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1.
Sci Transl Med ; 16(755): eadg3456, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38985854

RESUMO

Five hundred thirty-seven million people globally suffer from diabetes. Insulin-producing ß cells are reduced in number in most people with diabetes, but most individuals still have some residual ß cells. However, none of the many diabetes drugs in common use increases human ß cell numbers. Recently, small molecules that inhibit dual tyrosine-regulated kinase 1A (DYRK1A) have been shown to induce immunohistochemical markers of human ß cell replication, and this is enhanced by drugs that stimulate the glucagon-like peptide 1 (GLP1) receptor (GLP1R) on ß cells. However, it remains to be demonstrated whether these immunohistochemical findings translate into an actual increase in human ß cell numbers in vivo. It is also unknown whether DYRK1A inhibitors together with GLP1R agonists (GLP1RAs) affect human ß cell survival. Here, using an optimized immunolabeling-enabled three-dimensional imaging of solvent-cleared organs (iDISCO+) protocol in mouse kidneys bearing human islet grafts, we demonstrate that combination of a DYRK1A inhibitor with exendin-4 increases actual human ß cell mass in vivo by a mean of four- to sevenfold in diabetic and nondiabetic mice over 3 months and reverses diabetes, without alteration in human α cell mass. The augmentation in human ß cell mass occurred through mechanisms that included enhanced human ß cell proliferation, function, and survival. The increase in human ß cell survival was mediated, in part, by the islet prohormone VGF. Together, these findings demonstrate the therapeutic potential and favorable preclinical safety profile of the DYRK1A inhibitor-GLP1RA combination for diabetes treatment.


Assuntos
Quinases Dyrk , Exenatida , Harmina , Células Secretoras de Insulina , Peptídeos , Proteínas Serina-Treonina Quinases , Proteínas Tirosina Quinases , Animais , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Exenatida/farmacologia , Exenatida/uso terapêutico , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Harmina/farmacologia , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Camundongos , Peptídeos/farmacologia , Peptídeos/metabolismo , Peçonhas/farmacologia , Peçonhas/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Quimioterapia Combinada , Proliferação de Células/efeitos dos fármacos , Xenoenxertos
2.
Biomater Adv ; 162: 213903, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38824828

RESUMO

AIM: The aim of the present review is to shed light on the nanotechnological approaches adopted to overcome the shortcomings associated with the delivery of venom peptides which possess inherent anti-cancer properties. BACKGROUND: Venom peptides although have been reported to demonstrate anti-cancer effects, they suffer from several disadvantages such as in vivo instability, off-target adverse effects, limited drug loading and low bioavailability. This review presents a comprehensive compilation of different classes of nanocarriers while underscoring their advantages, disadvantages and potential to carry such peptide molecules for in vivo delivery. It also discusses various nanotechnological aspects such as methods of fabrication, analytical tools to assess these nanoparticulate formulations, modulation of nanocarrier polymer properties to enhance loading capacity, stability and improve their suitability to carry toxic peptide drugs. CONCLUSION: Nanotechnological approaches bear great potential in delivering venom peptide-based molecules as anticancer agents by enhancing their bioavailability, stability, efficacy as well as offering a spatiotemporal delivery approach. However, the challenges associated with toxicity and biocompatibility of nanocarriers must be duly addressed. PERSPECTIVES: The everlasting quest for new breakthroughs for safer delivery of venom peptides in human subjects is fuelled by unmet clinical needs in the current landscape of chemotherapy. In addition, exhaustive efforts are required in obtaining and purifying the venom peptides followed by designing and optimizing scale up technologies.


Assuntos
Antineoplásicos , Nanotecnologia , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Nanotecnologia/métodos , Peçonhas/administração & dosagem , Peçonhas/uso terapêutico , Peçonhas/farmacocinética , Peçonhas/química , Peptídeos/administração & dosagem , Peptídeos/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Portadores de Fármacos/química
3.
Life Sci ; 351: 122777, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38851419

RESUMO

Cerebral stroke is a pressing global health concern, ranking as the second leading cause of mortality and resulting in persistent neurobehavioral impairments. Cerebral strokes, triggered by various embolic events, initiate complex signaling pathways involving neuroexcitotoxicity, ionic imbalances, inflammation, oxidative stress, acidosis, and mitochondrial dysfunction, leading to programmed cell death. Currently, the FDA has approved tissue plasminogen activator as a relatively benign intervention for cerebral stroke, leaving a significant treatment gap. However, a promising avenue has emerged from Earth's toxic creatures. Animal venoms harbor bioactive molecules, particularly neuropeptides, with potential in innovative healthcare applications. These venomous components, affecting ion channels, receptors, and transporters, encompass neurochemicals, amino acids, and peptides, making them prime candidates for treating cerebral ischemia and neurological disorders. This review explores the composition, applications, and significance of toxin-derived peptides as viable therapeutic agents. It also investigates diverse toxins from select venomous creatures, with the primary objective of shedding light on current stroke treatments and paving the way for pioneering therapeutic strategies capable of addressing neurobehavioral deficits.


