Project description:Previously we found that human pluripotent stem cells (hPSCs) utilize glucose differently depending on the presence of the feeder cells, which are mouse embryonic fibroblasts, or MEFs. More specifically, feeder-free cultured hPSCs are more reliant on glycolysis for proliferation. Therefore, we hypothesized that secreted factors by MEFs might be responsible for reprogramming the metabolism of hPSCs. To test this hypothesis, we separated the components in the MEF-conditioned medium by using size-based fractionation columns, and tested whether each fraction alters the reliance of feeder-free hPSCs on glucose. We concluded that it was the protein fraction of the MEF-conditioned medium potentially responsible for reprogramming glycolytic metabolism in hPSCs. To further understand which specific protein(s) could alter the metabolism of hPSCs, we here conduct mass spectrometry based proteomics experiment.
Project description:We performed bulk mRNA sequencing of either control or Zfp266 KO mouse embryonic fibroblasts (MEFs), intermediate reprogramming populations, iPSCs and ESCs. We reveal enhanced and early upregulation of pluripotent and ESC associated genes in Zfp266 KO reprogramming populations.
Project description:Fibroblasts can be reprogrammed into cardiomyocyte-like cells by overexpressing transcription factors, GATA4, Hand2, Mef2C and Tbx5 (GHMT). A83-01, an inhibitor of ALK4, ALK5 and ALK7 and two microRNA, miR-1 and miR-133 increase the efficiency of cardiac reprogramming. RNA_Seq was performed to anyalyze effects of these factors on gene expression. Total RNAs were prepared from mouse embryonic fibroblasts (MEFs); Reprogramming fibroblasts including MEFs transduced with retroviruses encoding GHMT, MEFs transduced with with retroviruses encoding GHMT plus miR-1 and miR-133 (GHMT2m), MEFs transduced with with retroviruses encoding GHMT2m treated with A83-01, at day 7 after viral transduction; and neonatal mouse cardiomyocytes (NMCMs).
Project description:Tet-mediated DNA oxidation is a new type of epigenetic modification in mammals and its role in the regulation of cell fate transition remains poorly understood. Here, we derive mouse embryonic fibroblasts (MEFs) deleted in all three Tet genes and examine their capability to be reprogrammed into iPS cells. We demonstrate that these Tet-deficient MEFs cannot be reprogrammed due to a blockage in the mesenchymal-to-epithelial transition (MET). Reprogramming of MEFs deficient in TDG is similarly blocked. The blockage is caused by impaired activation of crucial microRNAs, which depends on oxidative demethylation promoted by Tet and TDG. Reintroduction of either miR-200c or catalytically active Tet and TDG restores reprogramming to the respective knockout MEFs. Thus, oxidative demethylation is essential for somatic cell reprogramming. These findings provide mechanistic insights into the operation of epigenetic barriers in cell lineage conversion. Reduced Representation Bisulfite (RRBS, MspI,~75-400bp size fraction) and Tet-Assisted RRBS (TARRBS) of MEFs & reprogramming MEFs at Day 5
Project description:During reprogramming of fibroblasts into cardiomyocyte-like cells by overexpression of transcription factors, GATA4, Hand2, Mef2C and Tbx5 (GHMT), H3K4Me2, an active histone code, shifts from fibroblast-exclusive peaks to cardiomyocyte-exclusive peaks. Important cardiac genes are gradually marked by this active histone marker. Mouse embryonic fibroblasts (MEFs) and neonatal mouse ventricular cardiomyocytes (NMVMs) represent fibroblasts and cardiomyocytes, respectively. Chromatins harvested from MEFs infected with retroviruses carrying GHMT at day 3, day 5, day 7 post-viral infection were prepared for immunoprecipitation.
Project description:Gene expression in mouse embryonic fibroblasts (MEFS) during adaptation to cell culture conditions was analysed, and revealed rapid reprogramming of the transcription in culture.
Project description:Fibroblasts can be directly reprogrammed to induced renal tubular epithelial cells (iRECs) using four transcription factors. These engineered cells may be used for disease modeling, cell replacement therapy or drug and toxicity testing. Direct reprogramming induces drastic changes in the transcriptional landscape, protein expression, morphological and functional properties of cells. However, how the metabolome is changed by reprogramming and to what degree it resembles the target cell type remains unknown. Using untargeted gas chromatography-mass spectrometry (GC-MS) and targeted liquid chromatography-MS, we characterized the metabolome of mouse embryonic fibroblasts (MEFs), iRECs, mIMCD-3 cells, and whole kidneys. Metabolic fingerprinting can distinguish each cell type reliably, revealing iRECs are most similar to mIMCD-3 cells and clearly separate from MEFs used for reprogramming. Treatment with the cytotoxic drug cisplatin induced typical changes in the metabolic profile of iRECs commonly occurring in acute renal injury. Interestingly, metabolites in the medium of iRECs, but not of mIMCD-3 cells or fibroblast could distinguish treated and non-treated cells by cluster analysis. In conclusion, direct reprogramming of fibroblasts into renal tubular epithelial cells strongly influences the metabolome of engineered cells, suggesting that metabolic profiling may aid in establishing iRECs as in vitro models for nephrotoxicity testing in the future.
Project description:AIM: To detect differences in transcriptional profiles after knocking down Brca1, Bard1 or Wdr5, compared to a negative control in early reprogramming to pluripotency. DESCRIPTION: RNA-seq profiles of early reprogramming mouse embryonic fibroblasts (MEFs) transduced with lentivirus containing doxycycline-inducible OSKM factors to induce pluripotency . Before starting reprogramming, OSKM-MEFs were transfected with different siRNAs and then they were reprogrammed for 3 or 6 days.