Endogenous Fibroblastic Progenitor Cells in the Adult Mouse Lung Are Highly Enriched in the Sca-1 Positive Cell Fraction (original) (raw)
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Isolation of an Adult Mouse Lung Mesenchymal Progenitor Cell Population
2007
Contained within the adult lung are differentiated mesenchymal cell types (cartilage, smooth muscle, and myofibrobasts) that provide structural support for airways and vessels. Alterations in the number and phenotype of these cells figure prominently in the pathogenesis of a variety of lung diseases. While these cells are thought to arise locally, progenitors have yet to be purified. In previous work, we developed a method for isolating progenitors from lung tissue: this technique takes advantage of the unique ability of cell populations enriched for somatic stem and progenitor activity to efflux the vital dye Hoechst 33342, a feature that permits isolation by flow cytometry-based procedures. Using this method, we determined that a rare population of mesenchymal progenitors resides within the CD45؊ CD31؊ Hoechst low fraction of the adult murine lung. Similar to other mesenchymal progenitors, these cells express Sca-1, CD106, and CD44; can be serially passaged; and can differentiate to smooth muscle, cartilage, bone, and fat. Overall, these findings demonstrate that a phenotypically distinct mesenchymal progenitor resides within the adult murine lung, and provide a scheme for their isolation and study.
Isolation of stem/progenitor cells from normal lung tissue of adult humans
Cell Proliferation, 2009
Objectives: This study aimed to isolate and characterize stem/progenitor cells, starting from normal airway epithelia, obtained from human adults.Materials and methods: Cultures of multicellular spheroids were obtained from human lung tissue specimens after mechanical and enzymatic digestion. Tissue-specific markers were detected on their cells by immunohistochemical and immunofluorescent techniques. Ultrastructural morphology of the spheroids (termed as bronchospheres) was evaluated by electron microscopy, gene expression analysis was performed by reverse transcription–polymerase chain reaction, and gene down-regulation was analysed by an RNA interference technique.Results: Bronchospheres were found to be composed of cells with high expression of stem cell regulatory genes, which was not or was only weakly detectable in original tissues. Morphological analysis showed that bronchospheres were composed of mixed phenotype cells with type II alveolar and Clara cell features, highlighting their airway resident cell origin. In addition to displaying specific pulmonary and epithelial commitment, bronchospheres showed mesenchymal features. Silencing of the Slug gene, known to play a pivotal role in epithelial–mesenchymal transition processes and which was highly expressed in bronchospheres but not in original tissue, led bronchospheres to gain a differentiated bronchial/alveolar phenotype and to lose the stemness gene expression pattern.Conclusions: Ours is the first study to describe ex vivo expansion of stem/progenitor cells resident in human lung epithelia, and our results suggest that the epithelial–mesenchymal transition process, still active in a subset of airway cells, may regulate transit of stem/progenitor cells towards epithelial differentiation.
Stem/progenitor cells in the developing human lung
2016
Human lungs are composed of more than 40 cell types. The lung is classified as a “conditionally renewing” tissue and is able of a quick response to cellular damage thanks to the presence of multiple stem/progenitor cells. Embryonic and fetal progenitors actively proliferate determining lung size, shape and cellular composition and could be of paramount importance in understanding lung development and mechanisms of congenital diseases. Furthermore, developmental molecular pathways may be chronically or aberrantly activated in tumorigenesis or in lung diseases later in life. Lungs have a mixed endodermal and mesodermal origin. Endoderm progenitors are early marked by TTF1. Other reported markers of endodermal respiratory progenitors are Sox2, Sox9 and Id2. Proximal versus distal differentiation is guided by the expression of Fgf10. Little is known about mesodermal stem/progenitor cells in the developing lung. A signaling interplay among endoderm, mesoderm and mesothelium plays a role ...
Isolation Of Alveolar Epithelial Type II Progenitor Cells From The Adult Human Lungs
C59. STEM CELLS, PROGENITOR CELLS AND TISSUE REGENERATION, 2010
Resident stem/progenitor cells in the lung are important for tissue homeostasis and repair. However, a progenitor population for alveolar type II (ATII) cells in adult human lungs has not been identified. The aim of this study is to isolate progenitor cells from adult human lungs with the ability to differentiate into ATII cells. We isolated colony-forming cells that had the capability for self-renewal and the potential to generate ATII cells in vitro. These undifferentiated progenitor cells expressed surface markers of mesenchymal stem cells (MSCs) and surfactant proteins associated with ATII cells, such as CD90 and pro-surfactant protein-C (pro-SP-C), respectively. Microarray analyses indicated that transcripts associated with lung development were enriched in the pro-SP-C þ /CD90 þ cells compared with bone marrow-MSCs. Furthermore, pathological evaluation indicated that pro-SP-C and CD90 double-positive cells were present within alveolar walls in normal lungs, and significantly increased in ATII cell hyperplasias contributing to alveolar epithelial repair in damaged lungs. Our findings demonstrated that adult human lungs contain a progenitor population for ATII cells. This study is a first step toward better understanding of stem cell biology in adult human lung alveoli.
