Successful host defense against numerous pulmonary infections depends on bacterial clearance by polymorphonuclear leukocytes (PMNs); however, excessive PMN accumulation can result in life-threatening lung injury. Local expression of CXC chemokines is critical for PMN recruitment. The impact of chemokine-dependent PMN recruitment during pulmonary
Geraldine Nouailles, Anca Dorhoi, Markus Koch, Jens Zerrahn, January Weiner 3rd, Kellen C. Faé, Frida Arrey, Stefanie Kuhlmann, Silke Bandermann, Delia Loewe, Hans-Joachim Mollenkopf, Alexis Vogelzang, Catherine Meyer-Schwesinger, Hans-Willi Mittrücker, Gayle McEwen, Stefan H.E. Kaufmann
There is increasing evidence that vitamin A deficiency in utero correlates with abnormal airway smooth muscle (SM) function in postnatal life. The bioactive vitamin A metabolite retinoic acid (RA) is essential for formation of the lung primordium; however, little is known about the impact of early fetal RA deficiency on postnatal lung structure and function. Here, we provide evidence that during murine lung development, endogenous RA has a key role in restricting the airway SM differentiation program during airway formation. Using murine models of pharmacological, genetic, and dietary vitamin A/RA deficiency, we found that disruption of RA signaling during embryonic development consistently resulted in an altered airway SM phenotype with markedly increased expression of SM markers. The aberrant phenotype persisted postnatally regardless of the adult vitamin A status and manifested as structural changes in the bronchial SM and hyperresponsiveness of the airway without evidence of inflammation. Our data reveal a role for endogenous RA signaling in restricting SM differentiation and preventing precocious and excessive SM differentiation when airways are forming.
Felicia Chen, Hector Marquez, Youn-Kyung Kim, Jun Qian, Fengzhi Shao, Alan Fine, William W. Cruikshank, Loredana Quadro, Wellington V. Cardoso
Chronic obstructive pulmonary disease (COPD) involves aberrant airway inflammatory
responses to cigarette smoke (CS) that are associated with epithelial cell
dysfunction, cilia shortening, and mucociliary clearance disruption. Exposure to CS
reduced cilia length and induced autophagy in vivo and in differentiated mouse
tracheal epithelial cells (MTECs). Autophagy-impaired
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Hilaire C. Lam, Suzanne M. Cloonan, Abhiram R. Bhashyam, Jeffery A. Haspel, Anju Singh, J. Fah Sathirapongsasuti, Morgan Cervo, Hongwei Yao, Anna L. Chung, Kenji Mizumura, Chang Hyeok An, Bin Shan, Jonathan M. Franks, Kathleen J. Haley, Caroline A. Owen, Yohannes Tesfaigzi, George R. Washko, John Quackenbush, Edwin K. Silverman, Irfan Rahman, Hong Pyo Kim, Ashfaq Mahmood, Shyam S. Biswal, Stefan W. Ryter, Augustine M.K. Choi
The use of induced pluripotent stem cells (iPSCs) has been postulated to be the most effective strategy for developing patient-specific respiratory epithelial cells, which may be valuable for lung-related cell therapy and lung tissue engineering. We generated a relatively homogeneous population of alveolar epithelial type II (AETII) and type I (AETI) cells from human iPSCs that had phenotypic properties similar to those of mature human AETII and AETI cells. We used these cells to explore whether lung tissue can be regenerated in vitro. Consistent with an AETII phenotype, we found that up to 97% of cells were positive for surfactant protein C, 95% for mucin-1, 93% for surfactant protein B, and 89% for the epithelial marker CD54. Additionally, exposing induced AETII to a Wnt/β-catenin inhibitor (IWR-1) changed the iPSC-AETII–like phenotype to a predominantly AETI-like phenotype. We found that of induced AET1 cells, more than 90% were positive for type I markers, T1α, and caveolin-1. Acellular lung matrices were prepared from whole rat or human adult lungs treated with decellularization reagents, followed by seeding these matrices with alveolar cells derived from human iPSCs. Under appropriate culture conditions, these progenitor cells adhered to and proliferated within the 3D lung tissue scaffold and displayed markers of differentiated pulmonary epithelium.
Mahboobe Ghaedi, Elizabeth A. Calle, Julio J. Mendez, Ashley L. Gard, Jenna Balestrini, Adam Booth, Peter F. Bove, Liqiong Gui, Eric S. White, Laura E. Niklason
The molecular mechanisms that control innate immune cell trafficking during chronic
infection and inflammation, such as in tuberculosis (TB), are incompletely
understood. During active TB, myeloid cells infiltrate the lung and sustain local
inflammation. While the chemoattractants that orchestrate these processes are
increasingly recognized, the posttranscriptional events that dictate their
availability are unclear. We identified microRNA-223 (miR-223) as an upregulated
small noncoding RNA in blood and lung parenchyma of TB patients and during murine TB.