Assuntos
Peptídeos , Acidente Vascular Cerebral , Humanos , Animais , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Toxinas Biológicas , Peçonhas/uso terapêutico , Peçonhas/farmacologia
4.
Med Oncol ; 41(6): 138, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38705935

RESUMO

Breast cancer (BC) is associated with type 2 diabetes mellitus (T2DM) and obesity. Glucagon-like peptide (GLP)-1 regulates post-prandial insulin secretion, satiety, and gastric emptying. Several GLP-1 analogs have been FDA-approved for the treatment of T2DM and obesity. Moreover, GLP-1 regulates various metabolic activities across different tissues by activating metabolic signaling pathways like adenosine monophosphate (AMP) activated protein kinase (AMPK), and AKT. Rewiring metabolic pathways is a recognized hallmark of cancer, regulated by several cancer-related pathways, including AKT and AMPK. As GLP-1 regulates AKT and AMPK, we hypothesized that it alters BC cells' metabolism, thus inhibiting proliferation. The effect of the GLP-1 analogs exendin-4 (Ex4) and liraglutide on viability, AMPK signaling and metabolism of BC cell lines were assessed. Viability of BC cells was evaluated using colony formation and MTT/XTT assays. Activation of AMPK and related signaling effects were evaluated using western blot. Metabolism effects were measured for glucose, lactate and ATP. Exendin-4 and liraglutide activated AMPK in a cAMP-dependent manner. Blocking Ex4-induced activation of AMPK by inhibition of AMPK restored cell viability. Interestingly, Ex4 and liraglutide reduced the levels of glycolytic metabolites and decreased ATP production, suggesting that GLP-1 analogs impair glycolysis. Notably, inhibiting AMPK reversed the decline in ATP levels, highlighting the role of AMPK in this process. These results establish a novel signaling pathway for GLP-1 in BC cells through cAMP and AMPK modulation affecting proliferation and metabolism. This study suggests that GLP-1 analogs should be considered for diabetic patients with BC.


Assuntos
Neoplasias da Mama , Exenatida , Peptídeo 1 Semelhante ao Glucagon , Liraglutida , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Exenatida/farmacologia , Feminino , Liraglutida/farmacologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Linhagem Celular Tumoral , Proteínas Quinases Ativadas por AMP/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Efeito Warburg em Oncologia/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peçonhas/farmacologia , Adenilato Quinase/metabolismo , Peptídeos/farmacologia
5.
Eur J Pharm Biopharm ; 200: 114339, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38789061

RESUMO

Peptides, despite their therapeutic potential, face challenges with undesirable pharmacokinetic (PK) properties and biodistribution, including poor oral absorption and cellular uptake, and short plasma elimination half-lives. Lipidation of peptides is a common strategy to improve their physicochemical and PK properties, making them viable drug candidates. For example, the plasma half-life of peptides has been extended via conjugation to lipids that are proposed to promote binding to serum albumin and thus protect against rapid clearance. Recent work has shown that lipid conjugation to oligodeoxynucleotides, polymers and small molecule drugs results in association not only with albumin, but also with lipoproteins, resulting in half-life prolongation and transport from administration sites via the lymphatics. Enhancing delivery into the lymph increases the efficacy of vaccines and therapeutics with lymphatic targets such as immunotherapies. In this study, the plasma PK, lymphatic uptake, and bioavailability of the glucagon-like peptide-1 (GLP-1) receptor agonist peptides, liraglutide (lipidated) and exenatide (non-lipidated), were investigated following subcutaneous (SC) administration to rats. As expected, liraglutide displayed an apparent prolonged plasma half-life (9.1 versus 1 h), delayed peak plasma concentrations and lower bioavailability (∼10 % versus ∼100 %) compared to exenatide after SC administration. The lymphatic uptake of both peptides was relatively low (<0.5 % of the dose) although lymph to plasma concentration ratios were greater than one for several early timepoints suggesting some direct uptake into lymph. The low lymphatic uptake may be due to the nature of the conjugated lipid (a single-chain C16 palmitic acid in liraglutide) but suggests that other peptides with similar lipid conjugations may also have relatively modest lymphatic uptake. If delivery to the lymph is desired, conjugation to more lipophilic moieties with higher albumin and/or lipoprotein binding efficiencies, such as diacylglycerols, may be appropriate.


