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Abstract #15351 Published in IGR 1-3
AlphaB-crystallin in the trabecular meshwork is inducible by transforming growth factor-beta
Welge-Luessen U; May CA; Eichhorn M; Bloemendal H; Luetjen-Drecoll EInvestigative Ophthalmology and Visual Science 1999; 40: 2235-2241
PURPOSE: Because in glaucomatous eyes transforming growth factor-beta (TGF-β) and αB-crystallin are increased in the anterior eye segment, the effect of TGF-β1 and TGF-β2 on the expression of αB-crystallin and its corresponding mRNA was studied in human trabecular meshwork (TM) cells. METHODS: Monolayer cultures of 'cribriform' and 'corneoscleral' TM cells of five human donors (12-73 years of age) were treated with either 1.0 ng/ml TGF-β1, TGF-α2, or 5 x 10-7 dexamethasone (DEX) for 12-96 hours. Induction of αB-crystallin and the related mRNA was investigated by western and northern blot analyses. For comparison, human foreskin fibroblasts (HFF) and NIH 3T3 cells were treated in the same way as the TM cells. RESULTS: An increase of αB-crystallin mRNA was observed after treatment of TM cells with TGF-β1 and TGF-β2, whereas DEX had no effect. In the cribriform TM cells with a high basal level, the enhancement ranged between two and three times; whereas in the corneoscleral TM cells αB-crystallin mRNA increased between five and six times. Using western blot analysis, the increase of αB-crystallin expression in the cribriform TM cells was only small compared with the significant increase in the corneoscleral TM cells. Treatment of HFF and NIH 3T3 cells with TGF-β did not induce αB-crystallin mRNA. CONCLUSIONS: This is the first time to show that αB-crystallin is not only induced by stress factors but also by TGF-β in TM cell cultures. The difference in induction of mRNA and protein seems to be dependent on αB-crystallin concentration before treatment.
Dr. U. Welge-Luessen, Department of Anatomy II, University of Erlangen-Nuernberg, Erlangen; Germany
Classification:
2.5 Meshwork (Part of: 2 Anatomical structures in glaucoma)
