Expression And Significance Of Matrix Metalloproteinase-3 (MMP-3) And Matrix Metalloproteinase-9 (MMP-9) In Lens Epithelial Cells (LECs) Of Penetrating Cataract In Rats

Objective:To investigate the expression and significance of matrix metalloproteinase-3(MMP-3) and matrix metalloproteinase-9(MMP-9) in lens epithelial cells(LECs) of cataract induced by penetrating in rats.To study the effects of MMP-3 and MMP-9 on rats with penetrating cataract and the relationship between MMP-3 and MMP-9.Method:Thirty-two healthy adult SD rats(weighing 250～300g) were used to establish penetrating cataract model on single eyes and then divided into post-traumatic 1d,3d.7d and 14d groups randomly.Lens were examined using a slitlamp on every time point.At the first day,the third day,the seventh day and the fourteenth day after the operation,lens were isolated. Immunohistochemical streptavidin-peroxidases (SP) method was used to detect the expression of MMP-3 and MMP-9 in lens of every group.Scanning eletron microscope (SEM) was used to observed LECs and lens fibers of normal lens and penetrating cataract. Results:1 The normal lens were always completely transparent throughout the period of experiment.Finally.twenty-nine eyes developed cataract in the thirty-two traumatic eyes.On the post-traumatic ld.cloudy lens opacity began to appear in the part which lens were pinpricked.On the post-traumatic 3d,lens opacity aggravated and extend.On the post-traumatic 7d,lens opacity becomed more widespread,and the most of lens appeared creamy white.On the post-traumatic 14d,lens get completed opaque,opaque lens becomed small obviously2 SEM observation:The normal LECs of rats appeared irregular oblate cubic and ranked neatly only one layer,and adjacent cells linked distinctly.The normal lens fibers of rats keeped complete and arranged in parallel and orientation,and microvilli inlayed between the adjacent cells.The free surface of LECs was ligule or lamellar in traumatic eyes of rats.The number of LECs layers increased,and the connection of adjacent cells broadened.Lens fibers occurred denaturation in traumatic eyes of rats.The denatured lens fibers lost normal shape and the range of them was in disorder.3 Both MMP-3 and MMP-9 had no expression in LECs of all normal eyes.Both MMP-3 and MMP-9 had expression in LECs of all traumatic eyes.The expression of MMP-3 and MMP-9 was significantly different between normal eyes and traumatic eyes(P<0.01)4 During the progression of cataract.the expression of MMP-3 and MMP-9 gradually increased.Multiple comparisons between every time point showed the expression of MMP-3 and MMP-9 was significantly different(P<0.05) expect the post-traumatic 7d and the post-traumatic 14d (P>0.05). 5 The expression of MMP-3 was positively correlated with that of MMP-9 (r=0.967, P<0.01)Conclusio:The expression of MMP-3 and MMP-9 continually increased.and the expression of MMP-3 was positively correlated with that of MMP-9,which indicated that the two protein and their interaction participated the pathologic process in which penetrating cataract formed.