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Antibiotic resistance has recently been recognized as an alarming issue and one of the leading causes of death worldwide [...].
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BACKGROUND: Neuroendocrine prostate cancer (NEPC) is a multi-resistant variant of prostate cancer (PCa) that has become a major challenge in clinics. Understanding the neuroendocrine differentiation (NED) process at the molecular level is therefore critical to define therapeutic strategies that can prevent multi-drug resistance. METHODS: Using RNA expression profiling and immunohistochemistry, we have identified and characterised a gene expression signature associated with the emergence of NED in a large PCa cohort, including 169 hormone-naïve PCa (HNPC) and 48 castration-resistance PCa (CRPC) patients. In vitro and preclinical in vivo NED models were used to explore the cellular mechanism and to characterise the effects of castration on PCa progression. RESULTS: We show for the first time that Neuropilin-1 (NRP1) is a key component of NED in PCa cells. NRP1 is upregulated in response to androgen deprivation therapies (ADT) and elicits cell survival through induction of the PKC pathway. Downmodulation of either NRP1 protein expression or PKC activation suppresses NED, prevents tumour evolution toward castration resistance and increases the efficacy of docetaxel-based chemotherapy in preclinical models in vivo. CONCLUSIONS: This study reveals the NRP1/PKC axis as a promising therapeutic target for the prevention of neuroendocrine castration-resistant variants of PCa and indicates NRP1 as an early transitional biomarker.
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Neoplasias de la Próstata Resistentes a la Castración , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/patología , Neuropilina-1 , Neoplasias de la Próstata Resistentes a la Castración/patología , Antagonistas de Andrógenos , Resistencia a Medicamentos , Diferenciación Celular , Línea Celular TumoralRESUMEN
Antimicrobial peptides (AMPs) are produced by all living organisms exhibiting antimicrobial activities and representing the first line of innate defense against pathogens. In this context, AMPs are suggested as an alternative to classical antibiotics. However, several researchers reported their involvement in different processes defining them as Multifunctional AMPs (MF-AMPs). Interestingly, these agents act as the endogenous responses of the human organism against several dangerous stimuli. Still, they are identified in other organisms and evaluated for their anticancer therapy. Chromogranin A (CgA) is a glyco-phosphoprotein discovered for the first time in the adrenal medulla but also produced in several cells. CgA can generate different derived AMPs influencing numerous physiological processes. Dermaseptins (DRSs) are a family of α-helical-shaped polycationic peptides isolated from the skin secretions of several leaf frogs from the Phyllomedusidae family. Several DRSs were identified as AMPs and, until now, more than 65 DRSs have been classified. Recently, these exogenous molecules were characterized for their anticancer activity. In this review, we summarize the role of these two classes of MF-AMPs as an example of endogenous molecules for CgA-derived peptides, able to modulate inflammation but also as exogenous molecules for DRSs, exerting anticancer activities.
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Dermaseptin B2 (DRS-B2) is an antimicrobial peptide secreted by Phyllomedusa bicolor, which is an Amazonian tree frog. Here, we show that the adsorption of DRS-B2 on alginate nanoparticles (Alg NPs) results in a formulation (Alg NPs + DRS-B2) with a remarkable antibacterial activity against Escherichia coli ATCC 8739 and E. coli 184 strains, which are sensitive and resistant, respectively, to colistin. The antibacterial activity, obtained with this new formulation, is higher than that obtained with DRS-B2 alone. Of note, the addition of lactic acid or menthol to this new formulation augments its antibacterial activity against the aforementioned Gram-negative bacilli. The safety of DRS-B2, and also that of the new formulation supplemented or not with a small molecule such as lactic acid or menthol has been proven on the human erythrocytes and the eukaryotic cell line types HT29 (human) and IPEC-1 (animal). Similarly, their stability was determined under the conditions mimicking the gastrointestinal tract with different conditions: pH, temperature, and the presence of digestive enzymes. Based on all the obtained data, we assume that these new formulations are promising and could be suggested, after in vivo approval and completing regulation aspects, as alternatives to antibiotics to fight infections caused by Gram-negative bacilli such as E. coli.
