The role of Crim-1 in lens development and eye disease.

点击翻译按钮获取中文摘要

We have recently isolated a novel gene (Crim1) and shown it to be strongly expressed during eye development. Its protein structure indicates that it may act to regulate the activities of two growth factor families, the TGF superfamily and the insulin-IGFs. These growth factors effect the behaviour of many cell types that influence events in normal and pathological development. For example in the eye lens, TGF 1 can induce cataractous changes in epithelial cells and early differentiating fibres; however, TGF signalling appears to be required for events in late stages of fibre cell maturation. Cataract is the leading cause of blindness and arises when lens cell architecture is disrupted and-or proteins aggregate abnormally. In humans, following ocular trauma, eye surgery, or in association with other diseases, cataracts can develop. These cataracts feature the development of subcapsular fibrotic plaques which obscure vision. We have shown that lenses cultured in the presence of TGF can mimic production of these plaques suggesting that these cataracts result from inappropriate activation of TGF . TGF is expressed in the lens and is abundant in the ocular media that bathes the lens. Thus, it appears that complex regulation of TGF bioavailability is required; epithelial cells and young fibre cells need to be protected from its cataractogenic effects, whereas older fibres require TGF signalling for maturation and-or survival. The expression pattern of Crim1 in the lens is consistent with it having a key role in inhibiting TGF in the lens. Thus, we hypothesise that Crim1 plays important roles in the lens, possibly via the modulation of members of the TGF superfamily and insulin-IGFs. We predict that Crim1 acts to maintain the lens epithelial phenotype and facilitate events in early fibre differentiation. If so, this may have implications for devising molecular strategies for preventing or slowing diseases, such as the various forms of human cataract.