Day vs. night variation in the LPS effects on toad's immunity and endocrine mediators

Autor(es)

Titon, Stefanny C. M. ; Titon Jr, Braz ; Muxel, Sandra M. ; de Figueiredo, Aymam C. ; Floreste, Felipe R. ; Lima, Alan S. ; Gomes, Fernando R. ; Assis, Vania R.

• Tipo de documento: Artigo Científico
• Fonte: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY; v. 267, p. 9-pg., 2022-05-01.

Resumo

The immune-endocrine interactions following an immune challenge have been demonstrated in amphibians. When considering immune challenges, the immune-endocrine implications can vary with the injection time (day or night), a pattern not explored in amphibians. We investigated the immune response following a lipopolysaccharide -LPS injection, measured as plasma bacterial killing ability -BKA, phagocytosis of blood cells -PP, and neutrophil to lymphocyte ratio -NLR, splenic proinflammatory cytokines mRNA (IL-1 beta and IL-6), and also endocrine mediators (corticosterone -CORT and melatonin -MEL plasma levels) in Rhinella icterica adult male toads injected at day (10 am) or night (10 pm). LPS induced increases in CORT, NLR, PP, and IL-1 beta mRNA compared with amphibian phosphate-buffer saline-injected individuals. For plasma CORT, the response was more pronounced during the night. While for the PP and IL-1 beta mRNA, the effect was more evident during the day. For NLR, the increase happened at both times, day and night, in the LPS-injected toads. Meanwhile, no changes were observed in BKA, IL-6 mRNA, and MEL levels. Overall, our results demonstrated an LPS-induced inflammatory response in R. icterica toads, characterized by higher PP, NLR, and IL-1 beta mRNA, followed by activation of the hypothalamic-pituitary-interrenal axis (higher CORT levels). The time in which the toads received the LPS injection affected the endocrine and immune mediators. The higher CORT and lower inflammatory response at night suggested a potential functional interaction between CORT and immune reactivity associated with the differences in night vs. day in R. icterica toads. These results highlight the relevance of investigating different injection times and mechanistic pathways to understand LPS-induced immunomodulation in anurans. (AU)

• 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: 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: 19/24950-4 - Dinâmica temporal da resposta inflamatória em anfíbios
• Beneficiário: Fernando Ribeiro Gomes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• 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