Patient-Specific iPSC-Derived RPE for Modeling of Retinal Diseases

Inherited retinal diseases, such as age-related macular degeneration and retinitis pigmentosa, are the leading cause of blindness in the developed world. Currently, treatments for these conditions are limited. Recently, considerable attention has been given to the possibility of using patient-specific induced pluripotent stem cells (iPSCs) as a treatment for these conditions. iPSCs reprogrammed from adult somatic cells offer the possibility of generating patient-specific cell lines in vitro. In this review, we will discuss the current literature pertaining to iPSC modeling of retinal disease, gene therapy of iPSC-derived retinal pigmented epithelium (RPE) cells, and retinal transplantation. We will focus on the use of iPSCs created from patients with inherited eye diseases for testing the efficacy of gene or drug-based therapies, elucidating previously unknown mechanisms and pathways of disease, and as a source of autologous cells for cell replacement.

Association of age-related macular degeneration with polymorphisms in vascular endothelial growth factor and its receptor

OBJECTIVE

To analyze the association between age-related macular degeneration (AMD) and polymorphisms in vascular endothelial growth factor (VEGF) and VEGF receptor KDR gene polymorphisms. A complex, multifactorial disease in which genetic and environmental factors interact, AMD is the leading cause of blindness in the elderly. Vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, is considered an important factor for the pathogenetic processes of AMD. Previous studies investigated the possible association between VEGF-A gene polymorphisms and AMD, with contrasting data. No study examined the possible role of VEGF receptor KDR gene polymorphisms.

DESIGN

Case-control study.

PARTICIPANTS AND CONTROLS

We enrolled 226 AMD cases and 248 controls from an ophthalmology hospital center.

METHODS

Genotypying for 16 polymorphic markers (single nucleotide polymorphisms [SNPs]) in VEGF-A and KDR genes.

MAIN OUTCOME MEASURES

Distribution of genotypes in AMD cases and controls.

RESULTS

Two polymorphisms (rs833069 in intron 2 of the VEGF-A gene, rs2071559 in the promoter of the KDR gene) were significantly associated with risk of AMD. In particular, for VEGF-A rs833069 the AMD risk was increased >5-fold for G homozygotes compared with homozygous carriage of the A allele. For KDR rs2071559 the AMD risk was increased >3-fold for T homozygotes compared with homozygous carriage of the C allele. Carriers of risk alleles for both markers have a >6-fold increased risk of AMD with respect to carriers of non-risk alleles.

CONCLUSIONS

We expand previous data on the association of AMD with VEGF-A gene variations and identify for the first time an association with variations in the KDR gene. Because the SNP-604T-bearing KDR promoter has higher transcription activity, our findings further support the role of the VEGF pathway in the pathophysiology of AMD. It is possible that applications of haplotype/genotype analysis in these genes will play a role in risk assessment and pharmacogenomic approaches to AMD diagnosis and management.