Deletion of miR-223 rendered TB-resistant mice highly susceptible to acute lung
infection. The lethality of
Anca Dorhoi, Marco Iannaccone, Maura Farinacci, Kellen C. Faé, Jörg Schreiber, Pedro Moura-Alves, Geraldine Nouailles, Hans-Joachim Mollenkopf, Dagmar Oberbeck-Müller, Sabine Jörg, Ellen Heinemann, Karin Hahnke, Delia Löwe, Franca Del Nonno, Delia Goletti, Rosanna Capparelli, Stefan H.E. Kaufmann
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.
Christina E. Barkauskas, Michael J. Cronce, Craig R. Rackley, Emily J. Bowie, Douglas R. Keene, Barry R. Stripp, Scott H. Randell, Paul W. Noble, Brigid L.M. Hogan
Atopic asthma is a chronic inflammatory disease of the lungs generally marked by excessive Th2 inflammation. The role of allergen-specific IgG in asthma is still controversial; however, a receptor of IgG–immune complexes (IgG-ICs), FcγRIII, has been shown to promote Th2 responses through an unknown mechanism. Herein, we demonstrate that allergen-specific IgG-ICs, formed upon reexposure to allergen, promoted Th2 responses in two different models of IC-mediated inflammation that were independent of a preformed T cell memory response. Development of Th2-type airway inflammation was shown to be both FcγRIII and TLR4 dependent, and T cells were necessary and sufficient for this process to occur, even in the absence of type 2 innate lymphoid cells. We sought to identify downstream targets of FcγRIII signaling that could contribute to this process and demonstrated that bone marrow–derived DCs, alveolar macrophages, and respiratory DCs significantly upregulated IL-33 when activated through FcγRIII and TLR4. Importantly, IC-induced Th2 inflammation was dependent on the ST2/IL-33 pathway. Our results suggest that allergen-specific IgG can enhance secondary responses by ligating FcγRIII on antigen-presenting cells to augment development of Th2-mediated responses in the lungs via an IL-33–dependent mechanism.
Melissa Y. Tjota, Jesse W. Williams, Tiffany Lu, Bryan S. Clay, Tiara Byrd, Cara L. Hrusch, Donna C. Decker, Claudia Alves de Araujo, Paul J. Bryce, Anne I. Sperling
Increased airway smooth muscle (ASM) contractility and the development of airway hyperresponsiveness (AHR) are cardinal features of asthma, but the signaling pathways that promote these changes are poorly understood. Tyrosine phosphorylation is tightly regulated by the opposing actions of protein tyrosine kinases and phosphatases, but little is known about whether tyrosine phosphatases influence AHR. Here, we demonstrate that genetic inactivation of receptor-like protein tyrosine phosphatase J (
Tamiko R. Katsumoto, Makoto Kudo, Chun Chen, Aparna Sundaram, Elliott C. Callahan, Jing W. Zhu, Joseph Lin, Connor E. Rosen, Boryana N. Manz, Jae W. Lee, Michael A. Matthay, Xiaozhu Huang, Dean Sheppard, Arthur Weiss
Chemically modified mRNA is capable of inducing therapeutic levels of protein expression while circumventing the threat of genomic integration often associated with viral vectors. We utilized this novel therapeutic tool to express the regulatory T cell transcription factor, FOXP3, in a time- and site-specific fashion in murine lung, in order to prevent allergic asthma in vivo. We show that modified
Lauren E. Mays, Susanne Ammon-Treiber, Benedikt Mothes, Mohammed Alkhaled, Jennifer Rottenberger, Eva Sophie Müller-Hermelink, Melanie Grimm, Markus Mezger, Sandra Beer-Hammer, Esther von Stebut, Nikolaus Rieber, Bernd Nürnberg, Matthias Schwab, Rupert Handgretinger, Marco Idzko, Dominik Hartl, Michael S.D. Kormann
Alveolar capillary dysplasia (ACD) is a congenital, lethal disorder of the pulmonary vasculature. Phosphatase and tensin homologue deleted from chromosome 10 (Pten) encodes a lipid phosphatase controlling key cellular functions, including stem/progenitor cell proliferation and differentiation; however, the role of PTEN in mesodermal lung cell lineage formation remains unexamined. To determine the role of mesodermal PTEN in the ontogeny of various mesenchymal cell lineages during lung development, we specifically deleted Pten in early embryonic lung mesenchyme in mice. Pups lacking Pten died at birth, with evidence of failure in blood oxygenation. Analysis at the cellular level showed defects in angioblast differentiation to endothelial cells and an accompanying accumulation of the angioblast cell population that was associated with disorganized capillary beds. We also found decreased expression of Forkhead box protein F1 (Foxf1), a gene associated with the ACD human phenotype. Analysis of human samples for ACD revealed a significant decrease in PTEN and increased activated protein kinase B (AKT). These studies demonstrate that mesodermal PTEN has a key role in controlling the amplification of angioblasts as well as their differentiation into endothelial cells, thereby directing the establishment of a functional gas exchange interface. Additionally, these mice could serve as a murine model of ACD.
Caterina Tiozzo, Gianni Carraro, Denise Al Alam, Sheryl Baptista, Soula Danopoulos, Aimin Li, Maria Lavarreda-Pearce, Changgong Li, Stijn De Langhe, Belinda Chan, Zea Borok, Saverio Bellusci, Parviz Minoo