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.
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.
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.
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.
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.