Thiol oxidation in the crystalline lens I. The rate-limiting role of hexokinase in aging rat and human lenses

Reduction of nonprotein disulfides required, both glucose or glucose-6-phosphate (G6P

LEDGF: survival of embryonic chick retinal photoreceptor cells

PURPOSE. Lens epithelium-derived growth factor (LEDGF) is a novel adhesive, survival, and growth factor for lens epithelial cells, keratinocytes, fibroblasts, and cos7 cells. In the presence of LEDGF, these cells acquire resistance to environmental stresses, and in the absence of LEDGF they die. The effects of LEDGF on survival of embryonic chick retinal photoreceptor cells under serum starvation and heat stress were studied. METHODS. The expression pattern of LEDGF in embryonic chick retinal photoreceptor cells was investigated with protein blot analysis and immunohistochemistry using antibodies (Abs) to LEDGF. Retinal cells were cultured in serum-free medium for up to 6 days in the presence of varying amounts of LEDGF at 37°or 41°C. The photoreceptor cells were immunostained with Abs to arrestin and counted to evaluate the photoreceptor cell viability. Heat shock proteins in the cultured cells were quantified by protein blot analysis with Ab probes and semiquantitative reverse transcription-polymerase chain reaction analysis. RESULTS. LEDGF was found predominantly in the nucleus of neuroretinal cells, including photoreceptor cells. In the presence of LEDGF, photoreceptor cells manifested increased resistance to serum starvation and thermal stress and survived for a longer period. The levels of heat shock protein 90 were elevated in those cells. Most retinal cells died in the absence of LEDGF

Cellular distribution of lens epithelium-derived growth factor (LEDGF) in the rat eye: loss of LEDGF from nuclei of differentiating cells

Lens epithelium-derived growth factor (LEDGF) enhances the survival and growth of cells. To understand LEDGF's spatial localization and its putative function(s) during proliferation and differentiation, we localized LEDGF during terminal differentiation in whole rat lenses, lens epithelial cell (LEC) explants stimulated with FGF-2, and insulin, iris, human LECs with lentoids. In addition, intracellular localization of LEDGF was performed in other ocular tissues: ciliary body, retina, and cornea. We found the immunopositivity of nuclear LEDGF decreased in LECs of the equatorial region. In contrast, immunopositivity of LEDGF was detected in the cytoplasm of LECs and superficial fiber cells. After treating LEC explants with FGF-2 and insulin, which are known to be differentiating factors for LECs, the nuclei of these cells showed no LEDGF immunopositivity, but explants did express p57 kip2 , a differentiation marker protein. Also, immunopositive LEDGF was not detected in the nuclei of differentiated cells, lentoid body, and corneal epithelial cells. This demonstrated that the loss of LEDGF from the nucleus may be associated with the process of terminal differentiation that might be in some way common with the biochemical mechanisms of apoptosis. The spatial and temporal distribution of LEDGF in the present study also provides a vision for further investigation as to how this protein is involved in cell fate determination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42235/1/s00418-003-0518-3.pd

Classification of human senile cataractous change by the American Cooperative Cataract Research Group. I. Instrumentation and Technique. Invest Ophthalmol Vis Sci 24:424,

In 1978,' a system of cataract photography and classification was described that provided lens scientists with an opportunity to examine and photograph the lens immediately after extraction and to document objectively, in artifact-free photos, the cataractous change independently of nuclear color. These photographs provided a record of the complexity and variability of cataract anatomy. The system of cataract classification has evolved over the years to its present form

Stability of mammalian lens phosphofructokinase

Two interconvertible phosphofructokinase (PFK) forms were found in rat and human lenses; whereas only one predominant form was found in calf lens. PFK isolated from these lenses possessed a common property, i.e., pH-dependent cold (or acid) best described by the pH-dependent cold sensitivity behavior, 5 ' 6 which in effect is identical to the pH-dependent inactivation at higher temperatures and lower pH's. 7 The inactivation can be prevented by addition of substances such as adenosine triphosphate (ATP), fructose-6-phosphate (fru-6-P), or related materials, depending on the PFK in question, to the incubating media. In this paper, we attempt to compare PFK's isolated from lenses of rat, calf, and human beings on their resistance to cold treatment at acidic pH's. Also, lens organ cultures are employed to show the effect of ATP deprivation on PFK stability. We hope to define the conditions for maintenance of PFK stability, since the loss of PFK may contribute to cataractogenesis by disruption of ATP formation in the lens. Materials and methods Isolation of the PFK's was carried out at 25 c 26° C. to avoid cold inactivation