Assuntos
Exenatida , Liraglutida , Peptídeos , Ratos Sprague-Dawley , Animais , Exenatida/farmacocinética , Exenatida/administração & dosagem , Exenatida/farmacologia , Liraglutida/farmacologia , Liraglutida/farmacocinética , Liraglutida/administração & dosagem , Ratos , Masculino , Peptídeos/farmacocinética , Peptídeos/administração & dosagem , Lipídeos/química , Meia-Vida , Peçonhas/farmacocinética , Peçonhas/administração & dosagem , Disponibilidade Biológica , Distribuição Tecidual , Injeções Subcutâneas , Linfa/metabolismo , Linfa/efeitos dos fármacos , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacocinética , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Sistema Linfático/metabolismo , Sistema Linfático/efeitos dos fármacos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia
6.
Neuropharmacology ; 252: 109946, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38599494

RESUMO

The spontaneous firing activity of nigral dopaminergic neurons is associated with some important roles including modulation of dopamine release, expression of tyrosine hydroxylase (TH), as well as neuronal survival. The decreased neuroactivity of nigral dopaminergic neurons has been revealed in Parkinson's disease. Central glucagon-like peptide-1 (GLP-1) functions as a neurotransmitter or neuromodulator to exert multiple brain functions. Although morphological studies revealed the expression of GLP-1 receptors (GLP-1Rs) in the substantia nigra pars compacta, the possible modulation of GLP-1 on spontaneous firing activity of nigral dopaminergic neurons is unknown. The present extracellular in vivo single unit recordings revealed that GLP-1R agonist exendin-4 significantly increased the spontaneous firing rate and decreased the firing regularity of partial nigral dopaminergic neurons of adult male C57BL/6 mice. Blockade of GLP-1Rs by exendin (9-39) decreased the firing rate of nigral dopaminergic neurons suggesting the involvement of endogenous GLP-1 in the modulation of firing activity. Furthermore, the PKA and the transient receptor potential canonical (TRPC) 4/5 channels are involved in activation of GLP-1Rs-induced excitatory effects of nigral dopaminergic neurons. Under parkinsonian state, both the exogenous and endogenous GLP-1 could still induce excitatory effects on the surviving nigral dopaminergic neurons. As the mild excitatory stimuli exert neuroprotective effects on nigral dopaminergic neurons, the present GLP-1-induced excitatory effects may partially contribute to its antiparkinsonian effects.


Assuntos
Potenciais de Ação , Neurônios Dopaminérgicos , Exenatida , Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Camundongos Endogâmicos C57BL , Substância Negra , Animais , Masculino , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Exenatida/farmacologia , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Camundongos , Peçonhas/farmacologia , Peptídeos/farmacologia , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/fisiopatologia , Fragmentos de Peptídeos/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo
7.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38493344

RESUMO

Venomous organisms have independently evolved the ability to produce toxins 101 times during their evolutionary history, resulting in over 200 000 venomous species. Collectively, these species produce millions of toxins, making them a valuable resource for bioprospecting and understanding the evolutionary mechanisms underlying genetic diversification. RNA-seq is the preferred method for characterizing toxin repertoires, but the analysis of the resulting data remains challenging. While early approaches relied on similarity-based mapping to known toxin databases, recent studies have highlighted the importance of structural features for toxin detection. The few existing pipelines lack an integration between these complementary approaches, and tend to be difficult to run for non-experienced users. To address these issues, we developed DeTox, a comprehensive and user-friendly tool for toxin research. It combines fast execution, parallelization and customization of parameters. DeTox was tested on published transcriptomes from gastropod mollusks, cnidarians and snakes, retrieving most putative toxins from the original articles and identifying additional peptides as potential toxins to be confirmed through manual annotation and eventually proteomic analysis. By integrating a structure-based search with similarity-based approaches, DeTox allows the comprehensive characterization of toxin repertoire in poorly-known taxa. The effect of the taxonomic bias in existing databases is minimized in DeTox, as mirrored in the detection of unique and divergent toxins that would have been overlooked by similarity-based methods. DeTox streamlines toxin annotation, providing a valuable tool for efficient identification of venom components that will enhance venom research in neglected taxa.


