11-cis-retinal and Retinal-Detachment

Persistent subretinal fluid after rhegmatogenous retinal detachment (RRD) surgery is responsible for delayed recovery, and may affect the final visual outcome. Cause, consequences, and treatment remain elusive.. Literature review and case series.. We reviewed the pathophysiological principles and therapeutic options from the literature, and we report the results from a subretinal fluid cytology study. Nine eyes from nine patients with macula-involving RRD underwent surgical repair. The cellular content of subretinal fluid (SRF) was studied by electron microscopy and anti-rhodopsin immunostaining. All eyes were assessed postoperatively with optical coherence tomography for the detection of persistent submacular fluid (PSF) (Ethics Committee Ghent University Hospital, registration number B6702006169).. Certain patient characteristics as well as surgical methods were implicated. PSF appears to occur more frequently in patients with longstanding detachments treated with buckling surgery. Several therapeutic options have been suggested but safety and efficacy remain unclear. We found PSF in three eyes on postoperative OCT scans, which corresponded to the three cell-rich subretinal samples.. PSF after successful RRD repair seems to be related to fluid composition. We hypothesize, in the absence of an effective treatment, that a modified surgical drainage, including a washout of the subretinal space, could evacuate the subretinal fluid more completely, and may prevent this complication.

Topics: Aged; Aged, 80 and over; Drainage; Female; Humans; Immunohistochemistry; Male; Microscopy, Electron, Transmission; Middle Aged; Postoperative Complications; Retinal Detachment; Rhodopsin; Rod Cell Outer Segment; Scleral Buckling; Subretinal Fluid; Tomography, Optical Coherence; Visual Acuity; Vitrectomy

Our study aimed to evaluate the protective role and mechanisms of bone marrow mesenchymal stem cells (BMSCs) in hypoxic photoreceptors and experimental retinal detachment. The cellular morphology, viability, apoptosis and autophagy of hypoxic 661w cells and cells cocultured with BMSCs were analysed. In retinal detachment model, BMSCs were intraocularly transplanted, and then, the retinal morphology, outer nuclear layer (ONL) thickness and rhodopsin expression were studied as well as apoptosis and autophagy of the retinal cells. The hypoxia-induced apoptosis of 661w cells obviously increased together with autophagy levels increasing and peaking at 8 hours after hypoxia. Upon coculturing with BMSCs, hypoxic 661w cells had a better morphology and fewer apoptosis. After autophagy was inhibited, the apoptotic 661w cells under the hypoxia increased, and the cell viability was reduced, even in the presence of transplanted BMSCs. In retina-detached eyes transplanted with BMSCs, the retinal ONL thickness was closer to that of the normal retina. After transplantation, apoptosis decreased significantly and retinal autophagy was activated in the BMSC-treated retinas. Increased autophagy in the early stage could facilitate the survival of 661w cells under hypoxic stress. Coculturing with BMSCs protects 661w cells from hypoxic damage, possibly due to autophagy activation. In retinal detachment models, BMSC transplantation can significantly reduce photoreceptor cell death and preserve retinal structure. The capacity of BMSCs to reduce retinal cell apoptosis and to initiate autophagy shortly after transplantation may facilitate the survival of retinal cells in the low-oxygen and nutrition-restricted milieu after retinal detachment.

Topics: Animals; Apoptosis; Autophagy; Bone Marrow Cells; Cell Differentiation; Cell Hypoxia; Cell Line; Cell Survival; Coculture Techniques; Female; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Rats; Rats, Wistar; Retinal Cone Photoreceptor Cells; Retinal Detachment; Rhodopsin

Rhegmatogenous retinal detachment (RRD) is a potentially blinding condition characterized by a physical separation between neurosensory retina and retinal pigment epithelium. Quantitative proteomics can help to understand the changes that occur at the cellular level during RRD, providing additional information about the molecular mechanisms underlying its pathogenesis. In the present study, iTRAQ labeling was combined with two-dimensional LC-ESI-MS/MS to find expression changes in the proteome of vitreous from patients with RRD when compared to control samples. A total of 150 proteins were found differentially expressed in the vitreous of patients with RRD, including 96 overexpressed and 54 underexpressed. Several overexpressed proteins, several such as glycolytic enzymes (fructose-bisphosphate aldolase A, gamma-enolase, and phosphoglycerate kinase 1), glucose transporters (GLUT-1), growth factors (metalloproteinase inhibitor 1), and serine protease inhibitors (plasminogen activator inhibitor 1) are regulated by HIF-1, which suggests that HIF-1 signaling pathway can be triggered in response to RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Nevertheless, the differentially expressed proteins found in this study suggest that different mechanisms are activated after RRD to promote the survival of retinal cells through complex cellular responses.

