scholarly journals Dynamic Regulation of GH–IGF1 Signaling in Injury and Recovery in Hyperoxia-Induced Neonatal Lung Injury

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2947
Author(s):  
Christina Vohlen ◽  
Jasmine Mohr ◽  
Alexey Fomenko ◽  
Celien Kuiper-Makris ◽  
Tiffany Grzembke ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Lung Injury ◽  
Alveolar Epithelial Cell ◽  
Receptor Expression ◽  
Type I ◽  
Short Term ◽  
Newborn Mice ◽  
Alveolar Epithelial ◽  
Gh Receptor ◽  
Neonatal Lung

Prematurely born infants often require supplemental oxygen that impairs lung growth and results in arrest of alveolarization and bronchopulmonary dysplasia (BPD). The growth hormone (GH)- and insulin-like growth factor (IGF)1 systems regulate cell homeostasis and organ development. Since IGF1 is decreased in preterm infants, we investigated the GH- and IGF1 signaling (1) in newborn mice with acute and prolonged exposure to hyperoxia as well as after recovery in room air; and (2) in cultured murine lung epithelial cells (MLE-12) and primary neonatal lung fibroblasts (pLFs) after treatment with GH, IGF1, and IGF1-receptor (IGF1-R) inhibitor or silencing of GH-receptor (Ghr) and Igf1r using the siRNA technique. We found that (1) early postnatal hyperoxia caused an arrest of alveolarization that persisted until adulthood. Both short-term and prolonged hyperoxia reduced GH-receptor expression and STAT5 signaling, whereas Igf1 mRNA and pAKT signaling were increased. These findings were related to a loss of epithelial cell markers (SFTPC, AQP5) and proliferation of myofibroblasts (αSMA+ cells). After recovery, GH-R-expression and STAT5 signaling were activated, Igf1r mRNA reduced, and SFTPC protein significantly increased. Cell culture studies showed that IGF1 induced expression of mesenchymal (e.g., Col1a1, Col4a4) and alveolar epithelial cell type I (Hopx, Igfbp2) markers, whereas inhibition of IGF1 increased SFTPC and reduced AQP5 in MLE-12. GH increased Il6 mRNA and reduced proliferation of pLFs, whereas IGF1 exhibited the opposite effect. In summary, our data demonstrate an opposite regulation of GH- and IGF1- signaling during short-term/prolonged hyperoxia-induced lung injury and recovery, affecting alveolar epithelial cell differentiation, inflammatory activation of fibroblasts, and a possible uncoupling of the GH-IGF1 axis in lungs after hyperoxia.

scholarly journals Tumor necrosis factor-α small interfering RNA alveolar epithelial cell-targeting nanoparticles reduce lung injury in C57BL/6J mice with sepsis

2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098465
Author(s):  
Like Qian ◽  
Xi Yin ◽  
Jiahao Ji ◽  
Zhengli Chen ◽  
He Fang ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Epithelial Cell ◽  
Lung Injury ◽  
Tumor Necrosis ◽  
Alveolar Epithelial Cell ◽  
Weight Ratio ◽  
B Cell Lymphoma ◽  
Alveolar Epithelial ◽  
Tnf Α ◽  
Necrosis Factor

Background The role of tumor necrosis factor (TNF)-α small interfering (si)RNA alveolar epithelial cell (AEC)-targeting nanoparticles in lung injury is unclear. Methods Sixty C57BL/6J mice with sepsis were divided into normal, control, sham, 25 mg/kg, 50 mg/kg, and 100 mg/kg siRNA AEC-targeting nanoparticles groups (n = 10 per group). The wet:dry lung weight ratio, and hematoxylin and eosin staining, western blotting, and enzyme-linked immunosorbent assays for inflammatory factors were conducted to compare differences among groups. Results The wet:dry ratio was significantly lower in control and sham groups than other groups. TNF-α siRNA AEC-targeting nanoparticles significantly reduced the number of eosinophils, with significantly lower numbers in the 50 mg/kg group than in 25 mg/kg and 100 mg/kg groups. The nanoparticles also significantly reduced the expression of TNF-α, B-cell lymphoma-2, caspase 3, interleukin (IL)-1β, and IL-6, with TNF-α expression being significantly lower in the 50 mg/kg group than in 25 mg/kg and 100 mg/kg groups. Conclusion TNF-α siRNA AEC-targeting nanoparticles appear to be effective at improving lung injury-related sepsis, and 50 mg/kg may be a preferred dose option for administration.

