MMP2 Activity is Critical for TGFβ2-Induced Matrix Contraction—Implications for Fibrosis

PURPOSE. The fibrotic lens disorder posterior capsule opacification (PCO) develops in millions of patients following cataract surgery. PCO characteristics are extensive extracellular matrix (ECM) production and contraction of the posterior lens capsule, resulting in light-scattering ECM modification (wrinkling). The pro-fibrotic cytokine transforming growth factor beta (TGFb) is central to PCO development. This study aimed to elucidate the role of the ECM modulators matrix metalloproteinases (MMPs) in TGFb-mediated PCO formation. METHODS. The human lens epithelial cell-line FHL-124 and human capsular bag models were employed. Gene expression of MMP family members was determined by oligonucleotide microarray and quantitative real-time RT-PCR. MMP2 and MT1MMP protein levels were analyzed by ELISA and Western blotting, respectively. Matrix contraction was determined using an FHL-124 patch contraction assay; at end-point, cells were stained with Coomassie brilliant blue and area was determined using image analysis software. Cell coverage and wrinkle formation on the posterior capsule were also assessed using human capsular bag models. RESULTS. Active TGFb2 (10 ng/mL) increased gene and protein levels of MMP2 and MT1-MMP and induced matrix contraction in FHL-124 cells. Specific siRNA inhibition of MT1-MMP did not suppress TGFb2-induced matrix contraction. Active TGFb2mediated contraction was prevented by broad-spectrum MMP inhibitor GM6001 (25 lM), MMP2 siRNA, and MMP2 neutralizing antibody (4 lg/mL). TGFb2-induced wrinkle formation was attenuated in human capsular bags treated with MMP2 neutralizing antibody (20 lg/mL).