Efficient Non-integrating and Growth Factors-Free Culture System for Generation of Human Induced Pluripotent Stem Cells via Activation of Glycolysis
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ABSTRACT: we found that a dual-specificity tyrosine phosphorylation-regulated kinase inhibitor ID-8 robustly enhanced human somatic cell reprogramming by upregulation of PDK4 and activation of glycolysis. Furthermore, we identified a novel growth factor-free hiPSC generation system using ID-8/KGN (IK). IK combined with Low-dose bFGF supported the long-term expansion of human pluripotent stem cells. Also, IK-iPSCs showed high pluripotency and normal karyotype. Our studies provide a novel growth factor-free culture system to facilitate generation of hiPSCs for multiple application in regenerative medicine.
Project description:Transfer RNA-derived fragments have specific biological roles. However, it is still not characterized what factors are responsible for generation of 5′-tRHs in certain conditions, such as metabolic disease and maturation of reproductive cells. Here, we report that Inositol-requiring enzyme 1α (IRE1α), a major ER stress sensor protein, cleaves specifically anticodon stem-loop region of tRNAGly(GCC) and produces 5′-tRHs. Using an RNA-seq-based approach, we identified cleavage sites in tRNAGly(GCC), generating 5′-tRHs in KGN cells (human ovarian granulosa cells) in an IRE1α-expression dependent manner. In vitro cleavage analyses further supported that IRE1α generates 5′-tRHs from tRNAGly(GCC) (5′-tRH-GlyGCC) with highly selective target discrimination. The production of 5′-tRH-GlyGCC was promoted upon endoplasmic reticulum (ER) stress, which induced IRE1α expression, in KGN cells as well as other cancer cell lines such as HeLa and HepG. In addition, transfection of synthetic 5′-tRH-GlyGCC mimics promoted survival of KGN and HeLa cells; this effect required expression of HNRNPM and HNRNPH2, which were identified as binding proteins of 5′-tRH-GlyGCC.
Project description:Fibroblast growth factors (FGFs) are essential for maintaining self-renewal in human embryonic stem cells and induced pluripotent stem cells. Recombinant basic FGF (bFGF or FGF2) is conventionally used to culture pluripotent stem cells; however, because of bFGF instability, repeated addition of fresh bFGF into the culture medium is required in order to maintain its concentration. In this study, we demonstrate that a heat-stable chimeric variant of FGF, FGFC, can be successfully used for maintaining human pluripotent stem cells. FGFC is a chimeric protein composed of human FGF1 and FGF2 domains that exhibits higher thermal stability and protease resistance than do both FGF1 and FGF2. Both human embryonic stem cells and induced pluripotent stem cells were maintained in ordinary culture medium containing FGFC instead of FGF2. Comparison of cells grown in FGFC with those grown in conventional FGF2 media, showed no significant differences in terms of the expression of pluripotency markers, global gene expression, karyotype, or differentiation potential into the three germ lineages. We therefore propose FGFC, as an effective alternative to FGF2, for maintenance of human pluripotent stem cells.
Project description:The growth factors and signaling pathways that are essential for the inducing proliferation of chicken PGCs is unclear. We investigated the effect of basic fibroblast growth factor (bFGF) on the survival and proliferation of PGCs under feeder-free conditions. We used microarrays to examine the genes regulated by bFGF treatment in chicken PGCs. Cultured PGCs were collected before and after withdrawal of bFGF for 24 h, and 24 h after bFGF replacement. The RNA was extracted and hybridized on Affymetrix microarrays. Three replicates each.
Project description:Objective: Intellectual disability (ID) is often sporadic, and its complex etiology can make clinical diagnosis difficult. The aims of this study were to detect genomic copy number variations (CNVs) in Chinese patients with ID, and to analyze the correlation between pathogenic CNVs and clinical phenotypes. Methods: After excluding cases of ID caused by chromosomal aneuploidy, metabolic dysfunction, or environmental factors, we enrolled 60 patients with moderate to severe ID. We performed karyotype and single-nucleotide polymorphism (SNP) array analyses for all patients. Finally, we analyzed the relationship between CNVs and phenotype using CNV databases and genotype-phenotype comparisons. Results: Karyotype analysis showed chromosomal terminal abnormalities in five patients and balanced translocations in two patients. Using SNP array analysis for 60 patients, we detected 87 CNVs in 45 patients, which included 16 pathogenic CNVs in 12 patients with a diagnostic yield of 20.0% (12/60). In one patient, we observed 14 regions of homozygosity > 10 Mb to 266 Mb. We detected a large deletion at 16q22.2 or 3q24q25 in each of two patients, in regions that have not previously been associated with specific syndromes. One case carried a 210-kb deletion at 1q21, including only one coding gene, LPPR4, which may be a candidate gene for the ID phenotype. Conclusions: Use of the genome-wide array screening method can improve the detection rate of CNVs, reveal chromosomal abnormalities that have not been well characterized by cytology, and provide a new way to locate genes for patients with the ID phenotype. However, interpretation of CNVs remains a major challenge, which is why we believe that publicly shared data on CNVs and phenotypes can create a rich database of information.
