Lung Epithelial Progenitor Cells Research Articles

Lung Progenitor and Stem Cell Transplantation as a Potential Regenerative Therapy for Lung Diseases.

Chronic lung diseases are debilitating illnesses ranking among the top causes of death globally. Currently, clinically available therapeutic options capable of curing chronic lung diseases are limited to lung transplantation, which is hindered by donor organ shortage. This highlights the urgent need for alternative strategies to repair damaged lung tissues. Stem cell transplantation has emerged as a promising avenue for regenerative treatment of the lung, which involves delivery of healthy lung epithelial progenitor cells that subsequently engraft in the injured tissue and further differentiate to reconstitute the functional respiratory epithelium. These transplanted progenitor cells possess the remarkable ability to self-renew, thereby offering the potential for sustained long-term treatment effects. Notably, the transplantation of basal cells, the airway stem cells, holds the promise for rehabilitating airway injuries resulting from environmental factors or genetic conditions such as cystic fibrosis. Similarly, for diseases affecting the alveoli, alveolar type II cells have garnered interest as a viable alveolar stem cell source for restoring the lung parenchyma from genetic or environmentally induced dysfunctions. Expanding upon these advancements, the use of induced pluripotent stem cells to derive lung progenitor cells for transplantation offers advantages such as scalability and patient specificity. In this review, we comprehensively explore the progress made in lung stem cell transplantation, providing insights into the current state of the field and its future prospects.

Inhalable Textile Microplastic Fibers Impair Airway Epithelial Differentiation.

Rationale: Microplastics are a pressing global concern, and inhalation of microplastic fibers has been associated with interstitial and bronchial inflammation in flock workers. However, how microplastic fibers affect the lungs is unknown. Objectives: Our aim was to assess the effects of 12 × 31 μm nylon 6,6 (nylon) and 15 × 52 μm polyethylene terephthalate (polyester) textile microplastic fibers on lung epithelial growth and differentiation. Methods: We used human and murine alveolar and airway-type organoids as well as air-liquid interface cultures derived from primary lung epithelial progenitor cells and incubated these with either nylon or polyester fibers or nylon leachate. In addition, mice received one dose of nylon fibers or nylon leachate, and, 7 days later, organoid-forming capacity of isolated epithelial cells was investigated. Measurements and Main Results: We observed that nylon microfibers, more than polyester, inhibited developing airway organoids and not established ones. This effect was mediated by components leaching from nylon. Epithelial cells isolated from mice exposed to nylon fibers or leachate also formed fewer airway organoids, suggesting long-lasting effects of nylon components on epithelial cells. Part of these effects was recapitulated in human air-liquid interface cultures. Transcriptomic analysis revealed upregulation of Hoxa5 after exposure to nylon fibers. Inhibiting Hoxa5 during nylon exposure restored airway organoid formation, confirming Hoxa5's pivotal role in the effects of nylon. Conclusions: These results suggest that components leaching from nylon 6,6 may especially harm developing airways and/or airways undergoing repair, and we strongly encourage characterization in more detail of both the hazard of and the exposure to microplastic fibers.

Age-associated H3K9me2 loss alters the regenerative equilibrium between murine lung alveolar and bronchiolar progenitors

The lung contains multiple progenitor cell types, but how their responses are choreographed during injury repair and whether this changes with age is poorly understood. We report that histone H3 lysine 9 di-methylation (H3K9me2), mediated by the methyltransferase G9a, regulates the dynamics of distal lung epithelial progenitor cells and that this regulation deteriorates with age. In aged mouse lungs, H3K9me2 loss coincided with fewer alveolar type 2 (AT2) cell progenitors and reduced alveolar regeneration but increased the frequency and activity of multipotent bronchioalveolar stem cells (BASCs) and bronchiolar progenitor club cells. H3K9me2 depletion in young mice decreased AT2 progenitor activity and impaired alveolar injury repair. Conversely, H3K9me2 depletion increased chromatin accessibility of bronchiolar cell genes, increased BASC frequency, and accelerated bronchiolar cell injury repair. These findings indicate that during aging, the epigenetic regulation that coordinates lung progenitor cells' regenerative responses becomes dysregulated, aiding our understanding of age-related susceptibility to lung disease.

