Transcription-dependent control of stem cell self-renewal and differentiation by the splicing factor U2AF1
ABSTRACT: Purpose: Here we describe the modulation of a gene expression program involved in cell fate. Methods: We depleted U2AF1 in human induced pluripotent stem cells (hiPSCs) to the level found in differentiated cells using an inducible shRNA system, followed by high-throughput RNAseq, revealing a gene expression program involved in cell fate determination. Results: Approximately 85% of the total raw reads were mapped to the human genome sequence (GRCh37), giving an average of 200 million human reads per sample for total RNA and 15 million human reads per sample for small RNA libraries. Conclusions: Our results show that transcriptional control of gene expression in hiPSCs can be set by the CSF U2AF1, establishing a direct link between transcription and AS during cell fate determination. Overall design: hiPSCs were differentiated into the three germ layers following the described protocol in the study (Gifford et al., 2013).
Project description:In this study, we used CAGE followed by deep sequencing to globally profile the transcript 5’ isoforms in the translatome (i.e., polysome-associated RNA) and transcriptome (i.e., total RNA) of human HEK293 cells at single-nucleotide resolution. After removing low-quality sequencing reads, we obtained approximately 18 million and 14 million CAGE tags respectively for the translatome and transcriptome of HEK293 cells. These tags were then mapped to the human genome (assembly GRCh37) using bowtie with two mismatches allowed. Tags mapped to rRNA were less than 17.9% for translatome and 7.5% for transcriptome, indicating high quality of the two CAGE libraries. By comparing CAGE tags between HEK293's translatome and transcriptome, we revealed selective usage of the TSS-derived 5’ ends by polysome.
Project description:Metazoan development depends on accurate execution of differentiation programs that allow pluripotent stem cells to adopt specific fates. Differentiation is brought about by global changes to chromatin architecture and transcriptional networks, yet whether other regulatory events support cell fate determination is less well understood. Using a human embryonic stem cell model, we identified the vertebrate-specific ubiquitin ligase Cul3KBTBD8 as an essential regulator of neural crest cell formation. Cul3KBTBD8 monoubiquitylates NOLC1 and its paralog TCOF1, whose mutation underlies the developmental disease Treacher Collins Syndrome that is characterized by a loss of cranial neural crest cells. Ubiquitylation of NOLC1 and TCOF1 drives formation of a platform that connects RNA polymerase I with ribosome modification enzymes, thereby altering the translational program of differentiating cells to support the generation of neural crest cells. We conclude that the dynamic regulation of ribosome function is an important feature of cell fate determination. Affymetrix assays were performed according to the manufacturer's directions on total RNA isolated from three independent samples of human embryonic stem cells (hESC) H1 cells or cells that had been differentiated into embryoid bodies for 6 days. Where indicated, hESC cells were transduced with control shRNA or shRNA targeting KBTBD8 prior to mRNA isolation. HUMAN GENE 1.0 ST ARRAY chips were used.
Project description:HiPSCs and human myoblast cells were differentiated into myocytes, and the global gene expression profile were analyzed. Comparison of gene expressions among 8 experiments, 3 were derived from hiPSCs(cell line; 253G1), 1 was derived from hiPSCs(cell line; 253G4), 1 was derived from hiPSCs(cell line; 201B7), 2 were from human myoblast cell line (Hu5/E18) and 1 was undifferentiated hiPSCs.
Project description:Human induced pluripotent stem cells (hiPSCs) constitute an important breakthrough in regenerative medicine, particularly in orthopedics, where more effective treatments are urgently needed. Despite the promise of hiPSCs only limited data on in vitro chondrogenic differentiation of hiPSCs are available. Therefore, we compared the gene expression profile of pluripotent genes in hiPSC-derived chondrocytes (ChiPS) to that of an hiPSC cell line created by our group (GPCCi001-A). Overall design: The feeder-dependent hiPSC cell line (GPCCi001-A) generated by our group were differentiated into chondrocyte-like cells (ChiPS) via monolayer culture. The experiment was performed in triplicate. We performed global gene expression analysis using the Affymetrix platform—to better understand the processes directing cell fate during chondrogenic differentiation in vitro (hiPSC served as a control). This study had three primary aims: 1) to evaluate the similarities between hiPSC-derived chondrocytes (ChiPS) and parental” hiPSCs at the gene level, 2) to assess how the differentiation process changes the expression of essential genes involved in pluripotency; and 3) to determine whether the hiPSC cells maintain their pluripotency state in long term cultures.
Project description:Mutations in the splicing factor gene U2AF1 have been found in the bone marrow of patients with myelodysplastic syndrome and acute myeloid leukemia, as well as in other cancers. To study the effects of mutant U2AF1(S34F) expression on hematopoiesis and pre-mRNA splicing in hematopoietic cells, we generated two inducible transgenic mouse lines expressing either mutant U2AF1(S34F) or U2AF1(wildtype, WT) as control. We performed strand-specific transcriptome sequencing on bone marrow common myeloid progenitor cells from U2AF1(S34F) and U2AF1(WT)-expressing mice to examine the pre-mRNA splicing changes associated with expression of mutant U2AF1(S34F). Donor-derived common myeloid progenitor cells from mice transplanted with U2AF1(S34F)/rtTA or U2AF1(WT)/rtTA bone marrow were sorted by flow cytometry, and RNA was extracted for transcriptome analysis. Ribosomal RNA was depleted prior to strand-specific RNA sequencing (TruSeq stranded library production, followed by 2 x 100bp paired-end sequencing performed on the HiSeq2000 platform from Illumina). Three samples were sequenced per genotype (n=3), and each sample was composed of bone marrow from 4-5 mice pooled. Reads were aligned to the mouse mm9 reference genome using TopHat (version 2.0.8), and we performed all subsequent analyses in R.
