Browsing by Subject "Alveolar Epithelial Cells"

Now showing 1 - 8 of 8

Open Access
Chronic lung diseases are associated with gene expression programs favoring SARS-CoV-2 entry and severity.
(Nature communications, 2021-07) Bui, Linh T; Winters, Nichelle I; Chung, Mei-I; Joseph, Chitra; Gutierrez, Austin J; Habermann, Arun C; Adams, Taylor S; Schupp, Jonas C; Poli, Sergio; Peter, Lance M; Taylor, Chase J; Blackburn, Jessica B; Richmond, Bradley W; Nicholson, Andrew G; Rassl, Doris; Wallace, William A; Rosas, Ivan O; Jenkins, R Gisli; Kaminski, Naftali; Kropski, Jonathan A; Banovich, Nicholas E; Human Cell Atlas Lung Biological Network
Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyze the transcriptomes of 611,398 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observe a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD AT2 cells express higher levels of genes linked directly to the efficiency of viral replication and the innate immune response. Additionally, we identify basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection.
Open Access
Defined conditions for long-term expansion of murine and human alveolar epithelial stem cells in three-dimensional cultures.
(STAR protocols, 2022-06-10) Konishi, Satoshi; Tata, Aleksandra; Tata, Purushothama Rao
Alveolar type 2 cells (AT2s) serve as stem cells of the alveoli and restore cell numbers after injury. Here, we describe a detailed protocol for the isolation, purification, and culture of murine and human AT2s. We have developed chemically defined and stroma-free culture conditions that enable expansion and maintenance of AT2s. The culture conditions are scalable and compatible with high-throughput chemical and genetic screenings and can potentially be used to generate large AT2 numbers for cell-based therapies. For complete details on the use and execution of this protocol, please refer to Katsura et al. (2020).
Open Access
Epigenetic basis of oncogenic-Kras-mediated epithelial-cellular proliferation and plasticity.
(Developmental cell, 2022-02) Kadur Lakshminarasimha Murthy, Preetish; Xi, Rui; Arguijo, Diana; Everitt, Jeffrey I; Kocak, Dewran D; Kobayashi, Yoshihiko; Bozec, Aline; Vicent, Silvestre; Ding, Shengli; Crawford, Gregory E; Hsu, David; Tata, Purushothama Rao; Reddy, Timothy; Shen, Xiling
Oncogenic Kras induces a hyper-proliferative state that permits cells to progress to neoplasms in diverse epithelial tissues. Depending on the cell of origin, this also involves lineage transformation. Although a multitude of downstream factors have been implicated in these processes, the precise chronology of molecular events controlling them remains elusive. Using mouse models, primary human tissues, and cell lines, we show that, in Kras-mutant alveolar type II cells (AEC2), FOSL1-based AP-1 factor guides the mSWI/SNF complex to increase chromatin accessibility at genomic loci controlling the expression of genes necessary for neoplastic transformation. We identified two orthogonal processes in Kras-mutant distal airway club cells. The first promoted their transdifferentiation into an AEC2-like state through NKX2.1, and the second controlled oncogenic transformation through the AP-1 complex. Our results suggest that neoplasms retain an epigenetic memory of their cell of origin through cell-type-specific transcription factors. Our analysis showed that a cross-tissue-conserved AP-1-dependent chromatin remodeling program regulates carcinogenesis.
Open Access
Human distal lung maps and lineage hierarchies reveal a bipotent progenitor.
(Nature, 2022-04) Kadur Lakshminarasimha Murthy, Preetish; Sontake, Vishwaraj; Tata, Aleksandra; Kobayashi, Yoshihiko; Macadlo, Lauren; Okuda, Kenichi; Conchola, Ansley S; Nakano, Satoko; Gregory, Simon; Miller, Lisa A; Spence, Jason R; Engelhardt, John F; Boucher, Richard C; Rock, Jason R; Randell, Scott H; Tata, Purushothama Rao
Mapping the spatial distribution and molecular identity of constituent cells is essential for understanding tissue dynamics in health and disease. We lack a comprehensive map of human distal airways, including the terminal and respiratory bronchioles (TRBs), which are implicated in respiratory diseases^1-4. Here, using spatial transcriptomics and single-cell profiling of microdissected distal airways, we identify molecularly distinct TRB cell types that have not-to our knowledge-been previously characterized. These include airway-associated LGR5⁺ fibroblasts and TRB-specific alveolar type-0 (AT0) cells and TRB secretory cells (TRB-SCs). Connectome maps and organoid-based co-cultures reveal that LGR5⁺ fibroblasts form a signalling hub in the airway niche. AT0 cells and TRB-SCs are conserved in primates and emerge dynamically during human lung development. Using a non-human primate model of lung injury, together with human organoids and tissue specimens, we show that alveolar type-2 cells in regenerating lungs transiently acquire an AT0 state from which they can differentiate into either alveolar type-1 cells or TRB-SCs. This differentiation programme is distinct from that identified in the mouse lung^5-7. Our study also reveals mechanisms that drive the differentiation of the bipotent AT0 cell state into normal or pathological states. In sum, our findings revise human lung cell maps and lineage trajectories, and implicate an epithelial transitional state in primate lung regeneration and disease.
