Project description:Purpose: To elucidate the roles of airway epithelial STAT3 in allergic airway inflammation. Method: Doxycycline-induced airway epithelial cells-specific STAT3-deficient mice (STAT3-cKO) and their genetic control mice (STAT3-WT) were sensitized intratracheally twice with house dust mite (HDM) extract or PBS at a 7-day interval. Airway epithelial cells were isolated by a cell sorter 48 h after the last senstization. N=2 each. Results: Using an optimized data analysis workflow, 206 transcripts showed differential expression between HDM-treated STAT3-WT and STAT3-cKO with adjusted p value <0.05.
Project description:Echinoderm microtubule (MT)-associated protein-like 1 (Eml1) is mutated in the HeCo mouse, which exhibits subcortical band heterotopia (SBH), a developmental malformation of the cerebral cortex. EML1 mutations are also found in human patients affected by severe ribbon-like heterotopia, associated with epilepsy and intellectual disability (1). Neural progenitors in the ventricular zone (VZ) of the developing cerebral cortex undergo precisely regulated divisions, and mitotic perturbations contribute to pathological mechanisms (2). Eml1 is expressed in the mouse VZ and ectopic progenitors are present in the mutant developing cortex, when Eml1 is absent, at early stages of development (1). Thus, Eml1 is likely to play a role in neural progenitors during cortical development. We performed cell and molecular biology assays aiming to elucidate the function of Eml1 in neural progenitors, and explored the VZ of the HeCo mutant in order to find morphological perturbations that might explain the initiation of SBH formation (3). As part of this study, we searched for Eml1 molecular partners by pull-downs from mouse cortical extracts at embryonic day E13.5 and mass spectrometry (MS) analyses in order to identify the molecular pathways in which the protein is involved (3). Eml1 is formed by an N-terminal region that contains a dimerization domain and a C-terminal region that forms a ‘tandem atypical propeller in EMLs’ (TAPE) domain. The isolated N-terminal domain strongly binds MTs, while the C-terminal domain preferentially binds tubulin, and its beta-propeller structure is thought also to mediate the interaction with other molecules (4,5). We focused for this study on the N-terminal part of the protein (amino acids 1-178). Future study will validate or elucidate new interactions by using the C-terminal domain and/or the full-length protein. The results obtained from the N terminal MS data, integrated with other experimental findings, allow us to insert Eml1 in a network of proteins that are likely to regulate the assembly and function of the mitotic spindle in neural progenitors (3). More precisely, we showed that the protein regulates MT dynamics and its loss leads to perturbations in metaphase spindle length, which in turn impact progenitor morphology and behavior (3). References 1. Kielar, M., et al. Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human. Nat. Neurosci. 17, 923–933 (2014). 2. Bizzotto, S., & Francis, F. Morphological and functional aspects of progenitors perturbed in cortical malformations. Front Cell Neurosci. 9, 30; 10.3389/fncel00030 (2015). 3. Bizzotto, S., et al. Eml1 loss impairs apical progenitor spindle length and soma shape in the developing cerebral cortex. 4. Richards, M. W., et al. Crystal structure of EML1 reveals the basis for Hsp90 dependence of oncogenic EML4-ALK by disruption of an atypical β-propeller domain. Proc. Natl. Acad. Sci. U.S.A. 111, 5195–5200 (2014). 5. Richards, M. W., et al. Microtubule association of EML proteins and the EML4-ALK variant 3 oncoprotein require an N-terminal trimerization domain. Biochem. J. 467, 529–536 (2015).
Project description:Decoding heterogeneity of pluripotent stem cell (PSC)-derived neural progeny is fundamental for revealing the origin of diverse progenitors, for defining their lineages, and for identifying fate determinants driving transition through distinct potencies. Here we prospectively isolated consecutively appearing PSC-derived primary progenitors based on their Notch activation state. We first isolate early neuroepithelial cells and show their broad Notch-dependent developmental and proliferative potential. Neuroepithelial cells further yield successive Notch-dependent functional primary progenitors, from early and mid neurogenic radial glia and their derived basal progenitors, to gliogenic radial glia and adult-like neural progenitors, together recapitulating hallmarks of neural stem cell (NSC) ontogeny. Gene expression profiling reveals dynamic stage specific transcriptional patterns that may link development of distinct progenitor identities through Notch activation. Our observations provide a platform for characterization and manipulation of distinct progenitor cell types amenable for developing streamlined neural lineage specification paradigms for modeling development in health and disease. Human embryonic stem cells (hESCs) H9 were differentiated into 5 distinct populations of neural precursor cells (NPCs) over a time course of 200 days. Each neural precursor populations was then sorted for HES5 expression based on a GFP-HES5 reporter. Both the HES5 positive and HES5 negative populations were then subjected to microarray profiling in singlicate, as well as the hESCs using GeneChipPrimeView Human Gene Expression Array
Project description:Correct neural progenitor fate determination requires the coordination of extrinsic fate determinant signals with intrinsic responses. Post-translational modifications dynamically alter protein function and so are ideally situated to regulate development. Here we show that the deubiquitylaying enzyme, Usp9x modulates both intrinsic and extrinsic regulators of mouse neural progenitors. Nestin-cre mediated deletion of Usp9x from neural progenitors results in a transient disruption of cell adhesion and apical-basal polarity as well as the premature differentiation of intermediate neural progenitors. Ablation of Usp9x also significantly increased β-catenin protein levels, especially S33/S37/T41 phospho-β-catenin, and Wnt signalling. Usp9x was found to be part of the β-catenin destruction complex and loss of Usp9x affects destruction complex composition. Notch signalling was also increased in Usp9x ablated neural progenitors, coinciding with decreased Itch and Numb, and increased Notch intracellular domain protein levels. Usp9x co-localized and immunopreciptiated with Numb from neural progenitors suggesting it is required for Numb stabilisation. These data suggest Usp9x plays a role in coordinating intrinsic responses to extrinsic signals during neural development.
