The correlation analysis of MMP-13 and AGG and Col-II in the chondrocytes caused by nutritional deficiencies in rabbits

Abstract

Objective To explore the relationship among the expression level of MMP-13, AGG and Col-II in the chondrocytes caused by nutritional deficiencies in rabbits. Methods 30 New Zealand white rabbits were randomly divided into autologous chondrocyte transplantation group (control group,n=10), nutrition block group (surgery group,n=10), and peripheral nutrition block group (sham surgery group,n=10). 4 weeks after treatment, the rabbits were sacrificed for undergoing the observations on general and histological level; real-time PCR assay was employed for testing the expression level of MMP-13, AGG and Col-II; cellular apoptosis percentage was observed through TUNEL stain. The relationship among the apoptosis level, cartilage cells histological Mankin score as well as the expression level of MMP-13, AGG and Col-II were analyzed. Results Based on the Mankin score, there was a statistic difference between surgery group and control group. On the other side, there were no statistic differences between sham surgery group and control group. 4 weeks after treatment, surgery group presented a higher apoptotic percentage compared with control group; this value between sham surgery group and control showed no significant differences. There was an increased mRNA expression level of MMP-13 and a decreased mRNA expression level of AGG and Col-II in surgery group compared with control group; no statistic differences of all these values was found between sham surgery group and control group. Histological Mankin score and apoptotic percentage presented positive correlation (r=0.922,P <0.001), the regression equation: Y=-0.548+ 0.404X,R2=0.844 (F=157.735,P <0.001); the mRNA expression level of MMP-13 and apoptotic percentage presented positive correlation (r=0.942,P <0.001), the regression equation: Y=0.951+0.116X,R2=0.883 (F=219.054,P <0.001). There was a negative correlation between the mRNA expression level of MMP-13 and the mRNA expression level of AGG as well as Col-II (r=-0.956, -0.945,P <0.001). Conclusion Damage of cartilage cells causes the up-regulation of the MMP-13 expression which could exacerbate the degeneration of cells. It could induce the down-regulation of AGG and Col-II mRNA expression, which will cause the extracellular matrix synthesis disorder. Key words: Rabbits; Chondrocytes; Apoptosis; Gene expression