Injury to Cone Synapses by Retinal Detachment: Differences from Rod Synapses and Protection by ROCK Inhibition.

Attachment of a detached retina does not always restore vision to pre-injury levels, even if the attachment is anatomically successful. The problem is due in part to long-term damage to photoreceptor synapses. Previously, we reported on damage to rod synapses and synaptic protection using a Rho kinase (ROCK) inhibitor (AR13503) after retinal detachment (RD).

Concise Review: Update on Retinal Pigment Epithelium Transplantation for Age-Related Macular Degeneration.

Retinal cell therapy can have the objectives of rescue (i.e., modulation of metabolic abnormalities primarily for sight preservation) as well as replacement (i.

Fasudil, a Clinically Used ROCK Inhibitor, Stabilizes Rod Photoreceptor Synapses after Retinal Detachment.

Purpose: Retinal detachment disrupts the rod-bipolar synapse in the outer plexiform layer by retraction of rod axons. We showed that breakage is due to RhoA activation whereas inhibition of Rho kinase (ROCK), using Y27632, reduces synaptic damage. We test whether the ROCK inhibitor fasudil, used for other clinical applications, can prevent synaptic injury after detachment.

RhoA Signaling and Synaptic Damage Occur Within Hours in a Live Pig Model of CNS Injury, Retinal Detachment.

Purpose: The RhoA pathway is activated after retinal injury. However, the time of onset and consequences of activation are unknown in vivo. Based on in vitro studies we focused on a period 2 hours after retinal detachment, in pig, an animal whose retina is holangiotic and contains cones.

Two Bioactive Molecular Weight Fractions of a Conditioned Medium Enhance RPE Cell Survival on Age-Related Macular Degeneration and Aged Bruch's Membrane.

Purpose: To characterize molecular weight fractions of bovine corneal endothelial cell conditioned medium (CM) supporting retinal pigment epithelium (RPE) cell survival on aged and age-related macular degeneration (AMD) Bruch's membrane.

Methods: CM was subject to size separation using centrifugal filters. Retentate and filtrate fractions were tested for bioactivity by analyzing RPE survival on submacular Bruch's membrane of aged and AMD donor eyes and behavior on collagen I-coated tissue culture wells.

Biochemical restoration of aged human Bruch's membrane: experimental studies to improve retinal pigment epithelium transplant survival and differentiation.

Suspensions of human embryonic stem cell-derived retinal pigment epithelium (hES-RPE) and human fetal RPE resurface aged and age-related macular degeneration (AMD) Bruch's membrane to a limited degree at day 21 in organ culture. Survival and differentiation of hES-RPE and human fetal RPE on aged or AMD Bruch's membrane are enhanced greatly (200%) if a biologically synthesized extracellular matrix (bovine corneal endothelial cell extracellular matrix) is laid down on Bruch's membrane prior to transplantation. Transplanted RPE survival is enhanced even more (400-1,000%) if Bruch's membrane is treated with bovine corneal endothelial cell-conditioned medium during organ culture of hES-RPE or fetal RPE on aged or AMD Bruch's membrane.

Characterization of the effects of retinal pigment epithelium-conditioned media on porcine and aged human retina.

Background: Retinal pigment epithelium (RPE) cells produce neurotrophic factors that rescue photoreceptors from degeneration. Previously, we showed that conditioned medium (CM) from fetal vs adult RPE cells resulted in significantly better porcine retinal preservation, and possessed significantly higher levels of hepatocyte growth factor (HGF) and pigment epithelium-derived factor (PEDF). This study aimed to further describe the effects of human fetal RPE-CM on porcine and aged human retina, and to characterize its effects biochemically.

A method to enhance cell survival on Bruch's membrane in eyes affected by age and age-related macular degeneration.

Purpose: To determine whether conditioned medium (CM) derived from bovine corneal endothelial cells (BCECs) can support transplanted cells on aged and age-related macular degeneration (AMD) Bruch's membrane (BM).