Niche-Dependent Regulation of Lkb1 in the Proliferation of Lung Epithelial Progenitor Cells

Lung homeostasis and regeneration depend on lung epithelial progenitor cells. Lkb1 (Liver Kinase B1) has known roles in the differentiation of airway epithelial cells during embryonic development. However, the effects of Lkb1 in adult lung epithelial progenitor cell regeneration and its mechanisms of action have not been determined. In this study, we investigated the mechanism by which Lkb1 regulates lung epithelial progenitor cell regeneration. Organoid culture showed that loss of Lkb1 significantly reduced the proliferation of club cells and alveolar type 2 (AT2) cells in vitro. In the absence of Lkb1, there is a slower recovery rate of the damaged airway epithelium in naphthalene-induced airway epithelial injury and impaired expression of surfactant protein C during bleomycin-induced alveolar epithelial damage. Moreover, the expression of autophagy-related genes was reduced in club cells and increased in AT2 cells, but the expression of Claudin-18 was obviously reduced in AT2 cells after Lkb1 knockdown. On the whole, our findings indicated that Lkb1 may promote the proliferation of lung epithelial progenitor cells via a niche-dependent pathway and is required for the repair of the damaged lung epithelium.

Generation of Airway Epithelial Cell Air-Liquid Interface Cultures from Human Pluripotent Stem Cells

Diseases of the conducting airway such as asthma, cystic fibrosis (CF), primary ciliary dyskinesia (PCD), and viral respiratory infections are major causes of morbidity and mortality worldwide. In vitro platforms using human bronchial epithelial cells (HBECs) have been instrumental to our understanding of the airway epithelium in health and disease. Access to HBECs from individuals with rare genetic diseases or rare mutations is a bottleneck in lung research. Induced pluripotent stem cells (iPSCs) are readily generated by "reprogramming" somatic cells and retain the unique genetic background of the individual donor. Recent advances allow for the directed differentiation of iPSCs to lung epithelial progenitor cells, alveolar type 2 cells, as well as the cells of the conducting airway epithelium via basal cells, the major airway stem cells. Here we outline a protocol for the maintenance and expansion of iPSC-derived airway basal cells (hereafter iBCs) as well as their trilineage differentiation in air-liquid interface (ALI) cultures. iBCs are maintained and expanded as epithelial spheres suspended in droplets of extracellular matrix cultured in a primary basal cell medium supplemented with inhibitors of TGF-ß and BMP signaling pathways. iBCs within these epithelial spheres express key basal markers TP63 and NGFR, can be purified by fluorescence activated cell sorting (FACS), and when plated on porous membranes in standard ALI culture conditions, differentiate into a functional airway epithelium. ALI cultures derived from healthy donors are composed of basal, secretory and multiciliated cells and demonstrate epithelial barrier integrity, motile cilia, and mucus secretion. Cultures derived from individuals with CF or PCD recapitulate the dysfunctional CFTR-mediated chloride transport or immotile cilia, the respective disease-causing epithelial defects. Here, we present a protocol for the generation of human cells that can be applied for modeling and understanding airway diseases.

Generation of Airway Epithelial Cell Air-Liquid Interface Cultures from Human Pluripotent Stem Cells.

Diseases of the conducting airway such as asthma, cystic fibrosis (CF), primary ciliary dyskinesia (PCD), and viral respiratory infections are major causes of morbidity and mortality worldwide. In vitro platforms using human bronchial epithelial cells (HBECs) have been instrumental to our understanding of the airway epithelium in health and disease. Access to HBECs from individuals with rare genetic diseases or rare mutations is a bottleneck in lung research. Induced pluripotent stem cells (iPSCs) are readily generated by "reprogramming" somatic cells and retain the unique genetic background of the individual donor. Recent advances allow for the directed differentiation of iPSCs to lung epithelial progenitor cells, alveolar type 2 cells, as well as the cells of the conducting airway epithelium via basal cells, the major airway stem cells. Here we outline a protocol for the maintenance and expansion of iPSC-derived airway basal cells (hereafter iBCs) as well as their trilineage differentiation in air-liquid interface (ALI) cultures. iBCs are maintained and expanded as epithelial spheres suspended in droplets of extracellular matrix cultured in a primary basal cell medium supplemented with inhibitors of TGF-ß and BMP signaling pathways. iBCs within these epithelial spheres express key basal markers TP63 and NGFR, can be purified by fluorescence activated cell sorting (FACS), and when plated on porous membranes in standard ALI culture conditions, differentiate into a functional airway epithelium. ALI cultures derived from healthy donors are composed of basal, secretory and multiciliated cells and demonstrate epithelial barrier integrity, motile cilia, and mucus secretion. Cultures derived from individuals with CF or PCD recapitulate the dysfunctional CFTR-mediated chloride transport or immotile cilia, the respective disease-causing epithelial defects. Here, we present a protocol for the generation of human cells that can be applied for modeling and understanding airway diseases.

