Project description:We report RNA-Seq analysis of the transcriptome of retinas and RPE/choroids from Abca4 knockout, Abca4 L541P;A1038V knockin and control wild type mice in order to better understand changes in gene regulation that could lead to retinal pathology in mice with ABCA4 deficiency/defect. Retinal and RPE/choroidal mRNA profiles of 30-day-old wild type (WT), Abca4-/- and Abca4L541P;A1038V/L541P;A1038V mice were generated by RNA-Seq, using Illumina Hiseq 2500
Project description:This study aims to investigate the impact of ISL1 overexpression on hPSC-derived islet differentiation. hPSCs from four genotypes (WT, ISL1-/-, PDX1-/-, and PAX6-/-) were differentiated to pancreatic progenitors (day 11), transduced with ISL1-IRES2-BFP or BFP control lentivirus, and further differentiated to SC-islet (day 18). The BFP+ cells were isolated by flow cytometry sorting and subjected to RNA-seq to assess transcriptional responses to ISL1 overexpression across different genetic backgrounds.
Project description:We report RNA-Seq analysis of the transcriptome of retinas and RPE/choroids from Abca4 knockout, Abca4 L541P;A1038V knockin and control wild type mice in order to better understand changes in gene regulation that could lead to retinal pathology in mice with ABCA4 deficiency/defect.
Project description:Purpose: Understanding the functional genomics of M.tb (Mycobacterium tuberculosis) and development of novel anti-M.tb drugs and vaccines needs an efficient gene edit tool. The aim of this study was to describe an easy and efficient gene edit tool for functional genomics study of M.tb. Method: A plasmid was designed containing mini CRISPR array and 400bp up and downside homologues DNA sequences from the target gene interposed by EGFP or BFP. This plasmid was transformed into M.tb that guided the endogenous CRISPR system of M.tb to cut the target gene and insert EGFP or BFP through homologues ends joining. The EGFP/BFP insertion was confirmed and the total genomic was extracted from mutated and wild type strains and subjected to High-throughput DNA sequencing. Results: The raw data was filtered by Trimmomatic and the clean reads were mapped to M.tb H37Ra reference genome with bwa 99.94%, and 99.97% genome of wag31 and esxQ deletion strains were covered respectively.
Project description:We report the generation of CRISPR-dCas9 DNA methyltransferases to mediate targeted DNA methylation. Using the dCas9-BFP-DNMT3A and dCas9-BFP-DNMT3B methyltransferases, we have demonstrated that these two methyltransferase can mediate targeted methylation in three human genes tested: uPA, TGFBR3, and CDKN2A in human HEK293T cells. We also showed that these methyltransferases could mediate gene inhibition.
Project description:Advances in stem cell technologies open up new avenues for modelling development and diseases. The success of these pursuits however rely on the use of cells most relevant to those targeted by the disease of interest, for example, midbrain dopaminergic neurons for Parkinson’s disease. In the present study, we report the generation of a human induced pluripotent stem cell (iPSC) line capable of purifying and tracing nascent midbrain dopaminergic progenitors and their differentiated progeny via the expression of a Blue Fluorescent Protein (BFP). This was achieved by CRISPR/Cas9 assisted knock-in of BFP and Cre into the safe harbour locus AAVS1 and an early midbrain dopaminergic lineage marker gene LMX1A, respectively. Immunocytochemical analysis and single cell RNA sequencing of iPSC-derived neural cultures confirms developmental recapitulation of the human fetal midbrain and high quality midbrain cells. By modelling Parkinson’s disease-related drug toxicity using 1-Methyl-4-phenylpyridinium (MPP+), we showed preferential reduction of BFP+ cells, a finding demonstrated independently by cell death assays and single cell transcriptomic analysis of MPP+ treated neural cultures. Together, these results highlight the importance of disease relevant cell type in stem cell modelling.
Project description:Advances in stem cell technologies open up new avenues for modelling development and diseases. The success of these pursuits however rely on the use of cells most relevant to those targeted by the disease of interest, for example, midbrain dopaminergic neurons for Parkinson’s disease. In the present study, we report the generation of a human induced pluripotent stem cell (iPSC) line capable of purifying and tracing nascent midbrain dopaminergic progenitors and their differentiated progeny via the expression of a Blue Fluorescent Protein (BFP). This was achieved by CRISPR/Cas9 assisted knock-in of BFP and Cre into the safe harbour locus AAVS1 and an early midbrain dopaminergic lineage marker gene LMX1A, respectively. Immunocytochemical analysis and single cell RNA sequencing of iPSC-derived neural cultures confirms developmental recapitulation of the human fetal midbrain and high quality midbrain cells. By modelling Parkinson’s disease-related drug toxicity using 1-Methyl-4-phenylpyridinium (MPP+), we showed preferential reduction of BFP+ cells, a finding demonstrated independently by cell death assays and single cell transcriptomic analysis of MPP+ treated neural cultures. Together, these results highlight the importance of disease relevant cell type in stem cell modelling.
Project description:Stargardt retinopathy is an inherited form of macular degeneration caused by mutations in gene ABCA4 and characterized by the accumulation of lipid-rich deposits in the retinal pigment epithelium (RPE), RPE atrophy, and photoreceptor cell death. Inadequate mechanistic insights into pathophysiological changes occurring in Stargardt RPE have contributed to its lacking treatments. Here we show that ABCA4 knockout or Stargardt patient’s induced pluripotent stem cells-derived RPE (STGD1-iRPE) differentiate normally but display intracellular lipid and ceramide deposits reminiscent of the disease phenotype. STGD1-iRPE also shows defective photoreceptor outer segment (POS) processing and reduced cathepsin B activity, indicating higher lysosomal pH. Lipid deposits in STGD1-iRPE are reduced by increasing the activity of ABCA1, a lipid transporter, and ABCA4 ortholog. Overall, our work suggests that ABCA4 is involved in POS and lipid handling in RPE cells and provides guidance for ongoing gene therapy approaches to target both RPE and photoreceptor cells for an effective treatment.
