MicroRNA-124a contributes to glucocorticoid resistance in acute-on-chronic liver failure by negatively regulating glucocorticoid receptor alpha

Abstract

Introduction and objectivesGlucocorticoid resistance frequently associating with inflammation, may severely compromise the therapeutic effect of glucocorticoids. In this study, we aimed to investigate the regulation of glucocorticoid resistance by microRNA-124a (miR-124a) in patients with acute-on-chronic liver failure (ACLF). Materials and methodsThe miR-124a levels and glucocorticoid receptor alpha (GRα) expressions in peripheral blood monocytes and liver tissues were measured by quantitative reverse transcription–polymerase chain reaction (qRT-PCR), flow cytometry, and western blot analyses in the following four groups: healthy controls (HC), moderate chronic hepatitis B (CHB) patients, hepatitis B virus-related ACLF (HBV-ACLF) patients, and alcohol-induced ACLF (A-ACLF) patients. In addition, the serum miR-124a levels and multiple biochemical indices were determined. The effects of miR-124a transfection on GRα expression were assayed by qRT-PCR and western blotting in U937 and HepG2 cells stimulated with lipopolysaccharide (LPS). ResultsCompared with the CHB patients and HC, the miR-124a levels in HBV-ACLF and A-ACLF patients increased, while GRα expressions decreased. No significant differences in miR-124a levels and GRα expressions were observed between the HBV-ACLF and A-ACLF patients. For the ACLF patients, miR-124a level was negatively related to GRα expression in monocytes and positively correlated with the inflammatory factors such as interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). In U937 and HepG2 cells, LPS stimulated miR-124a levels but inhibited GRα expressions; meanwhile, increasing miR-124a levels reduced GRα expressions, and inhibiting miR-124a levels increased GRα expressions. ConclusionsThis study provides evidence that GRα expression was negatively regulated by miR-124a, which primarily determines the extent of acquired glucocorticoid resistance in ACLF.