In vitro effects of 11-deoxycorticosterone on hepatocytes and gill epithelial cells of rainbow trout (Oncorhynchus mykiss)

Abstract

The 11-deoxycorticosterone (DOC) corticosteroid has been recently described as having a potential role in fish, complementing cortisol action through distinct physiological effects. Although systemic effects of 11-deoxycorticosterone (DOC) have been reported, the specific mechanisms mediated through glucocorticoid (GR) and mineralocorticoid (MR) receptors remain poorly understood. Therefore, we evaluated the DOC effects through both receptors in rainbow trout hepatoma-derived (RTH-149) and gill epithelial (RTgill-W1) cell lines. Cultures were pretreated with GR (Mifepristone) or MR (Eplerenone) antagonists for 1 h (50 nM) and then with DOC (10 nM) or vehicle (DMSO-PBS1X) as control for 3 h (n = 3). First, to determine a DOC-induced response via GR or MR, we detected a decrease in transcriptional levels of mr and these results were recovered to basal levels by MR antagonist in both cell lines. Then, we evaluated different metabolites and solutes associated with carbohydrate metabolism in RTH-149 and osmoregulation in RTgill-W1, detecting that DOC through both GR and MR differentially modulates lactate, glycogen, calcium, and chloride levels. We also identified that DOC mainly by MR differentially regulates gene expression of glucose/glycogen metabolism in RTH-149, ionic cotransporters, and tight junction proteins in RTgill-W1. Subsequently, we determined that DOC significantly decreases glucose uptake in RTH-149 and apparent permeability in RTgill-W1, reversed by MR antagonist. However, DOC does not affect transepithelial resistance in RTgill-W1. This study provides the first evidence that DOC, primarily via MR, plays a role in regulating carbohydrate metabolism in fish hepatocytes and osmoregulation in gill epithelial cells.