scholarly journals Characteristics of Passive Solute Transport across Primary Rat Alveolar Epithelial Cell Monolayers

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 331
Author(s):  
Yong Ho Kim ◽  
Kwang-Jin Kim ◽  
David Z. D’Argenio ◽  
Edward D. Crandall
Keyword(s):  
Epithelial Cell ◽  
Tight Junctions ◽  
Pore Radius ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Cell Monolayers ◽  
Alveolar Epithelial ◽  
Epithelial Cell Monolayers ◽  
Hydrophilic Solutes

Primary rat alveolar epithelial cell monolayers (RAECM) were grown without (type I cell-like phenotype, RAECM-I) or with (type II cell-like phenotype, RAECM-II) keratinocyte growth factor to assess passive transport of 11 hydrophilic solutes. We estimated apparent permeability (Papp) in the absence/presence of calcium chelator EGTA to determine the effects of perturbing tight junctions on “equivalent” pores. Papp across RAECM-I and -II in the absence of EGTA are similar and decrease as solute size increases. We modeled Papp of the hydrophilic solutes across RAECM-I/-II as taking place via heterogeneous populations of equivalent pores comprised of small (0.41/0.32 nm radius) and large (9.88/11.56 nm radius) pores, respectively. Total equivalent pore area is dominated by small equivalent pores (99.92–99.97%). The number of small and large equivalent pores in RAECM-I was 8.55 and 1.29 times greater, respectively, than those in RAECM-II. With EGTA, the large pore radius in RAECM-I/-II increased by 1.58/4.34 times and the small equivalent pore radius increased by 1.84/1.90 times, respectively. These results indicate that passive diffusion of hydrophilic solutes across an alveolar epithelium occurs via small and large equivalent pores, reflecting interactions of transmembrane proteins expressed in intercellular tight junctions of alveolar epithelial cells.

A new rat type I-like alveolar epithelial cell line R3/1: bleomycin effects on caveolin expression

2004 ◽  
Vol 121 (6) ◽  
Author(s):  
Roland Koslowski ◽  
Kathrin Barth ◽  
Antje Augstein ◽  
Thomas Tschernig ◽  
Gerhard Bargsten ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Alveolar Epithelial Cell ◽  
Epithelial Cell Line ◽  
Type I ◽  
Alveolar Epithelial

scholarly journals Role of collagenase in mediating in vitro alveolar epithelial wound repair

1999 ◽  
Vol 112 (2) ◽  
pp. 243-252
Author(s):  
E. Planus ◽  
S. Galiacy ◽  
M. Matthay ◽  
V. Laurent ◽  
J. Gavrilovic ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Epithelial Cell ◽  
Type I Collagen ◽  
Alveolar Epithelial Cell ◽  
Cell Monolayer ◽  
Type I ◽  
Type Ii ◽  
Alveolar Epithelial

Type II pneumocytes are essential for repair of the injured alveolar epithelium. The effect of two MMP collagenases, MMP-1 and MMP-13 on alveolar epithelial repair was studied in vitro. The A549 alveolar epithelial cell line and primary rat alveolar epithelial cell cultures were used. Cell adhesion and cell migration were measured with and without exogenous MMP-1. Wound healing of a cell monolayer of rat alveolar epithelial cell after a mechanical injury was evaluated by time lapse video analysis. Cell adhesion on type I collagen, as well as cytoskeleton stiffness, was decreased in the presence of exogenous collagenases. A similar decrease was observed when cell adhesion was tested on collagen that was first incubated with MMP-1 (versus control on intact collagen). Cell migration on type I collagen was promoted by collagenases. Wound healing of an alveolar epithelial cell monolayer was enhanced in the presence of exogenous collagenases. Our results suggest that collagenases could modulate the repair process by decreasing cell adhesion and cell stiffness, and by increasing cell migration on type I collagen. Collagen degradation could modify cell adhesion sites and collagen degradation peptides could induce alveolar type II pneumocyte migration. New insights regarding alveolar epithelial cell migration are particularly relevant to investigate early events during alveolar epithelial repair following lung injury.

