RESUMO
The bioactive peptide bradykinin obtained from cleavage of precursor kininogens activates the kinin-B2 receptor functioning in induction of inflammation and vasodilatation. In addition, bradykinin participates in kidney and cardiovascular development and neuronal and muscle differentiation. Here we show that kinin-B2 receptors are expressed throughout differentiation of murine C2C12 myoblasts into myotubes. An autocrine loop between receptor activation and bradykinin secretion is suggested, since bradykinin secretion is significantly reduced in the presence of the kinin-B2 receptor antagonist HOE-140 during differentiation. Expression of skeletal muscle markers and regenerative capacity were decreased after pharmacological inhibition or genetic ablation of the B2 receptor, while its antagonism increased the number of myoblasts in culture. In summary, the present work reveals to date no functions described for the B2 receptor in muscle regeneration due to the control of proliferation and differentiation of muscle precursor cells.
Assuntos
Diferenciação Celular , Músculo Esquelético/fisiologia , Mioblastos/citologia , Receptor B2 da Bradicinina/metabolismo , Regeneração , Animais , Biomarcadores/metabolismo , Bradicinina/metabolismo , Cardiotoxinas/administração & dosagem , Linhagem Celular , Proliferação de Células , Citoesqueleto/metabolismo , Deleção de Genes , Cininogênios/genética , Cininogênios/metabolismo , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Cadeias Pesadas de Miosina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor B2 da Bradicinina/genéticaRESUMO
There has been an increase in the scale and frequency of coral bleaching around the world due mainly to changes in sea temperature. This may occur at large scales, often resulting in significant decline in coral coverage. In order to understand the molecular and cellular basis of the ever-increasing incidence of coral bleaching, we have undertaken a comparative proteomic approach with the endangered Caribbean coral Acropora palmata. Using a proteomic tandem mass spectrometry approach, we identified 285 and 321 expressed protein signatures in bleached and unbleached A. palmata colonies, respectively, in southwestern Puerto Rico. Overall the expression level of 38 key proteins was significantly different between bleached and unbleached corals. A wide range of proteins was detected and categorized, including transcription factors involved mainly in heat stress/UV responses, immunity, apoptosis, biomineralization, the cytoskeleton, and endo-exophagocytosis. The results suggest that for bleached A. palmata, there was an induced differential protein expression response compared with those colonies that did not bleach under the same environmental conditions.
Assuntos
Antozoários/fisiologia , Recifes de Corais , Monitoramento Ambiental/métodos , Proteoma/metabolismo , Animais , Calcificação Fisiológica , Região do Caribe , Espécies em Perigo de Extinção , Perfilação da Expressão Gênica , Proteômica , Porto Rico , TemperaturaRESUMO
It is not unusual to find common molecules among parasites of different species, genera, or phyla. When those molecules are antigenic, they may be used for developing drugs or vaccines that simultaneously target different species or genera of parasite. In the present study, we used a proteomic-based approach to identify proteins that are common to adult Fasciola hepatica and Schistosoma mansoni. Whole-worm extracts from each parasite were separated by 2-dimensional electrophoresis (2-DE), and digital images of both proteomes were superimposed using imaging software to identify proteins with identical isoelectric points and molecular weights. Protein identities were determined by mass spectrometry. Imaging and immunoblot analyses identified 28 immunoreactive proteins that are common to both parasites. Among these molecules are antioxidant proteins (thioredoxin and glutathione-S-transferase), glycolytic enzymes (glyceraldehyde 6-phosphate dehydrogenase and enolase), proteolytic enzymes (cathepsin-L and -D), inhibitors (Kunitz-type, Stefin-1), proteins with chaperone activity (heat shock protein 70 and fatty acid-binding protein), and structural proteins (calcium-binding protein, actin, and myosin). Some of the identified proteins could be used to develop drugs and vaccines against fascioliasis and schistosomiasis.
Assuntos
Fasciola hepatica/química , Proteínas de Helminto/isolamento & purificação , Proteoma/isolamento & purificação , Proteômica/métodos , Schistosoma mansoni/química , Animais , Western Blotting , Bovinos , Reações Cruzadas , Eletroforese em Gel Bidimensional , Proteínas de Helminto/química , Proteínas de Helminto/imunologia , Humanos , Processamento de Imagem Assistida por Computador , Ponto Isoelétrico , Camundongos , Peso Molecular , Proteoma/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Partial immune restoration may be obtained with highly active antiretroviral therapy (HAART), but specific anti-HIV-1 immune responses do not appear to improve substantially. We have demonstrated that a soluble factor(s) induced by a mixture of inactivated influenza and bacterial vaccines called polyantigenic immunomodulator (PAI), possesses strong immunoregulatory and anti-HIV-1 activities. In the present study, we show that culture fluids from both PAI-stimulated peripheral blood mononuclear cells (PBMC) and CD8+ T-cells of HIV-1 infected patients were able to suppress HIV-1 replication in an MHC-unrestricted fashion. The PAI-induced antiviral activity was eliminated when culture fluids were pre-heated at 100°C for 10 min. and it is associated with induction of IFN-γ, MIP-1α, MIP-1ß, and RANTES production, but inhibition of IL-10. Furthermore, this induction is dependent on the immunological status (CD4:CD8 ratio) of the HIV-1 infected patient. Taken together, our results suggest that the MHC-unrestricted HIV-1 suppression that is induced by culture fluids from PAI-stimulated PBMC may result from the stimulation of immune cell subpopulations to produce a heat-labile antiviral soluble factor(s), which in turn modulate cytokine and ß-chemokine production. The identification of this PAI-induced soluble factor(s) may have major therapeutic potential.