Topics: Aged; Arrestin; Eye Proteins; Female; Glucose Transporter Type 1; Glycolysis; GTP-Binding Protein Regulators; Humans; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Phosphoproteins; Proteome; Retina; Retinal Detachment; Rhodopsin

Retinal detachment (RD) is a leading cause of blindness, and although final surgical re-attachment rate has greatly improved, visual outcome in many macula-off detachments is disappointing, mainly because of photoreceptor cell death. We previously showed that lutein is anti-apoptotic in rodent models of ischemia/reperfusion injury. The objective of this study is to investigate lutein as a possible pharmacological adjunct to surgery.. Subretinal injections of 1.4 % sodium hyaluronate were used to induce RD in Sprague-Dawley rats until their retinae were approximately 70 % detached. Daily injections of corn oil (control group) or 0.5 mg/kg lutein in corn oil (treatment group) were given intraperitoneally starting 4 h after RD induction. Animals were euthanized 3 days and 30 days after RD and their retinae were analyzed for photoreceptor apoptosis and cell survival at the outer nuclear layer (ONL) using TUNEL staining and cell counting on retinal sections. Glial fibrillary acidic protein (GFAP) and rhodopsin (RHO) expression were evaluated with immunohistochemistry. Western blotting was done with antibodies against cleaved caspase-3, cleaved caspase-8 and cleaved caspase-9 to delineate lutein's mechanism of action in the apoptotic cascade. To seek a possible therapeutic time window, the same set of experiments was repeated with treatment commencing 36 h after RD.. When lutein was given 4 h after RD, there were significantly fewer TUNEL-positive cells in ONL 3 days after RD when compared with the vehicle group. Cell counting showed that there were significantly more nuclei in ONL in lutein-treated retinae by day 30. Treatment groups also showed significantly reduced GFAP immunoreactivity and preserved RHO expression. At day 3 after RD, Western blotting showed reduced expression of cleaved caspase-3 and cleaved caspase-8 in the treatment group. No difference was found for cleaved caspase-9. When lutein was given 36 h after RD similar results were observed.. Our results suggest that lutein is a potent neuroprotective agent that can salvage photoreceptors in rats with RD, with a therapeutic window of at least 36 h. The use of lutein in patients with RD may serve as an adjunct to surgery to improve visual outcomes.

Topics: Animals; Apoptosis; Blotting, Western; Caspase 3; Caspase 8; Cell Count; Cell Survival; Disease Models, Animal; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; In Situ Nick-End Labeling; Injections, Intraperitoneal; Lutein; Male; Neuroprotective Agents; Photoreceptor Cells, Vertebrate; Rats; Rats, Sprague-Dawley; Retinal Detachment; Rhodopsin

There is some in vitro evidence that the adult ciliary body might harbor an inactive population of stem/retinal progenitor cells (RPC), or that ciliary epithelial (CE) cells might have the capacity to trans-differentiate, which may result in a balance between neural and epithelial properties. We have reported alterations in the ciliary body (CB) and adjacent vitreous in vivo by endoscopic evaluation of human eyes with a history of retinal detachment (RD) and anterior proliferative vitreoretinopathy (PVR).. The present study examined with light microscopy three paraffin-embedded phthisic human eyes with RD and anterior PVR. One normal eye, exenterated for an orbital tumor, served as the control. All specimens were stained with hematoxilin and eosin safran (HES), and serial sections were immunostained with antibodies against EGFR, Ki67, CD133, NSE, rhodopsin, and GFAP.. We observed: (1) an intense proliferation and displacement of clusters of CE cells into the vitreous base in a "neurosphere-like" fashion; (2) differentiation of CE cells towards early and late neuronal [photoreceptor (PR)] lineages; and (3) strong staining of EGF and EGFR in the CE. Such proliferation, migration, and differentiation were not present in the CE of the control eye. GFAP staining was intensely positive in the three detached retinae, and was negative in the CE of eyes with RD, as well as in the retina of the control eye.. Our observations suggest that EGFR-positive CE cells in the adult human eye in vivo with RD and PVR form "neurosphere-like" structures; their differentiation seems to be directed towards the neural and photoreceptor lineage, and not towards glial formation. In the adult human eye, the CE in a pathological retinal environment such as RD might provide a spontaneous source of donor cells for retinal transplantation.

