Project description:Multipotent Nkx2-1-positive lung epithelial primordial progenitors of the foregut endoderm are thought to be the developmental precursors to all adult lung epithelial lineages. However, little is known about the global transcriptomic programs or gene networks that regulate these gateway progenitors in vivo due to their rarity and transient presence during a narrow developmental window, embryonic day E9.0 in mice. Here we describe the unique genetic program of in vivo lung primordial progenitors and computationally identify the signaling pathways that are involved in their cell-fate determination from pre-specified embryonic foregut. We integrate this information in computational models to generate in vitro engineered lung primordial progenitors from mouse pluripotent stem cells, improving the fidelity of the resulting cells through unbiased, easy-to-interpret similarity scores and modulation of cell culture conditions, including biomechanical cues. As the genetic characterization of early in vivo embryonic progenitors is rapidly expanding, the methodology proposed here can have wide applicability to the in vitro derivation of bona fide tissue progenitors of all germ layers.
Project description:Despite the progress in safety and efficacy of cell therapy with pluripotent stem cells (PSCs), the presence of residual undifferentiated stem cells or proliferating neural progenitor cells (NPCs) with rostral identity has remained a major challenge. Here we reported the generation of an LMX1A knock-in GFP reporter human embryonic stem cell (hESC) line that marks the early dopaminergic progenitors during neural differentiation. Purified GFP positive cells in vitro exhibited expression of mRNA and proteins that characterized and matched the midbrain dopaminergic identity. Further proteomic analysis of enriched LMX1A+ cells identified several membrane associated proteins including CNTN2, enabling prospective isolation of LMX1A+ progenitor cells. Transplantation of hPSC-derived purified CNTN2+ progenitors enhanced dopamine release from transplanted cells in the host brain and alleviated Parkinson’s disease symptoms in animal models. Our study establishes an efficient approach for purification of large numbers of hPSC-derived dopaminergic progenitors for therapeutic applications.
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:Sox2 is a key determinant of neural cell identity, expressed in neural progenitors from anterior to posterior levels. We asked if the occupancy of this factor changes in neural progenitors with different axial identities. To this end, we performed the directed differentiation of mouse embryonic stem cells to generate neural progenitors in vitro with either hindbrain or spinal cord identity. We then performed Sox2 ChIP-seq (antibody SC-17320X), to assess the difference in Sox2 occupancy at these two different axial levels. This revealed that the genome-wide occupancy of Sox2 in neural progenitors changes depending on axial identity.
Project description:The study aims to show that Sox9+ Chd1+ mouse embryonic lung progenitors can be isolated and expanded long-term in 3D culture while maintaining their multipotency. in vitro cultured Sox9+ Chd1+ lung progenitors transcriptionally resemble their in vivo counterparts and show significant difference from adult lung epithelial (Cdh1+ and EpCAM+) and non-epithelial (Cdh1- and EpCAM-) cells
Project description:To improve the standardization of cell therapies for Parkinson’s disease, methods for the selection and isolation of midbrain dopaminergic progenitors for transplantation are required. To facilitate this we established an expression profile for genes selectively expressed on transplantable midbrain dopaminergic progenitors using microarray analysis. Expression of GFP in the ventral mesencephalon of embryonic E12.5 Ngn2-GFP mice identifies a distinct sub-population of cells containing virtually all of the midbrain dopaminergic progenitors. Gene expression profiles from 3 biological replicates of FACS isolated GFP-positive cells from mouse Ngn2-GFP ventral mesencephalon were generated using microarrays. To reduce the likelihood of identifying transcripts from non-dopaminergic progenitors, 3 biological replicates of FACS isolated GFP-negative cells from mouse Lmx1a-GFP ventral mesencephalon (definitively non-dopaminergic) were used as a reference population.
Project description:We analyzed the generation of mouse gliomas following the overexpression of PDGF-B in embryonic neural progenitors. Comparison of our microarray data, with published gene expression data sets for many different murine neural cell types, revealed a closest relationship between our tumor cells and oligodendrocyte progenitor cells, confirming definitively that PDGF-B-induced gliomas are pure oligodendrogliomas.
Project description:The study aims to show that Sox9+ Chd1+ mouse embryonic lung progenitors can be isolated and expanded long-term in 3D culture while maintaining their multipotency. in vitro cultured Sox9+ Chd1+ lung progenitors transcriptionally resemble their in vivo counterparts and show significant difference from adult lung epithelial (Cdh1+ and EpCAM+) and non-epithelial (Cdh1- and EpCAM-) cells
Project description:Mamamlian cardiogenesis occurs through the development of discreate populations of first and second heart field progenitors. We have used a dual transgenic color reproter system to isolate purified populations of these progenitors. We used microarrays to detail the global programme of gene expression underlying cardiac development in mouse; All four populations of cells are derived from embryonic stem cells differentiating in vitro (day 6 of in vitro differentaition). The stem cell line has two transgenic reporters as follows:; 1. The second heart field (SHF) specific reporter of the Mef2C gene (E. Dodou, S. M. Xu, B. L. Black, Mech Dev 120, 1021 (Sep, 2003)) driving the expression of dsRed; 2. The cardiac specific enhancer ( C. L. Lien et al., Development 126, 75 (Jan, 1999)) driving the expression of eGFP. Thus, the red cells are SHF specific, the green cells are cardiac specific, and the red/green are SHF and cardiac specific. These cells are compared to the double negative cells which serve as a control. Experiment Overall Design: Embryonic stem cell derived progenitors were isolated into four distinct populations by FACS purifying these progenitors based on a two color reporter system. Four populations were then compared to each other by transcriptional profiling.