, mtDNA has been found to escape from autophagy and cause inflammation. Normally, mtDNA as an inflammatogenic factor cannot escape from autophagy and degradation by DNase II. In this study, we found elevated amounts of LL37-mtDNA complex in atherosclerotic plasma and plaques. The complex was resistant to DNase II degradation and escaped from autophagic recognition, leading to activation of Toll-like receptor 9 (TLR9)-mediated inflammatory responses. Mouse model studies indicated that Cramp-mtDNA complex aggravated atherosclerotic lesion formation in apolipoprotein E-deficient mice and antibody treatment against the complex alleviated the lesion. These findings suggest that the LL-37-mtDNA complex acts as a key mediator of atherosclerosis formation, and thus represents a promising therapeutic target.
Assuntos
Aterosclerose/metabolismo , Autofagia/fisiologia , Catelicidinas/metabolismo , DNA Mitocondrial/metabolismo , Placa Aterosclerótica/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Peptídeos Catiônicos Antimicrobianos , Aterosclerose/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Placa Aterosclerótica/patologiaRESUMO
Cryptococcus neoformans (C. neoformans) is a pathogenic fungus that can cause life-threatening meningitis, particularly in individuals with compromised immune systems. The current standard treatment involves the combination of amphotericin B and azole drugs, but this regimen often leads to inevitable toxicity in patients. Therefore, there is an urgent need to develop new antifungal drugs with improved safety profiles. We screened antimicrobial peptides from the hemolymph transcriptome of Blaps rhynchopetera (B. rhynchopetera), a folk Chinese medicine. We found an antimicrobial peptide named blap-6 that exhibited potent activity against bacteria and fungi. Blap-6 is composed of 17 amino acids (KRCRFRIYRWGFPRRRF), and it has excellent antifungal activity against C. neoformans, with a minimum inhibitory concentration (MIC) of 0.81 µM. Blap-6 exhibits strong antifungal kinetic characteristics. Mechanistic studies revealed that blap-6 exerts its antifungal activity by penetrating and disrupting the integrity of the fungal cell membrane. In addition to its direct antifungal effect, blap-6 showed strong biofilm inhibition and scavenging activity. Notably, the peptide exhibited low hemolytic and cytotoxicity to human cells and may be a potential candidate antimicrobial drug for fungal infection caused by C. neoformans.
Assuntos
Antifúngicos , Peptídeos Antimicrobianos , Besouros , Cryptococcus neoformans , Testes de Sensibilidade Microbiana , Cryptococcus neoformans/efeitos dos fármacos , Animais , Antifúngicos/farmacologia , Antifúngicos/química , Besouros/microbiologia , Besouros/efeitos dos fármacos , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Humanos , Biofilmes/efeitos dos fármacos , Sequência de AminoácidosRESUMO
Ischemic stroke is a leading cause of death and disability worldwide. Increasing evidence indicates that ischemic stroke is a thromboinflammatory disease in which the contact-kinin pathway has a central role by activating pro-coagulant and pro-inflammatory processes. The blocking of distinct members of the contact-kinin pathway is a promising strategy to control ischemic stroke. Here, a plasma kallikrein and active FXII (FXIIa) inhibitor (sylvestin, contained 43 amino acids, with a molecular weight of 4790.4 Da) was first identified from forest leeches (Haemadipsa sylvestris). Testing revealed that sylvestin prolonged activated partial thromboplastin time without affecting prothrombin time. Thromboelastography and clot retraction assays further showed that it extended clotting time in whole blood and inhibited clot retraction in platelet-rich plasma. In addition, sylvestin prevented thrombosis in vivo in FeCl3-induced arterial and carrageenan-induced tail thrombosis models. The potential role of sylvestin in ischemic stroke was evaluated by transient and permanent middle cerebral artery occlusion models. Sylvestin administration profoundly protected mice from ischemic stroke by counteracting intracerebral thrombosis and inflammation. Importantly, sylvestin showed no signs of bleeding tendency. The present study identifies sylvestin is a promising contact-kinin pathway inhibitor that can proffer profound protection from ischemic stroke without increased risk of bleeding.
Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Trombose , Animais , Inflamação/tratamento farmacológico , Inflamação/prevenção & controle , Cininas , Camundongos , Acidente Vascular Cerebral/tratamento farmacológico , Tromboinflamação , Trombose/tratamento farmacológicoRESUMO
Several adaptor molecules bind to cytoplasmic tails of ß-integrins and facilitate bidirectional signaling, which is critical in thrombosis and hemostasis. Interfering with integrin-adaptor interactions spatially or temporally to inhibit thrombosis without affecting hemostasis is an attractive strategy for the development of safe antithrombotic drugs. We show for the first time that the 14-3-3ζ-c-Src-integrin-ß3 complex is formed during platelet activation. 14-3-3ζ-c-Src interaction is mediated by the -PIRLGLALNFSVFYYE- fragment (PE16) on the 14-3-3ζ and SH2-domain on c-Src, whereas the 14-3-3ζ-integrin-ß3 interaction is mediated by the -ESKVFYLKMKGDYYRYL- fragment (EL17) on the 14-3-3ζ and -KEATSTF- fragment (KF7) on the ß3-integrin cytoplasmic tail. The EL17-motif inhibitor, or KF7 peptide, interferes with the formation of the 14-3-3ζ-c-Src-integrin-ß3 complex and selectively inhibits ß3 outside-in signaling without affecting the integrin-fibrinogen interaction, which suppresses thrombosis without causing significant bleeding. This study characterized a previously unidentified 14-3-3ζ-c-Src-integrin-ß3 complex in platelets and provided a novel strategy for the development of safe and effective antithrombotic treatments.
Assuntos
Proteínas 14-3-3/metabolismo , Integrina beta3/metabolismo , Ativação Plaquetária , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Proteínas 14-3-3/genética , Adulto , Animais , Feminino , Células HEK293 , Humanos , Integrina beta3/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Complexos Multiproteicos/metabolismo , Complexos Multiproteicos/fisiologia , Ativação Plaquetária/genética , Proteínas Proto-Oncogênicas pp60(c-src)/genética , Transdução de Sinais/fisiologiaRESUMO
RATIONALE: Epidemiological studies have identified an associate between iron deficiency (ID) and the use of oral contraceptives (CC) and ischemic stroke (IS). To date, however, the underlying mechanism remains poorly understood. Both ID and CC have been demonstrated to upregulate the level and iron-binding ability of Tf (transferrin), with our recent study showing that this upregulation can induce hypercoagulability by potentiating FXIIa/thrombin and blocking antithrombin-coagulation proteases interactions. OBJECTIVE: To investigate whether Tf mediates IS associated with ID or CC and the underlying mechanisms. METHODS AND RESULTS: Tf levels were assayed in the plasma of IS patients with a history of ID anemia, ID anemia patients, venous thromboembolism patients using CC, and ID mice, and in the cerebrospinal fluid of some IS patients. Effects of ID and estrogen administration on Tf expression and coagulability and the underlying mechanisms were studied in vivo and in vitro. High levels of Tf and Tf-thrombin/FXIIa complexes were found in patients and ID mice. Both ID and estrogen upregulated Tf through hypoxia and estrogen response elements located in the Tf gene enhancer and promoter regions, respectively. In addition, ID, administration of exogenous Tf or estrogen, and Tf overexpression promoted platelet-based thrombin generation and hypercoagulability and thus aggravated IS. In contrast, anti-Tf antibodies, Tf knockdown, and peptide inhibitors of Tf-thrombin/FXIIa interaction exerted anti-IS effects in vivo. CONCLUSIONS: Our findings revealed that certain factors (ie, ID and CC) upregulating Tf are risk factors of thromboembolic diseases decipher a previously unrecognized mechanistic association among ID, CC, and IS and provide a novel strategy for the development of anti-IS medicine by interfering with Tf-thrombin/FXIIa interactions.
