title: Immunohistochemical localization of transforming growth factor-beta in human photoreceptors.
abstract: Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor that can either stimulate or inhibit cellular proliferation depending on cell type and culture conditions. The immunohistochemical localization of TGF-beta was investigated in human retinas and choroids using streptavidin peroxidase immunohistochemistry and a polyclonal rabbit antibody directed against the N-terminal 30 amino acids of TGF-beta 1. This antibody recognizes the beta 1 form of TGF-beta but not beta 2. TGF-beta localization was observed exclusively in photoreceptors in all adult non-diabetic and non-insulin dependent diabetic eyes, and 4 of 6 insulin dependent eyes. It was determined that TGF-beta was associated with both rods and cones using localization of peanut agglutinin (PNA), a lectin which binds to cone sheaths, on serial sections. Chondroitinase ABC digestion of sections prior to immunohistochemistry did not reduce TGF-beta immunoreactivity, suggesting that binding was not to glycosaminoglycans in the interphotoreceptor matrix. TGF-beta immunoreactivity was not observed in 2 premature human eyes in which photoreceptor outer segments had not yet developed. Localization in photoreceptors was also not observed in photocoagulation scars, in atrophic regions in a diabetic retina, nor in detached areas of retina from a young victim of head trauma. Based on PNA binding, succinate dehydrogenase enzyme histochemistry and phase contrast microscopy on adjacent sections, the TGF-beta negative areas of these retinas did not appear to have viable photoreceptors. This work demonstrates that TGF-beta is found exclusively in viable adult human retinal photoreceptors. It's function in these cells is currently not known.
authors.affiliation: Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore MD 21205.
authors.forename: G
authors.initials: G
authors.lastname: Lutty
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: C
authors.initials: C
authors.lastname: Chandler
authors.forename: D S
authors.initials: DS
authors.lastname: McLeod
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001710:Biotin / Q000378:metabolism; D002921:Cicatrix / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000378:metabolism; D008028:Light Coagulation; D008875:Middle Aged; D019887:Peanut Agglutinin; D010786:Photoreceptor Cells / Q000378:metabolism*; D011180:Postmortem Changes; D011183:Postoperative Complications; D014018:Tissue Distribution; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D037102:Lectins; D019887:Peanut Agglutinin; D016212:Transforming Growth Factor beta; D001710:Biotin