Retinal gene therapy using epiretinal AAV-containing fibrin hydrogel implants.

Subretinal injection of adeno-associated virus (AAV) is generally more efficacious and less inflammatory than intravitreal injection for retinal gene therapy. However, adverse events (e.g.

Retinal Viral Gene Therapy: Impact of Route of Administration on Serious Adverse Events-A Systematic Review.

Background: To explore the prevalence of serious adverse events (SAEs) associated with retinal viral gene therapy and to examine trends influencing SAE occurrences in human gene therapy surgeries and pre-clinical animal trials.

Methods: Literature review was performed to identify peer-reviewed human and animal studies relevant to viral gene therapy, subretinal injections, and intravitreal injections. For clinical trials and post-approval LUXTURNA studies, only those that examined SAEs were included.

Detection of Residual iPSCs Following Differentiation of iPSC-Derived Retinal Pigment Epithelial Cells.

The goal of this study was to develop a lot release assay for iPSC residuals following directed differentiation of iPSCs to retinal pigment epithelial (RPE) cells. RNA Sequencing (RNA Seq) of iPSCs and RPE derived from them was used to identify pluripotency markers downregulated in RPE cells. Quantitative real time PCR (qPCR) was then applied to assess iPSC residuals in iPSC-derived RPE.

Early Choriocapillaris Loss in a Porcine Model of RPE Cell Debridement Precedes Pathology That Simulates Advanced Macular Degeneration.

Purpose: No large-mammal surgical models exist for geographic atrophy (GA), choroidal neovascularization (CNV), and pachychoroidal vascular remodeling. Our goal was to develop a porcine RPE debridement model of advanced macular degeneration to study photoreceptor cell loss and choroidal remodeling.

Methods: Seven 2-month-old female domestic pigs were used for this study.

Direct early growth response-1 knockdown decreases melanoma viability independent of mitogen-activated extracellular signal-related kinase inhibition.

To investigate downstream molecular changes caused by mitogen-activated protein kinase (MEK) inhibitor treatment and further explore the impact of direct knockdown of early growth response-1 ( EGR1 ) in melanoma cell culture. RNA-sequencing (RNA-Seq) was performed to determine gene expression changes with MEK inhibitor treatment. Treatment with MEK inhibitor (trametinib) was then assessed in two cutaneous (MEL888, MEL624) and one conjunctival (YUARGE 13-3064) melanoma cell line.

Carbonic Anhydrase Inhibitor Modulation of Intraocular Pressure Is Independent of Soluble Adenylyl Cyclase.

We investigated whether a clinically used carbonic anhydrase inhibitor (CAIs) can modulate intraocular pressure (IOP) through soluble adenylyl cyclase (sAC) signaling. IOP was measured 1 h after topical treatment with brinzolamide, a topically applied and clinically used CAIs, using direct cannulation of the anterior chamber in sAC knockout (KO) mice or C57BL/6J mice in the presence or absence of the sAC inhibitor (TDI-10229). Mice treated with the sAC inhibitor TDI-10229 had elevated IOP.

Methodological Approach to Improve Surgical Outcomes of a Pig Subretinal Implantation Model.

Purpose: To improve outcomes for subretinal implantation surgery in pigs.

Methods: Analysis of variables affecting the success of subretinal implantation surgery was performed on videos of 37 surgeries. Ex vivo experiments were conducted to measure intraocular pressure (IOP) and test various prototyped implanters for effectiveness at maintaining IOP.

Alteration of fibrin hydrogel gelation and degradation kinetics through addition of azo dyes.

Fibrin is a degradable biopolymer with an excellent clinical safety profile. Use of higher mechanical strength fibrin hydrogels is limited by the rapid rate of fibrin polymerization. We recently demonstrated the use of higher mechanical strength (fibrinogen concentrations >30 mg/ml) fibrin scaffolds for surgical implantation of cells.

Visual Acuity and Foveal Structure in Eyes with Fragmented Foveal Avascular Zones.

Purpose: To assess the frequency and impact of abnormal foveal avascular zone (FAZ) topography (i.e., a fragmented FAZ) on visual acuity and foveal anatomic features.

Fibrin hydrogels are safe, degradable scaffolds for sub-retinal implantation.

Retinal pigment epithelium (RPE) transplantation for the treatment of macular degeneration has been studied for over 30 years. Human clinical trials have demonstrated that RPE monolayers exhibit improved cellular engraftment and survival compared to single cell suspensions. The use of a scaffold facilitates implantation of a flat, wrinkle-free, precisely placed monolayer.

Stanniocalcin-1 is a Modifier of Oxygen-Induced Retinopathy Severity.

: Abnormal activation of signaling pathways related to angiogenesis, inflammation, and oxidative stress has been implicated in the pathophysiology of retinopathy of prematurity (ROP), a leading cause of blindness in pre-term infants. Therapies for ROP include laser and anti-vascular endothelial growth factor agents. However, these therapies have side effects, and even with adequate treatment, visual acuity can be impaired.

Human Fibrinogen for Maintenance and Differentiation of Induced Pluripotent Stem Cells in Two Dimensions and Three Dimensions.

