β1-integrin controls cell fate specification in early lens development.

Integrins are heterodimeric cell surface molecules that mediate cell-extracellular matrix (ECM) adhesion, ECM assembly, and regulation of both ECM and growth factor induced signaling. However, the developmental context of these diverse functions is not clear. Loss of β1-integrin from the lens vesicle (mouse E10.

Beta-1 integrin is important for the structural maintenance and homeostasis of differentiating fiber cells.

β1-Integrin is a heterodimeric transmembrane protein that has roles in both cell-extra-cellular matrix and cell-cell interactions. Conditional deletion of β1-integrin from all lens cells during embryonic development results in profound lens defects, however, it is less clear whether this reflects functions in the lens epithelium alone or whether this protein plays a role in lens fibers. Thus, a conditional approach was used to delete β1-integrin solely from the lens fiber cells.

CD44 expression is developmentally regulated in the mouse lens and increases in the lens epithelium after injury.

Hyaluronan is an oligosaccharide found in the pericellular matrix of numerous cell types and hyaluronan-induced signaling is known to facilitate fibrosis and cancer progression in some tissues. Hyaluronan is also commonly instilled into the eye during cataract surgery to protect the corneal endothelium from damage. Despite this, little is known about the distribution of hyaluronan or its receptors in the normal ocular lens.

Conditional deletion of beta1-integrin from the developing lens leads to loss of the lens epithelial phenotype.

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.

Inbred FVB/N mice are mutant at the cp49/Bfsp2 locus and lack beaded filament proteins in the lens.

Purpose: FVB/N is considered an ideal inbred mouse strain for transgenic mouse production because of the ease of pronuclear microinjection and its overall fecundity. It is well established that vertebrate lens fiber cells normally express a modified intermediate filament network consisting of the proteins filensin and CP49, and it was recently reported that the mouse strain 129 harbors mutations in CP49 that have the potential to confound the interpretation of gene knockout studies of the lens. The purpose of this study was to evaluate the status of the CP49/Bfsp2 gene in the FVB/N strain.

Expression of tissue plasminogen activator during eye development.

Tissue plasminogen activator (tPA) is a serine protease responsible for the activation of plasminogen to plasmin as well as extracellular matrix remodeling. While tPA is used clinically to treat some retinal disorders and it is expressed at low levels in the adult eye, its expression pattern during eye development had never been determined. tPA protein is broadly dispersed in the lens placode and optic vesicle of the mouse eye and it becomes highly localized to the apical surfaces of both the lens pit and the optic cup as they invaginate.