Project description:Epithelial tip progenitor cells are an important epithelial progenitor population in the developing lung. At early stages of development they produce SOX2+ bronchiolar progenitor cells. At later stages of embryonic lung development they produce SOX2- alveolar progenitor cells. We purified the tip progenitor cells from early (E11.5, bronchiolar progenitor producing) and late (E17.5, alveolar progenitor producing) stages of mouse lung development and used Affymetrix microarrays to compare their gene expression profiles.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Underdeveloped lungs are the primary cause of death in premature infants, however, little is known about stem and progenitor cell maintenance during human lung development. In this study, we have identified that FGF7, Retinoic Acid and CHIR-99021, a small molecule that inhibits GSK3 to activate Wnt signaling, support in vitro maintenance of primary human fetal lung bud tip progenitor cells in a progenitor state. Furthermore, these factors are sufficient to derive a population of human bud tip-like progenitor cells in 3D organoid structures from human pluripotent stem cells (hPSC). Functional studies showed that hPSC-derived bud tip progenitor organoids do not contain any mesenchymal cell types, maintain multilineage potential in vitro and are able to engraft into the airways of injured mice and respond to systemic factors. We performed RNA-sequencing to assess the degree of similarity in global gene expression profiles between the full human fetal lung (59-127 days gestation), isolated human fetal bud tip progenitors, organoids grown from primary fetal bud tip progenitors, and hPSC-derived bud tip organoids. Results showed that hPSC-derived organoids have molecular profiles similar to organoids generated from primary human fetal lung tissue. Gene expression differences between hPSC-derived bud tip organoids and fetal progenitor organoids may be related to the presence of contaminating mesenchymal cells in primary cultures. hPSC-derived bud tip organoids are generated from a well-defined human cell sources, offering a distinct advantage over rare primary tissue as a means to study human specific lung development, homeostasis and disease.<br>Sample Nomenclature - Description<br> -------------------------------------------------------------------------<br> Peripheral fetal lung the distal/peripheral portion of the fetal lung (i.e., distal 0.5 cm) was excised from the rest of the lung using a scalpel. This includes all components of the lung (e.g., epithelial, mesenchymal, vascular). <br>Isolated fetal bud tip the bud peripheral portion of the fetal lung was excised with a scalpel and subjected to enzymatic digestion and microdissection. The epithelium was dissected and separated from the mesenchyme, but a small amount of associated mesenchyme likely remained. <br>Fetal progenitor organoid 3D organoid structures that arose from culturing isolated fetal epithelial bud tips. <br>Foregut spheroid 3D foregut endoderm structure as described in Dye et al. (2015). Gives rise to patterned lung organoid (PLO) when grown in 3F medium. <br> Patterned lung organoid (PLO) lung organoids that were generated by differentiating hPSCs, as described throughout the manuscript. <br> Bud tip organoid organoids derived from PLOs, enriched for SOX2/SOX9 co-expressing cells, and grown/passaged in 3F medium.