Methods: Retinal pigment epithelium (RPE) cells derived from human embryonic stem cells (hES-RPE) and cultured fetal and aged adult RPE were seeded onto the inner collagenous layer of submacular BM-choroid-sclera explants generated from aged and AMD human donor eyes. Paired explants were cultured in BCEC-CM or CM vehicle.

Characterization of conditioned media collected from cultured adult versus fetal retinal pigment epithelial cells.

Purpose: To characterize trophic factor secretion of cultured adult and fetal retinal pigment epithelial (RPE) cells and to assess the impact on porcine retinal survival in vitro.

Methods: Conditioned media (CM) were collected from cultured adult and fetal RPE cells and analyzed for trophic factor composition and concentration by multiplex ELISA. Trophic factor receptor occupancy was calculated to evaluate the potential biological effectiveness of the differences in trophic factor concentrations.

Cell-deposited matrix improves retinal pigment epithelium survival on aged submacular human Bruch's membrane.

Purpose: To determine whether resurfacing submacular human Bruch's membrane with a cell-deposited extracellular matrix (ECM) improves retinal pigment epithelial (RPE) survival.

Methods: Bovine corneal endothelial (BCE) cells were seeded onto the inner collagenous layer of submacular Bruch's membrane explants of human donor eyes to allow ECM deposition. Control explants from fellow eyes were cultured in medium only.

Characterization of conditioned media collected from aged versus young human eye cups.

Purpose: To characterize secretion of in situ retinal pigment epithelium (RPE) from healthy, aged adult, age-related macular degeneration (AMD) adult, and fetal donor eyes and to assess the impact on retinal survival in vitro.

Methods: Conditioned medium (CM) was collected from adult and fetal donor eyes and analyzed for trophic factor composition by multiplex ELISA. Trophic factor receptor occupancy was calculated to evaluate differences in trophic factor concentrations.

Influence of fatty liver on plasma small, dense LDL- cholesterol in subjects with and without metabolic syndrome.

Aim: Small, dense low density lipoprotein (sLDL) is known as an atherogenic lipoprotein and is often associated with metabolic syndrome (MS). A high frequency of sLDL is found in hypertriglyceridemic subjects. Also, fatty liver (FL) is often associated with MS; therefore, we studied whether the association of FL increases sLDL- cholesterol (C) in subjects with MS.

Culture-induced increase in alpha integrin subunit expression in retinal pigment epithelium is important for improved resurfacing of aged human Bruch's membrane.

The purpose of this study was to examine the change in integrin expression in adult human retinal pigment epithelium (RPE) after culturing and to characterize the role of integrins in RPE adhesion to aged submacular human Bruch's membrane. Expression of alpha integrin subunits 1 through 6 in adult RPE cells, cultured or uncultured, was examined by reverse transcription/real-time polymerase chain reaction (PCR) and Western blotting. RPE was cultured on bovine corneal endothelial cell-secreted extracellular matrix (BCE-ECM).

Migration and proliferation of retinal pigment epithelium on extracellular matrix ligands.

We compared aged adult and fetal retinal pigment epithelium (RPE) migration and proliferation in cell culture. Aged adult RPE resurfaced on dishes coated with human or mouse laminin, human or rat collagen I, human or mouse collagen IV, or human fibronectin. Resurfacing was best on bovine corneal endothelial cell extracellular matrix.

Retinal pigment epithelium resurfacing of aged submacular human Bruch's membrane.

Purpose: To determine whether cultured fetal human retinal pigment epithelium (RPE) cells can attach and differentiate on submacular Bruch's membrane from donors over age 55.

Methods: Differential debridements of Bruch's membrane were performed to expose three different surfaces: the RPE basement membrane, the superficial inner collagenous layer (ICL) directly below the RPE basement membrane, and the deeper ICL. Approximately 3,146 cells/mm2 were seeded onto these Bruch's membrane explants and cultured for 1 or 7 days.

Impaired RPE survival on aged submacular human Bruch's membrane.

