Hypothalamic extraretinal photoreceptor Opsin3 regulates water balance, body temperature and motor activity

Abstract

Opsin 3 (Opn3) is a light-sensitive protein present throughout the mammalian brain, although its functions in this organ are currently unknown. Since Opn3 encoded mRNA increases in the supraoptic nucleus (SON) of the hypothalamus in response to hyperosmotic stimuli, we have explored the role of Opn3 in this nucleus. By in situ hybridization, we have demonstrated that Opn3 is expressed in neurones expressing both arginine vasopressin and oxytocin in the rat SON, suggesting that OPN3 functions in both neuronal types. Gene profiling analysis by RNA-seq suggested that neuropeptide production is impaired when knocking down Opn3 in the rat SON, as confirmed by quantitative PCR and immunolabelling. Knocking down Opn3 in the rat SON altered physiological parameters including water intake, body temperature and motor activity. Altogether the data indicates that Opn3 in the SON is involved in the regulation of a number of neuropeptides and other proteins that participate in water homeostasis, body temperature and motor activity.

Translational and Posttranslational Dynamics in a Model Peptidergic System

“…We then explored the relationship between the transcriptomes and the proteomes of SONs in the basal condition. In order to generate a complete rat transcriptome, we generated a dataset which included the entire transcriptome determined by RNA-seq of Wistar Han ( 20 ) and Sprague Dawley ( 42 ) rats in basal conditions ( supplemental Fig. S2 ).…”

“…The relationship between basal transcriptomes and proteomes was examined by comparing the proteome output obtained in the present study in basal conditions with a complete rat transcriptome combining all the genes detected in previous SON transcriptomic analysis in Sprague Dawley ( 42 ) and Wistar Han ( 20 ) rats in basal conditions. We found that 14.846 genes are commonly expressed in both strains, while only 356 and 545 genes are uniquely expressed in the SON of Wistar Han and Sprague Dawley rats ( supplemental Fig.…”