Transforming growth factor-β1 regulates lung epithelial barrier function and fluid transport

2003 ◽  
Vol 285 (6) ◽  
pp. L1190-L1191 ◽  
Author(s):  
Christine Clerici ◽  
Michael A. Matthay
Keyword(s):  
Growth Factor ◽  
Barrier Function ◽  
Fluid Transport ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Lung Epithelial

scholarly journals Transforming Growth Factor β1 Ameliorates Intestinal Epithelial Barrier Disruption by Cryptosporidium parvum In Vitro in the Absence of Mucosal T Lymphocytes

2000 ◽  
Vol 68 (10) ◽  
pp. 5635-5644 ◽  
Author(s):  
James K. Roche ◽  
Clovis A. P. Martins ◽  
Rosana Cosme ◽  
Ronald Fayer ◽  
Richard L. Guerrant
Keyword(s):  
Epithelial Cell ◽  
Barrier Function ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Epithelial Barrier Function ◽  
Epithelial Monolayers ◽  
Tgf Β1

ABSTRACT Exposure to oocysts of the protozoan Cryptosporidium parvum causes intestinal epithelial cell dysfunction in vivo and in vitro, but effective means by which mucosal injury might be prevented remain unclear. We examined the ability of transforming growth factor β1 (TGF-β1)—a cytokine synthesized and released by cells in the intestine—to preserve the barrier function of human colonic epithelia when challenged with C. parvum oocysts and then studied the mechanisms involved. Epithelial barrier function was monitored electrophysiologically, receptors for TGF-β1 were localized by confocal microscopy, and TGF-β1-induced protein kinase C activation was detected intracellularly by translocation of its α isozyme. TGF-β1 alone enhanced intestinal epithelial barrier function, while exposure to C. parvum oocysts (≥105/monolayer) markedly reduced barrier function to ≤40% of that of the control. When epithelial monolayers were pretreated with TGF-β1 at 5.0 ng/ml, the barrier-disrupting effect ofC. parvum oocysts was almost completely abrogated for 96 h. Further investigation showed that (i) the RI and RII receptors for TGF-β1 were present on 55 and 65% of human epithelial cell line cells, respectively, over a 1-log-unit range of receptor protein expression, as shown by flow cytometry and confirmed by confocal microscopy; (ii) only basolateral and not apical TGF-β1 exposure of the polarized epithelial monolayer resulted in a protective effect; and (iii) TGF-β1 had no direct effect on the organism in reducing its tissue-disruptive effects. In exploring mechanisms to account for the barrier-preserving effects of TGF-β1 on epithelium, we found that the protein kinase C pathway was activated, as shown by translocation of its 80-kDa α isozyme within 30 s of epithelial exposure to TGF-β1; the permeability of epithelial monolayers to passage of macromolecules was reduced by 42% with TGF-β1, even in the face of active protozoal infection; and epithelial cell necrosis monitored by lactate dehydrogenase release was decreased by 50% 70 h after oocyst exposure. Changes in epithelial function, initiated through an established set of surface receptors, likely accounts for the remarkable barrier-sparing effect of nanogram-per-milliliter concentrations of TGF-β1 when human colonic epithelium is exposed to an important human pathogen, C. parvum.

scholarly journals The relative balance of GM-CSF and TGF-β1 regulates lung epithelial barrier function

2015 ◽  
Vol 308 (12) ◽  
pp. L1212-L1223 ◽  
Author(s):  
Christian E. Overgaard ◽  
Barbara Schlingmann ◽  
StevenClaude Dorsainvil White ◽  
Christina Ward ◽  
Xian Fan ◽  
...  
Keyword(s):  
Barrier Function ◽  
Transforming Growth Factor ◽  
Cultured Cells ◽  
Lung Epithelial Cells ◽  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Gm Csf ◽  
Lung Epithelial ◽  
Tgf Β1

Lung barrier dysfunction is a cardinal feature of the acute respiratory distress syndrome (ARDS). Alcohol abuse, which increases the risk of ARDS two- to fourfold, induces transforming growth factor (TGF)-β1, which increases epithelial permeability and impairs granulocyte/macrophage colony-stimulating factor (GM-CSF)-dependent barrier integrity in experimental models. We hypothesized that the relative balance of GM-CSF and TGF-β1 signaling regulates lung epithelial barrier function. GM-CSF and TGF-β1 were tested separately and simultaneously for their effects on lung epithelial cell barrier function in vitro. TGF-β1 alone caused an ∼25% decrease in transepithelial resistance (TER), increased paracellular flux, and was associated with projections perpendicular to tight junctions (“spikes”) containing claudin-18 that colocalized with F-actin. In contrast, GM-CSF treatment induced an ∼20% increase in TER, decreased paracellular flux, and showed decreased colocalization of spike-associated claudin-18 with F-actin. When simultaneously administered to lung epithelial cells, GM-CSF antagonized the effects of TGF-β1 on epithelial barrier function in cultured cells. Given this, GM-CSF and TGF-β1 levels were measured in bronchoalveolar lavage (BAL) fluid from patients with ventilator-associated pneumonia and correlated with markers for pulmonary edema and patient outcome. In patient BAL fluid, protein markers of lung barrier dysfunction, serum α2-macroglobulin, and IgM levels were increased at lower ratios of GM-CSF/TGF-β1. Critically, patients who survived had significantly higher GM-CSF/TGF-β1 ratios than nonsurviving patients. This study provides experimental and clinical evidence that the relative balance between GM-CSF and TGF-β1 signaling is a key regulator of lung epithelial barrier function. The GM-CSF/TGF-β1 ratio in BAL fluid may provide a concentration-independent biomarker that can predict patient outcomes in ARDS.

