RESUMO
The lipid mediators, platelet-activating factor (PAF) and lysophosphatidylcholine (LPC), play relevant pathophysiological roles in Trypanosoma cruzi infection. Several species of LPC, including C18:1 LPC, which mimics the effects of PAF, are synthesized by T. cruzi. The present study identified a receptor in T. cruzi, which was predicted to bind to PAF, and found it to be homologous to members of the progestin and adiponectin family of receptors (PAQRs). We constructed a three-dimensional model of the T. cruzi PAQR (TcPAQR) and performed molecular docking to predict the interactions of the TcPAQR model with C16:0 PAF and C18:1 LPC. We knocked out T. cruzi PAQR (TcPAQR) gene and confirmed the identity of the expressed protein through immunoblotting and immunofluorescence assays using an anti-human PAQR antibody. Wild-type and knockout (KO) parasites were also used to investigate the in vitro cell differentiation and interactions with peritoneal mouse macrophages; TcPAQR KO parasites were unable to react to C16:0 PAF or C18:1 LPC. Our data are highly suggestive that PAF and LPC act through TcPAQR in T. cruzi, triggering its cellular differentiation and ability to infect macrophages.
Assuntos
Lisofosfatidilcolinas/metabolismo , Fator de Ativação de Plaquetas/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/genética , Trypanosoma cruzi/metabolismo , Sequência de Aminoácidos , Animais , Diferenciação Celular , Doença de Chagas/parasitologia , Técnicas de Inativação de Genes/métodos , Interações Hospedeiro-Parasita , Humanos , Lisofosfatidilcolinas/química , Macrófagos , Camundongos , Simulação de Acoplamento Molecular , Filogenia , Fator de Ativação de Plaquetas/química , Conformação Proteica , Proteínas de Protozoários/química , Receptores de Adiponectina/química , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Receptores de Progesterona/química , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Trypanosoma cruzi/químicaRESUMO
A new species of Bessierus Thomas Orth, formerly a monotypic genus, is described from Amapá State, Brazil. The type species of the genus, B. doloris Thomas Orth, had only its nymphs described until recently, when its male imago was associated to nymphs mainly based on pigmentation pattern. Bessierus riobranco sp. n. here described has no significant difference on pigmentation pattern from B. doloris, thus the new species could be the male imago of B. doloris, and the putative imago of B. doloris a new species, or even both described imagoes could be new species. Still, a new male imago existence cannot be neglected and we opted to provide a properly description, diagnosis and illustration, hence contributing to the knowledge of mayfly neotropical diversity and future research on the genus. The generic concept of Bessierus and its type species diagnoses are altered to accommodate the new species, and a new record of B. doloris is provided.
Assuntos
Ephemeroptera , Animais , Brasil , Masculino , Ninfa , PigmentaçãoRESUMO
Three unusual nymphs of Euthyplociidae, subfamily Euthyplociinae, are described from Ecuador. A new genus and new species are established to accommodate these individuals. The morphologically unique specimens are defined by the following characters: short, stout tusks lacking spine-like setae but densely covered with long, hair-like setae; head almost as long as wide; long, quadrate clypeus with acute apicolateral projections; apex of 3rd segment of labial palp acute; apex of 3rd segment of maxillary palp acute and narrow. The hind wing is small, similar to that of Mesoplocia. An ongoing study of the phylogeny of the family recovers Dasyplocia gen. nov. as closely related to Euthyplocia and Mesoplocia.
Assuntos
Ephemeroptera , Animais , Equador , Ninfa , Filogenia , Asas de AnimaisRESUMO
Trypanosomatids are protozoan parasites that infect thousands of globally dispersed hosts, potentially affecting their physiology. Several species of trypanosomatids are commonly found in phytophagous insects. Leptomonas wallacei is a gut-restricted insect trypanosomatid only retrieved from Oncopeltus fasciatus. The insects get infected by coprophagy and transovum transmission of L. wallacei cysts. The main goal of the present study was to investigate the effects of a natural infection by L. wallacei on the hemipteran insect O. fasciatus, by comparing infected and uninfected individuals in a controlled environment. The L. wallacei-infected individuals showed reduced lifespan and morphological alterations. Also, we demonstrated a higher infection burden in females than in males. The infection caused by L. wallacei reduced host reproductive fitness by negatively impacting egg load, oviposition, and eclosion, and promoting an increase in egg reabsorption. Moreover, we associated the egg reabsorption observed in infected females, with a decrease in the intersex gene expression. Finally, we suggest alterations in population dynamics induced by L. wallacei infection using a mathematical model. Collectively, our findings demonstrated that L. wallacei infection negatively affected the physiology of O. fasciatus, which suggests that L. wallacei potentially has a vast ecological impact on host population growth.
