Breaking down a paradigm? Melanopsin, a canonical photopigment, acting as a thermosensor for clock adjustment in non-exposed organs, and its possible interaction with TRP channels: a transdisciplinary study involving physiological and pathological aspects

Project description

The present study proposes to investigate the following hypothesis, based on our preliminary data and all the evidence produced by our group: melanopsin (OPN4) and / or potential transient receptor (TRP) channels, expressed in cardiomyocytes, possibly monitor changes in the internal temperature among other variables. We suggest that there is a variation in the temperature in the flow of oxygenated blood entering the fresh heart coming from the respiratory tract and the blood flow from the periphery, with lower pressure and poor oxygen, in addition to the circadian variation of internal temperature. This variation in temperature would be interpreted by the heart, for example, in the expression of its major hormones natriuretic peptides (NPs), among other possibilities, to regulate local clocks and the metabolism and clocks of target tissues and organs such as white adipose tissue (WAT) and brown (BAT), and the heart itself. Since a link (via release of NPs) between cardiac function and metabolism, and between metabolic dysfunctions and clock disruption (Tables 1, 2 and 3) is proposed, we could speculate that the exacerbated imbalance of this pathway would be responsible for pathologies not only of the heart itself, but also of the organism as a whole. In addition, understanding how this circuitry is altered in metabolic extremes such as obesity and cachexia will open the possibility of intervention in the pathological situation or in the prevention or mitigation of possible changes. We will evaluate the perception of temperature, the local clock and tissue-specific canonical processes in vivo and in explant or cell culture of suprachiasmatic nucleus (NSQ), basal mean, heart, WAT and BAT of WT and KO mice for Opn4, TrpV1 , M8 and A1 under physiological conditions and at metabolic extremes obesity and cachexia, associated to temperature variation assays. When we initially get the transcriptome of the organs in question of WT mice submitted at 22oC and 29oC (thermo-neutrality), we will have a north to focus the investigations on the pathways and thermo-receptive signs altered by the temperature challenge. In vivo assays will be performed at 22 and 29 ° C and in vitro at 34, 35, 36, 37, 38, 39, 40 ° C; part of the assays will be performed in the presence of agonists and antagonists of OPN4 and TRP channels, or in cells secreted by esiRNA or knocked out by CRISPER. We will analyze the clock genes and tissue-specific genes identified by the comparative transcriptome using in principle the following methodologies: immunocytochemistry, quantitative PCR, Western blot, flow cytometry with image, CRISPER. Throughout the project we intend to establish the lineage of knockout mice for organ-specific Opn4 by Cre-lox system.