MICU1-dependent mitochondrial calcium uptake regulates lung alveolar type 2 cell plasticity and lung regeneration.

Lung alveolar type 2 (AT2) cells are progenitors for alveolar type 1 (AT1) cells. Although many factors regulate AT2 cell plasticity, the role of mitochondrial calcium (mCa2+) uptake in controlling AT2 cells remains unclear. We previously identified that the miR-302 family supports lung epithelial progenitor cell proliferation and less differentiated phenotypes during development. Here, we report that a sustained elevation of miR-302 in adult AT2 cells decreases AT2-to-AT1 cell differentiation during the Streptococcus pneumoniae–induced lung injury repair. We identified that miR-302 targets and represses the expression of mitochondrial Ca2+ uptake 1 (MICU1), which regulates mCa2+ uptake through the mCa2+ uniporter channel by acting as a gatekeeper at low cytosolic Ca2+ levels. Our results reveal a marked increase in MICU1 protein expression and decreased mCa2+ uptake during AT2-to-AT1 cell differentiation in the adult lung. Deletion of Micu1 in AT2 cells reduces AT2-to-AT1 cell differentiation during steady-state tissue maintenance and alveolar epithelial regeneration after bacterial pneumonia. These studies indicate that mCa2+ uptake is extensively modulated during AT2-to-AT1 cell differentiation and that MICU1-dependent mCa2+ uniporter channel gating is a prominent mechanism modulating AT2-to-AT1 cell differentiation.

Organoid technology and lung injury mouse models evaluating effects of hydroxychloroquine on lung epithelial regeneration.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) damages lung epithelial stem/progenitor cells. Ideal anti-SARS-CoV-2 drug candidates should be screened to prevent secondary injury to the lungs. Here, we propose that in vitro three-dimensional organoid and lung injury repair mouse models are powerful models for the screening antiviral drugs. Lung epithelial progenitor cells, including airway club cells and alveolar type 2 (AT2) cells, were co-cultured with supportive fibroblast cells in transwell inserts. The organoid model was used to evaluate the possible effects of hydroxychloroquine, which is administered as a symptomatic therapy to the coronavirus disease 2019 (COVID-19) patients, on the function of mouse lung stem/progenitor cells. Hydroxychloroquine was observed to promote the self-renewal of club cells and differentiation of ciliated and goblet cells in vitro. Additionally, it inhibited the self-renewal ability of AT2 cells in vitro. Naphthalene- or bleomycin-induced lung injury repair mouse models were used to investigate the in vivo effects of hydroxychloroquine on the regeneration of club and AT2 cells, respectively. The naphthalene model indicated that the proliferative ability and differentiation potential of club cells were unaffected in the presence of hydroxychloroquine. The bleomycin model suggested that hydroxychloroquine had a limited effect on the proliferation and differentiation abilities of AT2 cells. These findings suggest that hydroxychloroquine has limited effects on the regenerative ability of epithelial stem/progenitor cells. Thus, stem/progenitor cell-derived organoid technology and lung epithelial injury repair mouse models provide a powerful platform for drug screening, which could possibly help end the pandemic.

Functional human iPSC-derived alveolar-like cells cultured in a miniaturized 96\u2011Transwell air\u2013liquid interface model

In order to circumvent the limited access and donor variability of human primary alveolar cells, directed differentiation of human pluripotent stem cells (hiPSCs) into alveolar-like cells, provides a promising tool for respiratory disease modeling and drug discovery assays. In this work, a unique, miniaturized 96-Transwell microplate system is described where hiPSC-derived alveolar-like cells were cultured at an air–liquid interface (ALI). To this end, hiPSCs were differentiated into lung epithelial progenitor cells (LPCs) and subsequently matured into a functional alveolar type 2 (AT2)-like epithelium with monolayer-like morphology. AT2-like cells cultured at the physiological ALI conditions displayed characteristics of AT2 cells with classical alveolar surfactant protein expressions and lamellar-body like structures. The integrity of the epithelial barriers between the AT2-like cells was confirmed by applying a custom-made device for 96-parallelized transepithelial electric resistance (TEER) measurements. In order to generate an IPF disease-like phenotype in vitro, the functional AT2-like cells were stimulated with cytokines and growth factors present in the alveolar tissue of IPF patients. The cytokines stimulated the secretion of pro-fibrotic biomarker proteins both on the mRNA (messenger ribonucleic acid) and protein level. Thus, the hiPSC-derived and cellular model system enables the recapitulation of certain IPF hallmarks, while paving the route towards a miniaturized medium throughput approach of pharmaceutical drug discovery.