Assuntos
Anemia Ferropriva/complicações , Coagulação Sanguínea , Anticoncepcionais Orais Hormonais/efeitos adversos , Estrogênios/toxicidade , AVC Isquêmico/etiologia , Trombofilia/etiologia , Transferrina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva/sangue , Anemia Ferropriva/diagnóstico , Animais , Biomarcadores/sangue , Estudos de Casos e Controles , Linhagem Celular , Modelos Animais de Doenças , Fator XIIa/metabolismo , Feminino , Humanos , AVC Isquêmico/sangue , AVC Isquêmico/diagnóstico , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Trombina/metabolismo , Trombofilia/sangue , Trombofilia/diagnóstico , Regulação para Cima , Adulto JovemRESUMO
Centipedes can subdue giant prey by using venom, which is metabolically expensive to synthesize and thus used frugally through efficiently disrupting essential physiological systems. Here, we show that a centipede (Scolopendra subspinipes mutilans, â¼3 g) can subdue a mouse (â¼45 g) within 30 seconds. We found that this observation is largely due to a peptide toxin in the venom, SsTx, and further established that SsTx blocks KCNQ potassium channels to exert the lethal toxicity. We also demonstrated that a KCNQ opener, retigabine, neutralizes the toxicity of a centipede's venom. The study indicates that centipedes' venom has evolved to simultaneously disrupt cardiovascular, respiratory, muscular, and nervous systems by targeting the broadly distributed KCNQ channels, thus providing a therapeutic strategy for centipede envenomation.
Assuntos
Venenos de Artrópodes/toxicidade , Artrópodes/fisiologia , Canais de Potássio KCNQ/antagonistas & inibidores , Doenças do Sistema Nervoso/induzido quimicamente , Comportamento Predatório/efeitos dos fármacos , Anormalidades do Sistema Respiratório/induzido quimicamente , Animais , Anticonvulsivantes/farmacologia , Carbamatos/farmacologia , Camundongos , Doenças do Sistema Nervoso/tratamento farmacológico , Doenças do Sistema Nervoso/metabolismo , Fenilenodiaminas/farmacologia , Anormalidades do Sistema Respiratório/tratamento farmacológico , Anormalidades do Sistema Respiratório/metabolismoRESUMO
Enzymes from various natural resources are valuable in management of thrombosis. Blood-sucking arthropods are one of these resources because they have a wide array of anti-hemostasis molecules in their salivary gland. However, it is difficult to purify enough protein samples from the salivary glands for pharmacological studies. In this work, a fibrinogenolytic enzyme (tablysin 2) identified from salivary glands of the horsefly Tabanus yao was expressed in Escherichia coli to further study its biological activities. The primary structure of tablysin 2 showed significant domain similarity to arthropod proteins from the antigen 5 family containing SCP domain, whose biological functions are poorly understood. Tablysin 2 cleaved the Aα and part of Bß chains of fibrinogen and did not affect γ chain and fibrin. It inhibited platelet aggregation induced by ADP. It did not directly induce hemorrhage or activate plasminogen. The fibrinogenolytic activity of tablysin 2 provides a clue for the functions of antigen 5-related proteins in other haematophagous arthropods. This work demonstrate a method of expression of arthropod salivary proteins which are difficult to obtain from natural resources for further functional studies.
Assuntos
Dípteros/genética , Fibrinolíticos , Glândulas Salivares , Animais , Dípteros/enzimologia , Fibrinolíticos/química , Fibrinolíticos/isolamento & purificação , Fibrinolíticos/metabolismo , Humanos , Proteínas de Insetos/biossíntese , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/isolamento & purificação , Proteínas Recombinantes , Proteínas e Peptídeos Salivares/biossíntese , Proteínas e Peptídeos Salivares/genética , Proteínas e Peptídeos Salivares/isolamento & purificaçãoRESUMO
Chicken meat processing generates a substantial number of byproducts, which are either underutilized or improperly disposed. In this study, we employed in silico approaches to identify antioxidant peptides in chicken liver byproducts. Notably, the peptide WYR exhibited remarkable 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity with an IC50 of 0.13 ± 0.01 mg/mL and demonstrated stability under various conditions, including thermal, pH, NaCl, and simulated gastrointestinal digestion. Molecular docking analysis revealed significant hydrogen bonding interactions, while molecular dynamics showed differential stability with ABTS and 2,2-Diphenyl-1-picrylhydrazyl (DPPH). WYR exhibited improved stress resistance, decreased levels of reactive oxygen species (ROS), elevated the activities of superoxide dismutase (SOD) and catalase (CAT), and modulated the expression of crucial genes through the insulin/insulin-like growth factor (IIS) signaling pathway, mitogen-activated protein kinase (MAPK), and heat shock transcription factor-1 (HSF-1) pathways. These effects collectively contributed to the extension of Caenorhabditis elegans' lifespan. This study not only provides an effective method for antioxidant peptide analysis but also highlights the potential for enhancing the utilization of poultry byproducts.
