Immune-pineal-ocular axis in amphibians

• Grant number: 24/00618-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2024
• End date: November 30, 2026
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Fernando Ribeiro Gomes
• Grantee: Stefanny Christie Monteiro Titon
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 25/00287-5 - Heatwaves and microplastic effects on the hypothalamic hypophyseal thyroid and immune pineal axes and the tadpole's resistance to ranavirus infection and antiviral immunity, BE.EP.PD

Abstract

Melatonin produced by the pineal gland, in addition to being the hormone that signals the dark phase of the day, also regulates immune and pre-immune defense. There is evidence that in anurans, like mammals, the daily melatonin rhythm could also interfere with defense processes. This project aims to describe a possible immune-pineal-(ocular?) axis in anurans and to investigate whether an infectious challenge represents a chronorupture factor, promoting suppression of chronobiotic melatonin and inducing the synthesis of this hormone by immune cells. By experimenting with immune-challenged animals and in vitro treatment of immune cells with zymosan, we will investigate whether: 1) There is an alternation between the production of melatonin induced by darkness and the melatonin produced by activated immunocompetent cells; 2) Increased expression of AANAT and ASMT; pineal and retina are associated with increased plasma melatonin levels 3) Increased expression of AANAT and/or ASMT by activated immune cells is associated with increased melatonin produced by immune cells 4) Melatonin produced by the retina and pineal also is negatively modulated by infectious agents in amphibians. 5) Like mammals, the NFºB transcription factor regulates the alternation of melatonin production by the pineal/retina and activated immunocompetent cells. Having confirmed these hypotheses, we will be able to describe a possible immune-pineal-ocular axis in amphibians. (AU)