RNA-seq transcriptonal profiling in E13.5 fetal liver erythroid cells from Tfam WT and KO mice
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ABSTRACT: The developing erythroid cells require highly coordinated gene expression and metabolism. By comparing the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells (HSPCs) and lineage-committed erythroid progenitors (ProEs), and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. To determine the role of TFAM in mitochondrial function during erythroid development, we generated Tfam conditional knockout (KO) mice by an erythroid-specific EpoR-Cre allele. We isolated the CD71+Ter119+ embryonic day (E)13.5 fetal liver erythroid cells by FACS sorting, and performed RNA-seq transcriptional profiling analysis.
Project description:The developing erythroid cells require highly coordinated gene expression and metabolism. By comparing the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells (HSPCs) and lineage-committed erythroid progenitors (ProEs), and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. To determine the role of TFAM and PHB2 in mitochondrial function during erythroid development, we employed shRNA-mediated depeltion of TFAM and PHB2 expression in differentiating erythroid cells, and performed RNA-seq transcriptional profiling analysis.
Project description:The developing erythroid cells require highly coordinated gene expression and metabolism. By comparing the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells (HSPCs) and lineage-committed erythroid progenitors (ProEs), and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. Depletion of TFAM in erythroid cells alters intracellular metabolism, leading to elevated histone acetylation, deregulated gene expression, defective mitochondria function and erythropoiesis.
Project description:Advances in sequencing-based genomic profiling present a new challenge of explaining how changes in DNA/RNA are translated into proteins linking genotypes to phenotypes. The developing erythroid cells require highly coordinated gene expression and metabolism, and serve as a unique model in dissecting regulatory events in development and disease. Here we compare the proteomic and transcriptomic changes in human hematopoietic stem/progenitor cells and lineage-committed erythroid progenitors, and uncover pathways related to mitochondrial biogenesis enhanced through post-transcriptional regulation. Two principal mitochondrial factors TFAM and PHB2 are tightly regulated at the protein level and indispensable for mitochondria and erythropoiesis. mTORC1 signaling is progressively enhanced to promote translation of mitochondrial proteins during erythroid specification. Genetic and pharmacological perturbation of mTORC1 or mitochondria impairs erythropoiesis. Our studies suggest a new mechanism for regulation of mitochondrial biogenesis through mTORC1-mediated protein translation, and may have direct relevance to the hematological defects associated with mitochondrial diseases and aging. Transcriptional profiling in human primary fetal and adult CD34+ hematopoietic stem/progenitor cells (HSPCs) erythroid progenitor cells (ProEs) by RNA-seq analysis.
Project description:BCL11A is a critical mediator of hemoglobin switching and gamma-globin silencing. In this study, we showed the BCL11A is required in vivo for developmental silencing of gamma-globin genes in adult animals. We used microarray to determine the changes in gene expression profile after loss of BCL11A in adult erythroid cells CD71+Ter119+ erythroid progenitor cells were FACS-sorted from bone marrows of 6-week old control (Bcl11a +/+) and BCL11A knockout (Bcl11a fl/fl EpoR-Cre+) mice.
Project description:ChIP-seq data characterizing the occupancy of TFAM over the mitochondrial and nuclear genomes in HeLa cells. Characterization of mitochondrial and nuclear genome-wide TFAM binding in HeLa cells
Project description:Gene expression analysis of 2-month-old Ctrl and Tfam-SCKO mice. At this age mitochondrial function is disrupted in the Schwann cells of Tfam-SCKO mice ,but their nerves display only very limited pathology. Mitochondrial dysfunction is a common cause of peripheral neuropathy. Much effort has been devoted to examining the role played by neuronal/axonal mitochondria, but how mitochondrial deficits in peripheral nerve glia (Schwann cells, SCs) contribute to peripheral nerve diseases remains unclear. Here, we investigate a mouse model of peripheral neuropathy secondary to SC mitochondrial dysfunction (Tfam-SCKOs). We show that disruption of SC mitochondria activates a maladaptive integrated stress response through actions of heme-regulated inhibitor kinase (HRI), and causes a shift in lipid metabolism away from fatty acid synthesis toward oxidation. These alterations in SC lipid metabolism result in depletion of important myelin lipid components as well as in accumulation of acylcarnitines, an intermediate of fatty acid b-oxidation. Importantly, we show that acylcarnitines are released from SCs and induce axonal degeneration. A maladaptive integrated stress response as well as altered SC lipid metabolism are thus underlying pathological mechanisms in mitochondria-related peripheral neuropathies. Total RNA samples were prepared by isolating and pooling RNA from three different 2-month-old MPZ-Tfam KO and Ctrl mice. 2 replicates per genotype were used in this experiment and they were prepared entirely independently.