Open Access
Meta-Analysis of COVID-19 BAL Single-Cell RNA Sequencing Reveals Alveolar Epithelial Transitions and Unique Alveolar Epithelial Cell Fates.
(American journal of respiratory cell and molecular biology, 2023-12) Karmaus, Peer WF; Tata, Aleksandra; Meacham, Julie M; Day, Frank; Thrower, David; Tata, Purushothama Rao; Fessler, Michael B
Single-cell RNA sequencing (scRNA-seq) of BAL cells has provided insights into coronavirus disease (COVID-19). However, reports have been limited by small patient cohorts. We performed a meta-analysis of BAL scRNA-seq data from healthy control subjects (n = 13) and patients with COVID-19 (n = 20), sourced from six independent studies (167,280 high-quality cells in total). Consistent with the source reports, increases in infiltrating leukocyte subtypes were noted, several with type I IFN signatures and unique gene expression signatures associated with transcellular chemokine signaling. Noting dramatic reductions of inferred NKX2-1 and NR4A1 activity in alveolar epithelial type II (AT-II) cells, we modeled pseudotemporal AT-II-to-AT-I progression. This revealed changes in inferred AT-II cell metabolic activity, increased transitional cells, and a previously undescribed AT-I state. This cell state was conspicuously marked by the induction of genes of the epidermal differentiation complex, including the cornified envelope protein SPRR3 (small proline-rich protein 3), upregulation of multiple KRT (keratin) genes, inferred mitochondrial dysfunction, and cell death signatures including apoptosis and ferroptosis. Immunohistochemistry of lungs from patients with COVID-19 confirmed upregulation and colocalization of KRT13 and SPRR3 in the distal airspaces. Forced overexpression of SPRR3 in human alveolar epithelial cells ex vivo did not activate caspase-3 or upregulate KRT13, suggesting that SPRR3 marks an AT-I cornification program in COVID-19 but is not sufficient for phenotypic changes.
Open Access
Rare SOX2+ Airway Progenitor Cells Generate KRT5+ Cells that Repopulate Damaged Alveolar Parenchyma following Influenza Virus Infection.
(Stem cell reports, 2016-11) Ray, Samriddha; Chiba, Norika; Yao, Changfu; Guan, Xiangrong; McConnell, Alicia M; Brockway, Brian; Que, Loretta; McQualter, Jonathan L; Stripp, Barry R
Recent studies have implicated keratin 5 (KRT5)+ cells in repopulation of damaged lung tissue following severe H1N1 influenza virus infection. However, the origins of the cells repopulating the injured alveolar region remain controversial. We sought to determine the cellular dynamics of lung repair following influenza infection and define whether nascent KRT5+ cells repopulating alveolar epithelium were derived from pre-existing alveolar or airway progenitor cells. We found that the wound-healing response begins with proliferation of SOX2+ SCGB1A1- KRT5- progenitor cells in airways. These cells generate nascent KRT5+ cells as an early response to airway injury and yield progeny that colonize damaged alveolar parenchyma. Moreover, we show that local alveolar progenitors do not contribute to nascent KRT5+ cells after injury. Repopulation of injured airway and alveolar regions leads to proximalization of distal airways by pseudostratified epithelium and of alveoli by airway-derived epithelial cells that lack the normal characteristics of mature airway or alveolar epithelium.
Open Access
Single-cell meta-analysis of SARS-CoV-2 entry genes across tissues and demographics.