Assuntos
Antioxidantes , Caenorhabditis elegans , Galinhas , Fígado , Simulação de Acoplamento Molecular , Peptídeos , Animais , Caenorhabditis elegans/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/química , Peptídeos/química , Peptídeos/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento/efeitos dos fármacos , Simulação por Computador , Superóxido Dismutase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Catalase/metabolismoRESUMO
Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke. The contact-kinin pathway, initiated by plasma kallikrein (PK) and activated factor XII (FXIIa), functions bidirectionally with the coagulation and inflammation cascades, providing a novel target for therapeutic drug development in ischemic stroke. In this study, we identified a bat-derived oligopeptide from Myotis myotis (Borkhausen, 1797), designated LE6 (Leu-Ser-Glu-Glu-Pro-Glu, 702 Da), with considerable potential in stroke therapy due to its effects on the contact kinin pathway. Notably, LE6 demonstrated significant inhibitory effects on PK and FXIIa, with inhibition constants of 43.97 µmol/L and 6.37 µmol/L, respectively. In vitro analyses revealed that LE6 prolonged plasma recalcification time and activated partial thromboplastin time. In murine models, LE6 effectively inhibited carrageenan-induced mouse tail thrombosis, FeCl 3-induced carotid artery thrombosis, and photochemically induced intracerebral thrombosis. Furthermore, LE6 significantly decreased inflammation and stroke injury in transient middle cerebral artery occlusion models. Notably, the low toxicity, hemolytic activity, and bleeding risk of LE6, along with its synthetic simplicity, underscore its clinical applicability. In conclusion, as an inhibitor of FXIIa and PK, LE6 offers potential therapeutic benefits in stroke treatment by mitigating inflammation and preventing thrombus formation.
Assuntos
Oligopeptídeos , Acidente Vascular Cerebral , Animais , Camundongos , Oligopeptídeos/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Quirópteros , Trombose , Inflamação , Masculino , Anti-Inflamatórios/farmacologiaRESUMO
Cross-talks (e.g., host-driven iron withdrawal and microbial iron uptake between host gastrointestinal tract and commensal microbes) regulate immunotolerance and intestinal homeostasis. However, underlying mechanisms that regulate the cross-talks remain poorly understood. Here, we show that bacterial products up-regulate iron-transporter transferrin and transferrin acts as an immunosuppressor by interacting with cluster of differentiation 14 (CD14) to inhibit pattern recognition receptor (PRR) signaling and induce host immunotolerance. Decreased intestinal transferrin is found in germ-free mice and human patients with ulcerative colitis, which are characterized by impaired intestinal immunotolerance. Intestinal transferrin and host immunotolerance are returned to normal when germ-free mice get normal microbial commensalism, suggesting an association between microbial commensalism, transferrin, and host immunotolerance. Mouse colitis models show that transferrin shortage impairs host's tolerogenic responses, while its supplementation promotes immunotolerance. Designed peptide blocking transferrin-CD14 interaction inhibits immunosuppressive effects of transferrin. In monkeys with idiopathic chronic diarrhea, transferrin shows comparable or even better therapeutic effects than hydrocortisone. Our findings reveal that by up-regulating host transferrin to silence PRR signaling, commensal bacteria counteract immune activation induced by themselves to shape host immunity and contribute for intestinal tolerance.
RESUMO
For millennia, scientists, researchers, and the general public have been intrigued by animal venoms due to their potent effects and paradoxical ability to both harm and heal [...].