Assuntos
Toxinas Biológicas , Peçonhas , Animais , Peçonhas/genética , Peçonhas/química , Proteômica , Toxinas Biológicas/genética , Serpentes , Peptídeos , Transcriptoma
8.
Toxicon ; 241: 107685, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38503352

RESUMO

Determination of protein concentration in Hymenoptera venoms requires an accurate and reproducible assay as the results will be used to support subsequent proteomic techniques employed in their analyses. However, all protein assay techniques have inherent strengths and weaknesses, demanding their assessment before selecting the most suitable platform for sample analysis. In this study, protein profiles of ant, honeybee, and wasp venoms, and bovine serum albumin (BSA) and hyaluronidase standards were qualitatively assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Their amino acid and protein concentration were quantitatively determined via Amino Acid Analysis (AAA). Amino acid concentration was determined via hydrolysis, derivatization, and chromatographic quantification. Protein concentration was estimated using four different protein concentration assays. The ratios of protein concentration in venom samples to protein standards were calculated, and the accuracy of the protein concentration assays was analysed relative to the concentration determined from AAA. SDS-PAGE analysis showed that BSA contained several protein bands, while hyaluronidase contained a mixture of peptide and protein bands. Ant and honeybee venoms contained a higher proportion of peptide bands, while wasp venom contained more protein bands. As determined by AAA, the ratio of protein concentration in Hymenoptera venoms varied between 1.01 and 1.11 to BSA, and between 0.96 and 1.06 to hyaluronidase. Overall, the Bradford assay was found to be the least accurate and the BCA assay was the most accurate in estimating protein concentration in Hymenoptera venoms. There was no significant advantage in using hyaluronidase as a standard or increasing incubation temperature of BCA assay when analysing Hymenoptera venoms. Diluent solutions containing phenol and human serum albumin interfered with Lowry-based assays.


Assuntos
Venenos de Artrópodes , Venenos de Abelha , Himenópteros , Abelhas , Humanos , Animais , Proteoma , Hialuronoglucosaminidase/análise , Proteômica , Venenos de Vespas , Peçonhas , Aminoácidos , Soroalbumina Bovina , Peptídeos , Alérgenos
9.
Toxins (Basel) ; 16(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38535792

RESUMO

Five peptides were isolated from the venom of the Mexican scorpion Centruroides bonito by chromatographic procedures (molecular weight sieving, ion exchange columns, and HPLC) and were denoted Cbo1 to Cbo5. The first four peptides contain 66 amino acid residues and the last one contains 65 amino acids, stabilized by four disulfide bonds, with a molecular weight spanning from about 7.5 to 7.8 kDa. Four of them are toxic to mice, and their function on human Na+ channels expressed in HEK and CHO cells was verified. One of them (Cbo5) did not show any physiological effects. The ones toxic to mice showed that they are modifiers of the gating mechanism of the channels and belong to the beta type scorpion toxin (ß-ScTx), affecting mainly the Nav1.6 channels. A phylogenetic tree analysis of their sequences confirmed the high degree of amino acid similarities with other known bona fide ß-ScTx. The envenomation caused by this venom in mice is treated by using commercially horse antivenom available in Mexico. The potential neutralization of the toxic components was evaluated by means of surface plasmon resonance using four antibody fragments (10FG2, HV, LR, and 11F) which have been developed by our group. These antitoxins are antibody fragments of single-chain antibody type, expressed in E. coli and capable of recognizing Cbo1 to Cbo4 toxins to various degrees.


Assuntos
Animais Peçonhentos , Perciformes , Peçonhas , Humanos , Cricetinae , Animais , Cavalos , Camundongos , Escorpiões , Cricetulus , Escherichia coli , Filogenia , Antivenenos , Aminoácidos , Fragmentos de Imunoglobulinas , Peptídeos
10.
J Vet Med Sci ; 86(5): 555-562, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38556323

RESUMO

Glucagon-like peptide-1 (GLP-1) is an incretin released into the gastrointestinal tract after food ingestion, and stimulates insulin secretion from the beta cells of the pancreatic islets. Incretins have recently been reported to have extrapancreatic actions, and they are anticipated to have potential efficacy for conditions such as male infertility as well as diabetes. However, the effects of incretins on male reproductive function remain unclear. In this study, GLP-1 receptor expression and the effects of GLP-1 on spermatogenesis-associated genes were investigated using mouse testes and testis-derived cultured cell lines. Glp1r mRNA and GLP-1 protein were expressed in mouse testes at levels comparable to or greater than those in positive control adipose tissue, and the liver and intestine, and also in a Sertoli cell line (TM4) and a Leydig cell line (MA-10) as well as the GC-1 spg and GC-2 spd (ts) germ cell lines. TM4 cells treated with the GLP-1 receptor agonist exenatide showed transiently and significantly upregulated Kitl, Pdgfa, and Glp1r mRNA expression. Furthermore, at 1 hr post-exenatide administration to male mice, Kitl and Glp1r mRNA expression levels were significantly increased, and Pdgfa mRNA expression level also showed a tendency toward increase. TM4 cells were treated with various cell-activating agents, and bucladesine elicited significantly increased Glp1r mRNA expression. We suggest that GLP-1 provides acute stimulation of Sertoli cells in the mouse testis and has a stimulatory effect on the expression of spermatogenesis-related genes.


