EXPRESSION OF GLUCOCORTICOID RECEPTOR BETA IN CHILDREN WITH
IDIOPATHIC NEPHROTIC SYNDROME
He QN, Yi ZW, He XJ,
Huang DL
Lab. of Pediatric
Nephrology, The Second Hospital of Xiangya School of Medicine, Changsha,
China
Objective: To evaluate the significance of glucocorticoid receptor beta (GRβ) expressed in idiopathic nephrotic
syndrome (INS).
Methods: INS were classified
as glucocorticoid-sensitive INS or glucocorticoid-resistance INS.
Heparinized venous blood was collected, and peripheral blood mononuclear
cells (PBMCs) were isolated. Immunocytochemical
assay was carried out to investigate the expression of GRαand GRβ isoforms
in PBMCs. Quantity of GRα or GRβ protein in PBMCs and GR-DNA binding activity were assessed by western blotting assay and
electrophoretic mobility shift assay, respectively.
Results: The numbers of GRβimmunoreactive PBMCs in glucocorticoid-resistance INS were significantly
higher than in glucocorticoid-sensitive INS (P<0.01)，Nevertheless,
no significant difference of GRα
immunoreactive PBMCs was detected between two INS groups(P>0.05). In glucocorticoid-resistance INS, the quantity of GRα protein
was significantly lower, and the quantity of GRβ protein
was significantly higher in nuclei than that in glucocorticoid-sensitive
INS, respective. GR-DNA binding activity in glucocorticoid-resistance INS was decreased compared with glucocorticoid-sensitive INS.
Conclusions: An altered
ratio of two GR isoforms may result in an alteration of glucocorticoid
responses, and increased
expression of GRβ in PBMCs may account for glucocorticoid-resistance
in INS.