Novel Therapeutic Approaches for the Treatment of Retinal Degenerative Diseases: Focus on CRISPR/Cas-Based Gene Editing

Abstract

Inherited retinal diseases encompass a highly heterogenous group of disorders caused by a wide range of genetic variants and with diverse clinical symptoms that converge in the common trait of retinal degeneration. Indeed, mutations in over 270 genes have been associated with some form of retinal degenerative phenotype. Given the immune privileged status of the eye, cell replacement and gene augmentation therapies have been envisioned. While some of these approaches, such as delivery of genes through recombinant adeno-associated viral vectors, have been successfully tested in clinical trials, not all patients will benefit from current advancements due to their underlying genotype or phenotypic traits. Gene editing arises as an alternative therapeutic strategy seeking to correct mutations at the endogenous locus and rescue normal gene expression. Hence, gene editing technologies can in principle be tailored for treating retinal degeneration. Here we provide an overview of the different gene editing strategies that are being developed to overcome the challenges imposed by the post-mitotic nature of retinal cell types. We further discuss their advantages and drawbacks as well as the hurdles for their implementation in treating retinal diseases, which include the broad range of mutations and, in some instances, the size of the affected genes. Although therapeutic gene editing is at an early stage of development, it has the potential of enriching the portfolio of personalized molecular medicines directed at treating genetic diseases.

Towards application of CRISPR-Cas12a in the design of modern viral DNA detection tools (Review)

“…CRISPR-Cas systems for nucleic acid detection have been critically discussed by Li et al [54], Zhang et al [156], Doudna et al [141], Gallego et al [157], Gootenberg et al [158], Bonini et al [159], Collins et al [160], Wang et al [161] and other authors [145,[162][163][164][165][166][167][168][169][170][171][172][173][174][175][176]. Here, we review the main powerful, sensitive analytical methods of CRISPR-Cas: (i) fluorescence in situ hybridization (DNA-FISH) assay based CRISPR-Cas9 technique for specific targeting with SYBR green I as a fluorescent probe (detection limit 10 CFU/ml); (ii) CRISPR-Cas triggered isothermal exponential amplification reaction (CAS-EXPAR) based CRISPR-Cas9 technique and isothermal exponential amplification with SYBR green as a fluorescent probe for a large number of DNA generation and target DNA detection at attomole (aM) sensitivity; (iii) CRISPR rolling circular amplification (CRISPR-RCA) assay based CRISPR-Cas9 technique and rolling circle amplification with SYBR green as a fluorescent probe for a large number of DNA generation, amplification;…”

Prime Editing for Inherited Retinal Diseases

“…For a detailed overview, Gallego et al . discuss CRISPR/Cas-based gene editing approaches for IRDs ( Gallego et al, 2020 ).…”

CRISPR-Cas and Its Wide-Ranging Applications: From Human Genome Editing to Environmental Implications, Technical Limitations, Hazards and Bioethical Issues

“…Early research seeking treatment for neurodegenerative diseases has shown that CRISPR can even be used in combination with other elements, e.g., nonpathogenic viruses, to help improve target specificity on any genomic sequences [ 105 , 106 ]. CRISPR-Cas9 may also be pooled with multiple guide RNAs, allowing the editing of multiple genes in one step.…”