Assuntos
Exenatida , Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Espermatogênese , Testículo , Animais , Masculino , Espermatogênese/efeitos dos fármacos , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Testículo/efeitos dos fármacos , Testículo/metabolismo , Camundongos , Exenatida/farmacologia , Linhagem Celular , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peçonhas/farmacologia , Peptídeos/farmacologia , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Agonistas do Receptor do Peptídeo 1 Semelhante ao Glucagon
11.
Comput Biol Chem ; 109: 108027, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38340414

RESUMO

Channel-regulated peptides (CRPs) derived from animal venom hold great promise as potential drug candidates for numerous diseases associated with channel proteins. However, discovering and identifying CRPs using traditional bio-experimental methods is a time-consuming and laborious process. While there were a few computational studies on CRPs, they were limited to specific channel proteins, relied heavily on complex feature engineering, and lacked the incorporation of multi-source information. To address these problems, we proposed a novel deep learning model, called DeepCRPs, based on graph neural networks for systematically mining CRPs from animal venom. By combining the sequence semantic and structural information, the classification performance of four CRPs was significantly enhanced, reaching an accuracy of 0.92. This performance surpassed baseline models with accuracies ranging from 0.77 to 0.89. Furthermore, we employed advanced interpretable techniques to explore sequence and structural determinants relevant to the classification of CRPs, yielding potentially valuable bio-function interpretations. Comprehensive experimental results demonstrated the precision and interpretive capability of DeepCRPs, making it an accurate and bio-explainable suit for the identification and categorization of CRPs. Our research will contribute to the discovery and development of toxin peptides targeting channel proteins. The source data and code are freely available at https://github.com/liyigerry/DeepCRPs.


Assuntos
Semântica , Peçonhas , Animais , Peptídeos , Redes Neurais de Computação
12.
Mar Drugs ; 22(2)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38393042

RESUMO

The venoms of various sea anemones are rich in diverse toxins, which usually play a dual role in capturing prey and deterring predators. However, the complex components of such venoms have not been well known yet. Here, venomics of integrating transcriptomic and proteomic technologies was applied for the first time to identify putative protein and peptide toxins from different tissues of the representative sea anemone, Heteractis magnifica. The transcriptomic analysis of H. magnifica identified 728 putative toxin sequences, including 442 and 381 from the tentacles and the column, respectively, and they were assigned to 68 gene superfamilies. The proteomic analysis confirmed 101 protein and peptide toxins in the venom, including 91 in the tentacles and 39 in the column. The integrated venomics also confirmed that some toxins such as the ShK-like peptides and defensins are co-expressed in both the tentacles and the column. Meanwhile, a homology analysis was conducted to predict the three-dimensional structures and potential activity of seven representative toxins. Altogether, this venomics study revealed the venom complexity of H. magnifica, which will help deepen our understanding of cnidarian toxins, thereby supporting the in-depth development of valuable marine drugs.


Assuntos
Venenos de Cnidários , Anêmonas-do-Mar , Toxinas Biológicas , Animais , Peçonhas/metabolismo , Anêmonas-do-Mar/metabolismo , Proteômica/métodos , Peptídeos/genética , Peptídeos/metabolismo , Venenos de Cnidários/química
13.
Toxins (Basel) ; 16(2)2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38393163

RESUMO

While the unique symbiotic relationship between anemonefishes and sea anemones is iconic, it is still not fully understood how anemonefishes can withstand and thrive within the venomous environment of their host sea anemone. In this study, we used a proteotranscriptomics approach to elucidate the proteinaceous toxin repertoire from the most common host sea anemone, Entacmaea quadricolor. Although 1251 different toxin or toxin-like RNA transcripts were expressed in E. quadricolor tentacles (0.05% of gene clusters, 1.8% of expression) and 5375 proteins were detected in milked venom, only 4% of proteins detected in venom were putative toxins (230), and they only represent on average 14% of the normalised protein expression in the milked venom samples. Thus, most proteins in milked venom do not appear to have a toxin function. This work raises the perils of defining a dominant venom phenotype based on transcriptomics data alone in sea anemones, as we found that the dominant venom phenotype differs between the transcriptome and proteome abundance data. E. quadricolor venom contains a mixture of toxin-like proteins of unknown and known function. A newly identified toxin protein family, Z3, rich in conserved cysteines of unknown function, was the most abundant at the RNA transcript and protein levels. The venom was also rich in toxins from the Protease S1, Kunitz-type and PLA2 toxin protein families and contains toxins from eight venom categories. Exploring the intricate venom toxin components in other host sea anemones will be crucial for improving our understanding of how anemonefish adapt to the venomous environment.


