Liu Yi-Nan, Mu Yu-Dong, Wang Hui, Zhang Meng, Shi Ya-Wen, Mi Ge, Peng Lei-Xuan, Chen Jing-Hong
School of Public Health, Xi'an Jiaotong University Health Science Center, Key Laboratory of Trace Elements and Endemic Diseases, National Health and Family Planning Commission, No. 76 Yanta West Road, Xi'an, 710061, Shaanxi, People's Republic of China.
Department of Clinical Laboratory, Tumor Hospital of Shaanxi Province, Affiliated to the Medical College of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China.
Toxicology. 2021 Dec;464:152989. doi: 10.1016/j.tox.2021.152989. Epub 2021 Oct 18.
T-2 toxin leads to chondrocyte apoptosis and excessive extracellular matrix degradation. The aim of this study is to investigate if endoplasmic reticulum stress (ERS) - initiated apoptosis is involved in the chondrocyte damage induced by T-2 toxin. In vivo, rats were divided into a control group, T-2 toxin 200 ng/g BW/d group, the protein levels of GRP78, CHOP, and caspase-12 were detected using immunohistochemistry in articular cartilage tissues. In vitro, C28/I2 and ATDC5 chondrocytes were treated with various concentrations of T-2 toxin. For the salubrinal protection assay, cells were pretreated with 20 μM salubrinal for 1 h, and treated with and without T-2 toxin for 24 h. The cell viability was determined using the MTT assay; and the cell apoptosis was determined using the Flow Cytometry Assay; the mRNA and protein levels of the ERS markers and ECM were determined using RT-PCR and western blotting. This study found that the expressions of GRP78, CHOP, and caspase-12 is higher in T-2 toxin group than in control group both in vivo and in vitro, and the T-2 toxin administration promoted chondrocyte apoptosis, suppressed matrix synthesis, and accelerated cellular catabolism via the ERS signaling pathway. In addition, this study found that salubrinal prevented chondrocyte injury by inhibiting ERS-mediated apoptosis via the PERK-eIF2α-ATF4-CHOP signaling pathway. Collectively, this study provides a new clue to elucidate the mechanism of T-2 toxin-induced chondrocyte damage, and presents a novel therapeutic possibility of salubrinal for Osteoarthropathy such as osteoarthritis (OA) and Kaschin-Beck disease (KBD).
T-2毒素可导致软骨细胞凋亡和细胞外基质过度降解。本研究旨在探讨内质网应激（ERS）引发的凋亡是否参与T-2毒素诱导的软骨细胞损伤。在体内，将大鼠分为对照组、200 ng/g体重/天T-2毒素组，采用免疫组化法检测关节软骨组织中GRP78、CHOP和caspase-12的蛋白水平。在体外，用不同浓度的T-2毒素处理C28/I2和ATDC5软骨细胞。对于沙芦比诺保护试验，细胞先用20 μM沙芦比诺预处理1小时，然后分别在有和无T-2毒素的情况下处理24小时。采用MTT法测定细胞活力；采用流式细胞术检测细胞凋亡；采用RT-PCR和蛋白质印迹法测定ERS标志物和细胞外基质的mRNA和蛋白水平。本研究发现，无论在体内还是体外，T-2毒素组中GRP78、CHOP和caspase-12的表达均高于对照组，且T-2毒素给药通过ERS信号通路促进软骨细胞凋亡、抑制基质合成并加速细胞分解代谢。此外，本研究发现沙芦比诺通过PERK-eIF2α-ATF4-CHOP信号通路抑制ERS介导的凋亡，从而预防软骨细胞损伤。总体而言，本研究为阐明T-2毒素诱导软骨细胞损伤的机制提供了新线索，并为骨关节炎（OA）和大骨节病（KBD）等骨关节病提供了沙芦比诺的新型治疗可能性。
