Navegando por Palavras-chave "Noradrenaline"
Agora exibindo 1 - 4 de 4
Resultados por página
Opções de Ordenação
- ItemSomente MetadadadosBeta2-adrenergic receptor signaling in CD4(+) Foxp3(+) regulatory T cells enhances their suppressive function in a PKA-dependent manner(Wiley-Blackwell, 2013-04-01) Guereschi, Marcia Grando [UNIFESP]; Araujo, Leandro Pires [UNIFESP]; Maricato, Juliana Terzi [UNIFESP]; Takenaka, Maisa Carla [UNIFESP]; Nascimento, Vanessa de Mendonça [UNIFESP]; Vivanco, Bruno Camolese [UNIFESP]; Reis, Vanessa Oliveira dos [UNIFESP]; Keller, Alexandre de Castro [UNIFESP]; Brum, Patricia C.; Basso, Alexandre Salgado [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Beta2-adrenergic receptor (B2AR) signaling is known to impair Th1-cell differentiation and function in a cAMP-dependent way, leading to inhibition of cell proliferation and decreased production of IL-2 and IFN-. CD4+ Foxp3+ Treg cells play a key role in the regulation of immune responses and are essential for maintenance of self-tolerance. Nevertheless, very little is known about adrenergic receptor expression in Treg cells or the influence of noradrenaline on their function. Here we show that Foxp3+ Treg cells express functional B2AR. B2AR activation in Treg cells leads to increased intracellular cAMP levels and to protein kinase A (PKA)-dependent CREB phosphorylation. We also found that signaling via B2AR enhances the in vitro suppressive activity of Treg cells. B2AR-mediated increase in Treg-cell suppressive function was associated with decreased IL-2 mRNA levels in responder CD4+ T cells and improved Treg-cell-induced conversion of CD4+ Foxp3 cells into Foxp3+ induced Treg cells. Moreover, B2AR signaling increased CTLA-4 expression in Treg cells in a PKA-dependent way. Finally, we found that PKA inhibition totally prevented the B2AR-mediated increase in Treg-cell suppressive function. Our data suggest that sympathetic fibers are able to regulate Treg-cell suppressive activity in a positive manner through B2AR signaling.
- ItemSomente MetadadadosCirculating renin-angiotensin system and catecholamines in childhood: is there a role for birthweight?(Portland Press Ltd, 2008-03-01) Franco, Maria do Carmo Pinho [UNIFESP]; Casarini, Dulce Elena [UNIFESP]; Carneiro-Ramos, Marcella S.; Sawaya, Ana Lydia [UNIFESP]; Barreto-Chaves, Maria Luiza M.; Sesso, Ricardo de Castro Cintra [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)There have been only a few reports on the sympathoadrenal and renin-angiotensin systems in children of small gestational age. the purpose of the present study was to investigate plasma levels of ACE (angiotensin-converting enzyme) activity, angiotensin and catecholamines in 8- to 13-year-old children and to determine whether there are correlations between the components of these systems with both birthweight and BP (blood pressure) levels. This clinical study included 66 children (35 boys and 31 girls) in two groups: those born at term with an appropriate birthweight [AGA (appropriate-for-gestational age) group, n = 31] and those born at term but with a small birthweight for gestational age [SGA (small-for-gestational age) group, n = 35]. Concentrations of angiotensin, catecholamines and ACE activity were determined in plasma. Circulating noradrenaline levels were significantly elevated in SGA girls compared with AGA girls (P = 0.036). in addition, angiotensin 11 and ACE activity were higher in SGA boys (P = 0.024 and P = 0.050 respectively). There was a significant association of the circulating levels of both angiotensin 11 and ACE activity with BP levels in our study population. Although the underlying mechanisms that link restricted fetal growth with later cardiovascular events are not fully understood, the findings in the present study support the link between low birthweight and overactivity of both sympathoadrenal and renin-angiotensin systems into later childhood.
- ItemSomente MetadadadosNeuroimmune interactions: dendritic cell modulation by the sympathetic nervous system(Springer Heidelberg, 2017) Takenaka, Maisa C. [UNIFESP]; Guereschi, Marcia G. [UNIFESP]; Basso, Alexandre S. [UNIFESP]Dendritic cells are of paramount importance bridging innate and adaptive immune responses. Depending on the context, after sensing environmental antigens, commensal microorganisms, pathogenic agents, or antigens from the diet, dendritic cells may drive either different effector adaptive immune responses or tolerance, avoiding tissue damage. Although the plasticity of the immune response and the capacity to regulate itself are considered essential to orchestrate appropriate physiological responses, it is known that the nervous system plays a relevant role controlling immune cell function. Dendritic cells present in the skin, the intestine, and lymphoid organs, besides expressing adrenergic receptors, can be reached by neurotransmitters released by sympathetic fibers innervating these tissues. These review focus on how neurotransmitters from the sympathetic nervous system can modulate dendritic cell function and how this may impact the immune response and immune-mediated disorders.
- ItemSomente MetadadadosRole of noradrenaline on the expression of the Na+/K+-ATPase alpha(2) isoform and the contractility of cultured rat vas deferens(Elsevier B.V., 2002-11-15) Quintas, Luis Eduardo Menezes; Lafayette, Simone Sette Lopes [UNIFESP]; Caricati-Neto, Afonso [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Noel, François; Universidade Federal do Rio de Janeiro (UFRJ); Universidade Federal de São Paulo (UNIFESP)Rat vasa deferentia were cultured for 3 days in Dulbecco's modified Eagle's medium in the absence or presence of 1 muM noradrenaline (NA) to investigate if the lack of NA release is the key factor to explain the selective reduction of the Na+/K+-ATPase alpha(2) isoform previously observed after in vivo denervation of this organ (Quintas et al., Biochem Pharmacol 2000;60:741-7). the lack of effects of the indirect sympathomimetic tyramine and the neuronal amine uptake blocker cocaine on NA curves indicated that cultured organs were denervated completely. Organ culture induced supersensitivity, expressed as a 6.3-fold increase of pD(2) and a 42% elevation of maximal contraction for NA but not for Ba2+. Western blotting indicated that the level of the alpha(1) isoform of Na+/K+-ATPase was unchanged after organ culture, but the alpha(2) isoform was down-regulated drastically to levels that were barely detectable. the addition of NA to the culture medium did not prevent the reduction of alpha(2) expression although it did impede NA supersensitivity (in fact a 4-fold decrease of pD(2) and a 32% reduction of maximal response were observed after incubation in the presence of NA). A striking reduction of L-type Ca2+ channel expression also was observed, indicated by an 85% decrease of [H-3]isradipine binding sites. These data suggest that NA is a trophic factor relevant to the control of muscle contraction, mediated by alpha(1)-adrenoceptors,but not to the expression of either Na+/K+-ATPase or the L-type Ca2+ channel. (C) 2002 Elsevier Science Inc. All rights reserved.