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Prostate cancer is the most common cancer in men. For patients with advanced or metastatic prostate cancer, available treatments can slow down its progression but cannot cure it. The development of innovative drugs resulting from the exploration of biodiversity could open new therapeutic alternatives. Dermaseptin-B2, a natural multifunctional antimicrobial peptide isolated from Amazonian frog skin, has been reported to possess antitumor activity. To improve its pharmacological properties and to decrease its peripheral toxicity and lethality we developed a hormonotoxin molecule composed of dermaseptin-B2 combined with d-Lys6-LHRH to target the LHRH receptor. This hormonotoxin has a significant antiproliferative effect on the PC3 tumor cell line, with an IC50 value close to that of dermaseptin-B2. Its antitumor activity has been confirmed in vivo in a xenograft mouse model with PC3 tumors and appears to be better tolerated than dermaseptin-B2. Biophysical experiments showed that the addition of LHRH to dermaseptin-B2 did not alter its secondary structure or biological activity. The combination of different experimental approaches indicated that this hormonotoxin induces cell death by an apoptotic mechanism instead of necrosis, as observed for dermaseptin-B2. These results could explain the lower toxicity observed for this hormonotoxin compared to dermaseptin-B2 and may represent a promising targeting approach for cancer therapy.
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Proteínas Anfibias/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Línea Celular Tumoral/efectos de los fármacos , Secuencia de Aminoácidos , Proteínas Anfibias/metabolismo , Animales , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Antimicrobianos/metabolismo , Péptidos Antimicrobianos/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Hormona Liberadora de Gonadotropina/análogos & derivados , Hormona Liberadora de Gonadotropina/metabolismo , Hormona Liberadora de Gonadotropina/farmacología , Humanos , Factores Inmunológicos/metabolismo , Ratones , Ratones Desnudos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Dermaseptins are a group of α-helical shaped polycationic peptides isolated from the Hylid frogs, with antimicrobial effects against bacteria, parasites, protozoa, viruses in vitro. Besides, anti-tumor effects have been demonstrated. However, few animal experiments and no clinical trials have been conducted thus far. This review summarizes the current knowledge on the pharmacology, ethno pharmacology, effectivity against infectious pathogens and tumors cells and the mechanism of action of the Dermaseptins. Future research should focus on further clarification of the mechanisms of action, the effectivity of Dermaseptins against several cancer cell lines and their applicability in humans.
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Network meta-analysis is a new tool used to summarize and compare studies for multiple interventions, irrespective of whether these interventions have been directly evaluated against each other. Network meta-analysis is quickly becoming the standard in conducting therapeutic reviews and clinical guideline development. However, little guidance is available to help pharmacists review network meta-analysis studies in their practice. Major institutions such as the Cochrane Collaboration, Agency for Healthcare Research and Quality, Canadian Agency for Drugs and Technologies in Health, and National Institute for Health and Care Excellence Decision Support Unit have endorsed utilizing network meta-analysis to establish therapeutic evidence and inform decision making. Our objective is to introduce this novel technique to pharmacy practitioners, and highlight key assumptions behind network meta-analysis studies.