Topics: AC133 Antigen; Adult; Antigens, CD; Cell Differentiation; Cell Movement; Cell Proliferation; Ciliary Body; ErbB Receptors; Female; Glial Fibrillary Acidic Protein; Glycoproteins; Humans; Immunoenzyme Techniques; Ki-67 Antigen; Male; Middle Aged; Paraffin Embedding; Peptides; Phosphopyruvate Hydratase; Photoreceptor Cells, Vertebrate; Pigment Epithelium of Eye; Retinal Detachment; Retinal Neurons; Rhodopsin; Vitreoretinopathy, Proliferative

In addition to the ability for self-renewal and functional differentiation, neural stem/progenitor cells (NSCs) can respond to CNS injuries by targeted migration. In lower vertebrates, retinal injury is known to activate NSCs in the ciliary marginal zone (CMZ). Cells expressing markers of NSCs are also present in the ciliary body epithelium (CE) and in Müller glia in the peripheral retina (PR) of the adult human eye. However, these cells seem to be quiescent in the adult human eye and recent reports have shown that CE cells have limited properties of NSCs. In order to further clarify whether NSCs exist in the adult human eye, we tested whether NSC-like cells could be activated in eyes with proliferative vitreoretinopathy (PVR). The PR and CE were studied for NSC-associated markers in human enucleated control eyes and eyes with confirmed PVR, as well as in a mouse model of PVR. Furthermore, cells isolated from vitreous samples obtained during vitrectomies for retinal detachment were directly fixed or cultured in a stem cell-promoting medium and compared to cells cultured from the post-mortem retina and CE. In situ characterization of the normal eyes revealed robust expression of markers present in NSCs (Nestin, Sox2, Pax6) only around peripheral cysts of the proximal pars plana region and the PR, the latter population also staining for the glial marker GFAP. Although there were higher numbers of dividing cells in the CE of PVR eyes than in controls, we did not detect NSC-associated markers in the CE except around the proximal pars plana cysts. In the mice PVR eyes, Nestin activation was also found in the CE. In human PVR eyes, proliferation of both non-glial and glial cells co-staining NSC-associated markers was evident around the ora serrata region. Spheres formed in 7/10 vitreous samples from patients with PVR compared to 2/15 samples from patients with no known PVR, and expressed glial - and NSC-associated markers both after direct fixation and repetitive passages. In conclusion, the adult human eye may harbor two different populations of neuroepithelial stem/progenitor cells; a non-glial population located in the proximal pars plana around peripheral cysts in addition to a population with Müller glia characteristics. Yet, we only found that the glial population was able to respond to retinal injury by targeted migration into the vitreous.

Topics: Adolescent; Adult; Aged, 80 and over; Animals; Biomarkers; Cadherins; Ciliary Body; Disease Models, Animal; Eye Proteins; Female; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; Homeodomain Proteins; Humans; Intermediate Filament Proteins; Male; Mice; Mice, Inbred C57BL; Middle Aged; Nerve Tissue Proteins; Nestin; Paired Box Transcription Factors; PAX6 Transcription Factor; Pigment Epithelium of Eye; Real-Time Polymerase Chain Reaction; Repressor Proteins; Retinal Detachment; Retinal Neurons; Rhodopsin; SOXB1 Transcription Factors; Stem Cells; Vitreoretinopathy, Proliferative; Vitreous Body

Activation of complement has been implicated as one of the major causes of age-related macular degeneration (AMD). Evidence is accumulating for a role of complement in other retinal diseases, such as diabetic retinopathy and proliferative vitreoretinopathy. Because of the paucity of animal models that directly investigate the role of complement in retinal pathology, the authors sought to develop a model of increased complement expression and activation, specifically in the murine retina.. The authors constructed a recombinant adenovirus-expressing murine complement component 3 (C3, AdcmvC3). Adult mice were injected in the subretinal space with either AdcmvC3 or a control virus, AdcmvGFP. After 1 to 2 weeks of exogenous C3 expression, mice were analyzed by scotopic electroretinography and fluorescein angiography. Eyes were harvested for histologic, immunohistochemical, and quantitative RT-PCR analyses.. Mice injected with C3-expressing adenovirus exhibited significantly increased vascular permeability, endothelial cell proliferation and migration, RPE atrophy, loss of photoreceptor outer segments, reactive gliosis, retinal detachment, and reduced retinal function relative to those injected with a control adenovirus. Deposition of the membrane attack complex was observed on endothelial cells and photoreceptor outer segments.. Adenovirus-mediated delivery of C3 to murine RPE induces significant functional and anatomic changes that reproduce many of the features of AMD as well as those of other retinal diseases. This novel model may be useful in assessing the role of complement in retinal pathology and in developing anti-complement therapies for retinal diseases associated with complement activation.

