Derivation of airway basal stem cells from human pluripotent stem cells
Ontology highlight
ABSTRACT: The derivation of self-renewing tissue-specific stem cells from human induced pluripotent stem cells (iPSCs) would shorten the time needed to engineer mature cell types in vitro and would have broad reaching implications for the field of regenerative medicine. Here we report the directed differentiation of human iPSCs into putative airway basal cells (“iBCs”), a population resembling the epithelial stem cell of lung airways. Using a dual fluorescent reporter system (NKX2-1GFP;TP63tdTomato) we track and purify these cells over time, as they first emerge from iPSC-derived foregut endoderm as developmentally immature NKX2-1GFP+ lung progenitors which then augment a TP63 program during subsequent proximal airway epithelial patterning. These cells clonally proliferate, initially as NKX2-1GFP+/ TP63tdTomato+ immature airway progenitors that lack expression of the adult basal cell surface marker, NGFR. However, in response to primary basal cell media, NKX2-1GFP+/ TP63tdTomato+ cells upregulate NGFR and display the molecular and functional phenotype of airway basal stem cells, including the capacity to clonally self-renew or undergo multilineage ciliated and secretory epithelial differentiation in air-liquid interface cultures. iBCs and their differentiated progeny recapitulate several fundamental physiologic features of normal primary airway epithelial cells and model perturbations that characterize acquired and genetic airway diseases. In an asthma model of mucus metaplasia, the inflammatory cytokine IL-13 induced an increase in MUC5AC+ cells similar to primary cells. CFTR-dependent chloride flux in airway epithelium generated from cystic fibrosis iBCs or their syngeneic CFTR-corrected controls exhibited a pattern consistent with the flux measured in primary diseased and normal human airway epithelium, respectively. Finally, multiciliated cells generated from an individual with primary ciliary dyskinesia recapitulated the ciliary beat and ultrastructural defects observed in the donor. Thus, we demonstrate the successful de novo generation of a tissue-resident stem cell-like population in vitro from iPSCs, an approach which should facilitate disease modeling and future regenerative therapies for a variety of diseases affecting the lung airways.Single-cell RNA-Sequencing profiling of human iPSC-derived basal cells, airway epithelium compared to primary human basal cells and airway epithelium.
Project description:We performed transcriptomic profiling of human iPSC-derived airway epithelial cells after infection with SARS-Co-V2. Using a recently described protocol to first generate airway basal cells from iPSCs and sunsequently differentiate those basal cells (iBCs) into a mucociliary epithelium in air-liquid interface culture. In this experiment we generated airway epithelial cultures from two different iPSC lines ("BU3 NGPT" and "1566"). In stage 6 of this protocol (>D45) iBCs are identified and purified by sorting on NGFR+ cells, and purified cells are expanded and differentiated on Transwells in dual-SMAD inhibition media then transitioned to ALI media when >80% confluent. Apical chamber media is removed to initiate ALI to recapitulate a physiologically-relevant environment and stimulate differentiation. After 14 days, iBCs form a pseudostratified airway epithelium that displays morphologic, molecular, and functional similarities to primary human airway epithelial cells and is comprised of the major airway cell types of multi-ciliated, secretory, and basal cellscomposed of the major airway epithelial cell types, that is permissive to SARS-CoV-2 infection. We studied the response of these iPSC-derived airway epithelial cells to SARS-CoV-2 infection using RNA-Sequencing 1 and 3 days post infection (DPI).
Project description:It has been postulated that during human fetal development all cells of the lung epithelium derive from an embryonic endodermal NKX2-1+ precursor, however, this hypothesis has not been formally tested due to an inability to purify or track this theorized cell for detailed characterization. Progress has been made in deriving lung epithelial cells from human induced pluripotent stem cells (iPSCs). However, little is known about the heterogeneity or genetic programs of the cells generated using these lung differentiation protocols. We engineered and differentiated NKX2-1GFP reporter iPSCs in vitro, recapitulating the major developmental milestones of lung development, to generate and isolate human primordial lung progenitors (day 15 of differentiation) that expresses NKX2-1 but are initially devoid of markers of differentiated lung lineages. To further characterize the cells generated in the lung directed differentiation protocol we performed single cell RNA-seq analysis of cells on day 15 of lung directed differentiation. We analyzed sorted NKX2-1GFP+ cells for the iPSC line C17 and cells from the iPSC line BU3.