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Toma de Decisiones , Metaanálisis en Red , Farmacéuticos/normas , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricosRESUMEN
Dermaseptin-B2 (DRS-B2) is a multifunctional cationic antimicrobial peptide (CAP) isolated from frog skin secretion. We previously reported that DRS-B2 possesses anticancer and antiangiogenic activities in vitro and in vivo. In the present study, we evaluated the antiproliferative activity of DRS-B2 on numerous tumor cell lines, its cell internalization and studies of its molecular partners as well as their influences on its structure. Confocal microscopy using ([Alexa594]-(Cys0)-DRS-B2) shows that in sensitive human tumor cells (PC3), DRS-B2 seems to accumulate rapidly at the cytoplasmic membranes and enters the cytoplasm and the nucleus, while in less sensitive tumor cells (U87MG), DRS-B2 is found packed in vesicles at the cell membrane. Furthermore FACS analysis shows that PC3 cells viability decreases after DRS-B2 treatment while U87 MG seems to be unaffected. However, "pull down" experiments performed with total protein pools from PC3 or U87MG cells and the comparison between the antiproliferative effect of DRS-B2 and its synthetic analog containing all D-amino acids suggest the absence of a stereo-selective protein receptor. Pretreatment of PC3 cells with sodium chlorate, decreases the antiproliferative activity of DRS-B2. This activity is partially restored after addition of exogenous chondroitin sulfate C (CS-C). Moreover, we demonstrate that at nanomolar concentrations CS-C potentiates the antiproliferative effect of DRS-B2. These results highlight the partial implication of glycosaminoglycans in the mechanism of antiproliferative action of DRS-B2. Structural analysis of DRS-B2 by circular dichroism in the presence of increasing concentration of CS-C shows that DRS-B2 adopts an α-helical structure. Finally, structure-activity-relationship studies suggest a key role of the W residue in position 3 of the DRS-B2 sequence for its antiproliferative activity.
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Proteínas Anfibias/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Glicosaminoglicanos/metabolismo , Neoplasias/tratamiento farmacológico , Secuencia de Aminoácidos , Proteínas Anfibias/química , Animales , Péptidos Catiónicos Antimicrobianos/química , Antineoplásicos/química , Anuros , Línea Celular Tumoral , Humanos , Neoplasias/metabolismo , Relación Estructura-ActividadRESUMEN
The search for new bioactive molecules that could be used in therapeutics is a major public health issue, particularly in the treatment of certain diseases such as cancer. In this context the exploration of the venom of animals (snakes, amphibians, cones, scorpions, insects...) that produce molecules of various structures and biological activities, is a very promising direction. Research in this area led to the discovery of neuropeptides, hormones, toxins, antimicrobial peptides and other extremely potent mediators. These are now used in many areas both in fundamental research and in translational research, respectively, to understand biochemical and physiological mechanisms, or to use as medical diagnostic tools and for therapeutic purposes. Pr. V. Erspamer is the first researcher to have shown, in the 1930s, that in addition to biogenic amines and alkaloids, granular glands from the skin of amphibians also produced huge amounts of peptides with various structures and biological activities. He also showed that these peptides had their counterparts, most often in the form of identical or similar peptides, in the central nervous system and the gastrointestinal tract of mammals. These observations are summarized in the form of a triangle concept of "brain-gut-skin" that states that any peptide found in a compartment should be present in the other two. In addition, abundance, ease of extraction and identification of peptides from amphibian skin make this model a means to search for their counterparts in mammals where they are present in minute quantities. This approach has two advantages: (i) at the fundamental level, the large peptide diversity, ubiquity and multiplicity of functions to which they participate, constitute a true chemical library to understand the mechanisms of recognition and signal transduction and study the physicochemical basic of the specificity; and (ii) in terms of applications, the relative simplicity of these peptides and the rise of the production techniques by chemical or recombinant synthesis offer an innovative potential for the development of molecules with pharmacological or therapeutic purposes.