Isolation of alveolar epithelial type II progenitor cells from adult human lungs
Laboratory Investigation, 2011
Resident stem/progenitor cells in the lung are important for tissue homeostasis and repair. However, a progenitor population for alveolar type II (ATII) cells in adult human lungs has not been identified. The aim of this study is to isolate progenitor cells from adult human lungs with the ability to differentiate into ATII cells. We isolated colony-forming cells that had the capability for self-renewal and the potential to generate ATII cells in vitro. These undifferentiated progenitor cells expressed surface markers of mesenchymal stem cells (MSCs) and surfactant proteins associated with ATII cells, such as CD90 and pro-surfactant protein-C (pro-SP-C), respectively. Microarray analyses indicated that transcripts associated with lung development were enriched in the pro-SP-C þ /CD90 þ cells compared with bone marrow-MSCs. Furthermore, pathological evaluation indicated that pro-SP-C and CD90 double-positive cells were present within alveolar walls in normal lungs, and significantly increased in ATII cell hyperplasias contributing to alveolar epithelial repair in damaged lungs. Our findings demonstrated that adult human lungs contain a progenitor population for ATII cells. This study is a first step toward better understanding of stem cell biology in adult human lung alveoli.
Laboratory Investigation, 2005
Mesenchymal stem cells (MSCs) are multipotent cells able to differentiate along different pathways including chondrogenic, osteogenic and adipogenic lineages. MSCs with a fibroblast-like morphology have been identified in human fetal lung. However, their frequency and characterization in human adult lung have not been yet evaluated. Therefore, we analyzed the mesenchymal phenotype and differentiation ability of cultured human adult bronchial fibroblast-like cells (Br) in comparison with those of mesenchymal cell progenitors isolated from fetal lung (ICIG7) and adult bone marrow (BM212) tissues. Surface immunophenotyping by flow cytometry revealed a similar expression pattern of antigens characteristic of marrow-derived MSCs, including CD34 (À), CD45 (À), CD90/Thy-1 ( þ ), CD73/SH3, SH4 ( þ ), CD105/SH2 ( þ ) and CD166/ALCAM ( þ ) in Br, ICIG7 and BM212 cells. There was one exception, STRO-1 antigen, which was only weakly expressed in Br cells. Analysis of cytoskeleton and matrix composition by immunostaining showed that lung and marrow-derived cells homogeneously expressed vimentin and nestin proteins in intermediate filaments while they were all devoid of epithelial cytokeratins. Additionally, a-smooth muscle actin was also present in microfilaments of a low number of cells. All cell types predominantly produced collagen and fibronectin extracellular matrix as evidenced by staining with the monoclonal antibodies to collagen prolyl 4-hydroxylase and fibronectin isoforms containing the extradomain (ED)-A together with ED-B in ICIG7 cells. Br cells similarly to fetal lung and marrow fibroblasts were able to differentiate along the three adipogenic, osteogenic and chondrogenic mesenchymal pathways when cultured under appropriate inducible conditions. Altogether, these data indicate that MSCs are present in human adult lung. They may be actively involved in lung tissue repair under physiological and pathological circumstances. Laboratory Investigation (2005) 85, 962-971.
Journal of Tissue Engineering and Regenerative Medicine, 2012
Compensatory growth is mediated by multiple cell types that interact during organ repair. To elucidate the relationship between the stem/progenitor cells that proliferate or differentiate and the somatic cells of lung, we utilized a novel ex vivo pneumoexplant system. Applying this technique, we identified a sustained culture of repopulating adult progenitors in the form of free floating anchorage-independent cells (AICs). AICs did not express integrin proteins α5, β3, and β7, and constituted 37% of the total culture at day 14, yielding a mixed yet conserved population that recapitulated RNA expression patterns of the healthy lung. AICs exhibited rapid proliferation manifested by a marked 60-fold increase in cell numbers by day 21. Over 50% of the AIC population was cKit + or double-positive for CD45 + and CD11b + antigenic determinants, consistent with cells of hematopoietic origin. The latter subset was found to be enriched with prosurfactant protein-C and SCGB1A1 expressing putative stem cells and with aquaporin-5 producing cells, characteristic of terminally differentiated alveolar epithelial type-1 pneumocytes.
Journal of Clinical Investigation, 2007
The origin and turnover of connective tissue cells in adult human organs, including the lung, are not well understood. Here, studies of cells derived from human lung allografts demonstrate the presence of a multipotent mesenchymal cell population, which is locally resident in the human adult lung and has extended life span in vivo. Examination of plastic-adherent cell populations in bronchoalveolar lavage samples obtained from 76 human lung transplant recipients revealed clonal proliferation of fibroblast-like cells in 62% (106 of 172) of samples. Immunophenotyping of these isolated cells demonstrated expression of vimentin and prolyl-4-hydroxylase, indicating a mesenchymal phenotype. Multiparametric flow cytometric analyses revealed expression of cell-surface proteins, CD73, CD90, and CD105, commonly found on mesenchymal stem cells (MSCs). Hematopoietic lineage markers CD14, CD34, and CD45 were absent. Multipotency of these cells was demonstrated by their capacity to differentiate into adipocytes, chondrocytes, and osteocytes. Cytogenetic analysis of cells from 7 sex-mismatched lung transplant recipients harvested up to 11 years after transplant revealed that 97.2% ± 2.1% expressed the sex genotype of the donor. The presence of MSCs of donor sex identity in lung allografts even years after transplantation provides what we believe to be the first evidence for connective tissue cell progenitors that reside locally within a postnatal, nonhematopoietic organ. Nonstandard abbreviations used: aP2, adipocyte fatty acid binding protein 2; BAL, bronchoalveolar lavage; BOS, bronchiolitis obliterans syndrome; CFU-F, CFU-fibroblast; FABP4, fatty acid binding protein 4, adipocyte; MSC, mesenchymal stem cell. Conflict of interest: The authors have declared that no conflict of interest exists. Citation for this article: J. Clin. Invest. 117:989-996 (2007).