Project description:Retinitis pigmentosa (RP) is an irreversible and inherited retinopathy. RPGR mutations are the most common causes of this disease. It remains challenging to decipher the mechanism of RPGR mutation because of the lack of appropriate study models. The substitution of patient-specific diseased retina without ethical restrictions is desired and iPSC-derived 3D retina is the best choice. In our experiment, we generated iPSCs from one RP patient with 2-bp frameshift mutation in the exon14 of RPGR gene, which were differentiated into retinal organoids. Also we generated iPSCs from a normal control and differentiated those control-iPSCs into healthy retinal organoids. Samples of patient- and control-retinal organoids at W0, W7, W13 (two replicates), W18 (two replicates) and W22 (two replicates for patient) were collected for RNA-seq. Corrected-iPSC were derived from CRISPR/Cas9-mediated gene correction. Then we collected the corrected-iPSC derived retinal organoids at W0, W7, W13 (two replicates), W18 (two replicates) and W22 (two replicates) for RNA-seq. Through the RNA-seq data, we demonstrate that patient-specific iPSC-dervied 3D retinae can recapitulate disease progress of Retinitis Pigmentosa through presenting defects in photoreceptors' gene profile. CRISPR/Cas9-mediated gene correction can rescue photoreceptor gene profile. Those transcriptome are consistent with the phenotype and function.
Project description:Mutations in LMNA, encoding Lamin A/C, lead to a variety of diseases known as laminopathies that include dilated cardiomyopathy (DCM). The role of epigenetic mechanisms. such as DNA methylation, has not been thoroughly investigated. Furthermore, the impact of patient-specific LMNA mutations on DNA methylation is unknown. To explore the role of DNA methylation in the context of unique LMNA mutations, we performed reduced representation bisulfite sequencing (RRBS) on ten pairs of fibroblasts and their induced pluripotent stem cell (iPSC) derivatives from two families with DCM due to distinct LMNA mutations. Family-specific differentially methylated regions (DMRs) were identified by comparing the DNA methylation landscape of patient and control samples. Fibroblast DMRs were found to enrich for distal regulatory features and transcriptionally repressed chromatin and to associate with genes related to phenotypes found in laminopathies. These DMRs, in combination with transcriptome-wide expression data and Lamina-associated domain (LAD) organization, revealed the presence of inter-family epimutation hotspots near differentially expressed genes, most of which were located near redistributed LADs. Comparison of DMRs found in fibroblasts and iPSCs identified regions where epimutations were persistent across both cell types. Finally, a network of disease-associated genes dysregulated in LMNA mutated cells was uncovered, potentially due to aberrant methylation changes. In conclusion, the use of in vitro culture models of patient-derived cells and differential methylation analysis enabled the identification of epimutation hotspots and dysregulated genes, consistent with a Lamin A/C mutation-specific epigenetic disease mechanism that arose in somatic and early-developmental cell stages.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:We performed transcriptomic profiling of patient induced pluripotent stem cell (iPSC)-derived iAEC2s containing E690K and W308R ABCA3 mutations as well as their syngeneic, gene-corrected iAEC2s (total of four iPSC-derived iAEC2 lines). We first reprogrammed iPSCs from 2 patients with two homozyguos ABCA3 mutations (E690K and W308R ABCA3 mutations). Next we utilized TALENs gene-editing technique previously published in Jacob et al. (2017) to monoallelically target the endogenous SFTPC locus with the tdTomato reporter, allowing for sorting and isolation of SFTPCtdTomato positive iAEC2s. Finally, we used CRISPR-Cas9 footprint-free gene-correction to generate syngeneic patient iPSCs which were dfferentiated into the corresponding iAEC2s for syngeneic comparisons. Following tripplicate differentiations of all 4 patient iPSC lines, we sorted the SFTPCtdTomato+ iAEC2s on day 43-44 of differentiation for transcriptomic analyses.
Project description:Nucleotide repeat expansion disorders, a group of genetic diseases characterized by the expansion of specific DNA sequences, pose significant challenges to treatment and therapy development. Here, we present a precise and programmable method called prime editor–mediated correction of nucleotide repeat expansion (PE-CORE) for correcting pathogenic nucleotide repeat expansion. PE-CORE leverages a prime editor and paired pegRNAs to achieve targeted correction of repeat sequences. We demonstrate the effectiveness of PE-CORE in HEK293T cells and patient-derived induced pluripotent stem cells (iPSCs). Specifically, we focus on spinal and bulbar muscular atrophy and spinocerebellar ataxia type, two diseases associated with nucleotide repeat expansion. Our results demonstrate the successful correction of pathogenic expansions in iPSCs and subsequent differentiation into motor neurons. Specifically, we detect distinct downshifts in the size of both the mRNA and protein, confirming the functional correction of the iPSC-derived motor neurons. These findings highlight PE-CORE as a precision tool for addressing the intricate challenges of nucleotide repeat expansion disorders, paving the way for targeted therapies and potential clinical applications.
Project description:Fibroblasts from a Fanconi anemia (FA) patient (FA-52) before and after correction by gene editing and transduction with a lentiviral vector expressing telomerase (geFA-52T fibroblasts). IPCs were generated from fibroblasts corrected by gene editing using STEMCCA LV (geFA-52T IPSCs clone 16) and finally the reprogramming cassette was excised (excised geFA-52T IPSCs clone 16.1) Four groups: Fibroblasts from a FA patient (FA-52) before and after correction by gene editing and transduction with a lentiviral vector expressing telomerase (geFA-52T) and gene editied IPSCs before and after excision of the reprogramming cassette (geFA-52T IPSCs clone 16 and excised geFA-52T IPSCs clone 16.1)