scholarly journals Lung Fibrosis-associated Surfactant Protein A1 and C Variants Induce Latent Transforming Growth Factor β1 Secretion in Lung Epithelial Cells

2013 ◽  
Vol 288 (38) ◽  
pp. 27159-27171 ◽  
Author(s):  
Meenakshi Maitra ◽  
Moushumi Dey ◽  
Wen-Cheng Yuan ◽  
Peter W. Nathanielsz ◽  
Christine Kim Garcia
Keyword(s):  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Lung Fibrosis ◽  
Transforming Growth Factor ◽  
Surfactant Protein ◽  
Transforming Growth Factor Β1 ◽  
Lung Epithelial Cells ◽  
Missense Mutations ◽  
Lung Epithelial ◽  
Tgf Β1

Missense mutations of surfactant proteins are recognized as important causes of inherited lung fibrosis. Here, we study rare and common surfactant protein (SP)-A1 and SP-C variants, either discovered in our familial pulmonary fibrosis cohort or described by others. We show that expression of two SP-A1 (R219W and R242*) and three SP-C (I73T, M71V, and L188Q) variant proteins lead to the secretion of the profibrotic latent transforming growth factor (TGF)-β1 in lung epithelial cell lines. The secreted TGF-β1 is capable of autocrine and paracrine signaling and is dependent upon expression of the latent TGF-β1 binding proteins. The dependence upon unfolded protein response (UPR) mediators for TGF-β1 induction differs for each variant. TGF-β1 secretion induced by the expression of the common SP-A1 R219W variant is nearly completely blocked by silencing the UPR transducers IRE-1α and ATF6. In contrast, the secretion of TGF-β1 induced by two rare SP-C mutant proteins (I73T and M71V), is largely unaffected by UPR silencing or by the addition of the small molecular chaperone 4-phenylbutyric acid, implicating a UPR-independent mechanism for these variants. Blocking TGF-β1 secretion reverses cell death of RLE-6TN cells expressing these SP-A1 and SP-C variants suggesting that anti-TGF-β therapeutics may be beneficial to this molecularly defined subgroup of pulmonary fibrosis patients.

Effects of insulin-like growth factor I on growth, epithelial barrier and iodide transport in polarized pig thyrocyte monolayers

1996 ◽  
Vol 135 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Lars E Ericson ◽  
Mikael Nilsson
Keyword(s):  
Growth Factor ◽  
Barrier Function ◽  
Potential Difference ◽  
Epithelial Barrier ◽  
Insulin Like Growth Factor ◽  
Epithelial Barrier Function ◽  
Iodide Transport ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I

Ericson LE, Nilsson M. Effects of insulin-like growth factor I on growth, epithelial barrier and iodide transport in polarized pig thyrocyte monolayers. Eur J Endocrinol 1996;135:118–27. ISSN 0804–4643 The effects of insulin-like growth factor I (IGF-I) on mitogenesis, epithelial barrier function and transepithelial iodide transport were studied in confluent, polarized monolayers of pig thyrocytes cultured on filter in Transwell bicameral chambers. The growth rate in controls cultured in 1% fetal calf serum was low. Insulin-like growth factor I stimulated dose-dependently the incorporation of [3H]thymidine, maximally at 100 ng/ml, which corresponded to an increase of DNA content by 60% after 6 days. Thyrotropin (1 mU/ml) alone did not stimulate cell multiplication but inhibited partially the stimulatory effect of IGF-I. Insulin-like growth factor I(100 ng/ml) increased within 10 min the transepithelial potential difference, which remained elevated for several days, but did not significantly change the transepithelial resistance. When added together, IGF-I reinforced the effects of TSH on potential difference (increase) and resistance (decrease). A preserved epithelial barrier in IGF-I-treated cultures was confirmed by observing a normal immunolocalization of the tight junction protein ZO-1 and an unchanged ultrastructure of the junctional complex. Insulin-like growth factor I increased the transepithelial flux of 125I− in the basal-to-apical, but not in the opposite, direction. Stimulation of iodide transport by IGF-I was modest after 2 days and pronounced after 6 days. In comparison, TSH-stimulated iodide transport was higher after 2 days but lower after 6 days. Both TSH and IGF-I were strongly synergistic, after 6 days amounting to a 90-fold increase over the control basoapical 125I− transfer. The simultaneous accumulation of 125I− in the cell layer was increased two- to fourfold by IGF-I and/or TSH. In conclusion, IGF-I is able to induce growth in preformed monolayers of pig thyrocytes cultured on permeable filter. During these conditions, the mitogenic effect of IGF-I is partially inhibited by TSH, which has no growth-promoting action on its own. The transepithelial transport of iodide and bulk electrolytes is altered by IGF-I without affecting the epithelial barrier function. Specifically, IGF-I up-regulates the activity of the basolateral iodide pump and increases the iodide permeability of the apical plasma membrane. The action of IGF-I on iodide transport is independent of, although synergistic with, that of TSH. The findings support the notion that IGF-I may be an important regulator of thyroid growth and differentiated functions. Lars E Ericson, Institute of Anatomy and Cell Biology, Göteborg University, Medicinaregatan 3, S-413 90 Göteborg, Sweden

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