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Objective To determine effects of T-2 toxin and selenium on expression of aggrecanase in human chondrocyte.Methods Human chondrocytes were treated with T-2 toxin(0,1,10,20 μg/L),and/or sodium selenite(final concentration of selenium 0,0.1 mg/L) for 5 days.Aggrecan expression was determined by Western blotting,aggrecanase-1 and aggrecanase-2 mRNA levels were measured by RT-PCR.ResultsSelenium and T-2 toxin had effects on both aggrecan protein levels and its aggrecanases(include aggrecanase-1 and aggrecanase-2 ) mRNA levels(F =0.294,27.71 for aggrecan,F =107.45,362.25 for aggrecanase-l,F =34.68,22.26 for aggrecanase-2,respectively,all P ＜ 0.05),and there was interaction between selenium and T-2 toxin on aggrecan,aggrecanase-1 and aggrecanase-2 expression(F =79.99,230.76,388.33,all P ＜ 0.05).Furthermore,selenium presented significant antagonism to T-2 toxin on aggrecan,aggrecanase-1 and aggrecanase-2 expression.Aggrecan expression levels(0.278 ± 0.015,0.235 ± 0.029,0.195 ± 0.028,0.399 ± 0.028,0.299 ± 0.020,0.263 ±0.019) induced by both 1,10,20 μg/L T-2 toxin and 0,0.1 mg/L selenium were significantly decreased than the levels(0.472 ± 0.0358,0.197 ± 0.018,all P ＜ 0.05) in control group(0 mg/L toxin).Selenium partially blocked the effects induced by 1,10,and 20 μg/L T-2 toxin(all P＜ 0.05).One,10,20 μg/L T-2 toxin and 0,0.1 mg/L selenium increased both aggrecanase-1 mRNA levels(0.535 ± 0.033,1.071 ± 0.043,1.454 ± 0.058,1.057 ±0.048,0.555 ± 0.036,0.902 ± 0.045) and aggrecanase-2 mRNA levels(0.596 ± 0.038,0.656 ± 0.033,0.949 ±0.049,0.600 ± 0.040,0.453 ± 0.031,0.164 ± 0.011),when compared with control(0.481 ± 0.023,0.346 ±0.020 for aggrecanase-1 and 0.387 ± 0.020,1.021 ± 0.046 for aggrecanase-2,respectively,all P ＜ 0.05).Selenium partially blocked 10,20 μg/L T-2 toxins induced upregulation of aggrecanase-1 (all P ＜ 0.05) and aggrecanase-2 (all P ＜ 0.05 ).Conclusions These data suggest a possible molecular mechanism that T-2 toxin could induce cartilage matrix degradation through the upregulation of aggrecanases expression and enzyme activities.Trace element selenium has some protective effect on cartilage proteoglycan degradation induced by T-2 toxins.
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Objective To observe the activities of serum peroxidase capacity,and lipid peroxidation of children from Kaschin-Beck disease (KBD) areas of Xinghai county in Qinhai province,and to explore the relationship between antioxidant capacity and KBD.Methods Sixty four KBD and forty six health subjects without KBD were chosen from KBD endemic areas,which included primary schools of Tangnaihai,Xialujuan and Qushian of Xinghai county in Qinghai province,and fifty nine age-matched healthy control subjects without KBD were from a non-KBD endemic area,Nanfan primary school of Chang'an county in Shaanxi province.Twenty patients with KBD and twenty control subjects from KBD areas and non-KBD area were extracted by simple random sampling method.2,3-DAN fluorescence technique was used to test the hair and blood selenium.The biochemical techniques were used to test the indicators of oxidative stress including malondialdehyde(MDA),antioxidant enzyme activities,total antioxidant capacity(T-AOC),serum superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GSHPx).ResultsAll patients with KBD had significantly lower serum GSH-Px activities[ (59.53 ± 25.23)kU/L] and selenium levels in hair[ (67.64 ± 17.28)μg/L] and blood[(36.27 ± 13.29)μg/L],respectively,than that of control subjects from KBD areas [ ( 91.88 ± 22.99 ) kU/L,( 153.32 ± 24.31 ) μg/L,( 63.06 ± 13.66) μg/L ] and nonKBD areas[ ( 122.68 ± 41.74)kU/L,(242.35 ± 38.56)μg/L,(98.93 ± 17.18)μg/L,all P ＜ 0.05].Serum MDA levels in KBD patients[ (4.64 ± 1.11 )μmol/L] were significantly higher than that in control subjects from KBD [(3.31 ± 1.22)μmol/L] and non-KBD areas[ (3.43 ± 1.29)μmol/L,all P ＜ 0.05].On the other hand,T-AOC,SOD and CAT activities were significantly higher in both KBD[(19.80 ± 6.64),(55.80 ± 8.14),(16.45 ± 5.61 ) kU/L] and control subjects[ (21.71 ± 8.82),(57.45 ± 6.96),(15.63 ± 9.18)kU/L] from KBD areas than that of control subjects from non-KBD area[ (13.56 ± 5.38),(42.79 ± 8.10),(6.05 ± 2.71 )kU/L,all P ＜ 0.05 ].Hair selenium levels,blood selenium levels and GSH-Px activity of control subjects from KBD areas were,respectively,significantly lower than that in control subjects from non-KBD area(all P ＜ 0.05).Conclusions These findings strongly confirm the evidence that KBD patients are susceptible to oxidative stress.The results also show the increase in antioxidant enzymes,which could probably be due to adaptive response to pro-oxidant in KBD state.Hence,there seems to be an imbalance between oxidant and antioxidant systems in KBD patients.