Topics: Adenoviridae; Animals; Atrophy; Capillary Permeability; Cell Movement; Cell Proliferation; Complement C3; Complement Membrane Attack Complex; Electroretinography; Endothelium, Vascular; Fluorescein Angiography; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Green Fluorescent Proteins; Macular Degeneration; Mice; Mice, Inbred C57BL; Photoreceptor Cells, Vertebrate; Retina; Retinal Detachment; Retinal Pigment Epithelium; Reverse Transcriptase Polymerase Chain Reaction; Rhodopsin

PURPOSE. Retinal degeneration initiated by loss of photoreceptors is the prevalent cause of visual impairment and blindness in industrialized countries. Transplantation of photoreceptor cells represents a possible replacement strategy. This study determined that identification of cell surface antigens can assist in enriching photoreceptor precursors for transplantation. METHODS. The expression profile of rod photoreceptors at postnatal day 4 was investigated by microarray analysis to identify photoreceptor-specific cell surface antigens. For enrichment of transplantable photoreceptors, neonatal retinas from rod photoreceptor-specific reporter mice were dissociated, and the rods were purified by magnetic associated cell sorting (MACS) with CD73 antibodies. MAC-sorted cell fractions were transplanted into the subretinal space of adult wild-type mice. The number of rod photoreceptors contained in unsorted, CD73-negative, and CD73-positive cell fractions were quantified in vitro and after grafting in vivo. RESULTS. Microarray analysis revealed that CD73 is a marker for rod photoreceptors. CD73-based MACS resulted in enrichment of rods to 87%. Furthermore, in comparison with unsorted cell fractions, CD73-positive MAC-sorted cells showed an approximately three-fold increase in the number of integrated, outer segment-forming photoreceptors after transplantation. CONCLUSIONS. CD73-based MACS is a reliable method for the enrichment of integrating photoreceptors. Purification via cell surface markers represents a new tool for the separation of transplantable photoreceptor precursors from a heterogeneous cell population, avoiding the need of reporter gene expression in target cells.

Topics: 5'-Nucleotidase; Animals; Animals, Newborn; Basic-Leucine Zipper Transcription Factors; Biomarkers; Cell Culture Techniques; Cell Lineage; Cell Tracking; Cell Transplantation; Eye Proteins; Flow Cytometry; Fluorescent Antibody Technique, Indirect; Gene Expression Profiling; Green Fluorescent Proteins; Immunomagnetic Separation; Mice; Mice, Inbred C57BL; Mice, Transgenic; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Retinal Detachment; Retinal Rod Photoreceptor Cells; Rhodopsin; Stem Cell Transplantation

