scholarly journals Bestrophinopathies: perspectives on clinical disease, Bestrophin-1 function and developing therapies

2021 ◽  
Vol 13 ◽  
pp. 251584142199719
Author(s):  
Simranjeet Singh Grewal ◽  
Joseph J. Smith ◽  
Amanda-Jayne F. Carr
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Induced Pluripotent Stem Cell ◽  
Underlying Disease ◽  
Incomplete Penetrance ◽  
Inherited Retinal Dystrophies ◽  
Retinal Dystrophies ◽  
High Acuity ◽  
Induced Pluripotent

Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that typically affect the macular region, an area synonymous with central high acuity vision. This spectrum of disorders is caused by mutations in bestrophin1 ( BEST1), a protein thought to act as a Ca2+-activated Cl- channel in the retinal pigment epithelium (RPE) of the eye. Although bestrophinopathies are rare, over 250 individual pathological mutations have been identified in the BEST1 gene, with many reported to have various clinical expressivity and incomplete penetrance. With no current clinical treatments available for patients with bestrophinopathies, understanding the role of BEST1 in cells and the pathological pathways underlying disease has become a priority. Induced pluripotent stem cell (iPSC) technology is helping to uncover disease mechanisms and develop treatments for RPE diseases, like bestrophinopathies. Here, we provide a comprehensive review of the pathophysiology of bestrophinopathies and highlight how patient-derived iPSC-RPE are being used to test new genomic therapies in vitro.

scholarly journals Compromised Barrier Function in Human Induced Pluripotent Stem-Cell-Derived Retinal Pigment Epithelial Cells from Type 2 Diabetic Patients

2019 ◽  
Vol 20 (15) ◽  
pp. 3773 ◽  
Author(s):  
Mostafa Kiamehr ◽  
Alexa Klettner ◽  
Elisabeth Richert ◽  
Ali Koskela ◽  
Arto Koistinen ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Induced Pluripotent Stem Cell ◽  
Diabetic Patients ◽  
Rpe Cells ◽  
Normal Glucose ◽  
Healthy Control ◽  
Induced Pluripotent ◽  
Type 2 Diabetic

In diabetic patients, high blood glucose induces alterations in retinal function and can lead to visual impairment due to diabetic retinopathy. In immortalized retinal pigment epithelial (RPE) cultures, high glucose concentrations are shown to lead to impairment in epithelial barrier properties. For the first time, the induced pluripotent stem-cell-derived retinal pigment epithelium (hiPSC-RPE) cell lines derived from type 2 diabetics and healthy control patients were utilized to assess the effects of glucose concentration on the cellular functionality. We show that both type 2 diabetic and healthy control hiPSC-RPE lines differentiate and mature well, both in high and normal glucose concentrations, express RPE specific genes, secrete pigment epithelium derived factor, and form a polarized cell layer. Here, type 2 diabetic hiPSC-RPE cells had a decreased barrier function compared to controls. Added insulin increased the epithelial cell layer tightness in normal glucose concentrations, and the effect was more evident in type 2 diabetics than in healthy control hiPSC-RPE cells. In addition, the preliminary functionality assessments showed that type 2 diabetic hiPSC-RPE cells had attenuated autophagy detected via ubiquitin-binding protein p62/Sequestosome-1 (p62/SQSTM1) accumulation, and lowered pro- matrix metalloproteinase 2 (proMMP2) as well as increased pro-MMP9 secretion. These results suggest that the cellular ability to tolerate stress is possibly decreased in type 2 diabetic RPE cells.

scholarly journals Expression of Pro-Angiogenic Markers Is Enhanced by Blue Light in Human RPE Cells

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1154 ◽  
Author(s):  
Concetta Scimone ◽  
Simona Alibrandi ◽  
Sergio Zaccaria Scalinci ◽  
Edoardo Trovato Battagliola ◽  
Rosalia D’Angelo ◽  
...  
Keyword(s):  
Blue Light ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
R Package ◽  
Rpe Cells ◽  
Inherited Retinal Dystrophies ◽  
Retinal Dystrophies ◽  
Increased Risk ◽  
Angiogenic Markers

