Profiling mRNA encoding glucocorticoid receptor α in saliva: Relationship to hair cortisol levels in individuals aged 15–25 years

Abstract

Objective

We assessed levels of mRNA encoding two glucocorticoid receptor (GR) isoforms (GRα and GRβ) in saliva and examined their relationship with hair cortisol levels and dental caries experience.

Design

Adolescents and young adults were assessed for dental caries experience, and hair cortisol was measured by ELISA. RNA was extracted from whole saliva using TRIzol, followed by quantitative real-time PCR analysis of GRα, GRβ, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH).

Results

GRβ mRNA was not detectable in most samples, whereas GRα mRNA was observed in all samples. There were significantly lower levels of GRα mRNA in individuals with elevated hair cortisol levels than in those with normal cortisol levels. Levels of GRα mRNA did not differ significantly in individuals with dental caries experience compared to individuals with no caries experience.

Conclusions

We identified and quantified mRNA encoding GRα in saliva. Its levels were inversely associated with hair cortisol (a marker of chronic stress). Although caries experience was associated with hair cortisol levels, there was no significant association between GRα levels and caries experience. Chronic stress has been proposed to be associated with reduced expression of GRα and this association appears to hold for GRα mRNA levels in saliva.