This study compared the effects of intraocular injections of ranibizumab (RBZ) and bevacizumab (BVZ) in transgenic mouse models in which human vascular endothelial growth factor (VEGF) causes subretinal neovascularization (NV) or exudative retinal detachment.. Randomized trials in animal models.. Transgenic mice in which the rhodopsin promoter drives expression of human VEGF in photoreceptors (rho/VEGF mice) and double transgenic mice with doxycycline-inducible expression of human VEGF in photoreceptors (Tet/opsin/VEGF mice).. Rho/VEGF mice received intraocular injections of RBZ, BVZ, or vehicle, and after various time periods the area of subretinal NV was measured. Tet/opsin/VEGF mice were given an intraocular injection of RBZ, BVZ, or vehicle, and after 5 days of doxycycline treatment the presence or absence of retinal detachment was determined.. Area of subretinal NV per retina in rho/VEGF mice and the occurrence of retinal detachment in Tet/opsin/VEGF mice.. In rho/VEGF mice, intraocular injections of RBZ or BVZ strongly suppressed subretinal NV, but the duration of effect was greater for BVZ. Three injections of 10 microg of BVZ over the course of 2 weeks not only suppressed subretinal NV in the injected eye but also caused significant suppression in the fellow eye, indicating a systemic effect. In doxycycline-treated Tet/opsin/VEGF mice, intraocular injection of 10 microg of BVZ significantly reduced the incidence of exudative retinal detachment compared with injection of 10 microg of RBZ. Injection of 25 microg of BVZ reduced the incidence of retinal detachment in both eyes.. Intraocular injections of RBZ and BVZ had similar efficacy in rho/VEGF mice, but the duration of effect was greater for BVZ. In Tet/opsin/VEGF mice, in which expression levels of human VEGF are very high and the phenotype is severe, BVZ showed greater efficacy than RBZ. In both models, higher doses or repeated injections of BVZ, but not RBZ, resulted in a systemic effect. These data suggest that BVZ is not inferior to RBZ for treatment of subretinal NV in mice and is superior in a severe model. The systemic effects of BVZ after intraocular injection deserve further study and consideration of their potential consequences.. Proprietary or commercial disclosure may be found after the references.

Topics: Angiogenesis Inhibitors; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Bevacizumab; Doxycycline; Gene Expression Regulation; Injections; Mice; Mice, Transgenic; Microscopy, Fluorescence; Ranibizumab; Retinal Detachment; Retinal Neovascularization; Rhodopsin; Vascular Endothelial Growth Factor A; Vitreous Body

To determine whether systemic minocycline can protect photoreceptors in experimental retinal detachment (RD).. Retinal detachment was induced in mice by subretinal injection of sodium hyaluronate, 1.4%. In 1 experiment, mice received daily injections of minocycline (group 1) or saline (group 2). In a second experiment, mice were treated with minocycline or saline beginning 24 hours prior, immediately after, or 24 hours after experimental RD. In both experiments, photoreceptor cell survival and apoptosis were assessed by immunohistochemistry with primary antibodies against photoreceptor cell markers, rod rhodopsin, and cone opsin, and by terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling.. Photoreceptor cell apoptosis was detected at day 1 after experimental RD, with apoptotic cells peaking in number at day 3 and dropping by day 7. Treatment with minocycline significantly reduced the number of apoptotic photoreceptor cells associated with RD when given 24 hours before or even 24 hours after RD.. Our data suggest that minocycline may be useful in the treatment of photoreceptor degeneration associated with RD, even when given up to 24 hours after RD.. Use of minocycline in patients with macula-off RD may prevent photoreceptor apoptosis and glial cell proliferation, improving final visual outcomes.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Caspase 3; Cell Survival; Disease Models, Animal; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Minocycline; Monocytes; Opsins; Photoreceptor Cells, Vertebrate; Retinal Degeneration; Retinal Detachment; Rhodopsin

To study the neuroprotective effect of experimental retinal detachment (RD) on photoreceptor degeneration in rd1 mice.. RD was produced in the eyes of rd1 mice at postnatal day (P) 9. These eyes were collected and compared to controls without RD. The effects of RD on retinal degeneration were evaluated by histochemical staining of nuclei in the outer nuclear layer (ONL), rod and cone photoreceptors, and retinal vessels at P30 in retinal sections and flatmounts. Apoptotic photoreceptors were detected by TdT-mediated dUTP nick-end labeling (TUNEL) at P15. Mice with or without RD were also reared in darkness and evaluated immunohistochemically at P30.. The numbers of rhodopsin-positive (rod), peanut agglutinin-positive (cone), and diamino-2-phenyl-indol-stained (rod-plus-cone) cells in the ONL were increased by 2.0-fold, 1.3-fold, and 1.2-fold, respectively, in the rd1 eyes with RD compared to those without RD at P30. In the detached retina, the cone photoreceptor inner/outer segment structures and the deep retinal vessels surrounding the inner nuclear layer and the ONL, but not the ganglion cell layer, were preserved. At P15, TUNEL-positive cell numbers in the ONL were significantly reduced in the eyes with RD. Light exposure had no effect on photoreceptor degeneration in the eyes with or without RD.. RD mediates the preservation of cone and rod photoreceptors in the ONL and surrounding vascular structures by reducing the rate of apoptosis of photoreceptors in rd1 mice. Light deprivation does not appear to be one of the mechanisms of photoreceptor protection in the detached retinas in these mice.

