Ex vivo analysis of the contribution of FGF10⁺ cells to airway smooth muscle cell formation during early lung development

© 2017 Wiley Periodicals, Inc.Background: Airway smooth muscle cells (ASMCs) have been widely studied during embryonic lung development. These cells have been shown to control epithelial bifurcation during branching morphogenesis. Fibroblast growth factor 10-positive (FGF10+) cells, originally residing in the submesothelial mesenchyme, contribute to ASMC formation in the distal lung. The reported work aims at monitoring the response of FGF10+ progenitors and differentiated ASMCs to growth factor treatment in real time using lineage tracing in the background of an air-liquid interface (ALI) culture system. Results: FGF ligands impose divergent effects on iterative lung branching in vitro. Moreover, time-lapse imaging and endpoint analysis show that FGF9 treatment leads to amplification of the FGF10+ lineage and represses its differentiation to ASMCs. Sonic hedgehog (SHH) treatment reduces the amplification of this lineage and leads to decreased lung branching. Finally, differentiated ASMCs in proximal regions fail to expand upon FGF9 treatment. Conclusions: Our data demonstrate, in real time, that FGF9 is an important regulator of amplification, migration, and subsequent differentiation of ASMC progenitors during early lung development. The attained results agree with previous findings regarding ASMC formation and highlight the complexity of growth factor signaling networks in controlling mesenchymal cell-fate decisions in the developing mouse lung

Origin and characterization of alpha smooth muscle actin-positive cells during murine lung development

© 2017 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed PressACTA2 expression identifies pulmonary airway and vascular smooth muscle cells (SMCs) as well as alveolar myofibroblasts (MYF). Mesenchymal progenitors expressing fibroblast growth factor 10 (Fgf10), Wilms tumor 1 (Wt1), or glioma-associated oncogene 1 (Gli1) contribute to SMC formation from early stages of lung development. However, their respective contribution and specificity to the SMC and/or alveolar MYF lineages remain controversial. In addition, the contribution of mesenchymal cells undergoing active WNT signaling remains unknown. Using Fgf10CreERT2, Wt1CreERT2, Gli1CreERT2, and Axin2CreERT2 inducible driver lines in combination with a tdTomatoflox reporter line, the respective differentiation of each pool of labeled progenitor cells along the SMC and alveolar MYF lineages was quantified. The results revealed that while FGF10+ and WT1+ cells show a minor contribution to the SMC lineage, GLI1+ and AXIN2+ cells significantly contribute to both the SMC and alveolar MYF lineages, but with limited specificity. Lineage tracing using the Acta2-CreERT2 transgenic line showed that ACTA2+ cells labeled at embryonic day (E)11.5 do not expand significantly to give rise to new SMCs at E18.5. However, ACTA2+ cells labeled at E15.5 give rise to the majority (85%–97%) of the SMCs in the lung at E18.5 as well as alveolar MYF progenitors in the lung parenchyma. Fluorescence-activated cell sorting-based isolation of different subpopulations of ACTA2+ lineage-traced cells followed by gene arrays, identified transcriptomic signatures for alveolar MYF progenitors versus airway and vascular SMCs at E18.5. Our results establish a new transcriptional landscape for further experiments addressing the function of signaling pathways in the formation of different subpopulations of ACTA2+ cells. Stem Cells 2017;35:1566–1578

卒後13年目の研修医

© 2015. Published by The Company of Biologists Ltd. Lipid-containing alveolar interstitial fibroblasts (lipofibroblasts) are increasingly recognized as an important component of the epithelial stem cell niche in the rodent lung. Although lipofibroblasts were initially believed merely to assist type 2 alveolar epithelial cells in surfactant production during neonatal life, recent evidence suggests that these cells are indispensable for survival and growth of epithelial stem cells during adulthood. Despite increasing interest in lipofibroblast biology, little is known about their cellular origin or the molecular pathways controlling their formation during embryonic development. Here, we showthat a population of lipid-droplet-containing stromal cells emerges in the developing mouse lung between E15.5 and E16.5. This is accompanied by significant upregulation, in the lung mesenchyme, of peroxisome proliferator-activated receptor gamma (master switch of lipogenesis), adipose differentiation-related protein (marker of mature lipofibroblasts) and fibroblast growth factor 10 (previously shown to identify a subpopulation of lipofibroblast progenitors). We also demonstrate that although only a subpopulation of total embryonic lipofibroblasts derives from Fgf10+ progenitor cells, in vivo knockdown of Fgfr2b ligand activityand reduction in Fgf10 expression lead to global reduction in the expression levels of lipofibroblast markers at E18.5. Constitutive Fgfr1b knockouts and mutants with conditional partial inactivation of Fgfr2b in the lung mesenchyme reveal the involvement of both receptors in lipofibroblast formation and suggest a possible compensation between the two receptors. We also provide data from human fetal lungs to demonstrate the relevance of our discoveries to humans. Our results reveal an essential role for Fgf10 signaling in the formation of lipofibroblasts during late lung development

