Role of endogenous TGF-β in glucocorticoid-induced lung type II cell differentiation

2007 ◽  
Vol 292 (1) ◽  
pp. L249-L257 ◽  
Author(s):  
Theresa M. McDevitt ◽  
Linda W. Gonzales ◽  
Rashmin C. Savani ◽  
Philip L. Ballard
Keyword(s):  
Cell Differentiation ◽  
Transforming Growth Factor ◽  
Fetal Lung ◽  
Hormone Treatment ◽  
Type Ii ◽  
Gene Suppression ◽  
Surfactant Production ◽  
Type Ii Cell ◽  
Human Fetal Lung

In the fetal lung, endogenous transforming growth factor (TGF)-β inhibits early morphogenesis and blocks hormone-induced type II cell differentiation. We hypothesized that endogenous TGF-β inhibits type II cell differentiation and that the stimulatory effects of glucocorticoids result in part from suppression of TGF-β. Epithelial cells were isolated from human fetal lung and cultured under defined conditions with and without dexamethasone plus cAMP to promote type II cell differentiation. Control cells produced TGF-β, which was activated in part by αVβ6-integrin. Treatment with dexamethasone, but not cAMP, reduced TGF-β1 and -β2 transcripts and TGF-β bioactivity in culture medium. To examine the effects of decreased TGF-β in the absence of glucocorticoid, cells were treated with antibodies to TGF-β and its receptors. By real-time RT-PCR, antibody blockade of TGF-β reduced serpine1, a TGF-β-inducible gene, and increased gene expression for sftpa, sftpb, sftpc, and titf1, mimicking the response to hormone treatment. By microarray analysis, 29 additional genes were induced by both TGF-β antibody and hormone treatment, and 20 other genes were repressed by both treatments. For some genes, the fold response was comparable for antibody and hormone treatment. We conclude that endogenous TGF-β suppresses expression of surfactant proteins and selected other type II cell genes in fetal lung, in part secondary to increased expression of titf1, and we propose that the mechanism of glucocorticoid-induced type II cell differentiation includes antagonism of TGF-β gene suppression. Surfactant production during fetal development is likely influenced by relative levels of TGF-β and glucocorticoids.

scholarly journals The miR-200 Family and Its Targets Regulate Type II Cell Differentiation in Human Fetal Lung

2015 ◽  
Vol 290 (37) ◽  
pp. 22409-22422 ◽  
Author(s):  
Houda Benlhabib ◽  
Wei Guo ◽  
Brianne M. Pierce ◽  
Carole R. Mendelson
Keyword(s):  
Cell Differentiation ◽  
Fetal Lung ◽  
Type Ii ◽  
Type Ii Cell ◽  
Human Fetal Lung

scholarly journals Developmental Decline in the MicroRNA 199a (miR-199a)/miR-214 Cluster in Human Fetal Lung Promotes Type II Cell Differentiation by Upregulating Key Transcription Factors

2018 ◽  
Vol 38 (11) ◽  
Author(s):  
Ritu Mishra ◽  
Houda Benlhabib ◽  
Wei Guo ◽  
Connie B. Lerma Cervantes ◽  
Carole R. Mendelson
Keyword(s):  
Cell Differentiation ◽  
Epithelial Cells ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Type Ii ◽  
Type Ii Pneumocyte ◽  
Differentially Expressed Mirnas ◽  
Type Ii Cell ◽  
Cox 2 ◽  
Human Fetal Lung

ABSTRACTThe major surfactant protein, SP-A (a product of theSFTPAgene), serves as a marker of type II pneumocyte differentiation and surfactant synthesis.SFTPAexpression in cultured human fetal lung (HFL) epithelial cells is upregulated by hormones that increase cyclic AMP (cAMP) and activate TTF-1/NKX2.1 and NF-κB. To further define mechanisms for type II cell differentiation and induction of SP-A, we investigated roles of microRNAs (miRNAs). Using microarray to identify differentially expressed miRNAs in HFL epithelial cells during type II cell differentiation in culture, we observed that members of the miRNA 199a (miR-199a)/miR-214 cluster were significantly downregulated during differentiation. Validated and predicted targets of miR-199a-3p/miR-199a-5p and miR-214, which serve roles in type II cell differentiation (COX-2, NF-κB p50/p65, and CREB1), and the CREB1 target, C/EBPβ, were coordinately upregulated. Accordingly, overexpression of miR-199a-5p, miR-199a-3p, or miR-214 mimics in cultured HFL epithelial cells decreased COX-2, NF-κB p50/p65, CREB1, and C/EBPβ proteins, with an associated inhibition of SP-A expression. Interestingly, overexpression of the EMT factor, ZEB1, which declines during cAMP-induced type II cell differentiation, increased pri-miR-199a and reduced the expression of the targets NF-κB/p50 and COX-2. Collectively, these findings suggest that the developmental decline in miR-199a/miR-214 in HFL causes increased expression of critical targets that enhance type II cell differentiation and SP-A expression.

