scholarly journals Restored alveolar epithelial differentiation and reversed human lung fibrosis upon Notch inhibition

2019 ◽  
Author(s):  
RM Wasnick ◽  
M Korfei ◽  
K Piskulak ◽  
I Henneke ◽  
J Wilhelm ◽  
...  
Keyword(s):  
Surface Tension ◽  
Lung Fibrosis ◽  
Alveolar Epithelial Cell ◽  
Surfactant Protein ◽  
Epithelial Differentiation ◽  
Alveolar Epithelial ◽  
Matrix Deposition ◽  
Alveolar Collapse ◽  
Precision Cut Lung Slices

AbstractAlveolar epithelial cell type II (AEC2) injury underlies idiopathic pulmonary fibrosis (IPF). Here we show increased Notch1 signaling in AEC2s in human IPF and IPF models, causing enhanced proliferation and de-differentiation of AEC2s. As a result, we observed defective surfactant protein (SP)-B/C processing, elevated alveolar surface tension, repetitive alveolar collapse and development of lung fibrosis. Similar changes were encountered upon pharmacological inhibition of SP-B/C processing in vivo by pepstatin A. Inhibition of Notch signaling in cultured human IPF precision cut lung slices improved surfactant processing capacity of AEC2s and reversed fibrosis. Notch1 therefore offers as novel therapeutic target.One sentence summaryNotch1 inhibition restores alveolar epithelial differentiation and surface tension and reverses matrix deposition in lung fibrosis

Abrogation of bleomycin-induced epithelial apoptosis and lung fibrosis by captopril or by a caspase inhibitor

2000 ◽  
Vol 279 (1) ◽  
pp. L143-L151 ◽  
Author(s):  
Rongqi Wang ◽  
Olivia Ibarra-Sunga ◽  
Luba Verlinski ◽  
Ruth Pick ◽  
Bruce D. Uhal
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Lung Fibrosis ◽  
Enzyme Inhibitor ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Caspase Inhibitor ◽  
Converting Enzyme ◽  
Alveolar Epithelial ◽  
Male Wistar Rats

Angiotensin-converting enzyme is involved in apoptosis of alveolar epithelial cells (Wang R, Zagariya A, Ang E, Ibarra-Sunga O, and Uhal BD. Am J Physiol Lung Cell Mol Physiol 277: L1245–L1250, 1999). This study tested the ability of the angiotensin-converting enzyme inhibitor captopril or the caspase inhibitor Z-Val-Ala-Asp-fluoromethylketone (ZVAD-fmk) to block alveolar epithelial cell apoptosis and lung fibrosis in vivo in response to bleomycin (Bleo). Male Wistar rats received 8 U/kg of Bleo (bleomycin sulfate) or vehicle intratracheally. Subgroups of Bleo-treated rats received captopril, ZVAD-fmk, or vehicle alone. Lung collagen was assessed by picrosirius red or hydroxyproline assay at 1, 7, and 14 days post-Bleo, and apoptosis was detected by in situ end labeling (ISEL). Bleo increased alveolar septal and peribronchial collagen by 100 and 133%, respectively (both P < 0.01), by day 14 but not earlier. In contrast, ISEL was increased in alveolar and airway cells at all time points. Captopril or ZVAD-fmk inhibited collagen accumulation by 91 and 85%, respectively ( P < 0.01). Both agents also inhibited ISEL in alveoli by 99 and 81% and in airways by 67 and 63%, respectively. These data suggest that the efficacy of captopril to inhibit experimental lung fibrogenesis is related to inhibition of apoptosis. They also demonstrate the antifibrotic potential of a caspase inhibitor.

scholarly journals Differential Regulation of Gene Expression of Alveolar Epithelial Cell Markers in Human Lung Adenocarcinoma-Derived A549 Clones

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Hiroshi Kondo ◽  
Keiko Miyoshi ◽  
Shoji Sakiyama ◽  
Akira Tangoku ◽  
Takafumi Noma
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Mapk Pathway ◽  
Alveolar Epithelial Cell ◽  
Marker Gene ◽  
Regulation Of Gene Expression ◽  
Surfactant Protein ◽  
Specific Gene ◽  
Expression Levels ◽  
Alveolar Epithelial

