Project description:Here, human induced pluripotent stem cells (control-hiPSCs, CMT1A-hiPSCs, and PMP22-hiPSCs) were induced to differentiate to Schwann cells (control-SCs, CMT1A-SCs, and PMP22-SCs) through neural crest stage (control-NCSCs, CMT1A-NCSCs, and PMP22-NCSCs). We sequenced mRNA samples from Schwann cell differentiation of human pluripotent stem cells at 3 different stage to generate the gene expression profiles of these cells.
Project description:We obtained skin fibroblasts from CMT1A and control patients, and generated hiPSCs which were subsequently differentiated into cd49d+ human Schwann cells. We utilized microarray technology to explore the gene expression profiles of cd49d+ Schwann cells CMT1A hiPSCs, control hiPSCs, and control human embryonic stem cells in order to identify potentially disregulated pathways contributing to CMT1A pathogenesis. Patient-specific human induced pluripotent stem cells (hiPSCs) hold great promise for disease modeling of genetic disorders. Often the findings from hiPSC-based studies are validated with genetically-corrected hiPSCs generated by precise genome editing technologies, however, alternatives that have not yet been employed are validation with embryonic stem cells harboring the same disease mutation or utilizing another reprogramming approach from somatic cells of same patients. Here we report that disease-relevant phenotypes found in Charcot-Marie-Tooth 1A (CMT1A)-hiPSC-derived Schwann cells were further confirmed by two additional congruent CMT1A models as an alternative to gene correction. We have devised a defined and relatively fast protocol for the direct derivation and prospective isolation of Schwann cells from hiPSCs, leading us to uncover a phenotype of dysregulated immune signaling in CMT1A-hiPSCs-Schwann cells. Our study illustrates the promise of applying hiPSC technology to one of the most common hereditary neuropathies for gaining new insights into human disease pathogenesis and treatment, and these results demonstrate the feasibility of verifying disease phenotypes by utilizing the malleability of cellular fates.
Project description:Establishing robust models of human myelinating Schwann cells is critical for studying peripheral nerve injury and disease. Stem cell differentiation has emerged as a key model of human cells and disease motivating development of Schwann cell differentiation protocols. Human embryonic stem cells (hESCs) are considered the ideal pluripotent cell but ethical concerns regarding their use have propelled the popularity of human induced pluripotent stem cells (hiPSCs). Given that the equivalence of hESCs and hiPSCs remains controversial, we sought to compare the molecular and functional equivalence of hESC- and hiPSC-derived Schwann cells generated with our previously reported protocol. We identified only modest transcriptome differences by RNA sequencing and insignificant proteome differences by antibody array. Additionally, both cell types comparably improved nerve regeneration and function in a chronic denervation and regeneration animal model. Our findings demonstrate that Schwann cells derived from hESCs and hiPSCs with our protocol are molecularly comparable and functionally equivalent.
Project description:<p>Variability in induced pluripotent stem cell (iPSC) lines remains a roadblock for disease modeling and regenerative medicine. Through linear mixed models we have described different sources of gene expression variability from RNA sequencing data in 317 human iPSC lines from 101 individuals. We found that ~50% of genome-wide expression variability is explained by variation across individuals and identified a set of expression quantitative trait loci that contribute to this variation. These analyses coupled with allele specific expression show that iPSCs retain a subject-specific gene expression pattern. Pathway enrichment and key driver analyses, based on predictive causal gene networks, found that Polycomb targets explain a significant part of the non-genetic variability present in iPSCs within and across individuals. These publically available iPSC lines and genetic datasets will be a resource to the scientific community and will open new avenues to reduce variability in iPSCs and improve their utility in disease modeling.</p> <p>SNP array data from individuals included in RNA-seq transcriptome profiling study of human induced pluripotent stem cells to characterize gene expression variation across individuals and within multiple iPSC lines from the same individual. Genotyping was performed on patient blood.</p> Data availability: <ul> <li>SNP-genotyping: dbGaP - current study</li> <li>RNA-seq counts: <a href="http://www.ncbi.nlm.nih.gov/geo/">GEO</a> - GSE79636</li> <li>FASTQ files: <a href="http://www.ncbi.nlm.nih.gov/sra">SRA</a> - SRP072417</li> </ul>
Project description:There are a total of four samples each for this analysis. Each sample consists of the cells grown on three 10 cm culture plates. Each plate should have 2x106 cells for a total of 6x106 cells per sample when all three plates are combined. The first sample is undifferentiated human embryonic stem cells, the second sample is human glutamatergic neurons derived from those human embryonic stem cells, the third sample is undifferentiated human induced pluripotent stem cells and the fourth sample is human glutamatergic neurons derived from those human induced pluripotent stem cells.
Project description:Three CMT1A patient Schwann cell populations which were derived from hESC, hiPSC, or direct converted hiNC share the disease relevant phenotypes. From comparing deep sequencing results of these populations, potential therapeutic targets were newly identified.
Project description:Objective: To investigate transplantation of rat Schwann cells or human iPSC-derived neural crest cells and derivatives into models of acquired and inherited peripheral myelin damage. Methods: Primary cultured rat Schwann cells labeled with a fluorescent protein for monitoring at various times after transplantation. Human induced pluripotent stem cells (iPSCs) were differentiated into neural crest stem cells (NCSC), and subsequently toward a Schwann cell lineage via two different protocols. Protocol 1 = treated with MesenPRO with Heregulin. Protocol 2 = coculture with iPSC-derived Motor Neurons. Cell types were characterized using flow cytometry, immunocytochemistry and transcriptomics. Rat Schwann cells and human iPSC-derivatives were transplanted into (i) nude rats pretreated with lysolecithin to induce demyelination or (ii) a transgenic rat model of dysmyelination due to PMP22 overexpression. Results: Rat Schwann cells transplanted into sciatic nerves with either toxic demyelination or genetic dysmyelination engrafted successfully, and migrated longitudinally for relatively long distances, with more limited axial migration. Transplanted Schwann cells engaged existing axons and displaced dysfunctional Schwann cells to form normal appearing myelin. Human iPSC-derived neural crest stem cells and their derivatives shared similar engraftment and migration characteristics to rat Schwann cells after transplantation, but did not further differentiate into Schwann cells or form myelin. Interpretation: These results indicate that cultured Schwann cells surgically delivered to peripheral nerve can engraft and form myelin in either acquired or inherited myelin injury, as proof of concept for pursuing cell therapy for diseases of peripheral nerve. However, lack of reliable technology for generating human iPSC-derived Schwann cells for transplantation therapy remains a barrier in the field.