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Anfibios , Péptidos/aislamiento & purificación , Péptidos/uso terapéutico , Piel/química , Anfibios/fisiología , Animales , Aminas Biogénicas/aislamiento & purificación , Aminas Biogénicas/uso terapéutico , Humanos , Péptidos/metabolismo , Proteoma/análisis , Piel/metabolismo , Fenómenos Fisiológicos de la PielRESUMEN
Recently, we have found that the skin secretions of the Amazonian tree frog Phyllomedusa bicolor contains molecules with antitumor and angiostatic activities and identified one of them as the antimicrobial peptide dermaseptin (Drs) B2. In the present study we further explored the in vitro and in vivo antitumor activity of this molecule and investigated its mechanism of action. We showed that Drs B2 inhibits the proliferation and colony formation of various human tumor cell types, and the proliferation and capillary formation of endothelial cells in vitro. Furthermore, Drs B2 inhibited tumor growth of the human prostate adenocarcinoma cell line PC3 in a xenograft model in vivo. Research on the mechanism of action of Drs B2 on tumor PC3 cells demonstrated a rapid increasing amount of cytosolic lactate dehydrogenase, no activation of caspase-3, and no changes in mitochondrial membrane potential. Confocal microscopy analysis revealed that Drs B2 can interact with the tumor cell surface, aggregate and penetrate the cells. These data together indicate that Drs B2 does not act by apoptosis but possibly by necrosis. In conclusion, Drs B2 could be considered as an interesting and promising pharmacological and therapeutic leader molecule for the treatment of cancer.
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Proteínas Anfibias/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Antineoplásicos/farmacología , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , L-Lactato Deshidrogenasa/metabolismo , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Desnudos , Microscopía Confocal , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The discovery of new molecules with potential antitumor activity continues to be of great importance in cancer research. In this respect, natural antimicrobial peptides isolated from various animal species including humans and amphibians have been found to be of particular interest. Here, we report the presence of two anti-proliferative peptides active against cancer cells in the skin secretions of the South American tree frog, Phyllomedusa bicolor. The crude skin exudate was fractioned by size exclusion gel followed by reverse-phase HPLC chromatography. After these two purification steps, we identified two fractions that exhibited anti-proliferative activity. Sequence analysis indicated that this activity was due to two antimicrobial α-helical cationic peptides of the dermaseptin family (dermaseptins B2 and B3). This result was confirmed using synthetic dermaseptins. When tested in vitro, synthetic B2 and B3 dermaseptins inhibited the proliferation of the human prostatic adenocarcinoma PC-3 cell line by more than 90%, with an EC(50) of around 2-3 µM. No effect was observed on the growth of the NIH-3T3 non-tumor mouse cell line with Drs B2, whereas a slight inhibiting effect was observed with Drs B3 at high dose. In addition, the two fractions obtained after size exclusion chromatography also inhibited PC-3 cell colony formation in soft agar. Interestingly, inhibition of the proliferation and differentiation of activated adult bovine aortic endothelial cells was observed in cells treated with these two fractions. Dermaseptins B2 and B3 could, therefore, represent interesting new pharmacological molecules with antitumor and angiostatic properties for the development of a new class of anticancer drugs.
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Proteínas Angiostáticas/metabolismo , Proteínas Angiostáticas/farmacología , Antineoplásicos/farmacología , Piel/química , Piel/metabolismo , Proteínas Angiostáticas/análisis , Proteínas Angiostáticas/aislamiento & purificación , Animales , Antineoplásicos/análisis , Antineoplásicos/aislamiento & purificación , Anuros , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ratones , Células 3T3 NIH , Relación Estructura-Actividad , Células Tumorales CultivadasRESUMEN
Antimicrobial peptides (AMPs) produced by a wide variety of organisms are major actors of the host defense systems against invading pathogenic microorganisms. These peptides exhibit a broad spectrum of action against bacteria, yeasts, fungi, protozoa and viruses. It is widely believed that a large part of their antimicrobial effect derives from direct interactions with the lipid membrane surrounding the target cells, causing its permeabilization and cell lysis. However, the exact nature of these interactions is presently unclear. The skin of the amphibians has proved to be a remarkably rich storehouse of AMPs that encompass a wide variety of structural motifs. This natural AMP bank is used in combined approaches, based on biophysical and cellular biology methods, to elucidate how these peptides perturb the membrane and whether such membrane perturbations are related to the antimicrobial activity of these peptides. Here we review our current knowledge about the structure and the mechanism of action of the dermaseptin super-family, α-helical amphipathic AMPs isolated from the skin of frogs of the Phyllomedusa genus. Dermaseptins are genetically related, with a remarkable identity in signal sequences and acidic propieces of their preproforms but have clearly diverged to yield several families of microbicidal cationic peptides that are structurally distinct. Particularly, we focused on the orthologous peptides dermaseptin S and B of which the shortening from the carboxy terminal extremity causes a drastic change in their membrane disruption activity. These peptides could be good models to study the membrane-peptide interactions discussed in this review.
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Proteínas Anfibias/farmacología , Antiinfecciosos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Secuencia de Aminoácidos , Proteínas Anfibias/química , Animales , Péptidos Catiónicos Antimicrobianos/química , Biodiversidad , Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular , Humanos , Datos de Secuencia MolecularRESUMEN
D-aminoacyl residues have been detected in various animal peptides from several taxa, especially vertebrates and arthropods. This unusual polymorphism was shown to occur in isoforms of the crustacean hyperglycaemic hormone (CHH) of the American lobster because a D-phenylalanyl residue was found in position 3 of the sequence (CHH and D-Phe3 CHH). In the present study, we report the detailed strategy used to characterize, in the lobster neuroendocrine system, isomers of another member of the CHH family, vitellogenesis inhibiting hormone (VIH). We have demonstrated that the fourth residue is either an L- or a D- tryptophanyl residue (VIH and D-Trp4 VIH). Furthermore, use of antisera specifically recognizing the epimers of CHH and VIH reveals that aminoacyl isomerization occurs in specialized cells of the X organ-sinus gland neurosecretory system and that the D-forms of the two neuropeptides are not only present in the same cells, but, importantly, also are co-packaged within the same secretory vesicles.
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Nephropidae/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Aminoacilación , Animales , Proteínas de Artrópodos , Proteínas Portadoras/metabolismo , Hormonas de Invertebrados/metabolismo , Sistemas Neurosecretores/metabolismo , Isoformas de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , EstereoisomerismoRESUMEN
Detection of a D-amino acid residue in natural peptides by mass spectrometry remains a challenging task, as this post-translational modification does not induce any change in molecular mass. To our knowledge, the present article is the first report using matrix-assisted laser desorption/ionization (MALDI) for the discrimination and the quantification of peptide isomers. In this work, we used synthetic hepta- and decapeptides of biological relevance and their isomers. All-L sequences and some isomers containing a D-residue in various positions were analyzed.
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Aminoácidos/química , Péptidos/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Secuencia de Aminoácidos , Aminoácidos/análisis , Proteínas Portadoras/análisis , Hormonas de Invertebrados/análisis , Isomerismo , Péptidos Opioides/análisis , Péptidos/químicaRESUMEN
Dermaseptin B2 (Drs B2) is a 33-residue-long cationic, alpha-helical antimicrobial peptide endowed with membrane-damaging activity against a broad spectrum of microorganisms, including bacteria, yeasts, fungi, and protozoa, but its precise mechanism of action remained ill-defined. A detailed characterization of peptide-membrane interactions of Drs B2 was undertaken in comparison with a C-terminal truncated analogue, [1-23]-Drs B2, that was virtually inactive on bacteria despite retaining the cationic charge of the full-length peptide. Both peptides were tested on living cells using membrane permeabilization assays and on large unilamellar and multilamellar phospholipid vesicles composed of binary lipid mixtures by dye leakage assay, fluorescence spectroscopy, circular dichroism, and differential scanning calorimetry and also on SDS micelles using NMR spectroscopy. The results indicate that Drs B2 induces a strong perturbation of anionic lipid bilayers, resides at the hydrocarbon core-water interface, parallel to the plane of the membrane, and interacts preferentially with the polar head groups and glycerol backbone region of the anionic phospholipids, as well as the region of the lipid acyl chain near the bilayer surface. The interfacial location of Drs B2 induces a positive curvature of the bilayer and clustering of anionic lipids, consistent with a carpet mechanism, that may lead to the formation of mixed peptide-phospholipid toroidal, transient pores and membrane permeation/disruption once a threshold peptide accumulation is reached. In constrast, the truncated [1-23]-Drs B2 analogue interacts at the head group level without penetrating and perturbing the hydrophobic core of the bilayer. NMR study in SDS micelles showed that [1-23]-Drs B2 adopts a well-defined helix encompassing residues 2-20, whereas Drs B2 was previously found to adopt helical structures interrupted around the Val(9)-Gly(10) segment. Thus the antibacterial activity of Drs B2 depends markedly on a threshold number of hydrophobic residues to be present on both extremities of the helix. In a membrane environment with a strong positive curvature strain, Drs B2 can adopt a flexible helix-hinge-helix structure that facilitates the concomitant insertion of the strongly hydrophobic N- and C-termini of the peptide into the acyl core of the membrane.
