Downregulated expression of ADAM9 in anterior polar cataracts

Abstract

Purpose: To determine whether ADAM (a disintegrin and metalloproteinase) is regulated in lens epithelial cells (LECs) of patients with anterior polar cataracts and by transforming growth factor (TGF)-β1 in cultured LECs. Setting: Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea. Methods: Lens epithelial cells attached to the anterior capsules of human cataractous lenses with nuclear and anterior subcapsular cataracts and noncataractous lenses were analyzed by reverse transcribed-polymerase chain reaction for the expression of ADAMs. The effect of TGF-β1 on ADAM gene expression was also tested in mouse lens epithelial explants and cultured LEC lines (αTN-4 and HLE B-3). Results: Significantly reduced expression of mRNA for ADAM9 was observed in LECs from patients with anterior polar cataracts. The expression of mRNA for ADAM9 was downregulated by TGF-β1 in cultured human LECs. Treatment of cultured mouse LECs with TGF-β1 led to a reduction in ADAM1 mRNA. Conclusions: ADAMs are expressed and regulated in LECs. The downregulated expression of ADAM9 may serve as a marker for anterior polar cataracts in addition to previously known proteins, fibronectin, α-SMA, and βig-h3. The functions of this protein in lens pathology require further investigation.