Topics: Animals; Animals, Newborn; Apoptosis; Cell Count; Dark Adaptation; In Situ Nick-End Labeling; Light; Mice; Mice, Inbred C3H; Mice, Mutant Strains; Photoreceptor Cells, Vertebrate; Retinal Degeneration; Retinal Detachment; Retinal Vessels; Rhodopsin

Topics: Adult; Child; Eye Abnormalities; Female; Fluorescence; Humans; Lipofuscin; Macula Lutea; Male; Optic Disk; Photography; Photoreceptor Cells, Vertebrate; Pigment Epithelium of Eye; Pyridinium Compounds; Retinal Detachment; Retinoids; Rhodopsin; Tomography, Optical Coherence

To determine whether inhibiting the Fas proapoptosis pathway will result in increased photoreceptor survival after separation of the retina from the retinal pigment epithelium (RPE).. Retina/RPE separation was induced in rat and mouse eyes by the subretinal injection of hyaluronic acid, 1%. Fas-pathway signaling was inhibited by the concomitant injection of a Fas receptor-neutralizing antibody, small inhibitory RNA against the Fas-receptor transcript (siFAS), or the use of the Fas-receptor defective mouse strain LPR. Indices of photoreceptor death included terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining, cell counts, and retinal thickness measurements. Retinas were immunostained with antibodies against rhodopsin and cone opsin to evaluate rod and cone photopigment production, respectively.. Inhibition of Fas signaling using Fas receptor-neutralizing antibody, siFas, or LPR mice resulted in a significant reduction in the number of TUNEL-positive photoreceptor cells as well as in a significant preservation of outer nuclear layer cell counts and thickness as compared with retina/RPE separation in eyes with intact Fas signaling. Fas-pathway inhibition resulted in preservation of both rhodopsin- and cone opsin-positive cells.. Inhibition of the Fas proapoptosis pathway results in significant photoreceptor preservation after retinal separation from the RPE.. Fas-pathway inhibition might serve as a novel mechanism for preserving photoreceptor cells during retinal disease.

Topics: Animals; Antibodies, Blocking; Apoptosis; Cell Count; Cell Survival; fas Receptor; Fluorescent Antibody Technique, Indirect; Immunoblotting; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Photoreceptor Cells, Vertebrate; Rats; Rats, Inbred BN; Retinal Detachment; Reverse Transcriptase Polymerase Chain Reaction; Rhodopsin; RNA; RNA, Small Interfering; Rod Opsins; Signal Transduction

Platelet-derived growth factor-B (PDGF-B) has been implicated in the pathogenesis of proliferative retinopathies and other scarring disorders in the eye. In this study, we sought to test the therapeutic potential of an aptamer that selectively binds PDGF-B, ARC126, and its PEGylated derivative, ARC127. Both ARC126 and ARC127 blocked PDGF-B-induced proliferation of cultured fibroblasts with an IC50 of 4 nM. Pharmacokinetic studies in rabbits showed similar peak vitreous concentrations of approximately 110 microM after intravitreous injection of 1 mg of either ARC126 or ARC127, but the terminal half-life was longer for ARC127 (98 versus 43 h). Efficacy was tested in rho/PDGF-B transgenic mice that express PDGF-B in photoreceptors and develop severe proliferative retinopathy resulting in retinal detachment. Compared to eyes injected with 20 microg of scrambled aptamer in which five of six developed detachments (three total and two partial), eyes injected with ARC126 (no detachment in five of six and one partial detachment), or ARC127 (no detachment in six of six) had significantly fewer retinal detachments. They also showed a significant reduction in epiretinal membrane formation. These data demonstrate that a single intravitreous injection of an aptamer that specifically binds PDGF-B is able to significantly reduce epiretinal membrane formation and retinal detachment in rho/PDGF-B mice. These striking effects in an aggressive model of proliferative retinopathy suggest that ARC126 and ARC127 should be considered for treatment of diseases in which PDGF-B has been implicated, including ischemic retinopathies such as proliferative diabetic retinopathy, proliferative vitreoretinopathy (PVR), and choroidal neovascularization.