Stem cell therapy appears to be promising for restoring damaged or irreparable lung tissue. However, establishing a simple and reproducible protocol for preparing lung progenitor populations is difficult because the molecular basis for alveolar epithelial cell differentiation is not fully understood. We investigated anin vitrosystem to analyze the regulatory mechanisms of alveolus-specific gene expression using a human alveolar epithelial type II (ATII) cell line, A549. After cloning A549 subpopulations, each clone was classified into five groups according to cell morphology and marker gene expression. Two clones (B7 and H12) were further analyzed. Under serum-free culture conditions,surfactant protein C(SPC), an ATII marker, was upregulated in both H12 and B7.Aquaporin 5(AQP5), an ATI marker, was upregulated in H12 and significantly induced in B7. When the RAS/MAPK pathway was inhibited,SPCandthyroid transcription factor-1(TTF-1) expression levels were enhanced. After treatment with dexamethasone (DEX), 8-bromoadenosine 3′5′-cyclic monophosphate (8-Br-cAMP), 3-isobutyl-1-methylxanthine (IBMX), and keratinocyte growth factor (KGF),surfactant protein BandTTF-1expression levels were enhanced. We found that A549-derived clones have plasticity in gene expression of alveolar epithelial differentiation markers and could be useful in studying ATII maintenance and differentiation.

scholarly journals TRIM72 is required for effective repair of alveolar epithelial cell wounding

2014 ◽  
Vol 307 (6) ◽  
pp. L449-L459 ◽  
Author(s):  
Seong Chul Kim ◽  
Thomas Kellett ◽  
Shaohua Wang ◽  
Miyuki Nishi ◽  
Nagaraja Nagre ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Striated Muscle ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lung Cells ◽  
Alveolar Epithelial ◽  
High Tidal Volume Ventilation

The molecular mechanisms for lung cell repair are largely unknown. Previous studies identified tripartite motif protein 72 (TRIM72) from striated muscle and linked its function to tissue repair. In this study, we characterized TRIM72 expression in lung tissues and investigated the role of TRIM72 in repair of alveolar epithelial cells. In vivo injury of lung cells was introduced by high tidal volume ventilation, and repair-defective cells were labeled with postinjury administration of propidium iodide. Primary alveolar epithelial cells were isolated and membrane wounding and repair were labeled separately. Our results show that absence of TRIM72 increases susceptibility to deformation-induced lung injury whereas TRIM72 overexpression is protective. In vitro cell wounding assay revealed that TRIM72 protects alveolar epithelial cells through promoting repair rather than increasing resistance to injury. The repair function of TRIM72 in lung cells is further linked to caveolin 1. These data suggest an essential role for TRIM72 in repair of alveolar epithelial cells under plasma membrane stress failure.

scholarly journals Recent progress on surfactant protein A: cellular function in lung and kidney disease development

2020 ◽  
Vol 319 (2) ◽  
pp. C316-C320
Author(s):  
Skylar D. King ◽  
Shi-You Chen
Keyword(s):  
Kidney Diseases ◽  
Protein A ◽  
Active Surface ◽  
Surfactant Protein ◽  
Alveolar Epithelial Cells ◽  
Surfactant Protein A ◽  
Alveolar Epithelial ◽  
Host Immune Responses ◽  
Alveolar Collapse ◽  
Lung And Kidney

Pulmonary surfactant is a heterogeneous active surface complex made up of lipids and proteins. The major glycoprotein in surfactant is surfactant protein A (SP-A), which is released into the alveolar lumen from cytoplasmic lamellar bodies in type II alveolar epithelial cells. SP-A is involved in phospholipid absorption. SP-A together with other surfactant proteins and phospholipids prevent alveolar collapse during respiration by decreasing the surface tension of the air-liquid interface. Additionally, SP-A interacts with pathogens to prevent their propagation and regulate host immune responses. Studies in human and animal models have shown that deficiencies or mutations in surfactant components result in various lung or kidney pathologies, suggesting a role for SP-A in the development of lung and kidney diseases. In this mini-review, we discuss the current understanding of SP-A functions, recent findings of its dysfunction in specific lung and kidney pathologies, and how SP-A has been used as a biomarker to detect the outcome of lung diseases.