Project description:Platform: iPSC-derived airway plated on 2D-air liquid interface through basal cell intermediate. Purpose of experiment: To examine the role of mutant CFTR on IPSC-derived airway epithelium (ie. immune dysregulation; dysregulated calcium channel signaling etc). Description of samples:Typical phenotype CF F508del (1565) and syngeneic CFTR-corrected (1564) iPSCs- derived airway epithelium at D90 (D15 CD47hi/CD26lo; replated in 3DMG cultured in 210DCIY x 2 weeks, single-cell passaged and cultured in PNExPlus+dual smad media in 3D, s/p 2 NGFR sorts, cultured at air-liquid interface at 2D)
Project description:It has been postulated that during human fetal development all cells of the lung epithelium derive from an embryonic endodermal NKX2-1+ precursor, however, this hypothesis has not been formally tested due to an inability to purify or track this theorized cell for detailed characterization. Here we engineer and developmentally differentiate NKX2-1GFP reporter pluripotent stem cells (PSCs) in vitro to generate and isolate a human primordial lung progenitor that expresses NKX2-1 but is initially devoid of markers of differentiated lung lineages. As these progenitors move through the earliest moments of lung lineage specification from definitive endoderm they can be imaged in real time or isolated for time-series global transcriptomic profiling. We performed microarray analysis of 5 timepoints of human iPSC to lung directed differentiation compared to week 21 human fetal lung and Neural NKX2-1+ cell controls. These profiles indicate that evolutionarily conserved, stage-dependent developmental gene signatures are expressed in primordial human lung progenitors. Using a TALEN-targeted fluorescent reporter to purify iPSC-derived lung progenitors (C17 NKX2-1GFP) we analyzed cells at major developmental time points in vitro (undifferentiated iPSC, definitive endoderm, anterior foregut endoderm and sorted NKX2-1GFP+ and NKX2-1GFP- cells on day 15 and day 28 of the protocol). We also differentiated NXK2-1GFP iPSC in a neural protocol and isolated neural NKX2-1GFP+ cells. Approximately 90% pure human fetal lung epithelial cells from week 21 embryos were used as controls.
Project description:Purpose of experiment :To 1) evaluate for the presence of pulmonary ionocytes, 2) investigate the role of the CFTR in airway epithelium. Description of samples: 1564 (CF-repaired), 1565 (CF DF508homozygous) iPSC-airway epithelium through basal cell intermediate. iPSC-D15CD47/CD26sort- NGFR sort x 2
Project description:Two populations of Nkx2-1+ progenitors in the developing foregut endoderm give rise to the entire post-natal lung and thyroid epithelium, but little is known about these cells, as they are difficult to isolate in a pure form. We demonstrate here the purification and directed differentiation of primordial lung and thyroid progenitors derived from mouse embryonic stem cells (ESCs). Inhibition of TGFM-NM-2 and BMP signaling, followed by combinatorial stimulation of BMP and FGF signaling can specify these cells efficiently from definitive endodermal precursors. When derived using Nkx2-1GFP knock-in reporter ESCs, these progenitors can be purified for expansion in culture and have a transcriptome that overlaps with developing lung epithelium. Upon induction, they can express a broad repertoire of markers indicative of lung and thyroid lineages and can recellularize a 3D lung tissue scaffold. Thus, we have derived a pure population of progenitors able to recapitulate the developmental milestones of lung/thyroid development. Comparison between Nkx2-1 positive and Nkx2-1 negative cells derived after 14 days of differentiation of mouse ES cells carrying a knock-in reporter gene, Nkx2-1GFP.
Project description:We perform transcriptomic profiling of a directed differentiation protocol for generating distal lung epithelial cells and alveolar type II epithelial cells (AEC2s) from pluripotent stem cells (PSCs) using bi-fluorescently targeted iPSC cell line BU3-NGST. On day 33 of distal lung differentiation, we sorted SFTPCtdTomato/NKX2-1GFP double positive cells and NKX2-1GFP single positive cells for Fluidigm single cell RNA sequencing analysis. We find canonical AEC2s genes expressed in both sorted populations but at a higher level in the SFTPCtdTomato/NKX2-1GFP double positive population. We also find genes associated with cellular proliferation to be enriched in the NKX2-1GFP single positive population, suggestive of a less mature but more proliferative subset of PSC-derived AEC2s.