Ex vivo analysis of the contribution of FGF10⁺ cells to airway smooth muscle cell formation during early lung development

© 2017 Wiley Periodicals, Inc.Background: Airway smooth muscle cells (ASMCs) have been widely studied during embryonic lung development. These cells have been shown to control epithelial bifurcation during branching morphogenesis. Fibroblast growth factor 10-positive (FGF10+) cells, originally residing in the submesothelial mesenchyme, contribute to ASMC formation in the distal lung. The reported work aims at monitoring the response of FGF10+ progenitors and differentiated ASMCs to growth factor treatment in real time using lineage tracing in the background of an air-liquid interface (ALI) culture system. Results: FGF ligands impose divergent effects on iterative lung branching in vitro. Moreover, time-lapse imaging and endpoint analysis show that FGF9 treatment leads to amplification of the FGF10+ lineage and represses its differentiation to ASMCs. Sonic hedgehog (SHH) treatment reduces the amplification of this lineage and leads to decreased lung branching. Finally, differentiated ASMCs in proximal regions fail to expand upon FGF9 treatment. Conclusions: Our data demonstrate, in real time, that FGF9 is an important regulator of amplification, migration, and subsequent differentiation of ASMC progenitors during early lung development. The attained results agree with previous findings regarding ASMC formation and highlight the complexity of growth factor signaling networks in controlling mesenchymal cell-fate decisions in the developing mouse lung

Ex vivo analysis of the contribution of FGF10⁺ cells to airway smooth muscle cell formation during early lung development

© 2017 Wiley Periodicals, Inc.Background: Airway smooth muscle cells (ASMCs) have been widely studied during embryonic lung development. These cells have been shown to control epithelial bifurcation during branching morphogenesis. Fibroblast growth factor 10-positive (FGF10+) cells, originally residing in the submesothelial mesenchyme, contribute to ASMC formation in the distal lung. The reported work aims at monitoring the response of FGF10+ progenitors and differentiated ASMCs to growth factor treatment in real time using lineage tracing in the background of an air-liquid interface (ALI) culture system. Results: FGF ligands impose divergent effects on iterative lung branching in vitro. Moreover, time-lapse imaging and endpoint analysis show that FGF9 treatment leads to amplification of the FGF10+ lineage and represses its differentiation to ASMCs. Sonic hedgehog (SHH) treatment reduces the amplification of this lineage and leads to decreased lung branching. Finally, differentiated ASMCs in proximal regions fail to expand upon FGF9 treatment. Conclusions: Our data demonstrate, in real time, that FGF9 is an important regulator of amplification, migration, and subsequent differentiation of ASMC progenitors during early lung development. The attained results agree with previous findings regarding ASMC formation and highlight the complexity of growth factor signaling networks in controlling mesenchymal cell-fate decisions in the developing mouse lung

Ex vivo analysis of the contribution of FGF10⁺ cells to airway smooth muscle cell formation during early lung development

© 2017 Wiley Periodicals, Inc.Background: Airway smooth muscle cells (ASMCs) have been widely studied during embryonic lung development. These cells have been shown to control epithelial bifurcation during branching morphogenesis. Fibroblast growth factor 10-positive (FGF10+) cells, originally residing in the submesothelial mesenchyme, contribute to ASMC formation in the distal lung. The reported work aims at monitoring the response of FGF10+ progenitors and differentiated ASMCs to growth factor treatment in real time using lineage tracing in the background of an air-liquid interface (ALI) culture system. Results: FGF ligands impose divergent effects on iterative lung branching in vitro. Moreover, time-lapse imaging and endpoint analysis show that FGF9 treatment leads to amplification of the FGF10+ lineage and represses its differentiation to ASMCs. Sonic hedgehog (SHH) treatment reduces the amplification of this lineage and leads to decreased lung branching. Finally, differentiated ASMCs in proximal regions fail to expand upon FGF9 treatment. Conclusions: Our data demonstrate, in real time, that FGF9 is an important regulator of amplification, migration, and subsequent differentiation of ASMC progenitors during early lung development. The attained results agree with previous findings regarding ASMC formation and highlight the complexity of growth factor signaling networks in controlling mesenchymal cell-fate decisions in the developing mouse lung

Effect of silica on the susceptibility of mice to experimental histoplasmosis.