Project description:Decoding heterogeneity of pluripotent stem cell (PSC)-derived neural progeny is fundamental for revealing the origin of diverse progenitors, for defining their lineages, and for identifying fate determinants driving transition through distinct potencies. Here we prospectively isolated consecutively appearing PSC-derived primary progenitors based on their Notch activation state. We first isolate early neuroepithelial cells and show their broad Notch-dependent developmental and proliferative potential. Neuroepithelial cells further yield successive Notch-dependent functional primary progenitors, from early and mid neurogenic radial glia and their derived basal progenitors, to gliogenic radial glia and adult-like neural progenitors, together recapitulating hallmarks of neural stem cell (NSC) ontogeny. Gene expression profiling reveals dynamic stage specific transcriptional patterns that may link development of distinct progenitor identities through Notch activation. Our observations provide a platform for characterization and manipulation of distinct progenitor cell types amenable for developing streamlined neural lineage specification paradigms for modeling development in health and disease.
Project description:During organogenesis, neural and mesenchymal progenitor cells give rise to many cell lineages, but their molecular requirements for self-renewal and lineage decisions are incompletely understood. Here we show that their survival critically relies on the redundantly acting SoxC transcription factors Sox4, Sox11 and Sox12. The more SoxC alleles are deleted in mouse embryos, the more severe and widespread organ hypoplasia is. SoxC triple-null embryos die at mid-gestation unturned and tiny, with normal patterning and lineage specification, but with massively dying neural and mesenchymal progenitor cells. Specific inactivation of SoxC genes in neural and mesenchymal cells leads to selective apoptosis of these cells, suggesting SoxC cell-autonomous roles. Tead2 functionally interacts with the SoxC genes in embryonic development, and is a direct target of the SoxC proteins. The SoxC genes therefore ensure neural and mesenchymal progenitor cell survival and act in part by activating this transcriptional mediator of the Hippo signaling pathway. During organogenesis, neural and mesenchymal progenitor cells give rise to many cell lineages, but their molecular requirements for self-renewal and lineage decisions are incompletely understood. Here we show that their survival critically relies on the redundantly acting SoxC transcription factors Sox4, Sox11 and Sox12. The more SoxC alleles are deleted in mouse embryos, the more severe and widespread organ hypoplasia is. SoxC triple-null embryos die at mid-gestation unturned and tiny, with normal patterning and lineage specification, but with massively dying neural and mesenchymal progenitor cells. Specific inactivation of SoxC genes in neural and mesenchymal cells leads to selective apoptosis of these cells, suggesting SoxC cell-autonomous roles. Tead2 functionally interacts with the SoxC genes in embryonic development, and is a direct target of the SoxC proteins. The SoxC genes therefore ensure neural and mesenchymal progenitor cell survival and act in part by activating this transcriptional mediator of the Hippo signaling pathway. Total RNA isolated from limb bud cells in culture treated with Cre recombinase expressing adenovirus to inactivate floxed SoxC genes was compared to total RNA isolated from cells treated with LacZ expressing adenovirus as well as untreated cells as controls.
Project description:The coordination of developmental potential and proliferation in stem and progenitor cells is essential for mammalian development and tissue homeostasis. To better understand this coordination in human neural progenitor cells (hNPCs), we performed CRISPR-Cas9 screens and identified genes that limit their expansion. These screens revealed that knockout of growth-limiting genes, including CREBBP, NF2, PTPN14, TAOK1, or TP53, caused increased hNPC expansion via skipping of a transient G0-like state, accompanied by transcriptional reprogramming of G1 subpopulations. Hallmarks of the G0-like state included expression of genes associated with quiescent neural stem cells and neural development and molecular features found in quiescent cells (e.g., hypo-phosphorylated Rb, CDK2low activity, and p27high). Further, G0-skip genes act through both distinct and convergent downstream effectors, including cell cycle, Hippo-YAP, and novel targets. The results suggest that hNPC expansion is constrained by a transient G0-like state, regulated by multiple pathways, that facilitates retention of neurodevelopmental identity.
Project description:Many patients have cancers that have increased activity of a protein called STAT3 that contributes critically to the development and growth of their cancer. Despite our knowledge of STAT3’s importance to cancer, scientists and doctors have not developed a drug that targets it and that patients can take to treat their cancer more effectively than treatments that are now available. Tvardi Therapeutics, Incorporated has developed a compound, TTI-101, which can be given by mouth and acts as a direct inhibitor of STAT3. Administration of TTI-101 to mice demonstrated that it blocked growth of cancers of the breast, head and neck, lung, and liver and it was safe when administered at high doses to mice, rats, and dogs. In this application, Tvardi is proposing to further develop TTI-101 for treatment of solid tumors for which the prognosis is dismal. The investigators will determine how safe it is when administered to patients with cancer, determine whether an adequate dose can be administered to patients with cancer that will block STAT3 in their cancer, and determine whether treatment with TTI-101 leads to reduced growth of their cancer.