Assuntos
Peçonhas , Animais , Peçonhas/toxicidade , ChinaRESUMO
Drug resistance against bacteria and fungi has become common in recent years, and it is urgent to discover novel antimicrobial peptides to manage this problem. Many antimicrobial peptides from insects have been reported to have antifungal activity and are candidate molecules in the treatment of human diseases. In the present study, we characterized an antifungal peptide named blapstin that was isolated from the Chinese medicinal beetle Blaps rhynchopetera used in folk medicine. The complete coding sequence was cloned from the cDNA library prepared from the midgut of B. rhynchopetera. It is a 41-amino-acid diapause-specific peptide (DSP)-like peptide stabilized by three disulfide bridges and shows antifungal activity against Candida albicans and Trichophyton rubrum with MICs of 7 µM and 5.3 µM, respectively. The C. albicans and T. rubrum treated with blapstin showed irregular and shrunken cell membranes. In addition, blapstin inhibited the activity of C. albicans biofilm and showed little hemolytic or toxic activity on human cells and it is highly expressed in the fat body, followed by the hemolymph, midgut, muscle, and defensive glands. These results indicate that blapstin may help insects fight against fungi and showed a potential application in the development of antifungal reagents. IMPORTANCE Candida albicans is one of the conditional pathogenic fungi causing severe nosocomial infections. Trichophyton rubrum and other skin fungi are the main pathogens of superficial cutaneous fungal diseases, especially in children and the elderly. At present, antibiotics such as amphotericin B, ketoconazole, and fluconazole are the main drugs for the clinical treatment of C. albicans and T. rubrum infections. However, these drugs have certain acute toxicity. Long-term use can increase kidney damage and other side effects. Therefore, obtaining broad-spectrum antifungal drugs with high efficiency and low toxicity for the treatment of C. albicans and T. rubrum infections is a top priority. Blapstin is an antifungal peptide which shows activity against C. albicans and T. rubrum. The discovery of blapstin provides a novel clue for our understanding of the innate immunity of Blaps rhynchopetera and provides a template for designing antifungal drugs.
Assuntos
Besouros , Dermatomicoses , Animais , Criança , Humanos , Idoso , Antifúngicos/uso terapêutico , Candida albicans , Testes de Sensibilidade Microbiana , Dermatomicoses/tratamento farmacológico , Peptídeos/farmacologia , Peptídeos AntimicrobianosRESUMO
The venom and transcriptome profile of the captive Chinese cobra (Naja atra) is not characterized until now. Here, LC-MS/MS and illumine technology were used to unveil the venom and trascriptome of neonates and adults N. atra specimens. In captive Chinese cobra, 98 co-existing transcripts for venom-related proteins was contained. A total of 127 proteins belong to 21 protein families were found in the profile of venom. The main components of snake venom were three finger toxins (3-FTx), snake venom metalloproteinase (SVMP), cysteine-rich secretory protein (CRISP), cobra venom factor (CVF), and phosphodiesterase (PDE). During the ontogenesis of captive Chinese cobra, the rearrangement of snake venom composition occurred and with obscure gender difference. CVF, 3-FTx, PDE, phospholipase A2 (PLA2) in adults were more abundant than neonates, while SVMP and CRISP in the neonates was richer than the adults. Ontogenetic changes in the proteome of Chinese cobra venom reveals different strategies for handling prey. The levels of different types of toxin families were dramatically altered in the wild and captive specimens. Therefore, we speculate that the captive process could reshape the snake venom composition vigorously. The clear comprehension of the composition of Chinese cobra venom facilitates the understanding of the mechanism of snakebite intoxication and guides the preparation and administration of traditional antivenom and next-generation drugs for snakebite.
Assuntos
Naja naja , Mordeduras de Serpentes , Animais , Antivenenos/metabolismo , Cromatografia Líquida , Cisteína/metabolismo , Venenos Elapídicos/metabolismo , Metaloproteases/metabolismo , Naja naja/metabolismo , Fosfolipases A2/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Proteoma/metabolismo , Venenos de Serpentes/metabolismo , Espectrometria de Massas em TandemRESUMO
As said by former United Nations Secretary-General Kofi Annan, "Snakebite is the most important tropical disease you've never heard of." Listed as a priority neglected tropical disease by the World Health Organization, snakebite envenoming (SBE) kills in excess of 125,000 people per year. However, due to the complexity and overlap of snake venom compositions, few reliable venom diagnostic methods for genus-/species-specific identification, which is crucial for successful SBE therapy, are available. Here, we develop a strategy to select and prepare genus-specific snake venom antibodies, which allows rapid and efficient clinical diagnosis of snakebite. Multi-omics approaches are used to choose candidate antigens from snake venoms and identify genus-specific antigenic epitope peptide fragments (GSAEPs) with ideal immunogenicity, specificity, and spatial accessibility. Double-antibody sandwich ELISA kit was established by matching a polyclonal antibody against a natural antigen and a monoclonal antibody that was prepared by natural protein as antigen and can specifically target the GSAEPs. The kit shows the ability to accurately identify venoms from similar genera of Trimeresurus and Protobothrops with a detection limit of 6.25 ng/ml on the snake venoms and a little cross-reaction, thus proving high feasibility and applicability.