Modulation of ion conductance and active transport by TGF-β1 in alveolar epithelial cell monolayers

2003 ◽  
Vol 285 (6) ◽  
pp. L1192-L1200 ◽  
Author(s):  
Brigham C. Willis ◽  
Kwang-Jin Kim ◽  
Xian Li ◽  
Janice Liebler ◽  
Edward D. Crandall ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Active Transport ◽  
Alveolar Epithelial Cell ◽  
Alveolar Type ◽  
Type I ◽  
Ion Conductance ◽  
Cell Monolayers ◽  
Alveolar Epithelial ◽  
Epithelial Cell Monolayers ◽  
Tgf Β1

Transforming growth factor-β1 (TGF-β1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-β1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells. Exposure to TGF-β1 (0.1-100 pM) from day 0 resulted in a concentration- and time-dependent decrease in transepithelial resistance ( Rt) and increase in short-circuit current ( Isc). Apical amiloride or basolateral ouabain on day 6 inhibited Isc by 80 and 100%, respectively. Concurrent increases in expression of Na+-K+-ATPase α1- and β1-subunits were observed in TGF-β1-treated monolayers. No change in the α-subunit of the rat epithelial sodium channel (α-rENaC) was seen. Exposure of confluent monolayers to TGF-β1 from day 4 resulted in an initial decrease in Rt within 6 h, followed by an increase in Isc over 72-96 h. These results demonstrate that TGF-β1 modulates ion conductance and active transport characteristics of the alveolar epithelium, associated with increased Na+-K+-ATPase, but without a change in α-rENaC.

scholarly journals Simultaneous isolation of endothelial and alveolar epithelial type I and type II cells during mouse lung development in the absence of a transgenic reporter

2020 ◽  
Vol 318 (4) ◽  
pp. L619-L630 ◽  
Author(s):  
Yves Donati ◽  
Sanja Blaskovic ◽  
Isabelle Ruchonnet-Métrailler ◽  
Josefina Lascano Maillard ◽  
Constance Barazzone-Argiroffo
Keyword(s):  
Epithelial Cell ◽  
De Novo ◽  
Morphological Changes ◽  
Alveolar Epithelial Cell ◽  
Mouse Lung ◽  
Cell Populations ◽  
Type I ◽  
Type Ii ◽  
Alveolar Cells ◽  
Alveolar Epithelial

Mouse lung developmental maturation and final alveolarization phase begin at birth. During this dynamic process, alveolar cells modify their morphology and anchorage to the extracellular matrix. In particular, alveolar epithelial cell (AEC) type I undergo cytoplasmic flattening and folding to ensure alveoli lining. We developed FACS conditions for simultaneous isolation of alveolar epithelial and endothelial cells in the absence of specific reporters during the early and middle alveolar phase. We evidenced for the first time a pool of extractable epithelial cell populations expressing high levels of podoplanin at postnatal day (pnd)2, and we confirmed by RT-qPCR that these cells are already differentiated but still immature AEC type I. Maturation causes a decrease in isolation yields, reflecting the morphological changes that these cell populations are undergoing. Moreover, we find that major histocompatibility complex II (MHCII), reported as a good marker of AEC type II, is poorly expressed at pnd2 but highly present at pnd8. Combined experiments using LysoTracker and MHCII demonstrate the de novo acquisition of MCHII in AEC type II during lung alveolarization. The lung endothelial populations exhibit FACS signatures from vascular and lymphatic compartments. They can be concomitantly followed throughout alveolar development and were obtained with a noticeable increased yield at the last studied time point (pnd16). Our results provide new insights into early lung alveolar cell isolation feasibility and represent a valuable tool for pure AEC type I preparation as well as further in vitro two- and three-dimensional studies.

PMNS EXACERBATE HYPEROXIC LUNG INJURY VIA AUGMENTED ALVEOLAR EPITHELIAL CELL DEATH.

Shock ◽  
2004 ◽  
Vol 21 ◽  
pp. 27
Author(s):  
L. Mantell ◽  
E. J. Miller ◽  
T. Sakuragi ◽  
J. Romashko ◽  
H. Zhu ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cell ◽  
Lung Injury ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial ◽  
Hyperoxic Lung Injury ◽  
Epithelial Cell Death
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