PURPOSE Lens opacity 11 (lop11) is a spontaneous autosomal recessive mouse mutation resulting in cataracts. Insertion of an early transposable element (ETn) in intron 9 of heat shock factor 4 (Hsf4) was previously identified as responsible for lop11 cataracts. Although molecular analysis showed that the ETn insertion resulted in an aberrant Hsf4 transcript encoding a truncated mutant HSF4(lop11...

Segments of healthy human lenses and lenses with an anterior cortex cataract, prefixed in glutaraldehyde and subsequently postfixed in a mixture of tannic acid arginine osmium tetroxide, were examined by stereo-scopic imaging at 2 kV in a field emission scanning electron microscope. The degeneration process of the lens fibers was identified by the presence of spherical bodies or vacuoles in the...

Different mutations of alpha3 connexin (Cx46 or Gja8) and alpha8 connexin (Cx50 or Gja8), subunits of lens gap junction channels, cause a variety of cataracts via unknown mechanisms. We identified a dominant cataractous mouse line (L1), caused by a missense alpha8 connexin mutation that resulted in the expression of alpha8-S50P mutant proteins. Histology studies showed that primary lens fiber c...

The size of an organ must be tightly controlled so that it fits within an organism. The mammalian lens is a relatively simple organ composed of terminally differentiated, amitotic lens fiber cells capped on the anterior surface by a layer of immature, mitotic epithelial cells. The proliferation of lens epithelial cells fuels the growth of the lens, thus controling the size of the lens. We repor...

PURPOSE To test the ability of lens fiber cells at various stages of differentiation to transcribe and translate microinjected DNA templates. METHODS Expression plasmids encoding green fluorescent protein (GFP) or a GFP-tagged membrane protein (human CD46) were microinjected into organ-cultured embryonic chicken lenses. Protein expression was visualized by confocal microscopy. RESULTS GFP e...

PURPOSE To determine the mechanisms of action of phosphatidylinositol 3-kinase (PI3K) in lens cell differentiation and survival. METHODS Primary quail lens cell cultures were treated at different stages of differentiation with the PI3K inhibitor LY294002, and expression of survival proteins and differentiation markers were determined by immunoblot analysis. The connection between PI3K regulat...

Purpose Ocular lens fiber cell elongation, differentiation, and compaction are associated with extensive reorganization of cell adhesive interactions and cytoskeleton; however, our knowledge of proteins critical to these events is still evolving. This study characterizes the distribution pattern of neuronal-specific α-catenin (αN-catenin) and its interaction with the N-cadherin-associated adher...

PURPOSE To examine the role of calcium-dependent and -independent proteolytic activity in the globulization of isolated fiber cells and glucose-induced lens opacification. METHODS Fiber cells from rat lens cortex were isolated, and the [Ca(2+)](i) and protease activity in the isolated fibers were determined by using a calcium binding dye and the protease substrate t-butoxycarbonyl-Leu-Met-7-a...

PURPOSE To delineate the molecular mechanisms underlying autosomal dominant congenital cataracts caused by a 5 bp duplication in human CRYGC. METHODS c.119_123dup (CRYGC5bpd) and wild-type human γC-crystallin (CRYGC) were expressed in transgenic mouse lenses by the chicken βB1-crystallin promoter. Lenses were characterized histologically, by real-time PCR, SDS-PAGE, and Western blot. pET and ...

PURPOSE Fiber cells of the ocular lens are bounded by a highly specialized plasma membrane. Despite the pivotal role that membrane proteins play in the physiology and pathophysiology of the lens, our knowledge of the structure and composition of the fiber cell plasma membrane remains fragmentary. In the current study, we utilized mass spectrometry-based shotgun proteomics to provide a comprehen...