TNF-α and TNF-α receptor-1 in the retina of normal and glaucomatous eyes

To determine the expression and localization of tumor necrosis factor (TNF)-alpha and TNF-alpha receptor-1 in the retina of normal and glaucomatous eyes. Using immunohistochemistry and in situ hybridization, retinal expression and localization of TNF-alpha and TNF-alpha receptor-1 were studied in retina sections from 20 eyes of donors with glaucoma, and 20 eyes of age-matched normal donors. According to immunohistochemistry, the intensity of the immunostaining and the number of labeled cells for TNF-alpha or its receptor were greater in retina sections of glaucomatous eyes than in control eyes of age-matched normal donors. In situ hybridization showed that mRNA signals for TNF-alpha or TNF-alpha receptor-1 were similarly more intense in glaucomatous eyes than in age-matched control eyes. Both protein and mRNA of TNF-alpha or TNF-alpha receptor-1 were predominantly localized to the inner retinal layers. Double-immunofluorescence labeling demonstrated that retinal immunostaining for TNF-alpha was predominantly positive in the glial cells, whereas immunostaining for TNF-alpha receptor-1 was mainly positive in the retinal ganglion cells. Upregulation of TNF-alpha and its receptor-1 in glaucomatous retina suggest that TNF-alpha-mediated cell death is involved in the neurodegeneration process of glaucoma.