Lens Major Intrinsic Protein (MIP)/Aquaporin 0 Expression in Rat Lens Epithelia Explants Requires Fibroblast Growth Factor-induced ERK and JNK Signaling
| Autor: | Jianguo Fan, Ana B. Chepelinsky, Peggy S. Zelenka, Robert N. Fariss, Nady Golestaneh, Woo Kuen Lo |
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| Rok vydání: | 2004 |
| Předmět: |
MAPK/ERK pathway
MAP Kinase Signaling System Lens Capsule Crystalline Aquaporin Biology Aquaporins Fibroblast growth factor Biochemistry Epithelium Culture Techniques medicine Animals RNA Messenger Eye Proteins Promoter Regions Genetic Molecular Biology DNA Primers Mitogen-Activated Protein Kinase 1 Membrane Glycoproteins Mitogen-Activated Protein Kinase 3 Base Sequence JNK Mitogen-Activated Protein Kinases Cell Differentiation Cell Biology Transfection Molecular biology Lens Fiber Rats Cell biology Enzyme Activation medicine.anatomical_structure Gene Expression Regulation Membrane protein Lens (anatomy) Fibroblast Growth Factor 2 Mitogen-Activated Protein Kinases Signal transduction |
| Zdroj: | Journal of Biological Chemistry. 279:31813-31822 |
| ISSN: | 0021-9258 |
| Popis: | Lens major intrinsic protein (MIP), exclusive to the vertebrate lens, otherwise known as MIP26 and Aquaporin 0, is abundantly expressed as a lens fiber membrane protein. Although relatively less efficient compared with other aquaporins, MIP is suggested to function as a water channel, as an adhesion molecule, and is required for lens transparency. Because MIP is specifically expressed in lens fiber cells, we investigated in this study the activation of Mip expression after triggering differentiation of rat lens epithelia explants by fibroblast growth factor (FGF)-2. Here, we show that Mip expression in the lens cells is regulated by FGF-2. Using Real time PCR we demonstrate that endogenous Mip levels in the explants were up-regulated upon FGF-2 stimulation, in a concentration-dependent manner. Up-regulation of Mip at the transcriptional level was simultaneous with the activation of the FGF down-stream signaling components, ERK1/2 and JNK. Specific inhibitors, UO126 for ERK1/2 and SP600125 for JNK, abrogated Mip expression in response to FGF-2 in the explants. This inhibition pattern was recapitulated in reporter assays for transfection of the rat lens epithelia explants, driven by the Mip promoter (-1648/+44). Our studies show that ERK1/2 and JNK signaling pathways are required for Mip expression in lens epithelia explants induced to differentiate by FGF-2. |
| Databáze: | OpenAIRE |
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