Project description:Human induced pluripotent stem cells (hIPSCs) represent a unique opportunity for regenerative medicine since they offer the prospect of generating unlimited quantities of cells for autologous transplantation as a novel treatment for a broad range of disorders. However, the use of hIPSCs in the context of genetically inherited human disease will require correction of disease-causing mutations in a manner that is fully compatible with clinical applications. We analyzed hiPSC line and genetically modified derivatives using high-density SNP array to investigate genomic instability associated reprogramming and genetic modification. Primary iPSC lines derived from patients with alpha-1 antitrypsin deficiency were generated. This genetic disorder is caused by homozygous mutation (Glu342Lys) in the SERPINA1 gene. We carried out mutation correction by 2 steps: zinc-finger nuclease-stimuated gene targeting and piggyBac trasnsposon-mediated selection cassette elimination. Parental fibroblast lines, primary iPSC lines and homozygously targeted iPSC lines were subjected to SNP genotyping using Illumina CytoSNP-12 BeadChiP.
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:Asthma is a chronic inflammatory airway disease characterized by airway inflammation and remodeling. The role of 15-oxo-5Z,8Z,11Z,13E-eicosatetraenoic acid (15-oxoETE), a 15-HETE metabolite catalyzed by 15-prostaglandin dehydrogenase (15-PGDH), has been relatively unexplored in asthma. In this study, we used RNA-seq to explore the effect of 15-KETE on the transcriptome of airway epithelial cells, aiming to identify its potential downstream targets and mechanisms of action.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:We model liver phenotypes associated with telomere dysfunction using DC patient-derived iPS cells and isogenic controls with CRISPR/Cas9-mediated homology-directed repair correction of the disease-causing DKC1 mutation. Differentiation of these cells into hepatocyte-like cells or hepatic stellate cells indicates that the parenchymal hepatocytes are primarily affected by telomere dysfunction. We develop an admixed hepatostellate organoid culture model which further reveals that mutant hepatocytes exert dominant effects on hepatic stellate cells regardless of stellate cell genotype. Hepatostellate organoids containing DKC1-mutant hepatocytes exhibit hyperplasia in both the hepatocyte compartment and, remarkably, in stellate cells. Moreover, mutant hepatocytes can induce hallmarks of stellate cell activation independently of stellate cell genotype. Interestingly, mutant hepatostellate organoids also contain off-target PLVAP+ endothelial cells reminiscent of scar-associated endothelium observed in non-DC cirrhosis patients.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes