Role of type II collagen in protecting and preventing articular cartilage damage induced by T-2 toxin in sadsad

Abstract

Objective To observe the preventive effect of type Ⅱ collagen on experimental rat articular cartilage damage induced by T-2 toxin,to explore molecular biomarkers of articular cartilage damage and repair,and to provide a theoretical basis for control of articular cartilage damage.Methods Eighty Wistar rats were randomly divided into 4 groups according to their body weights:negative control,positive control,high-dose intervention,and low-dose intervention groups,20 rats in each group.Animals in negative control group were fed with standard rat chow,and animals in other three groups were fed with T-2-toxin-contaminated chow( 100 ng/kgfeed).Animals in negative and positive control groups drank distilled water,animals in high-dose intervention and low-dose intervention groups drank water containing type Ⅱ collagen(0.5,5.0 g/L,respectively).These rats were sacrificed after 3 and 5 months,respectively,and bilateral knee joints were collected.Histopathologic changes in hyaline cartilage were examined by light microscope,serum levels of type Ⅱ collagen carboxyl terminal peptide (CTX-Ⅱ ),cartilage oligomeric matrix protein (COMP) and urinary deoxypyridinoline (DPD) were determined by enzyme-linked immunosorbent assay(ELISA).Results HE staining showed,that the positive control articular chondrocytes were disarranged,deformated,degenerated,with necrosis and extensive areas of chondrocyte loss;but the two intervention groups only showed fibril formation and swelling and surface cartilage cells became round,flat cartilage cells decreased in number,and cartilage cells clustered and so on early pathological changes of osteoarthritis.At the ends of 3 month and 5 month experiment,the levels of serum CTX- Ⅱ in different groups were,negative control[(18.77 ± 4.61),(25.07 ± 9.17)μg/L],high-dose intervention[ (21.11 ± 5.02),(33.20 ± 9.74)μg/L ],low-dose intervention [ ( 19.87 ± 4.53 ),( 29.73 ± 9.32 ) μg/L ] and positive control [ ( 24.43 ± 5.23 ),( 39.17 ±10.49 ) μg/L ] ; the levels of serum COMP were,negative control group [ (5.43 ± 2.75 ),( 6.38 ± 2.23 ) μg/L ],highdose intervention group[ (17.27 ± 4.77),(20.32 ± 4.74)μg/L],low-dose intervention group[(20.13 ± 5.07),(19.44 ± 4.92)μg/L] and positive control group[ (21.37 ± 4.72),(24.52 ± 4.26)μg/L].At the end of 3 month,compared with negative control group,the level of serum CTX- Ⅱ in other three groups increased,but only positive control group increased significantly(P ＜ 0.05) ; at the end of 5 month,compared with negative control group,the level of serum CTX-Ⅱ in other three groups increased significantly,and the difference was statistically significant (all P ＜ 0.05),and the level of CTX-Ⅱ in the two intervention groups was significantly lower compared with that of positive control group(all P ＜ 0.05).Compared with negative control group,the level of serum COMP in other groups increased significantly at the end of 3 month (all P ＜ 0.05) and only the level of serum COMP in high-dose intervention group was significantly lower compared with that of positive control group(P ＜ 0.05).At the end of 5 month,compared with negative control group,the level of serum COMP in other three groups increased significantly,the difference were statistically significant (all P ＜ 0.05) ; the levels of serum COMP in the two intervention groups were significantly lower than that of positive control group(all P ＜ 0.05).At the ends of 3 month and 5 month,the content of urinary DPD in negative control group were[ (3.47 ± 2.20),(4.14 ± 1.06)μg/L],positive control group[ (4.09 ± 2.48),(4.33 ± 3.43)μg/L],high-dose intervention group[ (3.86 ± 2.31 ),(5.72 ± 3.89)μg/L] and low-dose intervention group[ (3.58 ± 2.77),(4.23 ± 2.90)μg/L].The difference between the 4 groups were not statistically significant (F =2.608,2.436,all P ＞ 0.05).Conclusions Type Ⅱ collagen could effectively reduce the level of serum CTX-Ⅱ and COMP in experimental rats and delay the process of articular cartilage damage induced by T-2 toxin. Key words: Cartilage, articular; Collagen type Ⅱ; T-2 toxin