Project description:We report on gene expression, chromatin accessibility, active histone marks distribution, and Tead DNA-binding in proliferating and postmitotic organ of Corti progenitor cells.
Project description:During placentation, placental cytotrophoblast cells differentiate into syncytiotrophoblast cells and extravillous trophoblast cells. In placenta, the expression of various genes is regulated by the Hippo pathway through the transcriptional coactivator YAP/TAZ-TEAD activity. To examine the effect of YAP/TAZ and/or TEAD on trophoblast differentiation, knockdown experiments were performed. Microarray analysis were performed to identify YAP/TAZ and/or TEAD target genes in human trophoblast.
Project description:The genomic regulatory programs that underlie human organogenesis are poorly understood. Human pancreas development, in particular, has pivotal implications for pancreatic regeneration, cancer, and diabetes. We have now created maps of transcripts, active enhancers, and transcription factor networks in pancreatic multipotent progenitors obtained from human embryos, or derived in vitro from human embryonic stem cells. This revealed that artificial progenitors recapitulate salient transcriptional and epigenomic features of their natural counterparts. Using this resource, we show that TEAD1, a transcription factor controlled by Hippo signaling, is a core component of the combinatorial code of pancreatic progenitor enhancers. TEAD thus activates genes encoding regulators of signaling pathways and stage-specific transcription factors that are essential for normal pancreas development. Accordingly, chemical and genetic perturbations of TEAD and its coactivator YAP inhibited expression of known regulators such as FGFR2 and SOX9, and suppressed the proliferation and expansion of mouse and zebrafish pancreatic progenitors. These findings provide a resource of active enhancers and transcripts in human pancreatic multipotent progenitors, and uncover a central role of TEAD and YAP as signal-responsive regulators of the transcriptional program of early pancreas development.
Project description:YAP1 (Yes-associated protein 1) is transcriptional co-activator that partners with the TEAD family of transcription factors to regulate gene expression. Increased YAP-TEAD activity is strongly implicated in the development, progression, and metastasis of several cancer types including melanoma, but the YAP-TEAD target genes that are responsible for YAP-TEAD-dependent melanoma progression and metastasis are largely unknown. To identify YAP-TEAD regulated genes in metastatic melanoma cells we used RNA-sequencing to compare gene expression in control A375 human melanoma cells to A375 cells expressing mutant forms of YAP with increased transcriptional activity due to the mutation of LATS inhibitory phosphorylation sites (YAPS127A or YAPS127A,S381A). To determine which YAP-dependent gene expression changes are mediated by TEADs we also included a mutant form of YAP that is unable to bind TEADS (YAPS94A,S127A).
Project description:The microRNA miR-96 is important for hearing; mutations in the seed region result in dominant progressive hearing loss in mice and humans. Mir96 is expressed in the sensory hair cells of the organ of Corti along with Mir182 and Mir183. miR-96 is a master regulator of hair cell development, controlling many genes in the organ of Corti, but the role of miR-182 and miR-183 in the hair cells is unknown. We carried out RNA-seq on mice carrying a knockout allele of Mir182, and mice carrying a double knockout allele of Mir183 and Mir96 (Mir183/96). RNA was extracted from the organ of Corti from P4 homozygotes and sex-matched wildtype littermates. Strand-specific libraries were prepared using the NuGEN Ovation Mouse RNA-Seq System 1-16 kit and sequenced on an Illumina HiSeq 2500 machine as paired-end 125bp reads.
Project description:Cre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation. We used microarrays to examine gene expression in apical versus basal organ of Corti from the cochleae of control and mutant mice in which Dicer1 was deleted and microRNAs were depleted specifically in sensory hair cells by Atoh1 promoter-driven Cre recombinase expression. Each biological replicate represents the combined apical or combined basal segments of organ of Corti from both cochleae of a single mouse. Two biological replicates for apical and basal organ of Corti from Dicer1 conditonal knockout and littermate controls were collected for RNA extraction and microarray analysis.
Project description:Angiogenesis, the process by which endothelial cells (ECs) form new blood vessels from existing ones, is intimately linked to the tissue's metabolic milieu and often occurs at nutrient-deficient sites. However, ECs rely on sufficient metabolic resources to support growth and proliferation. How endothelial nutrient acquisition and usage are regulated is unknown. Here we show that these processes are dictated by YAP/TAZ-TEAD – a transcriptional module whose function is highly responsive to changes in the tissue environment. ECs lacking YAP/TAZ or their transcriptional partners, TEAD1, 2, and 4 fail to divide, resulting in stunted vascular growth in mice. Conversely, activation of TAZ, the more abundant paralogue in ECs, boosts proliferation, leading to vascular hyperplasia. We find that YAP/TAZ promote angiogenesis by fueling nutrient mTORC1 signaling. By orchestrating the transcription of a repertoire of cell-surface transporters, YAP/TAZ-TEAD stimulate the import of amino acids and other essential nutrients, thereby enabling mTORC1 pathway activation. Dissociating mTORC1 from these nutrient inputs – elicited by the loss of Rag GTPases – inhibits mTORC1 activity and prevents YAP/TAZ-dependent vascular growth. These findings define a pivotal role for YAP/TAZ-TEAD in steering endothelial mTORC1 and illustrate the essentiality of coordinated nutrient fluxes in the vasculature.
Project description:We evaluated the effects of pioglitazone in mouse organ of Corti (OC) explants to characterize its influence on signaling pathways involved in auditory hair cell damage. Organ of Corti explants were cultured with pioglitazone, gentamicin, or a combination of both agents. Pioglitazone treatment resulted in a significant repression of interferon (IFN)-alpha and -gamma pathways and downstream cytokines, as assessed by RNA sequencing and quantitative PCR gene expression assays. More detailed investigation at the single gene and protein level showed that pioglitazone mediated its anti-inflammatory effects through alterations of the Toll-like receptor (TLR) and STAT pathways. Together, these results indicate that pioglitazone significantly represses IFN and TLR in the cochlea, dampening the activity of gentamicin-induced pathways. These data support our previous results demonstrating significant protection of auditory hair cells in organ of Corti explants exposed to pioglitazone and other PPAR-targeted agents.