Topics: 3T3 Cells; Animals; Aptamers, Nucleotide; Cell Proliferation; Disease Models, Animal; Epiretinal Membrane; Eye; Injections; Mice; Mice, Inbred C57BL; Mice, Transgenic; Proto-Oncogene Proteins c-sis; Rabbits; Retina; Retinal Detachment; Retinal Diseases; Rhodopsin

Transgenic mice with vascular endothelial growth factor (VEGF) driven by the rhodopsin promoter (rho/VEGF mice) develop neovascularization that originates from the deep capillary bed of the retina and grows into the subretinal space. In rho/VEGF mice, VEGF expression in photoreceptors begins between postnatal days 5 and 7, the period when the deep capillary bed is developing. An important question is whether or not the developmental stage of the deep capillary bed is critical for occurrence of neovascularization. Also, although rho/VEGF mice are extremely useful for the study of ocular neovascularization, there are some applications for which the early onset of VEGF expression is a disadvantage. In this study, we used the reverse tetracycline transactivator (rtTA) inducible promoter system coupled to either the rhodopsin or interphotoreceptor retinoid-binding protein (IRBP) promoter to control the time of onset of VEGF transgene expression in photoreceptors. In the absence of doxycycline, adult double-transgenic rho/rtTA-TRE/VEGF or IRBP/rtTA-TRE/VEGF mice showed little VEGF transgene expression and no phenotype. The addition of doxycycline to the drinking water resulted in prominent transgene expression and evidence of neovascularization within 3 to 4 days. Like rho/VEGF mice, the neovascularization originated from the deep capillary bed of the retina, but it was more extensive and caused outer retinal folds followed by total retinal detachment. Real-time polymerase chain reaction and enzyme-linked immunosorbent assay demonstrated that the mice with inducible expression of VEGF that developed retinal detachment had much higher ocular levels of VEGF mRNA and protein compared to rho/VEGF mice that manifest a much milder phenotype. These data demonstrate that regardless of developmental stage of the vascular bed, increased expression of VEGF in the retina is sufficient to cause neovascularization, and high levels of expression cause severe neovascularization and traction retinal detachment. Mice with inducible expression of VEGF in the retina provide a valuable new model of ocular neovascularization.

Topics: Animals; Anti-Bacterial Agents; Doxycycline; Endothelial Growth Factors; Gene Expression Regulation; Humans; Lymphokines; Mice; Mice, Transgenic; Phenotype; Promoter Regions, Genetic; Recombinant Fusion Proteins; Retina; Retinal Detachment; Retinal Neovascularization; Rhodopsin; Statistics as Topic; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

The lectin peanut agglutinin (PNA) and antibodies to short (S)- and medium to long wavelength (M/L)-sensitive cones were utilized in order to define the relative distributions of the two spectral types of cone across the domestic cat's retina. These values, in turn, were compared to those from retinas that had been experimentally detached from the retinal pigment epithelium. The pattern of cone distribution in the normal cat's retina is established by the preponderance of M-cones that constitute between 80% and 90% of all cones. Their peak density of over 26,000 cells/mm(2) resides at the area centralis. Though M-cone density decreases smoothly to the ora serrata where they have densities as low as 2,200 cells/mm(2), the density decrease along the nasotemporal axis is slower,creating a horizontal region of higher cone density. S-cones constitute between 10% and 20% of all cones, the number being quite variable even between individual animals of similar age. The highest S-cone densities are found in three distinct locations: at the superior far periphery near the ora serrata, immediately at the area centralis itself, and in a broad zone comprising the central and lower half of the inferior hemiretina. S-cones in the cat retina do not form a regular geometrical array at any eccentricity. As for the detached cat retina, the density of labeled S-cone outer segments (OS) decreases rapidly as early as 1 day postdetachment and continues decreasing to day 28 when the density of cones labeling with anti-S opsin has dropped to less than 10% of normal. This response points to a profound difference between rods and cones; essentially all rods, including those without OS, continue to express their opsin even in long-term detachments. The implications of these results for visual recovery after retinal reattachment are discussed.