Bone Marrow-Derived VSELs Engraft as Lung Epithelial Progenitor Cells after Bleomycin-Induced Lung Injury.

Background: Alveolar type 2 (AT2) cells and bronchioalveolar stem cells (BASC) perform critical regenerative functions in response to lung damage. Published data show that nonhematopoietic, bone marrow-derived “very small embryonic-like stem cells” (VSELs) can differentiate in vivo into surfactant protein C (SPC)-producing AT2 cells in the lung. Here, we test directly whether VSEL-derived BASC and AT2 cells function to produce differentiated progeny. Methods: using a reporter mouse in which the H2B-GFP fusion protein is driven from the murine SPC promoter, we tested whether bone marrow-derived VSELs or non-VSEL/nonhematopoietic stem cells (non-VSEL/non-HSCs) can differentiate into AT2 and BASC cells that function as progenitor cells. Immediately following bleomycin administration, WT recipient mice underwent intravenous administration of VSELs or non-VSEL/non-HSCs from SPC H2B-GFP mice. GFP+ AT2 and BASC were isolated and tested for progenitor activity using in vitro organoid assays. Results: after 21 days in vivo, we observed differentiation of VSELs but not non-VSEL/non-HSCs into phenotypic AT2 and BASC consistent with previous data in irradiated recipients. Subsequent in vitro organoid assays revealed that VSEL-derived AT2 and BASC maintained physiological potential for differentiation and self-renewal. Conclusion: these findings prove that VSELs produce functional BASC and AT2 cells, and this may open new avenues using VSELs to develop effective cell therapy approaches for patients with lung injury.

Isolation and Enrichment of Human Lung Epithelial Progenitor Cells for Organoid Culture

Isolation and Enrichment of Human Lung Epithelial Progenitor Cells for Organoid Culture

Isolation and Enrichment of Human Lung Epithelial Progenitor Cells for Organoid Culture.

Epithelial organoid models serve as valuable tools to study the basic biology of an organ system and for disease modeling. When grown as organoids, epithelial progenitor cells can self-renew and generate differentiating progeny that exhibit cellular functions similar to those of their in vivo counterparts. Herein we describe a step-by-step protocol to isolate region-specific progenitors from human lung and generate 3D organoid cultures as an experimental and validation tool. We define proximal and distal regions of the lung with the goal of isolating region-specific progenitor cells. We utilized a combination of enzymatic and mechanical dissociation to isolate total cells from the lung and trachea. Specific progenitor cells were then fractionated from the proximal or distal origin cells using fluorescence associated cell sorting (FACS) based on cell type-specific surface markers, such as NGFRfor sorting basal cells and HTII-280 for sorting alveolar type II cells. Isolated basal or alveolar type II progenitors were used to generate 3D organoid cultures. Both distal and proximal progenitors formed organoids with a colony forming efficiency of 9-13% in distal region and 7-10% in proximal region when plated 5000 cell/well on day 30. Distal organoids maintained HTII-280+ alveolar type II cells in culture whereas proximal organoids differentiated into ciliated and secretory cells by day 30. These 3D organoid cultures can be used as an experimental tool for studying the cell biology of lung epithelium and epithelial mesenchymal interactions, as well as for the development and validation of therapeutic strategies targeting epithelial dysfunction in a disease.

Distal lung epithelial progenitor cell function declines with age

Tissue stem cell exhaustion is a key hallmark of aging, and in this study, we characterised its manifestation in the distal lung. We compared the lungs of 3- and 22-month old mice. We examined the gross morphological changes in these lungs, the density and function of epithelial progenitor populations and the epithelial gene expression profile. Bronchioles became smaller in their cross-sectional area and diameter. Using long-term EdU incorporation analysis and immunohistochemistry, we found that bronchiolar cell density remained stable with aging, but inferred rates of bronchiolar club progenitor cell self-renewal and differentiation were reduced, indicative of an overall slowdown in cellular turnover. Alveolar Type II progenitor cell density and self-renewal were maintained per unit tissue area with aging, but rates of inferred differentiation into Type I cells, and indeed overall density of Type I cells was reduced. Microarray analysis revealed age-related changes in multiple genes, including some with roles in proliferation and differentiation, and in IGF and TGFβ signalling pathways. By characterising how lung stem cell dynamics change with aging, this study will elucidate how they contribute to age-related loss of pulmonary function, and pathogenesis of common age-related pulmonary diseases.

