A CRISPR and high-content imaging assay compliant with ACMG/AMP guidelines for clinical variant interpretation in ciliopathies
HUMAN GENETICS
Authors: Nazlamova, Liliya; Thomas, N. Simon; Cheung, Man-Kim; Legebeke, Jelmer; Lord, Jenny; Pengelly, Reuben J.; Tapper, William J.; Wheway, Gabrielle
Abstract
Ciliopathies are a broad range of inherited developmental and degenerative diseases associated with structural or functional defects in motile or primary non-motile cilia. There are around 200 known ciliopathy disease genes and whilst genetic testing can provide an accurate diagnosis, 24-60% of ciliopathy patients who undergo genetic testing do not receive a genetic diagnosis. This is partly because following current guidelines from the American College of Medical Genetics and the Association for Molecular Pathology, it is difficult to provide a confident clinical diagnosis of disease caused by missense or non-coding variants, which account for more than one-third of cases of disease. Mutations in PRPF31 are the second most common cause of the degenerative retinal ciliopathy autosomal dominant retinitis pigmentosa. Here, we present a high-throughput high-content imaging assay providing quantitative measure of effect of missense variants in PRPF31 which meets the recently published criteria for a baseline standard in vitro test for clinical variant interpretation. This assay utilizes a new PRPF31(+/-) human retinal cell line generated using CRISPR gene editing to provide a stable cell line with significantly fewer cilia in which novel missense variants are expressed and characterised. We show that high-content imaging of cells expressing missense variants in a ciliopathy gene on a null background can allow characterisation of variants according to the cilia phenotype. We hope that this will be a useful tool for clinical characterisation of PRPF31 variants of uncertain significance, and can be extended to variant classification in other ciliopathies.
Energy metabolism as a regulator of ferroptosis
CELL CYCLE
Authors: Ma, Yanhong; Han, Fei; Min, Junxia; Lin, Weiqiang
Abstract
Ferroptosis is a newly identified form of cell death that is regulated by many metabolic pathways, including iron, lipid and amino acids. Recent two studies reveal that the mitochondria and energy stress could also mediate ferroptosis. Gao et al. report that mitochondria play an essential role in ferroptosis induced by cysteine deprivation. In addition, Lee et al. show that energy stress depressed ferroptosis partly through activation of AMP-activated protein kinase. These findings provide potential therapeutic strategies for treating ferroptosis-related diseases, such as cancer, tissue injury and neurodegenerative diseases.