Assuntos
Anêmonas-do-Mar , Toxinas Biológicas , Animais , Anêmonas-do-Mar/genética , Peçonhas/genética , Toxinas Biológicas/genética , Transcriptoma , RNA
14.
Toxins (Basel) ; 16(2)2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38393171

RESUMO

Cone snails are carnivorous marine animals that prey on fish (piscivorous), worms (vermivorous), or other mollusks (molluscivorous). They produce a complex venom mostly made of disulfide-rich conotoxins and conopeptides in a compartmentalized venom gland. The pharmacology of cone snail venom has been increasingly investigated over more than half a century. The rising interest in cone snails was initiated by the surprising high human lethality rate caused by the defensive stings of some species. Although a vast amount of information has been uncovered on their venom composition, pharmacological targets, and mode of action of conotoxins, the venom-ecology relationships are still poorly understood for many lineages. This is especially important given the relatively recent discovery that some species can use different venoms to achieve rapid prey capture and efficient deterrence of aggressors. Indeed, via an unknown mechanism, only a selected subset of conotoxins is injected depending on the intended purpose. Some of these remarkable venom variations have been characterized, often using a combination of mass spectrometry and transcriptomic methods. In this review, we present the current knowledge on such specific predatory and defensive venoms gathered from sixteen different cone snail species that belong to eight subgenera: Pionoconus, Chelyconus, Gastridium, Cylinder, Conus, Stephanoconus, Rhizoconus, and Vituliconus. Further studies are needed to help close the gap in our understanding of the evolved ecological roles of many cone snail venom peptides.


Assuntos
Conotoxinas , Caramujo Conus , Humanos , Animais , Conotoxinas/toxicidade , Conotoxinas/química , Caramujo Conus/química , Venenos de Moluscos/química , Peptídeos , Peçonhas , Caramujos
15.
Eye (Lond) ; 38(7): 1374-1379, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38212401

RESUMO

BACKGROUND: Cognitive function can be affected in conditions with raised intracranial pressure (ICP) such as idiopathic intracranial hypertension (IIH). Drugs used off label to treat raised ICP also have cognitive side effects, underscoring the unmet need for effective therapeutics which reduce ICP without worsening cognition. The Glucagon Like Peptide-1 (GLP-1) receptor agonist, exenatide, has been shown to significantly reduce ICP in IIH, therefore this study aimed to determine the effects of exenatide on cognition in IIH. METHODS: This was an exploratory study of the IIH:Pressure trial (ISTCRN 12678718). Women with IIH and telemetric ICP monitors (n = 15) were treated with exenatide (n = 7) or placebo (n = 8) for 12 weeks. Cognitive function was tested using the National Institute of Health Toolbox Cognitive Battery at baseline and 12 weeks. RESULTS: Cognitive performance was impaired in fluid intelligence ((T-score of 50 = population mean), mean (SD) 37.20 (9.87)), attention (33.93 (7.15)) and executive function (38.07 (14.61)). After 12-weeks there was no evidence that exenatide compromised cognition (no differences between exenatide and placebo). Cognition improved in exenatide treated patients in fluid intelligence (baseline 38.4 (8.2), 12 weeks 52.9 (6.6), p = 0.0005), processing speed (baseline 43.7 (9.4), 12 weeks 58.4 (10.4), p = 0.0058) and episodic memory (baseline 49.4 (5.3), 12 weeks 62.1 (13.2), p = 0.0315). CONCLUSIONS: In patients with raised ICP due to IIH, exenatide, a drug emerging as an ICP lowering agent, does not adversely impact cognition. This is encouraging and has potential to be relevant when considering prescribing choices to lower ICP.