Wnt/β-catenin signaling is critical for regenerative potential of distal lung epithelial progenitor cells in homeostasis and emphysema

Wnt/β-catenin signaling regulates progenitor cell fate decisions during lung development and in various adult tissues. Ectopic activation of Wnt/β-catenin signaling promotes tissue repair in emphysema, a devastating lung disease with progressive loss of parenchymal lung tissue. The identity of Wnt/β-catenin responsive progenitor cells and the potential impact of Wnt/β-catenin signaling on adult distal lung epithelial progenitor cell function in emphysema are poorly understood. Here, we used TCF/ Lef:H2B/GFP reporter mice to investigate the role of Wnt/β-catenin signaling in lung organoid formation. We identified an organoid-forming adult distal lung epithelial progenitor cell population characterized by a low Wnt/β-catenin activity, which was enriched in club and alveolar epithelial type (AT)II cells. Endogenous Wnt/β-catenin activity was required for the initiation of multiple subtypes of distal lung organoids derived from the Wntlow epithelial progenitors. Further ectopic Wnt/β-catenin activation specifically led to an increase in alveolar organoid number; however, the subsequent proliferation of alveolar epithelial cells in the organoids did not require constitutive Wnt/β-catenin signaling. Distal lung epithelial progenitor cells derived from the mouse model of elastase-induced emphysema exhibited reduced organoid forming capacity. This was rescued by Wnt/β-catenin signal activation, which largely increased the number of alveolar organoids. Together, our study reveals a novel mechanism of lung epithelial progenitor cell activation in homeostasis and emphysema.

Regulation of Airway Progenitor Homeostasis and Cell Composition by Tight Junction Protein Claudin‐18

RationaleClaudin‐18 (Cldn18) is comprised of two isoforms, Cldn 18.1 and Cldn18.2. The lung‐specific isoform, Cldn18.1, regulates distal lung epithelial progenitor cell homeostasis. Its role in airway epithelium has not been elucidated, although Cldn18 expression is decreased in lungs of patients with chronic airway diseases (e.g., asthma and chronic obstructive pulmonary disease (COPD)). The airway epithelium is comprised of three progenitor populations, basal cells (BC), pulmonary neuroendocrine cells (PNEC) and club cells, and two non‐progenitor cell populations, namely goblet and ciliated cells. Club cells are secretory cells that are susceptible to naphthalene (NAP) injury. Club cell depletion occurs by day 3 post‐NAP, with spreading of ciliated cells to cover the denuded epithelial surface, and full reconstitution of the airway epithelium by day 14–21. Here we investigated the role of Cldn18.1 in airway epithelium using a previously developed global Cldn18 knockout (KO) mouse model.MethodsWild‐type (WT) and Cldn18 KO mice were injected intraperitoneally with NAP (225–275 mg/kg, corn oil as control). Lungs were harvested at baseline and 3‐days (maximal injury), 7‐days (beginning of regeneration) and 21‐days (full regeneration) post‐NAP, inflated with 4% paraformaldehyde and fixed overnight prior to embedding and sectioning. Hematoxylin and eosin, Periodic Acid‐Schiff (PAS) and immunofluorescence staining were performed.ResultsIn WT mice, Cldn18.1 was expressed in a small subset of airway ciliated cells. Cldn18 KO mice showed increased numbers of pulmonary neuroendocrine cells and neuroendocrine bodies, as well as ectopic localization of club cells and localization of keratin 5‐positive cells within the distal parenchyma. At day 3 post‐NAP in WT mice, Cldn18.1 was transiently expressed in all the ciliated cells covering the denuded epithelium, returning to being expressed in only a subset of cells by day 7. Cldn18 KO mice subjected to injury unexpectedly developed marked goblet cell hyperplasia at day 14–21 post‐NAP, with cells expressing markers for both club (CC‐10) and goblet (MUC5AC) cells.ConclusionsOur findings demonstrate an unexpected role for Cldn18.1 in regulating airway progenitor homeostasis and cell composition, implicating Cldn18.1 in regulation of downstream signaling pathways that inhibit goblet cell differentiation. A transient increase in the number of Cldn18.1‐positive ciliated cells in WT mice in the initial stages post‐injury suggests paracrine regulation of these inhibitory effects. Modulation of Cldn18 expression may be beneficial in the treatment of airway diseases characterized by goblet cell metaplasia.Support or Funding InformationFunding: American Lung Association, Hastings Foundation, NIH

Paradigms that define lung epithelial progenitor cell fate in development and regeneration.