Assuntos
Antivenenos/imunologia , Ensaio de Imunoadsorção Enzimática , Mordeduras de Serpentes/diagnóstico , Mordeduras de Serpentes/imunologia , Venenos de Serpentes/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Antivenenos/química , Ensaio de Imunoadsorção Enzimática/métodos , Mapeamento de Epitopos , Epitopos/química , Epitopos/imunologia , Humanos , Modelos Moleculares , Peptídeos/química , Peptídeos/imunologia , Conformação Proteica , Sensibilidade e Especificidade , Venenos de Serpentes/química , Especificidade da Espécie , Relação Estrutura-AtividadeRESUMO
A large number of protease inhibitors have been found from leeches, which are essential in various physiological and biological processes. In the curret study, a novel elastase inhibitor was purified and characterized from the leech of Hirudinaria manillensis, which was named HMEI-A. Primary structure analysis showed that HMEI-A belonged to a new family of proteins. HMEI-A exerted inhibitory effects on elastase and showed potent abilities to inhibit elastase with an inhibition constant (Ki) of 1.69 × 10-8 mol·L-1. Further study showed that HMEI-A inhibited the formation of neutrophil extracellular trap (NET). These results suggested that HMEI-A from the leech of H. manillensis is a novel elastase inhibitor which can suppress NET formation. It may play a significant role in blood-sucking of leeches and is a potential candidate as an anti-inflammatory agent.
Assuntos
Sanguessugas , Elastase Pancreática/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Sequência de Aminoácidos , Animais , Sanguessugas/química , ProteínasRESUMO
Bleeding and thrombocytopenia to readministration are the most serious side effects of clinical integrin αIIbß3 antagonists such as RGD-containing peptides. Here we show that a non-RGD peptide ZDPI, identified from skin secretions of Amolops loloensis, inhibited platelet aggregation induced by agonists, such as adenosine diphosphate, collagen, arachidonic acid, PAR1AP, and integrin αIIbß3 allosteric activator, and reduces soluble fibrinogen binding to activated platelets without perturbing adhesion numbers on immobilized fibrinogen. Further study showed that ZDPI preferred to bind to the active conformation of integrin αIIbß3, and thus inhibited c-Src-mediated integrin signaling transduction. In contrast to currently used clinical blockers of integrin αIIbß3, which are all conformation-unspecific blockers, ZDPI conformation specifically binds to activated integrin αIIbß3, subsequently suppressing platelet spreading. In vivo study revealed that ZDPI inhibited carotid arterial thrombosis with limited bleeding and thrombocytopenia. A non-RGD peptide which targets the active conformation of integrin αIIbß3, such as ZDPI, might be an excellent candidate or template to develop antithrombotics without significant bleeding and thrombocytopenia side effects.
Assuntos
Plaquetas/efeitos dos fármacos , Peptídeos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Animais , Plaquetas/citologia , Plaquetas/metabolismo , Fibrinogênio/metabolismo , Hemorragia/induzido quimicamente , Humanos , Masculino , Camundongos Endogâmicos C57BL , Peptídeos/efeitos adversos , Peptídeos/química , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/química , Conformação Proteica/efeitos dos fármacos , Trombocitopenia/induzido quimicamenteRESUMO
Snake venoms contain components selected to immobilize prey. The venoms from Elapidae mainly contain neurotoxins, which are critical for rapid prey paralysis, while the venoms from Viperidae and Colubridae may contain fewer neurotoxins but are likely to induce circulatory disorders. Here, we show that the venoms from Protobothrops mucrosquamatus and Trimeresurus stejnegeri are comparable to those of Naja atra in prey immobilization. Further studies indicate that snake C-type lectin-like proteins (snaclecs), which are one of the main nonenzymatic components in viper venoms, are responsible for rapid prey immobilization. Snaclecs (mucetin and stejnulxin) from the venoms of P. mucrosquamatus and T. stejnegeri induce the aggregation of both mammalian platelets and avian thrombocytes, leading to acute cerebral ischemia, and reduced animal locomotor activity and exploration in the open field test. Viper venoms in the absence of snaclecs fail to aggregate platelets and thrombocytes, and thus show an attenuated ability to cause cerebral ischemia and immobilization of their prey. This work provides novel insights into the prey immobilization mechanism of Viperidae snakes and the understanding of viper envenomation-induced cerebral infarction.