Nuclear HSP90 regulates the glucocorticoid responsiveness of PBMCs in patients with idiopathic nephrotic syndrome
Nuclear HSP90 regulates the glucocorticoid responsiveness of PBMCs in patients with idiopathic nephrotic syndrome
复制标题
核HSP90调节特发性肾病综合征患者PBMC的糖皮质激素反应
DOI：
10.1016/j.intimp.2012.08.012
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发表时间：
2012-11-01
影响因子：
5.6
通讯作者：
Li, Junxun
中科院分区：
文献类型：
--
作者：
Ouyang, Juan;Chen, Peisong;Li, Junxun
对糖皮质激素（GC）的耐药是原发性肾病综合征（INS）治疗的一大挑战。GC的大部分作用是由GC受体（GR）介导的。热休克蛋白90（HSP 90）是GR的重要分子伴侣，被认为是调节GC效应的关键因子。在以前的研究中，我们发现在GC抵抗的INS患者中，HSP 90的表达和核分布均增加。本研究的目的是探讨这些现象如何导致INS患者的GC抵抗。招募健康受试者和具有不同GC反应的INS患者。逆转录-PCR和流式细胞术检测HSP 90的表达。Western blot检测细胞核HSP 90的表达。采用免疫共沉淀法和凝胶迁移率分析法研究了HSP 90与GR在细胞核中的相互作用以及GR的DNA结合活性。GR的DNA结合活性和细胞对GC的凋亡反应性保持不变。此外，增加核HSP 90主要表现为结合到核中的GR，而GR的DNA结合活性显着下降，在GC耐药INS患者。目前的结果表明，HSP 90在细胞核中的积累可能会阻碍DNA结合活性和反式激活，这可能有助于INS患者的GC耐药性。（C）2012 Elsevier B. V.保留所有权利。
Resistance to glucocorticoid (GC) is a challenge for the treatment of patients with idiopathic nephrotic syndrome (INS). Most of the effects of GC are mediated by the GC receptor (GR). Heat shock protein 90 (HSP90) is an important molecular chaperone for the GR and is supposed to be the key factor in regulating GC effects. In a previous study, we found that both the expression and nuclear distribution of HSP90 were increased in GC resistant INS patients. The aim of this study is to explore how these phenomena contribute to GC resistance in INS patients. Healthy subjects and INS patients with different GC responses were recruited. The total HSP90 expression was determined by reverse transcription-PCR and flow cytometric analysis. Western blot analysis was used to evaluate the expression of nuclear HSP90. Co-immunoprecipitation and electrophoretic mobility gel shift assays were performed to explore the interaction between HSP90 and the GR in the nucleus as well as the DNA-binding activity of GR.We induced the upregulation of the expression of total HSP90 in PBMCs by treatment with interleukin-6 in vitro and found that the nuclear HSP90 level, the DNA-binding activity of the GR and the cell apoptotic responsiveness to GC remained unchanged. Furthermore, an increased nuclear HSP90 was demonstrated mainly by binding to GR in the nucleus, while the DNA-binding activity of the GR dramatically decreased in GC resistant INS patients. The present results suggest that the accumulation of HSP90 in the nucleus potentially hinders DNA-binding activity and transactivation, which may contribute to GC resistance in patients with INS. (C) 2012 Elsevier B.V. All rights reserved.