Throughout the lifespan, lung injury impedes the primary critical function essential for life-respiration. To repair quickly and efficiently is critical and is orchestrated by a diverse repertoire of progenitor cells and their niche. This review incorporates knowledge gained from early studies in lung epithelial morphogenesis and cell fate and explores its relevance to more recent findings of lung progenitor and stem cells in development and regeneration. Cell fate in the lung is organized into an early specification phase and progressive differentiation phase in lung development. The advent of single cell analysis combined with lineage analysis and projections is uncovering new functional cell types in the lung providing a topographical atlas for progenitor cell lineage commitment during development, homeostasis, and regeneration. Lineage commitment of lung progenitor cells is spatiotemporally regulated during development. Single cell sequencing technologies have significantly advanced our understanding of the similarities and differences between developmental and regenerative cell fate trajectories. Subsequent unraveling of the molecular mechanisms underlying these cell fate decisions will be essential to manipulating progenitor cells for regeneration.

BASC-ing in the glow: bronchioalveolar stem cells get their place in the lung.

Lung epithelial progenitor cell populations fulfill the needs of this complex facultative regenerative organ when exposed to insult and contribute to repair in either the airway or alveolar compartments. The presence of a cell that can populate both epithelia had been proposed previously but has remained elusive. In this issue, Salwig et al (2019) provide compelling, genetic evidence that supports a growing narrative—a rare population of bronchioalveolar stem cells (BASCs) that can contribute to both airway and alveolar epithelium in the distal murine lung.

BASCs, respiratory epithelial progenitors with geo-advantage

The lung is a much-branched organ consists of heterogeneous lineages of cells derived from both endoderm and mesoderm (1,2). Lung epithelial progenitor cells are orchestrated with endothelial and mesenchymal cells in a complicated manner to maintain the homeostasis of lung epithelium.

TGF-β activation impairs fibroblast ability to support adult lung epithelial progenitor cell organoid formation.

Transforming growth factor-β (TGF-β)-induced fibroblast-to-myofibroblast differentiation contributes to remodeling in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, but whether this impacts the ability of fibroblasts to support lung epithelial repair remains little explored. We pretreated human lung fibroblasts [primary (phFB) or MRC5 cells] with recombinant human TGF-β to induce myofibroblast differentiation, then cocultured them with adult mouse lung epithelial cell adhesion molecule-positive cells (EpCAM+) to investigate their capacity to support epithelial organoid formation in vitro. While control phFB and MRC5 lung fibroblasts supported organoid formation of mouse EpCAM+ cells, TGF-β pretreatment of both phFB and MRC5 impaired organoid-supporting ability. We performed RNA sequencing of TGF-β-treated phFB, which revealed altered expression of key Wnt signaling pathway components and Wnt/β-catenin target genes, and modulated expression of secreted factors involved in mesenchymal-epithelial signaling. TGF-β profoundly skewed the transcriptional program induced by the Wnt/β-catenin activator CHIR99021. Supplementing organoid culture media recombinant hepatocyte growth factor or fibroblast growth factor 7 promoted organoid formation when using TGF-β pretreated fibroblasts. In conclusion, TGF-β-induced myofibroblast differentiation results in Wnt/β-catenin pathway skewing and impairs fibroblast ability to support epithelial repair likely through multiple mechanisms, including modulation of secreted growth factors.

AMP Kinase Activation Attenuates Cardiac Remodeling in Pulmonary Hypertension due to Heart Failure with Preserved Ejection Fraction; Lung Epithelial Progenitor Cells in Alveolar Regeneration; and Drug Discovery and Novel Therapies for Lung Cancer.

AMP Kinase Activation Attenuates Cardiac Remodeling in Pulmonary Hypertension due to Heart Failure with Preserved Ejection Fraction; Lung Epithelial Progenitor Cells in Alveolar Regeneration; and Drug Discovery and Novel Therapies for Lung Cancer.