Project description:<p>Gene expression is a biological process regulated at different molecular levels, including chromatin accessibility, transcription, and RNA maturation and transport. In addition, these regulatory mechanisms have strong links with cellular metabolism. Here we present a multi-omics dataset that captures different aspects of this multi-layered process in yeast. We obtained RNA-seq, metabolomics, and H4K12Ac ChIP-seq data for wild-type and mip6delta strains during a heat-shock time course. Mip6 is an RNA-binding protein that contributes to RNA export during environmental stress and is informative of the contribution of post-transcriptional regulation to control cellular adaptations to environmental changes. The experiment was performed in quadruplicate, and the different omics measurements were obtained from the same biological samples, which facilitates the integration and analysis of data using covariance-based methods. We validate our dataset by showing that ChIP-seq, RNA-seq and metabolomics signals recapitulate existing knowledge about the response of ribosomal genes and the contribution of trehalose metabolism to heat stress.</p>
Project description:To identify direct NFIB target genes in HFSCs, we performed chromatin immunoprecipitation and deep sequencing (ChIP-seq) analysis using FACS-isolated HFSCs. Two independent NFIB ChIP-seq experiments were conducted.
Project description:Hereditary Leiomyomatosis and renal cell cancer is caused by fumarate hydratase loss of heterozygosity and subsequence accumulation of fumarate. Fumarate is known to activate the anti-oxidant response and is key for cellular survival. Fumarate succinates KEAP1 which releases NRF2 to activate the antioxidant response. The role of fumarate on the global regulatory chromatin landscape is less understood. Here, by integrating chromatin accessibility and histone ChIP-seq profiles, we identify complex transcription factor networks involved in the highly remodelled chromatin landscape of FH-deficient cells. We implicate FOXA2 in the maintenance of FH-deficient cells by regulating anti-oxidant response genes and subsequent metabolic output, independent of NRF2. These results identify new redox and amino acid metabolism regulators and provide new avenues for therapeutic intervention.
Project description:SARS-CoV-2 induces widespread transcriptomic changes in host cells upon infection, in part through activation and modulation of innate immunity pathways and downstream gene regulation. However, the mechanisms by which SARS-CoV-2 and its evolutionary variants differentially affect host cell transcriptomic states remain largely unclear. Through chromatin proteomic (iDAPT-MS) analysis, we found that although SARS-CoV-2 and other pathogenic coronaviruses exhibit similar proteomic shifts on chromatin, SARS-CoV-2 uniquely promotes TP53 nuclear accumulation and activation. Parallel assessment of SARS-CoV-2 viral protein expression on host chromatin states (ATAC-seq) identifies intracellular spike protein as a key determinant of virus-mediated chromatin accessibility changes. Multilevel chromatin profiling reveals increased TP53 nuclear accumulation, TP53-associated chromatin accessibility changes, and TP53 target gene activation upon expression of SARS-CoV-2 alpha (B.1.1.7) and delta (B.1.617.2) spike variants relative to the ancestral spike sequence. TP53, ACE2, and furin cleavage are required for these changes, driving decreased cellular proliferation, increased cellular senescence, and increased cytokine release. Finally, BA.1 but not BA.2, BA.2.12.1, nor BA.4/BA.5 spike expression leads to attenuated TP53 activity and fusogenicity relative to ancestral spike. Our findings implicate spike-mediated host TP53 activation as a “rheostat” of COVID-19 pathogenicity.
Project description:The mechanisms underlying cancer metastasis remain poorly understood. Here, we report that TFAM deficiency rapidly and stably induced spontaneous lung metastasis in mice with liver cancer. Interestingly, unexpected polymerization of nuclear actin was observed in TFAM-knockdown HCC cells when cytoskeleton was examined. Polymerization of nuclear actin is causally linked to the high-metastatic ability of HCC cells by modulating chromatin accessibility and coordinating the expression of genes associated with extracellular matrix remodeling, angiogenesis, and cell migration. Mechanistically, TFAM deficiency blocked the TCA cycle and increased the intracellular malonyl-CoA levels. Malonylation of mDia2, which drives actin assembly, promotes its nuclear translocation. Importantly, inhibition of malonyl-CoA production or nuclear actin polymerization significantly impeded the spread of HCC cells in mice. Moreover, TFAM was significantly downregulated in metastatic HCC tissues and was associated with overall survival and time to tumor recurrence of HCC patients. Taken together, our study connects mitochondria to the metastasis of human cancer via uncovered mitochondria-to-nucleus retrograde signaling, indicating that TFAM may serve as an effective target to block HCC metastasis.
Project description:Tissue homeostasis and regeneration rely upon resident stem cells (SCs), whose behavior is regulated through niche-dependent crosstalk. The mechanisms underlying SC maintenance are still unfolding. Here, using hair follicles (HFs) as model and spatiotemporal gene ablation in mice, we uncover transcription factors (TFs) NFIB and NFIX as guardians of the process. Complete NFI ablation causes SC depletion and hair loss which resembles irreversible alopecia in humans, who intriguingly also display reduced NFI. Through single cell transcriptomics, ATAC- and ChIP-seq profiling, we uncover a key role for NFIB/NFIX in governing chromatin accessibility of HFSC master TFs . When NFIB/NFIX are genetically removed, the stemness epigenetic landscape is lost, as enhancers driving HFSC identity are decommissioned and those of epidermal differentiation and wound-repair are de-repressed. Together, our findings expose NFIB/NFIX as crucial rheostats of tissue homeostasis, functioning to safeguard the SC epigenome from a breach in lineage confinement that otherwise triggers irreversible tissue degeneration.