© 2017 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed PressACTA2 expression identifies pulmonary airway and vascular smooth muscle cells (SMCs) as well as alveolar myofibroblasts (MYF). Mesenchymal progenitors expressing fibroblast growth factor 10 (Fgf10), Wilms tumor 1 (Wt1), or glioma-associated oncogene 1 (Gli1) contribute to SMC formation from early stages of lung development. However, their respective contribution and specificity to the SMC and/or alveolar MYF lineages remain controversial. In addition, the contribution of mesenchymal cells undergoing active WNT signaling remains unknown. Using Fgf10CreERT2, Wt1CreERT2, Gli1CreERT2, and Axin2CreERT2 inducible driver lines in combination with a tdTomatoflox reporter line, the respective differentiation of each pool of labeled progenitor cells along the SMC and alveolar MYF lineages was quantified. The results revealed that while FGF10+ and WT1+ cells show a minor contribution to the SMC lineage, GLI1+ and AXIN2+ cells significantly contribute to both the SMC and alveolar MYF lineages, but with limited specificity. Lineage tracing using the Acta2-CreERT2 transgenic line showed that ACTA2+ cells labeled at embryonic day (E)11.5 do not expand significantly to give rise to new SMCs at E18.5. However, ACTA2+ cells labeled at E15.5 give rise to the majority (85%–97%) of the SMCs in the lung at E18.5 as well as alveolar MYF progenitors in the lung parenchyma. Fluorescence-activated cell sorting-based isolation of different subpopulations of ACTA2+ lineage-traced cells followed by gene arrays, identified transcriptomic signatures for alveolar MYF progenitors versus airway and vascular SMCs at E18.5. Our results establish a new transcriptional landscape for further experiments addressing the function of signaling pathways in the formation of different subpopulations of ACTA2+ cells. Stem Cells 2017;35:1566–1578

Origin and characterization of alpha smooth muscle actin-positive cells during murine lung development

© 2017 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed PressACTA2 expression identifies pulmonary airway and vascular smooth muscle cells (SMCs) as well as alveolar myofibroblasts (MYF). Mesenchymal progenitors expressing fibroblast growth factor 10 (Fgf10), Wilms tumor 1 (Wt1), or glioma-associated oncogene 1 (Gli1) contribute to SMC formation from early stages of lung development. However, their respective contribution and specificity to the SMC and/or alveolar MYF lineages remain controversial. In addition, the contribution of mesenchymal cells undergoing active WNT signaling remains unknown. Using Fgf10CreERT2, Wt1CreERT2, Gli1CreERT2, and Axin2CreERT2 inducible driver lines in combination with a tdTomatoflox reporter line, the respective differentiation of each pool of labeled progenitor cells along the SMC and alveolar MYF lineages was quantified. The results revealed that while FGF10+ and WT1+ cells show a minor contribution to the SMC lineage, GLI1+ and AXIN2+ cells significantly contribute to both the SMC and alveolar MYF lineages, but with limited specificity. Lineage tracing using the Acta2-CreERT2 transgenic line showed that ACTA2+ cells labeled at embryonic day (E)11.5 do not expand significantly to give rise to new SMCs at E18.5. However, ACTA2+ cells labeled at E15.5 give rise to the majority (85%–97%) of the SMCs in the lung at E18.5 as well as alveolar MYF progenitors in the lung parenchyma. Fluorescence-activated cell sorting-based isolation of different subpopulations of ACTA2+ lineage-traced cells followed by gene arrays, identified transcriptomic signatures for alveolar MYF progenitors versus airway and vascular SMCs at E18.5. Our results establish a new transcriptional landscape for further experiments addressing the function of signaling pathways in the formation of different subpopulations of ACTA2+ cells. Stem Cells 2017;35:1566–1578