Project description:The goal of this analysis was to utilize microarray profiling to identify basal alterations in gene expression in response to TFAM depletion and mtDNA stress. Mitochondrial DNA (mtDNA) is normally present at thousands of copies per cell and is packaged into several hundred higher-order structures termed nucleoids. The abundant mtDNA-binding protein, TFAM (transcription factor A,mitochondrial), regulates nucleoid architecture, abundance and segregation. Complete mtDNA depletion profoundly impairs oxidative phosphorylation, triggering calcium-dependent stress signalling and adaptive metabolic responses. However, the cellular responses to mtDNA instability, a physiologically relevant stress observed in many human diseases and ageing, remain poorly defined. Here we show that moderate mtDNA stress elicited by TFAM deficiency engages cytosolic antiviral signalling to enhance the expression of a subset of interferon-stimulated genes. Mechanistically, we find that aberrant mtDNA packaging promotes escape of mtDNA into the cytosol, where it engages the DNA sensor cGAS (also known as MB21D1) and promotes STING (also known as TMEM173)–IRF3-dependent signalling to elevate interferon-stimulated gene expression, potentiate type I interferon responses and confer broad viral resistance. Furthermore, we demonstrate that herpesviruses induce mtDNA stress, which enhances antiviral signalling and type I interferon responses during infection. Our results further demonstrate that mitochondria are central participants in innate immunity, identify mtDNA stress as a cell-intrinsic trigger of antiviral signaling and suggest that cellular monitoring of mtDNA homeostasis cooperates with canonical virus sensing mechanisms to fully engage antiviral innate immunity. Murine embryonic fibroblasts were isolated from wild-type or Tfam+/- E13.5 littermate embryos. RNA from passage-matched wild-type and Tfam+/- MEF lines was extracted in duplicate and hybridized onto Affymetrix microarrays. Four arrays were performed in total with two technical replicates per genotype.
Project description:Using RNA-seq technology, we quantitatively determined the expression profile of microRNAs during mouse terminal erythroid differentiation. CFU-E erythroid progenitors were isolated from E14.5 fetal liver as the Ter119, B220, Mac-1, CD3 and Gr-1 negative, C-Kit positive and 20% high CD71 population. Mature Ter119+ erythroblasts were isolated from E14.5 fetal liver as C-Kit negative and Ter119 positive population. Consistent with nuclear condensation and global gene expression shut down during terminal erythroid differentiation, we found that the majority of microRNAs are downregulated in more mature Ter119+ erythroblasts compared with CFU-E erythroid progenitors.
Project description:Regulation of the cell cycle is intimately linked to erythroid differentiation, yet how these processes are coupled is not well understood. To gain insight into this coordinate regulation, we examined the role that the retinoblastoma protein (Rb), a central regulator of the cell cycle, plays in erythropoiesis. We found that Rb serves a cell-intrinsic role and its absence causes ineffective erythropoiesis, with a differentiation block at the transition from early to late erythroblasts. Unexpectedly, in addition to a failure to properly exit the cell cycle, mitochondrial biogenesis fails to be upregulated concomitantly, contributing to this differentiation block. The link between erythropoiesis and mitochondrial function was validated by inhibition of mitochondrial biogenesis. Erythropoiesis in the absence of Rb resembles the human myelodysplastic syndromes, where defects in cell cycle regulation and mitochondrial function frequently occur. Our work demonstrates how these seemingly disparate pathways play a role in coordinately regulating cellular differentiation. Experiment Overall Design: Microarray expression analysis from sorted CD71+/Ter-119+ bone marrow erythroid progenitors of Rb-null animals and controls. The Rb-null genotype was EpoR-GFPcre/+; Rb fl/fl and the control genotype was EpoR-GFPcre/+; Rb fl/+. We have analyzed 3 Rb-null datasets and 3 control datasets.
Project description:SIRT3 is a NAD+-dependent mitochondrial protein deacetylase participating in the regulation of central metabolism and mitochondrial proteostasis. SIRT3 is downregulated in clear cell renal cell carcinoma (ccRCC), a main type of renal cancers, but the function of SIRT3 in tumorigenesis and development of ccRCC remains unknown. In this study, we established a SIRT3 overexpressed cell line to explore the changes of proteomics and metabolomics regulated by SIRT3 expression. Both the results of quantitative proteomics, metabolomics and acetylome showed overexpression of SIRT3 increased mitochondrial biogenesis and reversed the mitochondrial dysfunctions in ccRCC. We found SIRT3 could increase the activity of TFAM through modulation of TFAM transcription, degradation and acetylation level. The acetylation of TFAM K154 decreased while TFAM protein expression increased after SIRT3 overexpression. Further study revealed that SIRT3 could bind with TFAM, and decrease the acetylation of TFAM, promoting TFAM activity in mitochondrial biogenesis. Overall, our results present a new mechanism of SIRT3 in regulating mitochondrial functions, and the downregulation of SIRT3 in ccRCC lowers the activity of TFAM, subsequently inhibits the transcription of mitochondrial genes and mitochondrial biogenesis.