Inherited retinal dystrophies are characterized by photoreceptor death. Oxidative stress usually occurs, increasing vision loss, and oxidative damage is often reported in retinitis pigmentosa (RP). More than 300 genes have been reported as RP causing. In contrast, choroidal neovascularization (CNV) only occasionally develops in the late stages of RP. We herein study the regulation of RP causative genes that are likely linked to CNV onset under oxidative conditions. We studied how the endogenous adduct N-retinylidene-N-retinylethanolamine (A2E) affects the expression of angiogenic markers in human retinal pigment epithelium (H-RPE) cells and a possible correlation with RP-causing genes. H-RPE cells were exposed to A2E and blue light for 3 and 6h. By transcriptome analysis, genes differentially expressed between A2E-treated cells and untreated ones were detected. The quantification of differential gene expression was performed by the Limma R package. Enrichment pathway analysis by the FunRich tool and gene prioritization by ToppGene allowed us to identify dysregulated genes involved in angiogenesis and linked to RP development. Two RP causative genes, AHR and ROM1, can be associated with an increased risk of CNV development. Genetic analysis of RP patients affected by CNV will confirm this hypothesis.

scholarly journals Reduction of lipid accumulation rescues Bietti’s crystalline dystrophy phenotypes

2018 ◽  
Vol 115 (15) ◽  
pp. 3936-3941 ◽  
Author(s):  
Masayuki Hata ◽  
Hanako O. Ikeda ◽  
Sachiko Iwai ◽  
Yuto Iida ◽  
Norimoto Gotoh ◽  
...  
Keyword(s):  
Free Cholesterol ◽  
Cell Damage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Patient Specific ◽  
Rpe Cells ◽  
Underlying Mechanisms ◽  
Induced Pluripotent ◽  
Bietti's Crystalline Dystrophy

Bietti’s crystalline dystrophy (BCD) is an intractable and progressive chorioretinal degenerative disease caused by mutations in the CYP4V2 gene, resulting in blindness in most patients. Although we and others have shown that retinal pigment epithelium (RPE) cells are primarily impaired in patients with BCD, the underlying mechanisms of RPE cell damage are still unclear because we lack access to appropriate disease models and to lesion-affected cells from patients with BCD. Here, we generated human RPE cells from induced pluripotent stem cells (iPSCs) derived from patients with BCD carrying a CYP4V2 mutation and successfully established an in vitro model of BCD, i.e., BCD patient-specific iPSC-RPE cells. In this model, RPE cells showed degenerative changes of vacuolated cytoplasm similar to those in postmortem specimens from patients with BCD. BCD iPSC-RPE cells exhibited lysosomal dysfunction and impairment of autophagy flux, followed by cell death. Lipidomic analyses revealed the accumulation of glucosylceramide and free cholesterol in BCD-affected cells. Notably, we found that reducing free cholesterol by cyclodextrins or δ-tocopherol in RPE cells rescued BCD phenotypes, whereas glucosylceramide reduction did not affect the BCD phenotype. Our data provide evidence that reducing intracellular free cholesterol may have therapeutic efficacy in patients with BCD.

scholarly journals Small-molecule–directed, efficient generation of retinal pigment epithelium from human pluripotent stem cells

2015 ◽  
Vol 112 (35) ◽  
pp. 10950-10955 ◽  
Author(s):  
Julien Maruotti ◽  
Srinivas R. Sripathi ◽  
Kapil Bharti ◽  
John Fuller ◽  
Karl J. Wahlin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Small Molecule ◽  
Pluripotent Stem Cells ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Induced Pluripotent Stem Cell ◽  
Human Pluripotent Stem Cells ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Induced Pluripotent

Age-related macular degeneration (AMD) is associated with dysfunction and death of retinal pigment epithelial (RPE) cells. Cell-based approaches using RPE-like cells derived from human pluripotent stem cells (hPSCs) are being developed for AMD treatment. However, most efficient RPE differentiation protocols rely on complex, stepwise treatments and addition of growth factors, whereas small-molecule–only approaches developed to date display reduced yields. To identify new compounds that promote RPE differentiation, we developed and performed a high-throughput quantitative PCR screen complemented by a novel orthogonal human induced pluripotent stem cell (hiPSC)-based RPE reporter assay. Chetomin, an inhibitor of hypoxia-inducible factors, was found to strongly increase RPE differentiation; combination with nicotinamide resulted in conversion of over one-half of the differentiating cells into RPE. Single passage of the whole culture yielded a highly pure hPSC-RPE cell population that displayed many of the morphological, molecular, and functional characteristics of native RPE.

Sign in / Sign up

Export Citation Format

Share Document