Assuntos
Cognição , Exenatida , Receptor do Peptídeo Semelhante ao Glucagon 1 , Pressão Intracraniana , Pseudotumor Cerebral , Humanos , Exenatida/uso terapêutico , Exenatida/farmacologia , Feminino , Adulto , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Pseudotumor Cerebral/tratamento farmacológico , Pseudotumor Cerebral/fisiopatologia , Cognição/efeitos dos fármacos , Pressão Intracraniana/efeitos dos fármacos , Método Duplo-Cego , Pessoa de Meia-Idade , Peptídeos/uso terapêutico , Peptídeos/farmacologia , Peçonhas/uso terapêutico , Adulto Jovem , Hipoglicemiantes/uso terapêutico
16.
BMC Genomics ; 25(1): 84, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245722

RESUMO

BACKGROUND: Venoms have evolved independently over a hundred times in the animal kingdom to deter predators and/or subdue prey. Venoms are cocktails of various secreted toxins, whose origin and diversification provide an appealing system for evolutionary researchers. Previous studies of the ant venom of Tetramorium bicarinatum revealed several Myrmicitoxin (MYRTX) peptides that gathered into seven precursor families suggesting different evolutionary origins. Analysis of the T. bicarinatum genome enabling further genomic approaches was necessary to understand the processes underlying the evolution of these myrmicitoxins. RESULTS: Here, we sequenced the genome of Tetramorium bicarinatum and reported the organisation of 44 venom peptide genes (vpg). Of the eleven chromosomes that make up the genome of T. bicarinatum, four carry the vpg which are organized in tandem repeats. This organisation together with the ML evolutionary analysis of vpg sequences, is consistent with evolution by local duplication of ancestral genes for each precursor family. The structure of the vpg into two or three exons is conserved after duplication events while the promoter regions are the least conserved parts of the vpg even for genes with highly identical sequences. This suggests that enhancer sequences were not involved in duplication events, but were recruited from surrounding regions. Expression level analysis revealed that most vpg are highly expressed in venom glands, although one gene or group of genes is much more highly expressed in each family. Finally, the examination of the genomic data revealed that several genes encoding transcription factors (TFs) are highly expressed in the venom glands. The search for binding sites (BS) of these TFs in the vpg promoters revealed hot spots of GATA sites in several vpg families. CONCLUSION: In this pioneering investigation on ant venom genes, we provide a high-quality assembly genome and the annotation of venom peptide genes that we think can fosters further genomic research to understand the evolutionary history of ant venom biochemistry.


Assuntos
Venenos de Formiga , Formigas , Humanos , Animais , Peçonhas/genética , Venenos de Formiga/química , Venenos de Formiga/genética , Venenos de Formiga/metabolismo , Peptídeos/metabolismo , Genoma , Formigas/genética , Evolução Molecular
17.
Mol Cancer Ther ; 23(2): 139-147, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38015557

RESUMO

The regulation of cellular processes by ion channels has become central to the study of cancer mechanisms. Designing molecules that can modify ion channels specific to tumor cells is a promising area of targeted drug delivery and therapy. Despite their potential in drug discovery, venom peptides-a group of natural products-have largely remained understudied and under-characterized. In general, venom peptides display high specificity and selectivity for their target ion channels. Therefore, they may represent an effective strategy for selectively targeting the dysregulation of ion channels in tumor cells. This review examines existing venom peptide therapies for different cancer types and focuses on the application of snail venom peptides in hepatocellular carcinoma (HCC), the most common form of primary liver cancer worldwide. We provide insights into the mode of action of venom peptides that have been shown to target tumors. We also explore the benefit of using new computational methods like de novo protein structure prediction to screen venom peptides and identify potential druggable candidates. Finally, we summarize the role of cell culture, animal, and organoid models in developing effective therapies against HCC and highlight the need for creating models that represent the most disproportionately affected ethnicities in HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Peçonhas/farmacologia , Peçonhas/uso terapêutico , Peçonhas/química , Neoplasias Hepáticas/tratamento farmacológico , Carcinoma Hepatocelular/tratamento farmacológico , Peptídeos/química , Canais Iônicos/metabolismo
18.
Toxicon ; 237: 107538, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38030096

