Purpose. Previously we reported that TGFβ induces cataract-like changes in lens epithelial explants and that TGFβ induces the formation of distinct anterior subcapsular opacities in cultured rat lenses. In both situations, TGFβ induces morphological and molecular markers for subcapsular cataracts. These include the formation of spindle-shaped cells which contain α-smooth muscle actin, localised capsule wrinkling, apoptotic cell death and accumulation of extracellular matrix including type I collagen. The aim of this study was to assess the sensitivity of lenses from adult and weanling rats to the cataract-inducing effects of TGFβ2. Methods. Lenses from weanling and adult rats were cultured in defined serum-free medium with 0.025, 0.15, 1 or 4 ng/ml TGFβ2. Controls received no TGFβ2. Lenses were cultured for up to 7 days and photographed daily, then fixed and prepared for histology and immunolocalisation. Opacification was quantified by image analysis. Results. Lenses underwent characteristic cataractous changes at all concentrations of TGFβ, including opacification and accumulation of α-smooth muscle actin and type I collagen. The intensity of the response was dose dependent and tended to be slower in adult than in weanling lenses. Distinct subcapsular opacities were observed at concentrations as low as 0.025 and 0.15 ng/ml in adults and weanlings, respectively. In weanlings, repeated exposure to 0.025 ng/ml TGFβ was shown to intensify the response. Exposure to 1 ng/ml TGFβ for only 8 hours was sufficient to induce opacities and other cataractous changes. Control lenses cultured without TGFβ remained transparent and retained normal lens morphology. Conclusions. This study shows that both weanling and adult rat lenses are highly responsive to TGFβ. Prolonged exposure to a very low concentration of TGFβ or brief exposure to a higher concentration are sufficient to induce cataractous changes, including opacities.
|Journal||Investigative Ophthalmology and Visual Science|
|Publication status||Published - 15 Feb 1996|
|Event||Association for Research in Vision and Ophthalmology 1996 annual meeting - Fort Lauderdale, United States|
Duration: 21 Apr 1996 → 26 Apr 1996