Phenotype of transgenic mice overexpressed with inducible nitric oxide synthase in the retina.

Background: Unlike its constitutive isoforms, including neuronal and endothelial nitric oxide synthase, inducible nitric oxide synthase (iNOS) along with a series of cytokines are generated in inflammatory pathologic conditions in retinal photoreceptors. In this study, we constructed transgenic mice overexpressing iNOS in the retina to evaluate the effect of sustained, intense iNOS generation in the photoreceptor damage.

Methods: For construction of opsin/iNOS transgene in the CMVSport 6 expression vector, the 4.

Immunopathologic processes in sympathetic ophthalmia as signified by microRNA profiling.

Purpose: Recent discovery of microRNAs and their negative gene regulation have provided new understanding in the pathogenesis of inflammatory diseases. This study demonstrated microRNA expression profiling and their likely role in sympathetic ophthalmia, using formalin-fixed, paraffin embedded samples.

Methods: Two groups of four enucleated globes (total eight globes) from patients with clinical and histopathological diagnosis of SO (experimental samples) and one group of four age-matched, noninflamed enucleated globes (control samples) were used.

Mitochondrial oxidative DNA damage in experimental autoimmune uveitis.

Purpose: In experimental autoimmune uveitis (EAU), recent work has demonstrated that retinal damage involves oxidative stress early in uveitis, before macrophage cellular infiltration. The purpose of this study was to determine whether oxidative mitochondrial DNA damage occurs early in EAU, before leukocyte infiltration.

Methods: Lewis rats were immunized with S-antigen mixed with complete Freund adjuvant (CFA) to induce EAU.

Elevated retina-specific expression of the small heat shock protein, alphaA-crystallin, is associated with photoreceptor protection in experimental uveitis.

Purpose: During the early phase of experimental autoimmune uveitis (EAU), before macrophages infiltrate the retina and uvea, photoreceptor mitochondrial oxidative stress, nitration of photoreceptor mitochondrial proteins, and release of cytochrome c have been observed. However, no apoptosis has been detected during this phase. In this study, alphaA-crystallin upregulation in the retina and its antiapoptotic protective role were evaluated in early EAU.

Direct detection of reactive nitrogen species in experimental autoimmune uveitis.

Purpose: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)(2)-Fe(2+), as a spin trap.

Methods: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR.

Photoreceptor mitochondrial tyrosine nitration in experimental uveitis.

Purpose: In experimental autoimmune uveitis (EAU), phagocytes are thought to be the primary cells in the initiation and maintenance of pathologic tissue damage through the release of cytotoxic agents. Recently, the presence of nitric oxide synthase has been shown in mammalian mitochondria. In this study, the effect of mitochondrial peroxynitrite on the modification of cellular proteins was evaluated in the early phase of uveitis, before the infiltration of leukocytes.

Peroxynitrite-induced apoptosis in photoreceptor cells.

Purpose: To study the mechanisms of peroxynitrite-induced photoreceptor cell damage, using retinal cultures and a peroxynitrite donor, 3-morpholinosydnonimine (SIN-1).

Methods: Retinal explants obtained from 20-day-old Lewis rat pups, were exposed to SIN-1 for varying lengths of time at varying concentrations. Apoptosis in the photoreceptor cells was detected using the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method and a DNA fragmentation assay.

Effects of a new dexamethasone-delivery system (Surodex) on experimental intraocular inflammation models.

Background: To investigate the effects of a new biodegradable dexamethasone drug delivery system, Surodex, in two experimental intraocular inflammation models; endotoxin-induced uveitis (EIU) and experimental autoimmune uveoretinitis (EAU).

Methods: Surodex was inserted into the right anterior chambers (ACs) of rats. In the EIU experiment, protein concentration, cell infiltration, and myeloperoxidase (MPO) activity in the aqueous humor were measured 24 h after injection.

Upregulation of chemokine expression in the retinal vasculature in ischemia-reperfusion injury.

Purpose: To evaluate chemokine expression at various retinal sites after ischemia-reperfusion injury, using reverse transcription-polymerase chain reaction (RT-PCR) analysis of selected tissue obtained by laser capture microdissection.

Methods: Retinal ischemia was produced in Lewis rats by increasing intraocular pressure for 75 minutes. At 3, 6, 12, and 24 hours after reperfusion, RT-PCR was used to measure the levels of monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, interleukin (IL)-8, and interferon-gamma-inducible 10-kDa protein (IP-10) mRNA expression in the ganglion cell layer (GCL), inner nuclear layer (INL), outer nuclear layer (ONL), and retinal vessels, after laser capture microdissection of these retinal layers.

Pathogenic role of retinal microglia in experimental uveoretinitis.

Purpose: To devise methods for unequivocal identification of activated retinal microglia in experimental autoimmune uveoretinitis (EAU) and to investigate their role in the development of EAU.

Methods: A group of Lewis rats underwent optic nerve axotomy with the application of N-4-(4-didecylaminostyryl)-N methylpyridinium iodide (4Di-10ASP) at the axotomy site. On days 3, 14, and 38 after axotomy, the rats were killed, the eyes were enucleated, and the retinas were stained for OX42.