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Proteínas Anfibias/química , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Membranas/metabolismo , Secuencia de Aminoácidos , Proteínas Anfibias/síntesis química , Proteínas Anfibias/metabolismo , Proteínas Anfibias/farmacología , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/síntesis química , Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Bioensayo , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Hidrocarburos/química , Membrana Dobles de Lípidos/química , Modelos Moleculares , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Péptidos/química , Péptidos/aislamiento & purificación , Estructura Secundaria de Proteína , Espectrometría de Fluorescencia , Agua/químicaRESUMEN
Temporin-SHa and temporin-SHc are 13 residue long antimicrobial peptides from frog skin that have similar sequences but differ markedly in their membrane-damaging properties. Temporin-SHa contains a single basic lysine residue and has a unique antimicrobial spectrum of action among temporins, being very potent against Gram-positive and Gram-negative bacteria, yeasts, fungi, and protozoa. Temporin-SHc, which contains a single basic histidine residue, is inactive against Gram-negative bacteria, has a reduced efficacy against Gram-positive bacteria, but is still active against yeasts and fungi. Temporin-SHb, with no basic residue, has no antimicrobial activity. The three-dimensional structures of the peptides bound to SDS micelles were analyzed by CD and NMR spectroscopy combined with restrained molecular dynamics calculations. The peptides adopt well-defined amphipathic alpha-helical structures extending from residue 3 to residue 12, when bound to SDS micelles. The structures are stabilized by extensive interactions between aliphatic and aromatic side chains on the nonpolar face. Relaxation enhancements caused by paramagnetic probes showed that the peptides adopt nearly parallel orientations to the micelle surface and do not deeply penetrate into the micelle. The interaction of the peptides with model membranes was investigated by differential scanning calorimetry on anionic and zwitterionic multilamellar vesicles and membrane-permeabilization assays on calcein-loaded large unilamellar vesicles. Calorimetric data indicated that both temporin-SHa and -SHc reside at the hydrocarbon core-water interface of the anionic lipid bilayer but interact with anionic bilayers in a very different manner. This suggests that the charge-induced activity of temporins-SH for bacterial cells is due to changes in the membrane-disturbing mechanism of the bound peptides.
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Proteínas Anfibias/química , Antiinfecciosos/química , Péptidos Catiónicos Antimicrobianos/química , Anuros/metabolismo , Rastreo Diferencial de Calorimetría/métodos , Espectroscopía de Resonancia Magnética/métodos , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Modelos Moleculares , Estructura Secundaria de Proteína , Proteínas , SolucionesRESUMEN
A growing number of cationic antimicrobial peptides have been isolated from the skin of hylid frogs belonging to the Phyllomedusinae subfamily. The amino acid sequences of these peptides are currently located in several databases under identifiers with no consistent system of nomenclature to describe them. In order to provide a workable terminology for antimicrobial peptides from Phyllomedusid frogs, we have made a systematic effort to collect, analyze, and classify all the Phyllomedusid peptide sequences available in databases. We propose that frogs belonging to the Phyllomedusinae subfamily should be described by the species names set out in Amphibian Species of the World: http://research.amnh.org/herpetology/amphibia/index.php, American Museum of Natural History, New York, USA. Multiple alignments analysis of at least 80 antimicrobial peptides isolated from 12 Phyllomedusinae species were distributed in seven distinct peptide families including dermaseptin, phylloseptin, plasticin, dermatoxin, phylloxin, hyposin and orphan peptides, and will be considered as the name of the headgroup of each family. The parent peptide's name should be followed by the first upper letter of the species for orthologous peptides and publication date determines priority. For example, the abbreviation B for bicolor and H for hypochondrialis. When two species begin with the same letter, two letters in upper case should be used (the first letter followed by the second or the third letter and so on). For example, the abbreviation DI for distincta, DU for duellmani, VA for vaillanti and VN for vanzolinii. Paralogous peptides should bear letter(s) in upper case followed by numbers.