scholarly journals The MicroRNA 29 Family Promotes Type II Cell Differentiation in Developing Lung

2016 ◽  
Vol 36 (16) ◽  
pp. 2141-2141 ◽  
Author(s):  
Wei Guo ◽  
Houda Benlhabib ◽  
Carole R. Mendelson
Keyword(s):  
Cell Differentiation ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Fetal Lung ◽  
Transforming Growth Factor Β ◽  
Late Gestation ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type Ii Cell

Lung alveolar type II cells uniquely synthesize surfactant, a developmentally regulated lipoprotein that is essential for breathing. Expression of the gene (SFTPA) encoding the major surfactant protein, SP-A, in midgestation human fetal lung (HFL) is dramatically induced by cyclic AMP (cAMP). cAMP induction of SP-A expression is repressed by transforming growth factor β (TGF-β) and by hypoxia. In this study, we found that expression of the microRNA 29 (miR-29) family was significantly upregulated in epithelial cells isolated from mouse fetal lung during late gestation and in epithelial cells isolated from HFL explants during type II cell differentiation in culture. miR-29 expression in cultured HFL epithelial cells was increased by cAMP and inhibited by hypoxia, whereas the miR-29 target, TGF-β2, was coordinately decreased. Knockdown of the miR-29 family in cultured HFL type II cells blocked cAMP-induced SP-A expression and accumulation of surfactant-containing lamellar bodies, suggesting their physiological relevance. This occurred through derepression of TGF-β signaling. Notably, cAMP increased binding of endogenous thyroid transcription factor 1 (TTF-1/Nkx2.1) to themiR-29ab1promoter in HFL type II cells, and TTF-1 increasedmiR-29ab1promoter-driven luciferase activity in cotransfection assays. Together, these findings identify miR-29 family members as TTF-1-driven mediators of SP-A expression and type II cell differentiation through repression of TGF-β signaling.

Human fetal lung organotypic cultures preserved by lipid-carbohydrate retaining methods

1978 ◽  
Vol 36 (2) ◽  
pp. 498-499
Author(s):  
C. J. Stratton ◽  
W. H. J. Douglas ◽  
J. A. McAteer
Keyword(s):  
Structural Complexity ◽  
Fetal Lung ◽  
Technical Difficulty ◽  
Cellular Heterogeneity ◽  
Type Ii ◽  
Organotypic Cultures ◽  
Electron Microscopic ◽  
Type Ii Cell ◽  
Human Fetal Lung

Surfactant studies in general, and particularly those on the type II cell are hindered by the intrinsic cellular heterogeneity and structural complexity of the lung. Indeed, electron microscopic investigations of the lung encounter problems with both non-uniform sampling, and the technical difficulty of preserving intra- and extracellular surfactant through the dehydration steps. Fetal lung organotypic cultures provide a highly enriched type II cell population in which the in vivo cellular relationship of an intact epithelial-mesenchymal interface is maintained. The new lipid-carbohydrate retaining electron microscopic procedures have been shown to preserve most of the structural components of biomembranes and carbohydrate gels, and thus retain the natural appearance of both intra- and extracellular surfactant.Human fetal lung (18 and 18. 5 weeks gestational age) was: enzymatically dissociated (0. 1% trypsin, 0. 1% collagenase, 1. 0% chicken serum in Moscona's saline); filtered; centrifuged (160 x G for 6 minutes); incubated at 37°C for one hour; resuspended in culture medium (Ham's F12K + 10% FBS); and cultured on a Gelfoam collagen sponge.

scholarly journals Adult Rat Bone Marrow-Derived Stem Cells Promote Late Fetal Type II Cell Differentiation in a Co-Culture Model

