title: Catecholamines are produced by ascidian immune cells: The involvement of PKA and PKC in the adrenergic signaling pathway.
abstract: The stress response is a complex mechanism, which includes changes in the immune system to enable organisms to maintain homeostasis. The neurohormones dopamine, noradrenaline (NA) and adrenalin are responsible for the physiological modulations that occur during acute stress. In the present study, we analyzed the effects of NA on the immune system specific to nitric-oxide (NO) production by subpopulations of immune cells (hemocytes) of the ascidian Phallusia nigra. We also investigated the capability of immune cells to produce catecholamine (CA). Finally, we tested the involvement of protein kinase A (PKA) and C (PKC) in the NA downstream signaling pathway. The results revealed that NA can reduce NO production by P. nigra hemocytes threefold, and that signet-ring cells, univacuolar refractile granulocytes and morula cells are the cell types most involved in this event. A challenge effected with Zymosan A induced CA production, and co-incubation with both inhibitors of the second messengers PKA and PKC revealed the involvement of these molecules in the adrenergic pathway of P. nigra hemocytes. Taken together, these results suggest that NO production can be down-regulated by NA through α- and β-adrenoceptors via the second messengers PKA and PKC.
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, RJ, Brazil; Pós-Graduação em Produtos Bioativos e Biociências, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, Macaé, RJ, Brazil.
authors.forename: Andressa
authors.initials: A
authors.lastname: de Abreu Mello
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, RJ, Brazil.
authors.forename: Jéssica
authors.initials: J
authors.lastname: Fernandes de Souza
authors.affiliation: Laboratório Integrado de Ciências Morfofuncionais, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, RJ, Brazil; Pós-Graduação em Produtos Bioativos e Biociências, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, Macaé, RJ, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Nunes da Fonseca
authors.affiliation: Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Allodi
authors.affiliation: Laboratório Integrado de Morfologia, Núcleo em Ecologia e Desenvolvimento Sócio Ambiental de Macaé - NUPEM, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, RJ, Brazil; Pós-Graduação em Produtos Bioativos e Biociências, Universidade Federal do Rio de Janeiro, Campus UFRJ-Macaé, Macaé, RJ, Brazil. Electronic address: cintiabarros@macae.ufrj.br.
authors.forename: Cintia
authors.initials: C
authors.lastname: Monteiro de Barros
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D006434:Hemocytes / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014561:Urochordata / Q000378:metabolism*
chemical_list: D002395:Catecholamines; D009569:Nitric Oxide; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C
keywords: Hemocytes; Nitric oxide; Noradrenaline; Phallusia nigra