Carbohydrate binding proteins galectin-1 and galectin-3 in human trabecular meshwork

Purpose. Galectins are a family of carbohydrate binding proteins involved in a variety of biological processes including cell-cell and cell-matrix interactions. We examined galectin-1 and galectin-3 to determine if galectins are expressed in the human trabecular meshwork and Schlemm's canal. Methods. Human trabecular meshworks were dissected from donor eyes within 12hr of death. Galectin-1 and galectin-3 expression was examined by RT-PCR and Western blot analysis. Immunohistochemistry of galectin-1 and galectin-3 was analyzed in normal and glaucomatous tissue. Results. Expression of mRNA and protein of Galectin-1 (14 kDa) and galectin-3 (31 kDa) was found in the outflow pathway. Immunostaining revealed galectin-1 and galectin-3 throughout the meshwork, cells lining Schlemm's canal, and extracellular spaces in the inner and outer walls of the canal. Comparison of normal, POAG and PEX samples revealed no difference in location or intensity for either galectin-1 and galectin-3. Conclusion. Galectin-1 and galectin-3 are present in human trabecular meshwork of normal and glaucomatous eyes.