Human fibrin hydrogels are a popular choice for use as a biomaterial within tissue engineered constructs because they are biocompatible, nonxenogenic, autologous use compatible, and biodegradable. We have recently demonstrated the ability to culture induced pluripotent stem cell (iPSC)-derived retinal pigment epithelium on fibrin hydrogels. However, iPSCs themselves have relatively few substrate options (e.

ADULT-ONSET VITELLIFORM MACULAR DYSTROPHY SECONDARY TO A NOVEL IMPG2 GENE VARIANT.

Purpose: To report a case of adult-onset vitelliform macular dystrophy in a patient who was found to have a previously unreported variant of the IMPG2 gene.

Methods: Case report.

Results: A 65-year-old white woman with no significant medical or ocular history presented with a complaint of persistent wavy vision for 10 months.

A novel missense mutation in BEST1 associated with an autosomal-dominant vitreoretinochoroidopathy (ADVIRC) phenotype.

Background: To report a 68-year-old female with an autosomal-dominant vitreoretinochoroidopathy (ADVIRC) phenotype associated with a subretinal hemorrhage (SRH) and novel BEST1 pathogenic variation p.Met571Thr.

Materials And Methods: The patient was assessed by fundus photography, fluorescence and indocyanine green angiography, spectral-domain optical coherence tomography, photopic and scotopic electroretinogram (ERG), and electrooculogram (EOG).

Mutant Best1 Expression and Impaired Phagocytosis in an iPSC Model of Autosomal Recessive Bestrophinopathy.

Autosomal recessive bestrophinopathy (ARB) is caused by mutations in the gene BEST1 which encodes bestrophin 1 (Best1), an anion channel expressed in retinal pigment epithelial (RPE) cells. It has been hypothesized that ARB represents the human null phenotype for BEST1 and that this occurs due to nonsense mediated decay (NMD). To test this hypothesis, we generated induced pluripotent stem cells (iPSCs) from a patient with ARB and her parents.

Disease modeling studies using induced pluripotent stem cells: are we using enough controls?

The comparison of differentiated induced pluripotent stem cells (iPSCs) derived from patients with disease to differentiated iPSCs derived from healthy patients enables powerful disease modeling. By performing an informal retrospective survey of disease modeling studies published in high impact journals, we found that the median and average number of controls used in these studies were 1 and 1.6, respectively.

Fibrin hydrogels as a xenofree and rapidly degradable support for transplantation of retinal pigment epithelium monolayers.

Unlabelled: Recent phase 1 trials of embryonic stem cell and induced pluripotent stem cell (iPSCs) derived RPE transplants for the treatment of macular degeneration have demonstrated the relative safety of this process. However, there is concern over clumping, thickening, folding, and wrinkling of the transplanted RPE. To deliver a flat RPE monolayer, current phase 1 trials are testing synthetic substrates for RPE transplantation.

Differential Intraocular Pressure Measurements by Tonometry and Direct Cannulation After Treatment with Soluble Adenylyl Cyclase Inhibitors.

Purpose: To validate the increase in intraocular pressure (IOP) caused by soluble adenylyl cyclase (sAC) inhibitors and determine reasons behind variation in IOP measurements performed by tonometry.

Methods: C57BL/6J mice were administered DMSO solubilized sAC inhibitors (KH7 or LRE-1) by intraperitoneal injection. Two hours post-treatment, mice were anesthetized with avertin or ketamine/xylazine/acepromazine (KXA).

Mutant Fibulin-3 Causes Proteoglycan Accumulation and Impaired Diffusion Across Bruch's Membrane.

Purpose: The mutation R345W in EFEMP1 (fibulin-3) causes macular degeneration. This study sought to determine whether proteoglycan content and diffusion across Bruch's membrane are altered in Efemp1ki/ki mice carrying this mutation or in Efemp1-/- mice.

Methods: Proteoglycans in mouse Bruch's membranes were stained with Cupromeronic Blue (CB).

Early AMD-like defects in the RPE and retinal degeneration in aged mice with RPE-specific deletion of or .

Purpose: To examine the effects of autophagy deficiency induced by RPE-specific deletion of or in mice as a function of age.

Methods: Conditional knockout mice with a floxed allele of or were crossed with inducible transgenic mice. -directed RPE-specific Cre recombinase expression was induced with doxycycline feeding in the resulting mice.

Deletion of Efemp1 Is Protective Against the Development of Sub-RPE Deposits in Mouse Eyes.

Purpose: EFEMP1 (fibulin-3) is mutated in Malattia Leventinese/Doyne's honeycomb retinal dystrophy (ML/DHRD), an inherited macular dystrophy similar to AMD. Both ML/DHRD and AMD are characterized by the presence of sub-RPE deposits. Efemp1 knockout mice do not develop sub-RPE deposits.

Bestrophin 1 and retinal disease.

Mutations in the gene BEST1 are causally associated with as many as five clinically distinct retinal degenerative diseases, which are collectively referred to as the "bestrophinopathies". These five associated diseases are: Best vitelliform macular dystrophy, autosomal recessive bestrophinopathy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy, and retinitis pigmentosa. The most common of these is Best vitelliform macular dystrophy.

Histopathologic Findings in the Areas of Orange Pigment Overlying Choroidal Melanomas.

Purpose: Orange pigment is an important sign of malignancy in melanocytic tumors. There is a question as to whether the pigment accumulation is inside of macrophages or retinal pigment epithelial (RPE) cells. We investigated which cells are involved with this color alteration.