1. The study of GPX3 methylation in patients with Kashin-Beck Disease and its mechanism in chondrocyte apoptosis.
- Author
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Han, Lixin, Yang, Xiaoli, Sun, Wenyan, Li, Zhaofang, Ren, Hao, Li, Baorong, Zhang, Rongqiang, Zhang, Dandan, Shi, Ziyun, Liu, Jifeng, Cao, Junling, Zhang, Jianjun, and Xiong, Yongmin
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METHYLATION , *GLUTATHIONE peroxidase genetics , *KASHIN-Beck disease , *SELENOPROTEINS , *CARTILAGE cells - Abstract
Abstract Objective Selenium deficiency is a risk factor for Kashin-Beck Disease (KBD), an endemic osteoarthropathy. Although promoter hypermethylation of glutathione peroxidase 3 (GPX3) (a selenoprotein) has been identified in several cancers, little is known about promoter methylation and expression of GPX3 and their relation to selenium in KBD. The present study was thus conducted to investigate this research question. Methods Methylation and expressions of GPX3 in whole blood drawn from 288 KBD patients and 362 healthy controls and in chondrocyte cell line were evaluated using methylation-specific PCR and qRT-PCR, respectively. The protein levels of PI3K/Akt/c-fos signaling in the whole blood and chondrocyte cell line were determined with Western blotting. Chondrocytes apoptosis were detected by Hoechst 33342 and Annexin V-FITC/PI staining. Results GPX3 methylation was increased, GPX3 mRNA was decreased, and protein levels in the PI3K/Akt/c-fos signaling pathway were up-regulated in the whole blood collected from KBD patients as compared with healthy controls. Similar results were obtained for chondrocytes injured by oxidative stress. There was a significant, decreasing trend in GPX3 expression across groups of unmethylation, partial methylation, and complete methylation for GPX3 , in sequence. Compared with unmethylation group, protein levels in PI3K/Akt/c-fos pathway were enhanced in partial and complete methylation groups. Treatment of chondrocytes with sodium selenite resulted in reduced methylation and increased expression of GPX3 as well as down-regulated level of PI3K/Akt/c-fos proteins. Conclusions The methylation and expression of GPX3 and expression of PI3K/Akt/c-fos pathway are altered in KBD and these changes are reversible by selenium supplementation. Highlights • GPX3 DNA hypermethylation and low expression of gene existed in KBD patients. • Up-regulation of PI3K/Akt/c-fos in KBD patients and oxidative damage chondrocytes. • Hypermethylation and low gene expression of GPX3 found in apoptotic chondrocyte. • GPX3 hypermethylation related to changes in gene expression and PI3K/Akt/c-fos. • Methylation, gene expression of GPX3 and PI3K/Akt/c-fos improved by Se supplement. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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