(Nature medicine, 2021-03) Muus, Christoph; Luecken, Malte D; Eraslan, Gökcen; Sikkema, Lisa; Waghray, Avinash; Heimberg, Graham; Kobayashi, Yoshihiko; Vaishnav, Eeshit Dhaval; Subramanian, Ayshwarya; Smillie, Christopher; Jagadeesh, Karthik A; Duong, Elizabeth Thu; Fiskin, Evgenij; Torlai Triglia, Elena; Ansari, Meshal; Cai, Peiwen; Lin, Brian; Buchanan, Justin; Chen, Sijia; Shu, Jian; Haber, Adam L; Chung, Hattie; Montoro, Daniel T; Adams, Taylor; Aliee, Hananeh; Allon, Samuel J; Andrusivova, Zaneta; Angelidis, Ilias; Ashenberg, Orr; Bassler, Kevin; Bécavin, Christophe; Benhar, Inbal; Bergenstråhle, Joseph; Bergenstråhle, Ludvig; Bolt, Liam; Braun, Emelie; Bui, Linh T; Callori, Steven; Chaffin, Mark; Chichelnitskiy, Evgeny; Chiou, Joshua; Conlon, Thomas M; Cuoco, Michael S; Cuomo, Anna SE; Deprez, Marie; Duclos, Grant; Fine, Denise; Fischer, David S; Ghazanfar, Shila; Gillich, Astrid; Giotti, Bruno; Gould, Joshua; Guo, Minzhe; Gutierrez, Austin J; Habermann, Arun C; Harvey, Tyler; He, Peng; Hou, Xiaomeng; Hu, Lijuan; Hu, Yan; Jaiswal, Alok; Ji, Lu; Jiang, Peiyong; Kapellos, Theodoros S; Kuo, Christin S; Larsson, Ludvig; Leney-Greene, Michael A; Lim, Kyungtae; Litviňuková, Monika; Ludwig, Leif S; Lukassen, Soeren; Luo, Wendy; Maatz, Henrike; Madissoon, Elo; Mamanova, Lira; Manakongtreecheep, Kasidet; Leroy, Sylvie; Mayr, Christoph H; Mbano, Ian M; McAdams, Alexi M; Nabhan, Ahmad N; Nyquist, Sarah K; Penland, Lolita; Poirion, Olivier B; Poli, Sergio; Qi, CanCan; Queen, Rachel; Reichart, Daniel; Rosas, Ivan; Schupp, Jonas C; Shea, Conor V; Shi, Xingyi; Sinha, Rahul; Sit, Rene V; Slowikowski, Kamil; Slyper, Michal; Smith, Neal P; Sountoulidis, Alex; Strunz, Maximilian; Sullivan, Travis B; Sun, Dawei; Talavera-López, Carlos; Tan, Peng; Tantivit, Jessica; Travaglini, Kyle J; Tucker, Nathan R; Vernon, Katherine A; Wadsworth, Marc H; Waldman, Julia; Wang, Xiuting; Xu, Ke; Yan, Wenjun; Zhao, William; Ziegler, Carly GK; NHLBI LungMap Consortium; Human Cell Atlas Lung Biological Network
Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2⁺TMPRSS2⁺ cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.
Open Access
Type 2 alveolar cells are stem cells in adult lung.
(The Journal of clinical investigation, 2013-07) Barkauskas, Christina E; Cronce, Michael J; Rackley, Craig R; Bowie, Emily J; Keene, Douglas R; Stripp, Barry R; Randell, Scott H; Noble, Paul W; Hogan, Brigid LM
Gas exchange in the lung occurs within alveoli, air-filled sacs composed of type 2 and type 1 epithelial cells (AEC2s and AEC1s), capillaries, and various resident mesenchymal cells. Here, we use a combination of in vivo clonal lineage analysis, different injury/repair systems, and in vitro culture of purified cell populations to obtain new information about the contribution of AEC2s to alveolar maintenance and repair. Genetic lineage-tracing experiments showed that surfactant protein C-positive (SFTPC-positive) AEC2s self renew and differentiate over about a year, consistent with the population containing long-term alveolar stem cells. Moreover, if many AEC2s were specifically ablated, high-resolution imaging of intact lungs showed that individual survivors undergo rapid clonal expansion and daughter cell dispersal. Individual lineage-labeled AEC2s placed into 3D culture gave rise to self-renewing "alveolospheres," which contained both AEC2s and cells expressing multiple AEC1 markers, including HOPX, a new marker for AEC1s. Growth and differentiation of the alveolospheres occurred most readily when cocultured with primary PDGFRα⁺ lung stromal cells. This population included lipofibroblasts that normally reside close to AEC2s and may therefore contribute to a stem cell niche in the murine lung. Results suggest that a similar dynamic exists between AEC2s and mesenchymal cells in the human lung.