2013 ◽  
Vol 7 (1) ◽  
pp. 46-53 ◽  
Author(s):  
AB Knoll ◽  
T Brockmeyer ◽  
R Chevalier ◽  
K Zscheppang ◽  
HC Nielsen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Differentiation ◽  
Fetal Lung ◽  
Type Ii Cells ◽  
Type Ii ◽  
Fibroblast Proliferation ◽  
Soluble Factors ◽  
Culture Model ◽  
Type Ii Cell

Bronchopulmonary dysplasia develops in preterm infants due to a combination of lung immaturity and lung injury. Cultured pluripotent bone marrow stem cells (BMSC) are known to reduce injury and induce repair in adult and in immature lungs, possibly through paracrine secretion of soluble factors. The paracrine relationship between BMSC and primary fetal lung epithelial type II cells is unknown. We determined the effects of BMSC on type II cell and fibroblast behavior using an in vitro co-culture model. Rat BMSC were isolated and co-cultured with primary fetal E21 rat type II cells or lung fibroblasts in a Transwell® system without direct cell contact. Effects of BMSC conditioned media (CM) on type II cell and fibroblast proliferation and on type II cell surfactant phospholipid (DSPC) synthesis and mRNA expression of surfactant proteins B and C (sftpb and sftpc) were studied. We also determined the effect of fibroblast and type II cell CM on BMSC proliferation and surface marker expression. Co-culture with BMSC significantly decreased type II cell and fibroblast proliferation to 72.5% and 83.7% of controls, respectively. Type II cell DSPC synthesis was significantly increased by 21% and sftpb and sftpc mRNA expressions were significantly induced (2.1 fold and 2.4 fold, respectively). BMSC proliferation was significantly reduced during the co-culture. Flow cytometry confirmed that BMSC retained the expression of undifferentiated stem cell markers despite their exposure to fetal lung cell CM. We conclude that BMSC induce fetal type II cell differentiation through paracrine release of soluble factors. These studies provide clues for how BMSC may act in promoting alveolar repair following injury.

scholarly journals MicroRNA 29 Family Serves a Key Role in Lung Development and the Prevention of Lung Pathology

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A507-A507
Author(s):  
Ritu Mishra ◽  
Carole R Mendelson
Keyword(s):  
Cell Differentiation ◽  
Bronchopulmonary Dysplasia ◽  
Lung Development ◽  
Lung Fibrosis ◽  
Molecular Mechanisms ◽  
Clinical Medicine ◽  
Lung Pathology ◽  
Type Ii ◽  
Type Ii Cell

Abstract Even with remarkable advances in the care of preterm infants, chronic lung disease in the form of bronchopulmonary dysplasia (BPD) continues to be a significant pathologic consequence of prematurity. BPD is caused by the interruption of physiologic lung development and exposure of the immature newborn lung to high O2 tensions. BPD is characterized by a simplified alveolar structure, arrested lung growth, impaired vascular development and lung fibrosis (1). To identify effective treatment strategies for BPD, it is important to understand the molecular mechanisms underlying this disorder. MicroRNAs (miRNA, miR) are known to regulate growth, development and repair of the developing lung; whereas, dysregulation of miRNA expression has been associated with pulmonary disease. Specifically, members of the miR-29 family have been linked to pulmonary cancers, fibrosis, and BPD. Previous studies from our laboratory indicate that developmental induction of miR-29 expression in the fetal lung near term serves a key role in promoting surfactant-producing type II cell differentiation and function through repression of TGF-β2 signaling (2). To understand the role of miR-29 in protection against BPD, in the present study, we created mice in which the entire miR-29 family (miR-29a/b1 and miR-29b2/c) (miR-29 dKO) was disrupted. Upon exposure of miR-29 dKO and WT neonatal mice to hyperoxia (95% O2) for 5 days immediately after birth, expression levels of the proinflammatory cytokines and chemokines, IL-1 β, TGF-β1, CXCL2 and IL-6, were significantly increased in the lungs of miR-29 dKO mice, compared to WT. Furthermore, lungs of miR-29 dKO adult mice manifested increased expression of their direct targets, TGF-β2 and TGF-β3. This was associated with increased collagen deposition, as evidenced by enhanced trichrome staining, suggesting the development of lung fibrosis. HDAC4 (a direct target of miR-29) and proinflammatory TNF-α, which have been implicated in pulmonary fibrosis, also were upregulated in the lungs of miR-29 dKO mice. Overall, our studies suggest a key role of the miR-29 family and its targets in prevention of inflammatory and profibrotic signaling in the neonatal lung leading to lung pathology. Supported by: NIH R01-HL050022 (C.R.M.) References: (1)Michael, Zoe, et al. “Bronchopulmonary dysplasia: an update of current pharmacologic therapies and new approaches.” Clinical Medicine Insights: Pediatrics 12 (2018): 1179556518817322.(2)Guo, Wei, Houda Benlhabib, and Carole R. Mendelson. “The microRNA 29 family promotes type II cell differentiation in developing lung.” Molecular and cellular biology 36.16 (2016): 2141-2141.