Assuntos
Heterópteros/fisiologia , Trypanosomatina/patogenicidade , Animais , Estudos de Casos e Controles , Feminino , Heterópteros/parasitologia , Longevidade , Masculino , Modelos Teóricos , Oviposição , Dinâmica Populacional , Caracteres SexuaisRESUMO
The species Phytomonas serpens is known to express some molecules displaying similarity to those described in trypanosomatids pathogenic to humans, such as peptidases from Trypanosoma cruzi (cruzipain) and Leishmania spp. (gp63). In this work, a population of P. serpens resistant to the calpain inhibitor MDL28170 at 70 µ m (MDLR population) was selected by culturing promastigotes in increasing concentrations of the drug. The only relevant ultrastructural difference between wild-type (WT) and MDLR promastigotes was the presence of microvesicles within the flagellar pocket of the latter. MDLR population also showed an increased reactivity to anti-cruzipain antibody as well as a higher papain-like proteolytic activity, while the expression of calpain-like molecules cross-reactive to anti-Dm-calpain (from Drosophila melanogaster) antibody and calcium-dependent cysteine peptidase activity were decreased. Gp63-like molecules also presented a diminished expression in MDLR population, which is probably correlated to the reduction in the parasite adhesion to the salivary glands of the insect vector Oncopeltus fasciatus. A lower accumulation of Rhodamine 123 was detected in MDLR cells when compared with the WT population, a phenotype that was reversed when MDLR cells were treated with cyclosporin A and verapamil. Collectively, our results may help in the understanding of the roles of calpain inhibitors in trypanosomatids.
Assuntos
Inibidores de Cisteína Proteinase/farmacologia , Dipeptídeos/farmacologia , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Peptídeo Hidrolases/efeitos dos fármacos , Trypanosomatina/efeitos dos fármacos , Calpaína/antagonistas & inibidores , Calpaína/química , Calpaína/efeitos dos fármacos , Calpaína/genética , Cisteína Endopeptidases/imunologia , Resistência a Medicamentos , Glicoproteínas/farmacologia , Leishmania/química , Leishmania/fisiologia , Proteínas de Membrana Transportadoras/genética , Peptídeo Hidrolases/genética , Proteínas de Protozoários/imunologia , Trypanosoma cruzi/química , Trypanosoma cruzi/fisiologia , Trypanosomatina/genéticaRESUMO
Polyplocia nebulosa sp. nov. is described based on male and female imagos from Malaysia, Sabah State. Nymphs provisionally assigned to this species are also described. This species can be readily separated from P. vitalisi by the color pattern of the wings, with light brown longitudinal veins, narrow dark brown clouds on cross veins and margins of wings tinged with brown. The male genitalia are distinct from those of other species of Polyplocia: penes are broad, T-shaped, with large lateral projecting lobes, which are apically rounded, and with a small dorsolateral spine on each lobe; the styliger plate is short and not projected posteriorly. Eggs of the genus are described for the first time using scanning electron microscopy. Eggs are 265-267 µm in length, 170-186 µm in width, barrel-shaped, without polar caps or other attachment structures, with one visible micropyle and with chorion forming an irregular mesh with raised ridges (mesh between 3.8-8 µm). A key to male adults of Polyplocia is provided and additional records of Polyplocia from Thailand are given.
Assuntos
Ephemeroptera/classificação , Animais , Cor , Ephemeroptera/anatomia & histologia , Feminino , Malásia , Masculino , Ninfa , Óvulo , Asas de AnimaisRESUMO
The former monotypic genus Oligoneuria Pictet was known solely by a female subimago of the type-species Oligoneuria anomala Pictet. A new species of the genus Oligoneuria from the Atlantic rainforest of Macaé, Rio de Janeiro is described. The description was based in males and females imagos of Oligoneuria macabaiba sp. nov. caught with light traps. This species presents similar wing venation, abdominal posterolateral spines, as well as a membranous extension on anterior portion of the head as seen in the genus. Based on features of the new species, the genus is herein redefined. The species represents the first record of the genus from Southeastern Brazil. Rev. Biol. Trop. 59 (4): 1553-1557. Epub 2011 December 01.
En la Floresta Atlántica de Macaé, Rio de Janeiro, se describe una nueva especie del género Oligoneuria. La descripción fue basada en imagos machos y hembras de Oligoneuria macabaiba sp. nov. recolectados con trampas de luz. Estas especies presentan alas con venación y espinas abdominales posterolaterales similares al género, así como la expansión membranosa en la región anterior de la cabeza propia de Oligoneuria. Basado en las características de la nueva especie, el género es redefinido. La especie representa el primer registro del género para el Sudeste del Brasil.
Assuntos
Animais , Feminino , Masculino , Insetos/anatomia & histologia , Insetos/classificação , Brasil , ÁrvoresRESUMO
The former monotypic genus Oligoneuria Pictet was known solely by a female subimago of the type-species Oligoneuria anomala Pictet. A new species of the genus Oligoneuria from the Atlantic rainforest of Macaé, Rio de Janeiro is described. The description was based in males and females imagos of Oligoneuria macabaiba sp. nov. caught with light traps. This species presents similar wing venation, abdominal posterolateral spines, as well as a membranous extension on anterior portion of the head as seen in the genus. Based on features of the new species, the genus is herein redefined. The species represents the first record of the genus from Southeastern Brazil.