Project description:Here we explored how the human macrophage response to tumor necrosis factor (TNF) is regulated by human synovial fibroblasts, the representative stromal cell type in the synovial lining of joints that become activated during inflammatory arthritis. Genome-wide transcriptome analysis (RNAseq) showed that co-cultured synovial fibroblasts modulate the expression of approximately one third of TNF-inducible genes in macrophages, including expression of target genes in pathways important for macrophage survival and polarization towards an alternatively activated phenotype. This work furthers our understanding of the interplay between innate immune and stromal cells during an inflammatory response, one that is particularly relevant to inflammatory arthritis. Our findings also identify modulation of macrophage phenotype as a new function for synovial fibroblasts that may prove to be a contributing factor in arthritis pathogenesis. Human CD14+ MCSF-differentiated macrophages were cultured with or without synovial fibroblasts in transwell chambers. TNF was added at Day 0, macrophages were harvested at Day 2. Total of 4 samples: (1) macrophages alone (2) macrophages with fibroblasts (3) macrophages with TNF (4) macrophages with fibroblasts and TNF. Macrophage RNA was purified using RNeasy mini kit (Qiagen). Tru-seq sample preparation kits (Illumina) were used to purify poly-A transcripts and generate libraries with multiplexed barcode adaptors. All samples passed quality control on a Bioanalyzer 2100 (Agilent). Paired-end reads (50 x 2 cycles, ~75x106 reads per sample) were obtained on an Illumina HiSeq 2500. The TopHat program was used to align the reads to the UCSC Hg19 human reference genome, while the Cufflinks program allowed for measurements of transcript abundance (represented by Fragments Per Kilobase of exon model per Million mapped reads (FPKM)).
Project description:We generated hiPSCs from patients fibloblast with retinitis pigmentosa (RP) using retrovirus and Sendai virus vectors, which we differentiated into hiPSC derived retinal pigment epithelium using two different methods (SDIA and SFEB methods). We investigated whether these hiPSC-RPE colonies, which were differentiated from various cell lines and methods, showed similar gene expression patterns to those of native RPE. We classified hiPSC-RPE, hiPSCs, and fibroblasts from RP patients, hRPE (commercially available human fetal RPE, Lonza) , ARPE19 (a human RPE cell line), and other human tissues from 54,675 probe sets using microarray data.
Project description:Deep high-throughput transcriptome sequencing (RNA-seq) performed on 3 pairs of matched tumor and adjacent non-tumorours (NT) tissues from HCC patients of Chinese origin generated 183.6-million reads that could be aligned. We discovered a number of differentially expressed genes and multiple types of somatic single nucleotide variations (SNVs) in expressed genes. After the removal of the error alignments, high-quality reads were mapped to the human reference sequence (GRCh37/hg19) using three different softwares TopHat, Burrows-Wheeler Aligner (BWA) and CLC Genomics Workbench (CLC). The high-quality variants were identified using VarScan with the following parameters: minimum coverage depth of 10, variation frequency of more than 30% and base quality of more than 15. A total of 568, 545 and 494 potential somatic single nucleotide variants (SNVs), including 94, 89 and 101 coding somatic SNVs (cSNVs), were identified in 3 tumor samples HCC448T, HCC473T and HCC510T, respectively. Validation analysis was carried out for 10 of the intersected cSNVs (all are non-synonymous substitutions) within selected genes of interests with the majority confirmed. Examination of 3 paired human hepatocellular carcinoma and matched non-tumor tissues
Project description:The splicing factor gene, U2AF1, is recurrently mutated in a variety of human cancers, including lung adenocarcinomas. The most frequent U2AF1 mutant, U2AF1 p.Ser34Phe (S34F), induces specific changes in pre-mRNA splicing, but it is unclear how these splicing changes are regulated. We have used genomic editing methods to modify the U2AF1 gene locus in an immortalized human bronchial epithelial cell line (HBEC3kt) and in human lung adenocarcinoma cells with pre-existing U2AF1 alleles, creating a U2AF1 S34F allele in the endogenous locus of HBEC3kts and inactivating U2AF1 S34F alleles in two lung adenocarcinoma cell lines (H441 and HCC78). By comparing global splicing alterations in these isogenic pairs of cell lines, we have identified many splicing alterations that are associated with the U2AF1 S34F mutation. Further, by decreasing the levels of wild-type U2AF1 in the isogenic HBEC3kt cells, we show that the magnitude of mutant-associated splicing is proportional to the ratio of S34F:WT gene products. This observation suggest that wild-type U2AF1 is a negative regulator of splicing alterations induced by U2AF1 S34F. Overall design: mRNA sequencing for the indicated isogenic cell lines using Illunima HiSeq2000 or HiSeq2500, paired-end 101 bp.