Beta1 integrin plays a role in lens fiber cell structure and interaction with the cytoskeleton

A conditional knockout for β1 integrin of lens fiber cells was produced. Scanning electron microscopy was used to assess the ultrastructure. Immunofluorescence of sectioned and whole lens was used to determine the expression of β1 integrin and its crosstalk with different cytoskeletal components. At 14.5 dpc (days post coitum) expression of β1 integrin is lost in lens fiber cells. Mice lacking β1 integrin in lens fiber cells have variable phenotypes of clear and cataract lens. The ultrastructure of the lenses was analyzed from two different areas. Cortical fiber cells are newly differentiated cells that contain a highly regular structurally repeated ball and socket pattern along the membranes of fiber cells in wildtype mice. Lens lacking β1 integrin have ball and socket structures that are disorganized exhibiting variable width and extension from the cell. Nuclear fiber cells are older cells that contain ball and sockets as well as a random arrangement of membrane furrows in wildtype mice. Lens lacking β1 integrin have a membrane furrow pattern that is highly organized into a lattice like geometric pattern, no ball and sockets and a defect of Aquaporin‐0. Lens lacking β1 integrin also have a modified f‐actin network. The lack of the f‐actin network disrupts the hexagonal packing arrangement and radial cell columns of these fiber cells. β1 integrin is needed for proper structure of lens fiber cells. Funded by NEI EY015279. Grant Funding Source : NEI EY015279