title: Low expression of glucocorticoid receptor alpha isoform in adult immune thrombocytopenia correlates with glucocorticoid resistance.
abstract: The expression of glucocorticoid receptor (GR) isoforms has been linked to glucocorticoid (GC) resistance in various diseases treated with GC. However, existing data are conflicting in these diseases, and little information is available regarding immune thrombocytopenia (ITP). To further investigate the role of GR isoforms in GC resistance in adult ITP patients, we measured the mRNA expression of GR isoforms (GRα, GRβ, GRγ, GRp) in peripheral blood mononuclear cells (PBMC) from 54 newly diagnosed ITP patients, including GC-sensitive (GCS) and GC-resistant (GCR) patients and 35 healthy volunteers. The GRα and GRβ proteins in PBMC, nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) in the nucleus were detected by Western blotting. Compared to normal subjects, both GRα and GRβ mRNAs were significantly increased in ITP patients (p < 0.05), while there was no significant difference in the mRNA expression of GRγ and GRp. Compared to GCR patients, the expressions of GRα mRNA and GRα protein were significantly higher in GCS patients (p < 0.05). Moreover, no significant difference in the mRNA expression of the GRβ, GRγ, and GRp isoforms was observed between GCS and GCR patients and the GRβ protein could not be detected. Compared to GCS group, the expression of p65/NF-κB was significantly higher in the GCR group (p < 0.05). Overall, we did not find differences in c-Jun/AP-1 protein expression between GCS and GCR patients. In summary, GC resistance in adult ITP patients is associated with a reduced expression of GRα, which may be related with increased NF-κB. GRβ was very low and may not be involved in GC resistance in adult ITP, warranting further exploration.
authors: Department of Hematology, the First Affiliated Hospital, Dalian Medical University, 222 Zhongshan Road, Dalian, 116011, People's Republic of China.
authors: Liangliang
authors: L
authors: Ma
authors: Meiyun
authors: M
authors: Fang
authors: Yan
authors: Y
authors: Liang
authors: Yang
authors: Y
authors: Xiang
authors: Zhilin
authors: Z
authors: Jia
authors: Xiuli
authors: X
authors: Sun
authors: Yi
authors: Y
authors: Wang
authors: Jixia
authors: J
authors: Qin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D011965:Receptors, Glucocorticoid / Q000096:biosynthesis / Q000235:genetics*; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D020033:Protein Isoforms; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; C411470:glucocorticoid receptor alpha