Project description:Lung adenocarcinoma is responsible for significant global mortality with limited effective treatments. Although some studies suggest that these tumors arise from alveolar epithelial type 2 cells (AEC2s), there is scant information regarding the early events that might occur in human AEC2s at the inception of oncogenesis. This limitation, is partially due to a lack of human model systems that recapitulate the initiation of oncogenesis in AEC2s. Unfortunately, primary AEC2s from patients are difficult to access in vivo or stably maintain in cell cultures. Hence, we sought to develop an in vitro system to model the early stages of oncogenesis utilizing human induced AEC2s (iAEC2s) generated through the directed differentiation of induced pluripotent stem cells (iPSCs). To this end, we selected a normal human iPSC line we have previously engineered to carry fluorochrome reporters targeted to lung epithelial-specific loci, NKX2-1GFP and SFTPCtdTomato that enable monitoring and purification of alveolar lung epithelial cells. To test the effects of adenocarcinoma oncogene induction in these cells, we targeted a third locus, AAVS1 using gene editing to engineer a doxycycline-inducible cassette encoding mutant KRASG12D, the most commonly found oncogene in lung adenocarcinomas. Successful induction of KRASG12D with doxycycline was demonstrated in both the targeted undifferentiated iPSCs as well as in the iAEC2s derived from these cells. We profiled the downstream effects of KRASG12D induction in iAEC2s, comparing dox vs vehicle exposed cells by cell counting, FACS for NKX2-1GFP/SFTPCtdTomato, RT-qPCR, deep proteomic and phosphoproteomic analyses, and scRNA-sequencing. Through this characterization, we found that induction of KRASG12D robustly activates MAPK signaling resulting in a shift of iAEC2s away from their mature alveolar program towards a distal lung epithelial progenitor phenotype. Successful modeling of lung adenocarcinoma with this model system has a variety of future applications, including testing unknown mechanisms for oncogenesis, discovery of novel biomarkers of disease, or development of new effective treatment methods through drug screening.
Project description:Background. The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem / progenitor cells for the other airway cell types. The objective of this study is to better understand basal cell biology by defining the subset of expressed genes that characterize the signature of human airway epithelial basal cells. Methodology / Principal Findings. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium of healthy nonsmokers obtained by bronchial brushings in comparison to the transcriptome of the complete differentiated airway epithelium. This analysis identified the “human airway basal cell signature” as 1,161 unique genes with >5-fold higher expression level in basal cells compared to the differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The human airway basal cell signature displayed extensive overlap with genes expressed in basal cells from other human tissues and murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the airway basal cell signature was characterized by genes encoding extracellular matrix components, and growth factors and growth factor receptors, including genes related to EGFR and VEGFR signaling. However, while human airway basal cells share similarity with basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, integrins, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. Conclusion / Significance. The human airway epithelial basal cells signature identified in the present study provides novel insights into the ontogeny, molecular phenotype and biology of the stem / progenitor cells of the human airway epithelium. This study was designed to distinguish the transcriptome of the airway epithelium basal cell from that of differentiated airway epithelium. A basal cell signature was derived and analyzed for functional significance. The signature was also evaluated as basal cells differentiated into ciliated epithelium in vitro.
Project description:Airway basal cells are crucial for regeneration of the human lung airway epithelium, and are thought to be important contributors to chronic obstructive pulmonary disease (COPD). However, to reveal how basal cells contribute to disease, the basal cells need to be further characterized. We aimed to study primary human basal cells from healthy donors and COPD patients in order to identify key differences that could further our understanding of the disease mechanisms. In this study, we optimized a sorting protocol for primary human basal cells dependent on cell size and NGFR expression. The basal cell population was found to be heterogeneous in contrast to cultured basal cells. In addition, significant differences such as KRT14 expression was found exclusively in cultured cells. Also, colony-forming capacity was significantly increased in cultured cells showing a clonal enrichment in vitro. Next, by single cell RNA sequencing on primary basal cells from healthy donors and COPD patients, the gene expression changes revealed a continuum ranging from healthy basal cell signatures to diseased basal cells phenotypes. We identified several upregulated genes that may be indicative of COPD, such as stress response related genes GADD45B and AHSA1, along with genes involved in the response to hypoxia such as CITED2 and SOD1. Taken together, the presence of both healthy and diseased basal cells in stage IV COPD demonstrates the potential for regeneration through the discovery of novel therapeutic targets. In addition, we show the importance of studying primary basal cells when investigating disease mechanisms in the human lung.