Prostaglandin E2 integrates the effects of fluid distension and glucocorticoid on lung maturation

1998 ◽  
Vol 274 (1) ◽  
pp. L106-L111 ◽  
Author(s):  
J. S. Torday ◽  
H. Sun ◽  
J. Qin
Keyword(s):  
Fetal Lung ◽  
Explant Culture ◽  
Lung Fibroblasts ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Maturation ◽  
Fetal Rat ◽  
Surfactant Production ◽  
Type Ii Cell ◽  
Fetal Lung Maturation

Both glucocorticoids and alveolar fluid distension affect the rate of fetal lung maturation, possibly representing a common cellular pathway. In an explant culture, there is a spontaneous increase in triglyceride incorporation into saturated phosphatidylcholine over time. This mechanism is stimulated by prostaglandin (PG) E2, blocked by both bumetanide and indomethacin, and overridden by exogenous PGE2. Type II cells synthesized and produced PGE2 between days 16 and 21 postconception, increasing fourfold between days 19 and 21. Fetal rat lung fibroblasts released triglyceride in response to PGE2, increasing 10- to 14-fold between days 19 and 21 postconception; phloretin (1 × 10−5 M) completely blocked this effect of PGE2 on triglyceride release. Dexamethasone stimulated both type II cell PGE2 synthesis (threefold) and fibroblast triglyceride release in response to PGE2 (60%) by day 20 cells. Stretching type II cells also increased PGE2 synthesis (∼100% at 1, 2, and 3 h vs. static cultures). Recombination of [3H]triglyceride-labeled fibroblasts with type II cells in an organotypic culture resulted in progressive incorporation of label into saturated phosphatidylcholine by type II cells. This process was also blocked by the addition of indomethacin and overridden by exogenous PGE2. These data suggest that the combined effects of alveolar fluid dilatation and glucocorticoids may coordinate the timely transfer of triglyceride from fibroblasts to type II cells for augmented surfactant production through their effects on PGE2 production and action as term approaches.

Regulation of extracellular matrix synthesis by TNF-α and TGF-β1 in type II cells exposed to coal dust

1998 ◽  
Vol 275 (4) ◽  
pp. L637-L644 ◽  
Author(s):  
Yu-Chen Lee ◽  
D. Eugene Rannels
Keyword(s):  
Extracellular Matrix ◽  
Cell Cultures ◽  
Transforming Growth Factor ◽  
Coal Dust ◽  
Transforming Growth Factor Β1 ◽  
Type Ii ◽  
Tnf Α ◽  
Type Ii Cell ◽  
Primary Type ◽  
Tgf Β1

Type II pulmonary epithelial cells respond to anthracite coal dust PSOC 867 with increased synthesis of extracellular matrix (ECM) components. Alveolar macrophages modulate this response by pathways that may involve soluble mediators, including tumor necrosis factor-α (TNF-α) or transforming growth factor-β1 (TGF-β1). The effects of TNF-α (10 ng/ml) and/or TGF-β1 (2 ng/ml) were thus investigated in dust-exposed primary type II cell cultures. In control day 1 or day 3 cultures, TNF-α and/or TGF-β1 had little or no effect on the synthesis of type II cellular proteins, independent of whether the cells were exposed to dust. With PSOC 867 exposure, where ECM protein synthesis is elevated, TNF-α and TGF-β1 further increased both the absolute and relative rates of ECM synthesis on day 3 but had little effect on day 1. Each mediator increased expression of fibronectin mRNA, as well as of ECM fibronectin content, in a manner qualitatively similar to their effects on synthesis. Thus TNF-α and TGF-β1 modulate both ECM synthesis and fibronectin content in coal dust-exposed type II cell cultures.

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