BACKGROUND: Clinical trials evaluating the use of steroids in septic shock have shown variable outcomes. Our previous studies have implicated human glucocorticoid receptor (hGR) polymorphisms as a possible cause of altered steroid response. To further evaluate this variability, we hypothesized that hGR polymorphisms along with type of steroid influence the functional response. METHODS: Total RNA was isolated from healthy human blood samples and surveyed for the hGR gene. The National Center for Biotechnology Information hGRα sequence was used as a reference, and two unique single nucleotide polymorphisms (SNPs) (A214G and T962C) were selected for evaluation. Functional response was measured using a luciferase reporting assay after transfecting hGR isoforms into tsA201 cells and stimulation with graded concentrations of hydrocortisone (HYD), methylprednisolone (MPS), and dexamethasone (DEX). RESULTS: Each isoform had a unique dose-response curve with the optimal activity depending on concentration and type of steroid. The presence of either SNP A214G or T962C resulted in a decreased response when compared with hGRα when stimulated with HYD (P < 0.01). The same decreased response occurred for the SNPs with DEX stimulation, but at a much lower concentration range than HYD (P < 0.01). However, in the presence of MPS, SNP A214G resulted in greater activity when compared with hGRα (P < 0.01), whereas the presence of T962C resulted in activity equivalent to hGRα. CONCLUSIONS: SNPs, type of steroid, and concentration range impact the functional response of the hGR. A greater understanding of hGR polymorphisms and steroid response may further elucidate mechanisms explaining the variable response seen with patient treatment.
BACKGROUND: Clinical trials evaluating the use of steroids in septic shock have shown variable outcomes. Our previous studies have implicated humanglucocorticoid receptor (hGR) polymorphisms as a possible cause of altered steroid response. To further evaluate this variability, we hypothesized that hGR polymorphisms along with type of steroid influence the functional response. METHODS: Total RNA was isolated from healthy human blood samples and surveyed for the hGR gene. The National Center for Biotechnology Information hGRα sequence was used as a reference, and two unique single nucleotide polymorphisms (SNPs) (A214G and T962C) were selected for evaluation. Functional response was measured using a luciferase reporting assay after transfecting hGR isoforms into tsA201 cells and stimulation with graded concentrations of hydrocortisone (HYD), methylprednisolone (MPS), and dexamethasone (DEX). RESULTS: Each isoform had a unique dose-response curve with the optimal activity depending on concentration and type of steroid. The presence of either SNP A214G or T962C resulted in a decreased response when compared with hGRα when stimulated with HYD (P < 0.01). The same decreased response occurred for the SNPs with DEX stimulation, but at a much lower concentration range than HYD (P < 0.01). However, in the presence of MPS, SNP A214G resulted in greater activity when compared with hGRα (P < 0.01), whereas the presence of T962C resulted in activity equivalent to hGRα. CONCLUSIONS: SNPs, type of steroid, and concentration range impact the functional response of the hGR. A greater understanding of hGR polymorphisms and steroid response may further elucidate mechanisms explaining the variable response seen with patient treatment.
Authors: Truls Gråberg; Emma Ahlén Bergman; Lovisa Strömmer; Louise K Sjöholm; Ann-Charlotte Wikström; Ola Winqvist; Max Winerdal Journal: Mol Med Rep Date: 2022-04-21 Impact factor: 2.952