Project description:The growth factors and signaling pathways that are essential for the inducing proliferation of chicken PGCs is unclear. We investigated the effect of basic fibroblast growth factor (bFGF) on the survival and proliferation of PGCs under feeder-free conditions.
Project description:We aimed to clarify the function of YBX2, a germ cell-specific Y-box-binding protein, in endometrial cancer stem cells. Our data demonstrated that expression of YBX2 was essential for a stem cell-like phenotype of endometrial cancer cells. We analyzed enhanced gene expression of IK cells that overexpressed YBX2 (IK-YBX2 cells) by introduction of YBX2 using microarray analysis. The CT45A5 gene was the most upregulated in IK-YBX2 cells, compared with mock cells. Therefore, we focused on CT45A5, which is considered a stemness factor.
Project description:Analysis of KhES-1 and H9 human ES cells in growth factors-dependent (E8) and -independent (AKIT) medium in feeder-free culture condition and KSR/bFGF medium on a feeder-layer. Results provide insight into genetic stability in different culture media/conditions.
Project description:We identified PDK4 as a gene with adaptive transcriptional response to chemical stress. Although PDK4 is an energy resource regulator induced by starvation, expression of other fasting-inducible genes was unaffected, indicating additional physiological role of PDK4 for liver adaptation to the chemical stress. We used microarrays to determine genes with altered transcriptional level by PDK4 overexpression. Mice were infected with Ad-control (empty adenovirus vector) or Ad-PDK4 (PDK4 overexpressing adenovirus vector) at a dose of 10^9 PFU/mouse by tail vein injection. 3 days after the infection, mice were sacrificed for RNA preparation from the liver. Ad-control infected = 4, Ad-PDK4 infected = 3. Specimens from mice of each group were pooled, and 10 ug RNA from each pool was used for cRNA synthesis.
Project description:Human embryonic stem (hES) cells have the capacities to propagate for extended periods and to differentiate into cell types from all three germ layers both in vitro and in vivo. These characteristics of self-renewal and pluripotency enable hES cells having the potential to provide an unlimited supply of different cell types for tissue replacement, drug screening, and functional genomics studies. The hES-T3 cells with normal female karyotype cultured on either mouse embryonic fibroblasts (MEF) in hES medium (containing 4 ng/ml bFGF) (T3MF) or feeder-free Matrigel in MEF-conditioned medium (supplemented with additional 4 ng/ml bFGF) (T3CM) were found to express very similar profiles of mRNAs and microRNAs, indicating that the unlimited self-renewal and pluripotency of hES cells can be maintained by continuing culture on these two conditions. However, the expression profiles, especially microRNAs, of the hES-T3 cells cultured on Matrigel in hES medium supplemented with 4 ng/ml bFGF and 5 ng/ml activin A (T3BA) were found to be different from those of T3MF and T3CM cells. In T3BA cells, four hES cell-specific microRNAs miR-372, miR-302d, miR-367 and miR-200c, as well as three other microRNAs miR-199a, miR-19a and miR-217, were found to be up-regulated, whereas five miRNAs miR-19b, miR-221, miR-222, let-7b and let-7c were down-regulated by activin A. Thirteen abundantly differentially expressed mRNAs, including NR4A2, ERBB4, CXCR4, PCDH9, TMEFF2, CD24 and COX6A1 genes, targeted by seven over-expressed miRNAs were identified by inverse expression levels of these seven microRNAs to their target mRNAs in T3BA and T3CM cells. The NR4A2, ERBB4 and CXCR4 target genes were further found to be regulated by EGF and/or TNF. The 50 abundantly differentially expressed genes targeted by five under-expressed miRNAs were also identified. The abundantly expressed mRNAs in T3BA and T3CM cells were also analyzed for the network and signaling pathways, and roles of activin A in cell proliferation and differentiation were found. These findings will help elucidate the complex signaling network which maintains the self-renewal and pluripotency of hES cells. In this investigation, both miRNA and mRNA expression profiles from human embryonic stem cells grown on MEF feeder (T3MF), feeder-free Matrigel in MEF-conditioned medium (T3CM) and in hES medium (containing 4 ng/ml bFGF) supplemented with 5 ng/ml activin A (T3BA) were quantitatively determined. Several target genes of T3BA and T3CM cells-specific miRNAs were identified. ***This submission represents the mRNA expression component of the study only***