Different Expression Of MMP-2 And MMP-9 In The Formation Of Posterior Capsule Opacification

ForewordECM is a dynamic reticulation between cells, which does not only formextracellular reticulum but also plays an important role in the transference,differentiation and multiplication of histiocyte, and in the pathological progress ofinflammation and neonatal vas. Matrix metalloproteinase, MMPs are a group ofendogenetic proteolytic ferments that can reduce ECM, take part in the dynamicbalance of ECM's production and reduction, the recovery and tissue rebuilding. Theeffect in the tissue fibrosis seems to catch more attention. After the operation ofaspirate lens, the transference, differentiation and multiplication of epithelium causesposterior capsule opacification ineluctably. The formation and development ofposterior capsule opacification may relate to MMPs. The expreesion of MMPs isfarthing in normal tissues, in the study of dynamic change of MMPs in the aqueoushumor, there a different change between MMP-2, MMP-9.PurposeTest the MMPs level in the formation of posterior capsule opacification after theoperation of aspirate lens, to discuss the effect of MMP-2 and MMP-9 in wanderingand transference of rabbit lens epithelia, and in the formation of posterior capsuleopacification。 Methods42 of 2-months healthy white rabbit from the experimental animal department ofCMU, weight from 0.9 to 1.1kg, sex randomly, are divided into 2 groups (7 incomparison group and 35 in test group) randomly; ketamine injected anaesthesia andaspirated both lens cortex of the test group: make a 3.2mm incision in limbal stem,inject viscoelastic, no stitch to the incision, 1% atropine ointment, then executed 7rabbits after 1 week, 1 month, 2 month, 3 month, 5 month of the operation;comparison group were executed with no operation; extirpate the eyeballs, remove thecornea iris and cut off the zonule ciliaire. Keep 4 lenses in 4% polyformaldehyde 24hours, embed in paraffine. Remove the capsula of the other 10 lenses, weigh, keep in-70℃. Zymography test and immunohistochemical technique are used separately todetermine the activity of MMP-2 and MMP-9 of the paraffine sample and therefrigeration sample.Results1, The formation of posterior capsule opacification in rabbit eyesObserve in different period after the operation: the inflammatory responseremarkable at the 3th day, iris congestion; edge of anterior capsule circularityopacification at the 1st week, but no remarkable change in the posterior capsule, justgauze-like at the 2nd week; strip-like opacification at the end of the 1st week;funicular opacification after 2～3 months while visible opacification at the 5th monthafter the operation.2, Result of immunohistochemical techniqueIt is clear that MMP-2 express less in lens epithelia and stroma, with a higherexpression of MMP-2 in 1-3 months after the operation. 3, Zymography testThere is very low expression of MMP-2 and MMP-9 in the comparison group;the activity of MMP-2 in the test groups is stronger that of comparison group; butthere was no remarkable difference of MMP-9.4, Analysis of activityThe activity of MMP-2 was 0.75±0.10 in the comparison group, and 3.68±0.12,5.18±0.11, 5.62±0.11, 6.58±0.11, 1.19±0.11 in the test groups. But there was noremarkable difference of MMP-9.Conclusion1. MMP-2,MMP-9 express in normal lens capsule.2. MMP-2 expreses highest in 2-3 months after the operation of aspirate lenscortex.3. No change in the expression of MMP-9 in lens capsule.4. MMP-2 plays a more important part in the formation of posterior capsuleopacification than MMP-9.