TGF-β2 Cocentration in Aqueous Humor and its Localization in Trabecular Meshwork in Glaucomatous Eyes

Abstract

Introduction: : Pupose:To examine the concentration of TGF-β2 in the aqueous humor and its localization in the trabecular meshwork (TM) of the eyes with glaucoma.

Methods: : The concentration of the TGF-β2 was measured by enzyme-linked immunosorbent assay (ELISA) in 31 eyes with glaucoma {23 primary open angle glaucoma (POAG) and 8 exfoliation glaucoma (EG)}, and 16 eyes with cataract (control). The distribution of TGF-β2 in the TM was studied immunohistochemically in 12 eyes with POAG, 3 eyes with EG and 3 enucleated eyes with the normal iridocorneal angle. For the immunohistochemistry analyses, frozen sections were stained by the avidin-biotin complex method using anti-human TGF-β2 rabbit monoclonal antibody.

Results: : The concentration of TGF-b2 in the aqueous humor of the eyes with POAG, EG or cataract was 433.0±119.1 (average ± standard deviation pg/ml), 313.8±124.1, and 187.5±57.0 respectively. There were significant differences in the concentration between POAG and the control (p<0.0001; man-whitney), and between POAG and EG (p<0.03; man-whitney). Immunohistochemically TGF-β2 staining was observed in the cytoplasm of the trabecular meshwork cells and of the endothelial cells covering Schlemm’s canal. The immunostainig in POAG was intense compared with that in the normal.

Conclusions: : The concentration of TGF-β2 in the aqueous humor of POAG is higher than those of PG and eyes without glaucoma. TGF- β2 is intensely located in the cells of TM in POAG.

Keywords: growth factors/growth factor receptors • trabecular meshwork • aqueous