Project description:Although being essential to respiratory and reproductive tracts multiciliogenesis, TAp73 is dispensable for multiciliogenesis in the ventricles. TAp73 KO is accompanied by dramatic changes in ciliogenic microRNAs miR34bc and miR449 family members, suggestin TAp73 functions partially thorugh posttranscriptional nodes in brain ciliogenesis.
Project description:Comparative RNA seq analysis of WT and global p73KO Mouse Tracheal Epithelial Cell (MTECs) during the course of their differentiation (Air-Liquid Interface ALI D0, D4, D7, D14) aimed to determine the role of p73 in motile multiciliogenesis.
Project description:Comparative small RNA seq analysis of WT and global p73KO Mouse Tracheal Epithelial Cell (MTECs) during the course of their differentiation (Air-Liquid Interface ALI D0, D4, D7, D14) aimed to determine the role of p73 in motile multiciliogenesis.
Project description:Developmental and homeostatic remodeling of cellular organelles is mediated by a complex process termed autophagy. The cohort of proteins that constitute the autophagy machinery function in a multistep biochemical pathway. Though components of the autophagy machinery are broadly expressed, autophagy can occur in specialized cellular contexts, and mechanisms underlying cell type-specific autophagy are poorly understood. We demonstrate that the master regulator of hematopoiesis GATA-1 directly activates transcription of genes encoding the essential autophagy component Microtubule Associated Protein 1 Light Chain 3B (LC3B) and its homologs (MAP1LC3A, GABARAP, GABARAPL1, GATE-16). In addition, GATA-1 directly activates genes involved in the biogenesis/function of lysosomes, which mediate autophagic protein turnover. We demonstrate that GATA-1 utilizes the forkhead protein FoxO3 to activate select autophagy genes. GATA-1-dependent LC3B induction is tightly coupled to accumulation of the active form of LC3B and autophagosomes, which mediate mitochondrial clearance as a critical step in erythropoiesis. These results illustrate a novel mechanism by which a master regulator of development establishes a genetic network to instigate cell type-specific autophagy. Genome-wide maps of GATA1 factor occupancy in primary human PBMC derived erythroblasts
Project description:Mechanical forces are increasingly recognized to regulate morphogenesis, but how this is accomplished in the context of the multiple tissues present within a developing organ remains unclear. Here we use bioengineered “microfluidic chest cavities” to precisely control the mechanical environment of the fetal lung. We show that transmural pressure controls airway branching morphogenesis and regulates the frequency of airway smooth muscle contraction. Next-generation sequencing analysis shows that lungs held at higher pressure are more mature than lungs held at lower pressure. Timelapse imaging reveals that branching events are synchronized across distant locations within the lung, and are preceded by long-duration waves of airway smooth muscle contraction. Higher transmural pressure decreases the interval between systemic smooth muscle contractions and increases the rate of morphogenesis of the airway epithelium. These data reveal that the mechanical properties of the microenvironment instruct crosstalk between tissues to control the rate of development of the embryonic lung.
Project description:"Master" transcription factors are the gatekeepers of lineage identity. As such, they have been a major focus of efforts to manipulate cell fate for therapeutic purposes. The ETS transcription factor PU.1 has a potent ability to confer macrophage phenotypes on cells already committed to a different lineage, but how it overcomes the presence of other master regulators is not known. The nuclear receptor PPARM-NM-3 is the master regulator of the adipose lineage, and its genomic binding pattern is well characterized in adipocytes. Here, we show that when expressed at macrophage levels in mature adipocytes, PU.1 bound a large fraction of its macrophage sites, where it induced chromatin opening and the expression of macrophage target genes. Strikingly, PU.1 markedly reduced the genomic binding of PPARM-NM-3 without changing its abundance. PU.1 expression repressed genes with nearby adipocyte-specific PPARM-NM-3 binding sites, while a common macrophage-adipocyte gene expression program was retained. Together, these data reveal unexpected lability within the adipocyte PPARM-NM-3 cistrome and show that even in terminally differentiated cells, PU.1 can remodel the cistrome of another master regulator. ChIP-seq was performed on 3T3-L1 adipocytes from two treatment groups: (1) adipocytes transduced with a control adenovirus expressing beta-galactosidase (LACZ-Ads) and (2) adipocytes transduced with an adenovirus expressing full-length murine PU.1 cDNA (PU.1-Ads). Nuclear lysates from each group were used for PPARg ChIP. For PU.1-Ads, PU.1 ChIP was also performed. To generate chromatin for ChIP-seq, DNA from three immunoprecipitations per condition was pooled. This process was repreated from a second set of L1 adipocytes to generate two biological replicates for sequencing. Genomic input DNA was sequenced from the first biological replicate only.
Project description:The epithelial-mesenchymal transition (EMT) is a multistep dedifferentiation program important in tissue repair. Here, we examined the role of the transcriptional regulator NFkB in EMT of human primary small airway epithelial cells (hSAECs). Surprisingly, transforming growth factor β (TGFβ) activated NFkB/RELA proto-oncogene, NFkB subunit (RELA) translocation within 1 day of stimulation, yet induction of its downstream gene regulatory network occurred only after 3 days. A time course of TGFβ-induced EMT transition was analyzed by RNA-Seq in the absence or presence of inducible shRNA-mediated silencing of RELA. In WT cells, TGFβ stimulation significantly affected the expression of 2,441 genes. Gene set enrichment analysis identified Wnt, cadherin, and NFkB signaling as the most prominent TGFβ-inducible pathways. By comparison, RELA controlled expression of 3,138 overlapping genes mapping to Wnt, cadherin, and chemokine signaling pathways. Conducting upstream regulator analysis, we found that RELA controls six clusters of upstream transcription factors, many of which overlapped with a transcription factor topology map of EMT developed earlier. RELA triggered expression of three key EMT pathways: (1) the Wnt/β-catenin morphogen pathway, (2) the JUN transcription factor, and (3) the Snail family transcriptional repressor 1 (SNAI1). RELA binding to target genes was confirmed by ChIP. Experiments independently validating Wnt dependence on RELA were performed by silencing RELA via genome editing and indicated that TGFβ-induced WNT5B expression and downstream activation of the Wnt target AXIN2 are RELA-dependent. We conclude that RELA is a master transcriptional regulator of EMT upstream of Wnt morphogen, JUN, SNAI1-ZEB1, and interleukin-6 autocrine loops.