Prolonged rhodopsin phosphorylation in light-induced retinal degeneration in rat models.

Purpose: The effects of various light-induced stresses on the retina were examined in the retinal degenerative rat model.

Methods: Retinal morphology and electroretinograms (ERGs) were analyzed after application of light-induced stress of several intensities (650, 1300, 2500, or 5000 lux). For evaluation of rhodopsin (Rho) function, the kinetics of Rho regeneration and dephosphorylation were studied by spectrophotometric analysis and immunofluorescence labeling with antibodies specifically directed toward the phosphorylated residues (334)Ser and (338)Ser in the C terminus of Rho.

Effects of antiglaucoma drops on MMP and TIMP balance in conjunctival and subconjunctival tissue.

Purpose: To study the effects of antiglaucoma drugs on metabolism within the extracellular matrix (ECM) of the ocular surface, including corneal, conjunctival, and subconjunctival tissue.

Method: Several antiglaucoma drugs--including beta-blockers, alpha/beta-blockers, alpha1-blocker, alpha2-agonist, and prostaglandin derivative-were topically administrated to rat eyes daily for 2 weeks or were incubated with human corneal cells or human fibroblasts for 72 hours. Thereafter, expression and enzymatic activity of the matrix metalloproteinases (MMPs), a group of enzymes proteolyzing ECM and their inhibitors, called tissue inhibitors of metalloproteinase (TIMPs), were evaluated.

Study of effects of antiglaucoma eye drops on N-methyl-D-aspartate-induced retinal damage.

Purpose: To study the effects of antiglaucoma eye drops on N-methyl-D-aspartate (NMDA)-induced retinal damage.

Methods: Several antiglaucoma eye drops, beta-blockers, alpha/beta-blockers, an alpha1-blocker, an alpha2-agonist, and a prostaglandin derivative, were topically administrated to NMDA-treated rat eyes daily for 2 weeks, and the retinal thickness, the number of retrograde-labeled retinal ganglion cells (RGCs), and the results of a cDNA microarray analysis were studied.

Results: Intravitreal administration of NMDA caused a significant decrease in the thickness of the retinal layers and induced upregulation of glial fibrillary acidic protein (GFAP).

Effects of matrix metalloproteinase-3 gene transfer by electroporation in glaucoma filter surgery.

To develop gene therapy that can be applied to glaucoma-filtering surgery, we studied effects of transfection of matrix metalloproteinase-3 (MMP-3) cDNA into rabbit conjunctiva by electroporation (EP) on changes of intraocular pressure (IOP) and bleb formation after glaucoma filtering surgery. pTracer-CMV2 vector containing MMP-3 cDNA was transfected into rabbit conjunctiva by EP and MMP-3 expression was studied by reverse transcription (RT)-PCR, zymography and western blot analysis. Three days after the EP transfection of MMP-3 cDNA or vector alone into rabbit conjunctiva, trabeculectomy was performed at the place of transfection in the presence or absence of 0.

Clinical and immunologic aspects of cancer-associated retinopathy.

Purpose: To report clinical and immunologic aspects of cancer-associated retinopathy (CAR).

Design: Observational consecutive case series.

Methods: A retrospective review was made of 18 consecutive patients with cancer-associated retinopathy who had antiretinal antibody determination by Western blot testing.

Study of drug effects of calcium channel blockers on retinal degeneration of rd mouse.

In the present study, we studied drug effects of Ca(2+) antagonists on the retinal degeneration of rd mouse to evaluate their efficacy. Several kinds of Ca(2+) antagonists, diltiazem, nicardipine, nilvadipine or nifedipine were administrated intraperitoneally and thereafter retinal morphology and functions were analyzed. In addition, we performed DNA microarray analysis both in nilvadipine treated and control retinas to understand their drug effects at molecular levels.

Low expression of rhodopsin kinase in pineal gland in Royal College of Surgeons rat.

The Royal College of Surgeons (RCS) rat has been extensively characterized as a model for inherited retinal dystrophy such as retinitis pigmentosa. We have found that significantly low levels of expression of rhodopsin kinase (RK) and alphaA-crystallin may be involved in the pathogenesis of retinal degeneration in the RCS rat (Invest Ophthalmol Vis Sci. 1999,40:2788-2794).

Prolonged survival of the phosphorylated form of rhodopsin during dark adaptation of Royal College Surgeons rat.

To study rhodopsin (Rho) phosphorylation and dephosphorylation in Royal College of Surgeons (RCS) rat retina, specific antibodies toward major Rho phosphorylation sites in vivo, 334Ser or 338Ser, were prepared by immunization of authentic phosphorylated peptides in rabbit. Enzyme-linked immunosorbent assay identified that the raised antibodies exclusively recognized either the phosphorylated 334Ser or 338Ser site. In immunofluorescence labeling, both antibodies recognized photoreceptor outer segments in light-adapted retinas from Sprague-Dawley (SD), Brown-Norway (BN) and RCS rat.

Study of pharmacological effects of nilvadipine on RCS rat retinal degeneration by microarray analysis.

In our recent study, we found that the Ca(2+) antagonist, nilvadipine caused significant preservation of photoreceptor cells in The Royal College of Surgeons (RCS) rats [Invest. Ophthalmol. Vis.

Role of Cys41 in the N-terminal domain of lumican in ex vivo collagen fibrillogenesis by cultured corneal stromal cells.

The keratan sulphate proteoglycan lumican regulates collagen fibrillogenesis to maintain the integrity and function of connective tissues such as cornea. We examined the role of a highly conserved cysteine-containing domain proximal to the N-terminus of lumican in collagen fibrillogenesis using site-specific mutagenesis to prepare plasmid DNA encoding wild-type murine lumican (Cys(37)-Xaa(3)-Cys(41)-Xaa-Cys-Xaa(9)-Cys) and a Cys-->Ser (C/S) mutant (Cys(37)-Xaa(3)-Ser(41)-Xaa-Cys-Xaa(9)-Cys). cDNAs were cloned into the pSecTag2A vector, and cultures of MK/T-1 cells (an immortalized cell line from mouse keratocytes) were transfected with the cDNAs.