Topics: Animals; Calbindins; Cats; Cell Count; Cell Death; Female; Immunohistochemistry; Nerve Regeneration; Peanut Agglutinin; Recovery of Function; Retinal Cone Photoreceptor Cells; Retinal Detachment; Rhodopsin; Rod Opsins; S100 Calcium Binding Protein G; Vision, Ocular

Results obtained in a previous study showed that, compared with a normal eyecup preparation, the amount of rhodopsin regenerated and the rate at which it was resynthesized after bleaching were reduced by about 50% when the skate retina was detached from its pigment epithelium (RPE) and replaced immediately on the apical surface of the RPE (Sun and Ripps, 1992). In the present study, these observations have been extended to preparations in which the detachment procedure was performed under fluid in order to dilute the IRBP content of the interphotoreceptor matrix. The goal initially was to determine whether lowering the IRBP concentration of the subretinal space affected the regenerative process. Using fundus reflectometry, it was found that allowing fluid to enter the subretinal space exposed by the detachment procedure caused profound deficits in both the rate and amount of rhodopsin that regenerated after bleaching. Results obtained with SDS-PAGE and immunohistochemistry showed that the molecular weight of the IRBP extracted from the skate retina is similar to that of many other vertebrate species, and that antibodies prepared against mammalian IRBP react with epitopes on skate IRBP within the interphotoreceptor matrix. Accordingly, it was investigated whether it is possible to reverse the detachment-induced anomalies in rhodopsin kinetics by introducing ligand-free IRBP purified from bovine retina to the subretinal space. Again using fundus reflectometry, it was found that instilling 5 microM of a 130 microM IRBP solution between the neural retina and the RPE increased significantly the rate of regeneration, and more than doubled the amount of rhodopsin reformed in darkness.

Topics: Adaptation, Ocular; Animals; Electrophoresis, Polyacrylamide Gel; Eye Proteins; Fluorescent Antibody Technique; Immunoblotting; Kinetics; Molecular Weight; Retina; Retinal Detachment; Retinol-Binding Proteins; Rhodopsin; Skates, Fish

Nonrhegmatogenous retinal detachments were formed in the eyes of Dutch rabbits by subretinal injection of Hanks' balanced salt solution. The electroretinogram (ERG) was recorded locally from the acutely detached retina, and simultaneously from the surrounding attached retina (vitreal ERG [VERG]), before and after exposure to diffuse intense irradiation. Light adaptation elevated b-wave threshold for both the local ERG (LERG) and VERG by about 3 log units; thresholds for both responses recovered fully within 60-90 min after the irradiation. The normal time course of dark adaptation of the LERG suggests the occurrence of substantial rhodopsin regeneration in the rod photoreceptors of nonrhegmatogenously detached retina. These results differ from reports that visual pigment regeneration is slow in central serous chorioretinopathy, possibly because our detachments were studied within hours of formation, whereas some photoreceptor degeneration may be present in older clinical detachments.

Topics: Animals; Dark Adaptation; Electroretinography; Light; Photic Stimulation; Photoreceptor Cells; Rabbits; Retinal Detachment; Rhodopsin

We determined the immunoreactive opsin content in the subretinal fluid from 16 patients with rhegmatogenous retinal detachment by enzyme-linked immunosorbent assay. The opsin content decreased, with the duration of the detachment, but there was no correlation between opsin content and the age of the patient or the extent of the retinal detachment.

Topics: Body Fluids; Enzyme-Linked Immunosorbent Assay; Eye Proteins; Humans; Retina; Retinal Detachment; Retinal Perforations; Rhodopsin; Rod Opsins

Patients with acute and chronic central serous retinopathy (CSR) were studied by psychophysical and photochemical means to establish the extent of visual depression and to investigate the basis of rod dysfunction in this disorder. In acute disease with serous detachment of the retina, the loss of sensitivity attains 3 log units and parallels the height of retinal elevation as does its recovery with resolution of the episode. Immediately after resolution, there is a residual 0.5 log unit threshold elevation. In chronic disease, marked loss of function exists over areas of abnormal retinal pigment epithelium in the absence of clinically detectable serous detachment. Although rhodopsin levels are low in both acute and chronic CSR, this relative lack of visual pigment does not totally account for the functional deficits in either situation.

Topics: Fluorescein Angiography; Humans; Photoreceptor Cells; Retina; Retinal Detachment; Retinal Diseases; Retinitis; Rhodopsin; Visual Perception

Topics: Animals; Autoradiography; Biological Transport; Eye Proteins; Humans; Light; Melatonin; Peptides; Phagocytosis; Phagosomes; Photoreceptor Cells; Pigment Epithelium of Eye; Ranidae; Retina; Retinal Detachment; Retinoids; Rhodopsin; Rod Opsins; Rodentia

Topics: Animals; Rabbits; Regeneration; Retinal Detachment; Rhodopsin