Project description:Detailed analysis comparing hiPSC lines that were newly generated and compared them to already established hiPSC lines We used microarrays to detail various hiPSC lines to confirm faithful reprogramming. hESCs, hiPSCs and human fibroblasts for RNA extraction and hybridization on Affymetrix arrays.
Project description:In our study, PRDM14 and NFRkB were found to enhance the reprogramming of human fibroblasts to hiPSCs in the presence of OCT4, SOX2, KLF4, with/without c-MYC (OSK/OSKC). To examnie if the obtained hiPSC share similar expression signature with hESC, we conducted the microarray analysis on the hiPSCs, hESCs and fibroblasts. The result showed that all of the examined hiPSCs resembled hESCs, but differed from fibroblasts MRC5. 4 hiPSC lines, 2 hESC lines and 1 type of fibroblasts were analyzed in total. Each sample is done in duplicates.
Project description:It remains controversial whether human induced pluripotent stem cells (hiPSCs) are distinct from human embryonic stem cells (hESCs) in their molecular signatures and differentiation properties. We examined the gene expression and DNA methylation of 49 hiPSC and 10 hESC lines and identified no molecular signatures that distinguished hiPSCs from hESCs. Comparisons of the in vitro directed neural differentiation of 40 hiPSC and four hESC lines showed that most hiPSC clones were comparable to hESCs. However, in seven hiPSC clones, significant amount of undifferentiated cells persisted even after neural differentiation and resulted in teratoma formation when transplantated into mouse brains. These differentiation-defective hiPSC clones were marked by higher expression of several genes, including those expressed from long terminal repeats of human endogenous retroviruses. These data demonstrated that many hiPSC clones are indistinguishable from hESCs, while some defective hiPSC clones need to be eliminated prior to their application for regenerative medicine. Bisulphite converted DNA from 10 hESCs, 49 hiPSCs, 2 hECCs, 6 somatic cells and 3 cancer cell lines were hybridized to the Illumina Infinium 27k Human Methylation Beadchip.
Project description:It remains controversial whether human induced pluripotent stem cells (hiPSCs) are distinct from human embryonic stem cells (hESCs) in their molecular signatures and differentiation properties. We examined the gene expression and DNA methylation of 49 hiPSC and 10 hESC lines and identified no molecular signatures that distinguished hiPSCs from hESCs. Comparisons of the in vitro directed neural differentiation of 40 hiPSC and four hESC lines showed that most hiPSC clones were comparable to hESCs. However, in seven hiPSC clones, significant amount of undifferentiated cells persisted even after neural differentiation and resulted in teratoma formation when transplantated into mouse brains. These differentiation-defective hiPSC clones were marked by higher expression of several genes, including those expressed from long terminal repeats of human endogenous retroviruses. These data demonstrated that many hiPSC clones are indistinguishable from hESCs, while some defective hiPSC clones need to be eliminated prior to their application for regenerative medicine. We extracted total RNA from 10 hESCs, 49 hiPSCs, 2 hECCs, 6 somatic cells and 3 cancer cell lines and hybridized them to Agilent miRNA expression microarrays.
Project description:It remains controversial whether human induced pluripotent stem cells (hiPSCs) are distinct from human embryonic stem cells (hESCs) in their molecular signatures and differentiation properties. We examined the gene expression and DNA methylation of 49 hiPSC and 10 hESC lines and identified no molecular signatures that distinguished hiPSCs from hESCs. Comparisons of the in vitro directed neural differentiation of 40 hiPSC and four hESC lines showed that most hiPSC clones were comparable to hESCs. However, in seven hiPSC clones, significant amount of undifferentiated cells persisted even after neural differentiation and resulted in teratoma formation when transplantated into mouse brains. These differentiation-defective hiPSC clones were marked by higher expression of several genes, including those expressed from long terminal repeats of human endogenous retroviruses. These data demonstrated that many hiPSC clones are indistinguishable from hESCs, while some defective hiPSC clones need to be eliminated prior to their application for regenerative medicine. We extracted total RNA from 10 hESCs, 49 hiPSCs, 2 hECCs, 6 somatic cells and 3 cancer cell lines and hybridized them to Agilent gene expression microarrays.
Project description:Schizophrenia is a debilitating neurological disorder for which no cure exists. Few defining characteristics of schizophrenic neurons have been identified and the molecular mechanisms responsible for schizophrenia are not well understood, in part due to the lack of patient material for study. Human induced pluripotent stem cells (hiPSCs) offer a new strategy for studying schizophrenia. We have created the first cell-based human model of a complex genetic psychiatric disease by generating hiPSCs from schizophrenic patients and subsequently differentiating these cells to hiPSC-derived neurons in vitro. Schizophrenic hiPSC-derived neurons showed diminished neuronal connectivity in conjunction with decreased neurite number, PSD95-protein levels and glutamate receptor expression. Gene expression profiles of schizophrenic hiPSC-derived neurons identified altered expression of many components of the cAMP and WNT signaling pathways. Key cellular and molecular elements of the schizophrenic phenotype were ameliorated following treatment of schizophrenic hiPSC-derived neurons with the antipsychotic loxapine. 3 independent differentiations (biological replicates) for each of four control and four schizophrenic patients were analyzed.
Project description:Cell-based models of many neurological and psychiatric diseases, established by reprogramming patient somatic cells into human induced pluripotent stem cells (hiPSCs), have now been reported. While numerous reports have demonstrated that neuronal cells differentiated from hiPSCs are electrophysiologically active mature neurons, the “age” of these cells relative to cells in the human brain remains unresolved. Comparisons of gene expression profiles of hiPSC-derived neural progenitor cells (NPCs) and neurons to the Allen BrainSpan Atlas indicate that hiPSC neural cells most resemble first trimester neural tissue. Consequently, we posit that hiPSC-derived neural cells may most accurately be used to model the early developmental defects that contribute to disease predisposition rather than the late features of the disease. Though the characteristic symptoms of schizophrenia (SCZD) generally appear late in adolescence, it is now thought to be a neurodevelopmental condition, often predated by a prodromal period that can appear in early childhood. Postmortem studies of SCZD brain tissue typically describe defects in mature neurons, such as reduced neuronal size and spine density in the prefrontal cortex and hippocampus, but abnormalities of neuronal organization, particularly in the cortex, have also been reported. We postulated that defects in cortical organization in SCZD might result from abnormal migration of neural cells. To test this hypothesis, we directly reprogrammed fibroblasts from SCZD patients into hiPSCs and subsequently differentiated these disorder-specific hiPSCs into NPCs. SCZD hiPSC differentiated into forebrain NPCs have altered expression of a number of cellular adhesion genes, reduced WNT signaling and aberrant cellular migration. 3 independent differentiations (biological replicates) for each of four control and four schizophrenic patients were analyzed.