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Journal of Diabetes Research
Volume 2016 (2016), Article ID 3765173, 7 pages
http://dx.doi.org/10.1155/2016/3765173
Research Article

High Glucose-Induced Oxidative Stress Mediates Apoptosis and Extracellular Matrix Metabolic Imbalances Possibly via p38 MAPK Activation in Rat Nucleus Pulposus Cells

1Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011, China
2Department of Orthopedics, Changzheng Hospital, Second Military Medical University, Shanghai, China
3Department of Toxicity Evaluation, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China

Received 16 November 2015; Revised 25 December 2015; Accepted 28 December 2015

Academic Editor: Mark A. Yorek

Copyright © 2016 Xiaofei Cheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objectives. To investigate whether high glucose-induced oxidative stress is implicated in apoptosis of rat nucleus pulposus cells (NPCs) and abnormal expression of critical genes involved in the metabolic balance of extracellular matrix (ECM). Methods. NPCs were cultured with various concentrations of glucose to detect cell viability and apoptosis. Cells cultured with high glucose (25 mM) were untreated or pretreated with N-acetylcysteine or a p38 MAPK inhibitor SB 202190. Reactive oxygen species (ROS) production was evaluated. Activation of p38 MAPK was measured by Western blot. The expression of ECM metabolism-related genes, including type II collagen, aggrecan, SRY-related high-mobility-group box 9 (Sox-9), matrix metalloproteinase 3 (MMP-3), and tissue inhibitor of metalloproteinase 1 (TIMP-1), was analyzed by semiquantitative RT-PCR. Results. High glucose reduced viability of NPCs and induced apoptosis. High glucose resulted in increased ROS generation and p38 MAPK activation. In addition, it negatively regulated the expression of type II collagen, aggrecan, Sox-9, and TIMP-1 and positively regulated MMP-3 expression. These results were changed by pretreatment with N-acetylcysteine or SB 202190. Conclusions. High glucose might promote apoptosis of NPCs, trigger ECM catabolic pathways, and inhibit its anabolic activities, possibly through a p38 MAPK-dependent oxidative stress mechanism.