Promotion of the articular cartilage proteoglycan degradation by T-2 toxin and selenium protective effect
Si-yuan LI1,Jun-ling CAO1,Zhong-li SHI1,Jing-hong CHEN1,Zeng-tie ZHANG1,Clare E. HUGHES2,Bruce CATERSON2 (1Institute of Endemic Diseases,College of Medicine,Xi’an Jiaotong University; Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University),Ministry of Education; Key Laboratory of Microelement and Endemic Disease (Xi’an Jiaotong University),Ministry of Health; Xi’an 710061,China) (2Laboratory of Connective Tissue Biology,School of Biosciences,Cardiff University,Cardiff CF10 3US,UK)
Objective: To identify the relationship between T-2 toxin and Kashin-Beck disease (KBD),the effects of T-2 toxin on aggrecan metabolism in human chondrocytes and cartilage were investigated in vitro. Methods: Chondrocytes were isolated from human articular cartilage and cultured in vitro. Hyaluronic acid (HA),soluble CD44 (sCD44),IL-1β and TNF-α levels in super-natants were measured by enzyme-linked immunosorbent assay (ELISA). CD44 content in chondrocyte membrane was deter-mined by flow cytometry (FCM). CD44,hyaluronic acid synthetase-2 (HAS-2) and aggrecanases mRNA levels in chondrocytes were determined using reverse transcription polymerase chain reaction (RT-PCR). Immunocytochemical method was used to investigate expressions of BC-13,3-B-3(-) and 2-B-6 epitopes in the cartilage reconstructed in vitro. Results: T-2 toxin inhibited CD44,HAS-2,and aggrecan mRNA expressions,but promoted aggrecanase-2 mRNA expression. Meanwhile,CD44 expression was found to be the lowest in the chondrocytes cultured with T-2 toxin and the highest in control plus selenium group. In addition,ELISA results indicated that there were higher sCD44,IL-1β and TNF-α levels in T-2 toxin group. Similarly,higher HA levels were also observed in T-2 toxin group using radioimmunoprecipitation assay (RIPA). Furthermore,using monoclonal antibodies BC-13,3-B-3 and 2-B-6,strong positive immunostaining was found in the reconstructed cartilage cultured with T-2 toxin,whereas no positive staining or very weak staining was observed in the cartilage cultured without T-2 toxin. Selenium could partly inhibit the effects of T-2 toxin above. Conclusion: T-2 toxin could inhibit aggrecan synthesis,promote aggrecanases and pro-inflammatory cytokines production,and consequently induce aggrecan degradation in chondrocytes. These will perturb metabolism balance between aggrecan synthesis and degradation in cartilage,inducing aggrecan loss in the end,which may be the initiation of the cartilage degradation.
【Fund】： Project supported by the National Natural Science Foundation of China (Nos. 30471499 and 30170831);; the Ministry of Education of China (No.Key 03152);; the Science Foundation of Shaanxi Province of China (No.2004KW-20)
【CateGory Index】： R684
【CateGory Index】： R684