First Author | Simirskii VN | Year | 2007 |
Journal | Dev Biol | Volume | 306 |
Issue | 2 | Pages | 658-68 |
PubMed ID | 17493607 | Mgi Jnum | J:122566 |
Mgi Id | MGI:3714685 | Doi | 10.1016/j.ydbio.2007.04.004 |
Citation | Simirskii VN, et al. (2007) Conditional deletion of beta1-integrin from the developing lens leads to loss of the lens epithelial phenotype. Dev Biol 306(2):658-68 |
abstractText | Beta1-integrins are cell surface receptors that participate in sensing the cell's external environment. We used the Cre-lox system to delete beta1-integrin in all lens cells as the lens vesicle transitions into the lens. Adult mice lacking beta1-integrin in the lens are microphthalmic due to apoptosis of the lens epithelium and neonatal disintegration of the lens fibers. The first morphological alterations in beta1-integrin null lenses are seen at 16.5 dpc when the epithelium becomes disorganized and begins to upregulate the fiber cell markers beta- and gamma-crystallins, the transcription factors cMaf and Prox1 and downregulate Pax6 levels demonstrating that beta1-integrin is essential to maintain the lens epithelial phenotype. Furthermore, beta1-integrin null lens epithelial cells upregulate the expression of alpha-smooth muscle actin and nuclear Smad4 and downregulate Smad6 suggesting that beta1-integrin may brake TGFbeta family signaling leading to epithelial-mesenchymal transitions in the lens. In contrast, beta1-integrin null lens epithelial cells show increased E-cadherin immunoreactivity which supports the proposed role of beta1-integrins in mediating complete EMT in response to TGFbeta family members. Thus, beta1-integrin is required to maintain the lens epithelial phenotype and block inappropriate activation of some aspects of the lens fiber cell differentiation program. |