Resurfacing of diseased or iatrogenically damaged Bruch's membrane with healthy retinal pigment epithelium (RPE) has been proposed as adjunctive treatment for age-related macular degeneration (AMD). The purpose of this study was to determine whether cultured fetal human RPE cells can attach and differentiate on aged submacular human Bruch's membrane. Bruch's membrane was debrided to expose native RPE basement membrane, the superficial inner collagenous layer directly below the RPE basement membrane, or the deep inner collagenous layer.

Iris pigment epithelium attachment to aged submacular human Bruch's membrane.

Purpose: To determine whether iris pigment epithelium (IPE) cells can attach to aged submacular human Bruch's membrane and to assess whether IPE cells express the integrin subunits that may be necessary to bind to the known extracellular matrix ligands present in Bruch's membrane.

Methods: IPE cells were seeded onto the RPE basement membrane (RPEbm) or inner collagenous layer (ICL) of aged submacular Bruch's membrane as microaggregates or were expanded in culture until enough cells could be obtained for seeding. Cell morphology and the percentage of cell coverage were determined 1 or 7 days after seeding.

Short-term study of retinal pigment epithelium sheet transplants onto Bruch's membrane.

The purpose of this study is to investigate the survival and behaviour of retinal pigment epithelium sheets transplanted onto hydraulically debrided Bruch's membrane. Uncultured retinal pigment epithelium sheets obtained from male cats and sandwiched between two gelatin sheets were transplanted onto the tapetal area of female cats after native retinal pigment epithelium was debrided. For controls, the gelatin carrier was transplanted after debridement.

Age-related macular degeneration and retinal pigment epithelium wound healing.

Choroidal new vessel (CNV) excision may improve vision in patients with age-related macular degeneration (AMD) by eliminating the source of subretinal bleeding and scarring. Visual recovery after CNV excision is usually poor in AMD patients, probably because of removal of the associated retinal pigment epithelium (RPE), coupled with the inability of native RPE at the edge of the dissection bed to resurface the iatrogenic RPE defect. Experiments using in vitro and in vivo RPE wound-healing models have provided insight into the factors that regulate RPE wound healing in situ.

Retinal pigment epithelium wound healing in human Bruch's membrane explants.

Purpose: To compare retinal pigment epithelium (RPE) resurfacing on the RPE basement membrane and inner collagenous layer (ICL) in human submacular Bruch's membrane explants.

Methods: Debridements were created in RPE-choroid-sclera explants (mean donor age 71.91 +/- 7.

Ultrastructural analysis of hydraulic and abrasive retinal pigment epithelial cell debridements.

Differential changes in Bruch's membrane, choriocapillaris, retinal pigment epithelium, retina, and tapetum after hydraulic or abrasive debridement of the retinal pigment epithelium in the cat area centralis were documented by fluorescein angiography, histology, and transmission electron microscopy at 1-hour, 1-day, 3-day, 1-week, or 4-week time points. Abrasive debridement is associated with abnormal fluorescein angiography and incomplete ingrowth of retinal pigment epithelial cells. Transmission electron microscopy shows that abrasive debridement inflicts more long-lasting ultrastructural damage to Bruch's membrane, the choriocapillaris, tapetum, and retina than does hydraulic debridement.

Adeno-associated virus encoding green fluorescent protein as a label for retinal pigment epithelium.

Purpose: To determine whether transduction with adeno-associated virus encoding green fluorescent protein (AAV-GFP) is useful for labeling transplanted retinal pigment epithelial cells (RPE).

Methods: Transduction was performed by infection of confluent or subconfluent cultured feline RPE or by subretinal injection. Cells transduced in vitro were analyzed to determine label stability over time and label conservation with cell division.

Early attachment of uncultured retinal pigment epithelium from aged donors onto Bruch's membrane explants.

Retinal pigment epithelium (RPE) transplantation might replace cells lost as a consequence of choroidal neovascular membrane excision in patients with age-related macular degeneration (AMD). Autologous transplantation of RPE cells harvested from a peripheral biopsy may overcome problems of immune rejection. To study the feasibility of autologous RPE cell transplantation, the authors examined the attachment of freshly harvested RPE cells from aged donors onto Bruch's membrane explants, debrided to (1) remove or (2) preserve the RPE basement membrane.