RESUMO

Epilepsy affects around 50 million people worldwide and 30% of patients have difficulty controlling the disease. The search for substances that can fill the existing gaps in the treatment of epilepsy is of great importance. Arthropod venoms are promising sources for this purpose due to the presence of small peptides that modulate the activity of ion channels and neuron receptors. The aim of this study was to investigate dinoponeratoxins from the Dinoponera quadriceps ant venom (M-PONTX-Dq3a, M-PONTX-Dq3b and M-PONTX-Dq3c) as potential anticonvulsants. We evaluated them in a seizure model induced by pentylenetetrazole (PTZ) in male swiss mice. Interestingly, intraperitoneal treatment with each peptide increased the time until the first seizure and the percentage of survival, with M-PONTX-Dq3b showing the best results. M-PONTX-Dq3a was discarded due to the appearance of some signs of toxicity with the increase in malondialdehyde (MDA) levels in the striatum. Both, M-PONTX-Dq3b and M-PONTX-Dq3c decreased iNOS and TNF-α in the hippocampus. Notably, M-PONTX-Dq3c treatment decreased the levels of MDA and nitrite in the cortex and hippocampus. Our results indicate that, M-PONTX-Dq3b and M-PONTX-Dq3c have anticonvulsant activity and exhibit anti-inflammatory effects in epilepsy, offering new perspectives for biopharmaceutical development.


Assuntos
Formigas , Epilepsia , Humanos , Camundongos , Animais , Masculino , Peptídeos Antimicrobianos , Pentilenotetrazol/toxicidade , Peçonhas/toxicidade , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/prevenção & controle , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Peptídeos/química
19.
Cell Metab ; 36(1): 130-143.e5, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38113888

RESUMO

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) exert anti-inflammatory effects relevant to the chronic complications of type 2 diabetes. Although GLP-1RAs attenuate T cell-mediated gut and systemic inflammation directly through the gut intraepithelial lymphocyte GLP-1R, how GLP-1RAs inhibit systemic inflammation in the absence of widespread immune expression of the GLP-1R remains uncertain. Here, we show that GLP-1R activation attenuates the induction of plasma tumor necrosis factor alpha (TNF-α) by multiple Toll-like receptor agonists. These actions are not mediated by hematopoietic or endothelial GLP-1Rs but require central neuronal GLP-1Rs. In a cecal slurry model of polymicrobial sepsis, GLP-1RAs similarly require neuronal GLP-1Rs to attenuate detrimental responses associated with sepsis, including sickness, hypothermia, systemic inflammation, and lung injury. Mechanistically, GLP-1R activation leads to reduced TNF-α via α1-adrenergic, δ-opioid, and κ-opioid receptor signaling. These data extend emerging concepts of brain-immune networks and posit a new gut-brain GLP-1R axis for suppression of peripheral inflammation.


Assuntos
Diabetes Mellitus Tipo 2 , Sepse , Humanos , Exenatida , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeos/farmacologia , Agonistas do Receptor Semelhante a Toll , Peçonhas/farmacologia , Fator de Necrose Tumoral alfa , Inflamação , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo
20.
Diabetes Obes Metab ; 26(3): 989-996, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38151964

RESUMO

AIM: To examine the real-world efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in monogenic obesity in patients with Alström syndrome (ALMS). METHODS: We screened 72 UK adult patients with ALMS and offered treatment to 34 patients meeting one of the following criteria: body mass index of 25 kg/m2 or higher, insulin resistance, suboptimal glycaemic control on antihyperglycaemic medications or non-alcoholic fatty liver disease. RESULTS: In total, 30 patients, with a mean age of 31 ± 11 years and a male to-female ratio of 2:1, completed 6 months of treatment with GLP-1 RAs either in the form of semaglutide or exenatide. On average, treatment with GLP-1 RAs reduced body weight by 5.4 ± 1.7 (95% confidence interval [CI] 3.6-7) kg and HbA1c by 12 ± 3.3 (95% CI 8.7-15.3) mmol/mol, equating to 6% weight loss (P < .01) and 1.1% absolute reduction in HbA1c (P < .01). Significant improvements were also observed in serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and alanine aminotransferase. The improvement of metabolic variables in our cohort of monogenic syndromic obesity was comparable with data for polygenic obesity, irrespective of weight loss. CONCLUSIONS: Data from our centre highlight the non-inferiority of GLP-1 RAs in monogenic syndromic obesity to the available GLP-1 RA-use data in polygenic obesity, therefore, these agents can be considered as a treatment option in patients with ALMS, as well as other forms of monogenic obesity.


Assuntos
Síndrome de Alstrom , Diabetes Mellitus Tipo 2 , Adulto , Humanos , Masculino , Feminino , Adulto Jovem , Peptídeo 1 Semelhante ao Glucagon/agonistas , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas , Síndrome de Alstrom/complicações , Síndrome de Alstrom/tratamento farmacológico , Síndrome de Alstrom/genética , Liraglutida/uso terapêutico , Peptídeos/uso terapêutico , Glicemia/metabolismo , Peçonhas/uso terapêutico , Hipoglicemiantes/uso terapêutico , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/genética , Redução de Peso , Colesterol , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas
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