Project description:An immortalized multipotent otic progenitor (iMOP) cell was generated by transient expression of c-Myc in Sox2-expressing otic progenitor cells. The procedure activated endogenous c-Myc expression in the cells and amplified existing Sox2-dependent transcripts to promote self-renewal. Downregulation of c-Myc expression following growth factor withdrawal resulted in a molecular switch from self-renewal to otic differentiation. ChIP-Seq was accomplished by immunoprecipitating endogenous RNA PolII, c-Myc and Sox2
Project description:An immortalized multipotent otic progenitor (iMOP) cell was generated by transient expression of c-Myc in Sox2-expressing otic progenitor cells. The procedure activated endogenous c-Myc expression in the cells and amplified existing Sox2-dependent transcripts to promote self-renewal. Downregulation of c-Myc expression following growth factor withdrawal resulted in a molecular switch from self-renewal to otic differentiation. Progenitor cells from embryonic inner ear that form otospheres were infected with a c-Myc retrovirus to promote self-renewal
Project description:An immortalized multipotent otic progenitor (iMOP) cell was generated by transient expression of c-Myc in Sox2-expressing otic progenitor cells. The procedure activated endogenous c-Myc expression in the cells and amplified existing Sox2-dependent transcripts to promote self-renewal. Downregulation of c-Myc expression following growth factor withdrawal resulted in a molecular switch from self-renewal to otic differentiation.
Project description:An immortalized multipotent otic progenitor (iMOP) cell was generated by transient expression of c-Myc in Sox2-expressing otic progenitor cells. The procedure activated endogenous c-Myc expression in the cells and amplified existing Sox2-dependent transcripts to promote self-renewal. Downregulation of c-Myc expression following growth factor withdrawal resulted in a molecular switch from self-renewal to otic differentiation.
Project description:Sox2 is a pleiotropic transcription factor that regulates self-renewal and differentiation capacity in different types of stem cells, raising the possibility that it regulates similar transcriptional programs controlling common stemness. Embryonic stem (ES) cells and trophoblast stem (TS) cells are two developmentally related types of stem cells, which originate from distinct lineages of peri-implantation embryos. We have found that Sox2 is a critical regulator of self-renewal in both of two stem cells. Genome-wide analysis of Sox2 target genes using Affymetrix Exon Arrays and chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) unraveled that it regulates distinct transcriptional networks in ES and TS cells. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
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
Project description:Other than in the development of the brain, SOX2 is essential for the long-term self-renewal of neural stem cells (NSCs). The mechanisms of how SOX2 maintains the stemness of NSCs is not yet understood. We have identified Fos as a downstream target of SOX2, and therefore used CUT&RUN to investigate where these transcription factors - and the c-FOS partner c-JUN - interact with the genome. By comparing binding patterns of c-FOS, c-JUN and SOX2, we find that they co-occupate the promoter of the SOCS3 locus, which we also have identified as a gene that rescues SOX2 deletion induced senescence when overexpressed in neurospheres grown from Sox2-deleted mouse NSCs. Taken together, our data provide a basis for elucidating a gene regulatory network necessary for the maintenance of self-renewal in post-embryonic neural stem cells.
Project description:The generation of pancreatic organoids from human pluripotent stem cells represents a major breakthrough for regenerative medicine and the modeling of diseases such as diabetes. However, current approaches remain inefficient due to lengthy multi-step differentiation protocols and limited functional maturity in the organoids. In this study, we overcome these challenges using multi-phase optimization screens to achieve rapid generation of functionally mature pancreatic organoids from a stable endocrine progenitor culture. We conducted stepwise culture condition screens that enabled the stable culture of multiple pancreatic progenitor cell states, including the unprecedented stable propagation of NEUROD1-expressing endocrine progenitor-like cells (EpSCs). Further transcriptomic profiling of EpSC confirmed similarity of that to previously reported endocrine progenitor populations. Using EpSCs, we significantly reduced the number of steps and timing required to generate pancreatic organoids, enabling rapid testing of conditions for organoid maturation. Utilizing this optimized protocol, we further tested conditions to promote pancreatic organoid maturation. We identified that exosome-delivered WNT5B, in combination with RSPO1 (exoW/R), could strongly induce non-canonical WNT/JNK signaling, promoting pancreatic organoid maturation. This combinatorial exosome treatment enhances epithelial organization, reduces immature cell states, and significantly improves glucose responsiveness and insulin secretion. Collectively, our work establishes a robust pancreatic differentiation platform that integrates long-term progenitor expansion with optimized organoid maturation. This system provides a reproducible experimental framework for studying pancreatic development, investigating disease mechanisms, and facilitating future translational applications involving pancreatic organoids.