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Péptidos Catiónicos Antimicrobianos/clasificación , Anuros/clasificación , Secuencia de Aminoácidos , Proteínas Anfibias/clasificación , Animales , Proteínas del Ojo/clasificación , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/clasificación , Péptidos/clasificación , Alineación de Secuencia , Terminología como AsuntoRESUMEN
Temporins are small antimicrobial peptides isolated from North American and Eurasian ranid frogs that are particularly active against Gram-positive bacteria. To date, no temporins have been characterized from North African frog species. We isolated three novel members of the temporin family, named temporin-1Sa (FLSGIVGMLGKLF(amide)), -1Sb (FLPIVTNLLSGLL(amide)), and -1Sc (FLSHIAGFLSNLF(amide)), from the skin of the Sahara frog Pelophylax (Rana) saharica originating from Tunisia. These temporins were identified by a combined mass spectrometry/molecular cloning approach. Temporin-1Sa was found to be highly active against Gram-positive and Gram-negative bacteria, yeasts and fungi (MIC=2-30 microM). To our knowledge, this is the first 13-residue member of the temporin family with a net charge of +2 that shows such broad-spectrum activity with particularly high potency on the clinically relevant Gram-negative strains, Escherichia coli (MIC=10 microM) and Pseudomonas aeruginosa (MIC=31 microM). Moreover, temporin-1Sa displays significant antiparasitic activity (IC50 approximately 20 microM) against the promastigote and amastigote stages of Leishmania infantum.
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Proteínas/aislamiento & purificación , Ranidae , Secuencia de Aminoácidos , Animales , Antibacterianos/farmacología , Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/farmacología , Antiprotozoarios/farmacología , Secuencia de Bases , Cromatografía Líquida de Alta Presión , Clonación Molecular , Eritrocitos/efectos de los fármacos , Hemolíticos/farmacología , Humanos , Leishmania infantum/efectos de los fármacos , Datos de Secuencia Molecular , Proteínas/químicaRESUMEN
The calcitonin gene-related peptide from the skin of the frog Phyllomedusa bicolor (pbCGRP) is a 37-residue neuropeptide that differs from human alpha CGRP (halphaCGRP) at 16 positions. The affinities of the C-terminal fragments of pbCGRP and halphaCGRP were evaluated in SK-N-MC cells: pbCGRP(8-37) (K(i)=0.2nM) and pbCGRP(27-37) (K(i)=95nM) were, respectively, 3 times and 20 times more potent than the human fragments halphaCGRP(8-37) and halphaCGRP(27-37). Their antagonistic potencies were measured in SK-N-MC and Col 29 cells, and the rat vas deferens. pbCGRP(8-37) inhibited the halphaCGRP-stimulated production of cAMP by SK-N-MC and Col 29 cells 3 to 4 times more strongly than halphaCGRP(8-37). Thus pbCGRP(8-37) is the most potent CGRP-1 competitive antagonist of all the natural sequences reported to date. pbCGRP(27-37) was also as potent as [D(31), A(34), F(35)] halphaCGRP(27-37), a prototypic antagonist analog derived from structure-activity relationship studies of halphaCGRP(8-37).