Time Course of Splenic Cytokine mRNA and Hormones during a Lipopolysaccharide-Induced Inflammation in Toads

Autor(es)

Floreste, Felipe R. ; Titon Jr, Braz ; Titon, Stefanny C. M. ; Muxel, Sandra M. ; Gomes, Fernando R. ; Assis, Vania R.

• Tipo de documento: Artigo Científico
• Fonte: INTEGRATIVE AND COMPARATIVE BIOLOGY; v. N/A, p. 11-pg., 2022-04-01.

Resumo

Synopsis Inflammation comprises alterations in glucocorticoids (in amphibians, corticosterone-CORT) and melatonin (MEL) levels, two hormones with immunomodulatory effects on cytokine production in several vertebrates. Cytokines mediate inflammation progress differently depending on their function. While some are secreted during the acute phase of the immune response, others prevail during the resolution phase. Major efforts have been made to understand the interaction of endocrine mediators and cytokine production in endotherms, but little is known for ectotherms so far. Characterizing the stages of inflammation and their interplay with endocrine mediators is crucial for an assertive and integrative approach to amphibian physiology and ecoimmunology. Herein, we investigated CORT and MEL plasma levels as well as splenic cytokine (IL-1 beta, IL-6, and IL-10) mRNA levels during the progression of the inflammatory response in toads (Rhinella diptycha) in four time-points (1, 3, 6, and 18 h) after an immune challenge with lipopolysaccharide (LPS) using independent samples. Toads were responsive to LPS, with all hormones and cytokines affected by LPS. IL-1 beta and IL-6 were up-regulated after 1 h, but IL-1 beta decreased right after 3 h, while IL-6 sustained up-regulation throughout all time-points. IL-10 had not been detected until 6 h post-LPS-stimulation, when it showed up-regulation, along with a CORT increase at the same time-point. After 18 h, CORT levels were still high, and IL-1 beta was up-regulated again, along with up-regulated IL-6 and an IL-10 decrease. We also found positive correlations between IL-1 beta with IL-6 for LPS and saline groups. LPS-treated individuals showed an overall decrease in MEL plasma levels compared to saline counterparts. Our results showcase the early endocrine and molecular events of the amphibian immune response. We also report activation of the hypothalamus-pituitary-interrenal (HPI) axis during inflammation and increasing evidence for an immune-pineal axis to be described in amphibians. (AU)

• Processo FAPESP: 15/23801-4 - Efeitos imuno-moduladores do estresse agudo em sapos do Gênero Rhinella
• Beneficiário: Vania Regina de Assis
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/16320-7 - Impactos das mudanças climáticas e ambientais sobre a fauna: uma abordagem integrativa
• Beneficiário: Carlos Arturo Navas Iannini
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 16/01782-0 - Relações entre as condições ambientais e fisiológicas de atividade e sua importância para alterações da distribuição de sapos frente às mudanças climáticas
• Beneficiário: Braz Titon Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/24950-4 - Dinâmica temporal da resposta inflamatória em anfíbios
• Beneficiário: Fernando Ribeiro Gomes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 20/00370-6 - Alterações da expressão gênica de citocinas em sapos do gênero Rhinella submetidos a desafio imunológico com lipopolissacarídeo (LPS)
• Beneficiário: Felipe Rangel Floreste
• Modalidade de apoio: Bolsas no Brasil - Mestrado