scholarly journals Surfactant Protein B Deficiency Induced High Surface Tension: Relationship between Alveolar Micromechanics, Alveolar Fluid Properties and Alveolar Epithelial Cell Injury

2019 ◽  
Vol 20 (17) ◽  
pp. 4243 ◽  
Author(s):  
Nina Rühl ◽  
Elena Lopez-Rodriguez ◽  
Karolin Albert ◽  
Bradford J Smith ◽  
Timothy E Weaver ◽  
...  
Keyword(s):  
Surface Tension ◽  
Lung Injury ◽  
High Surface ◽  
Surfactant Protein ◽  
Epithelial Injury ◽  
High Surface Tension ◽  
Alveolar Epithelial ◽  
Surfactant Protein B ◽  
Fluid Properties ◽  
Alveolar Epithelial Injury

High surface tension at the alveolar air-liquid interface is a typical feature of acute and chronic lung injury. However, the manner in which high surface tension contributes to lung injury is not well understood. This study investigated the relationship between abnormal alveolar micromechanics, alveolar epithelial injury, intra-alveolar fluid properties and remodeling in the conditional surfactant protein B (SP-B) knockout mouse model. Measurements of pulmonary mechanics, broncho-alveolar lavage fluid (BAL), and design-based stereology were performed as a function of time of SP-B deficiency. After one day of SP-B deficiency the volume of alveolar fluid V(alvfluid,par) as well as BAL protein and albumin levels were normal while the surface area of injured alveolar epithelium S(AEinjure,sep) was significantly increased. Alveoli and alveolar surface area could be recruited by increasing the air inflation pressure. Quasi-static pressure-volume loops were characterized by an increased hysteresis while the inspiratory capacity was reduced. After 3 days, an increase in V(alvfluid,par) as well as BAL protein and albumin levels were linked with a failure of both alveolar recruitment and airway pressure-dependent redistribution of alveolar fluid. Over time, V(alvfluid,par) increased exponentially with S(AEinjure,sep). In conclusion, high surface tension induces alveolar epithelial injury prior to edema formation. After passing a threshold, epithelial injury results in vascular leakage and exponential accumulation of alveolar fluid critically hampering alveolar recruitability.

scholarly journals TRIM72 promotes alveolar epithelial cell membrane repair and ameliorates lung fibrosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaofei Cong ◽  
Nagaraja Nagre ◽  
Jeremy Herrera ◽  
Andrew C. Pearson ◽  
Ian Pepper ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Membrane ◽  
Lung Fibrosis ◽  
Alveolar Epithelial Cell ◽  
Membrane Repair ◽  
Alveolar Epithelial

scholarly journals SIRT3 deficiency promotes lung fibrosis by augmenting alveolar epithelial cell mitochondrial DNA damage and apoptosis

2017 ◽  
Vol 31 (6) ◽  
pp. 2520-2532 ◽  
Author(s):  
Renea P. Jablonski ◽  
Seok‐Jo Kim ◽  
Paul Cheresh ◽  
David B. Williams ◽  
Luisa Morales‐Nebreda ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mitochondrial Dna ◽  
Epithelial Cell ◽  
Lung Fibrosis ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial ◽  
Mitochondrial Dna Damage

scholarly journals Pneumocystis Pneumonia Increases the Susceptibility of Mice to Sublethal Hyperoxia

2003 ◽  
Vol 71 (10) ◽  
pp. 5970-5978 ◽  
Author(s):  
James M. Beck ◽  
Angela M. Preston ◽  
Steven E. Wilcoxen ◽  
Susan B. Morris ◽  
Eric S. White ◽  
...  
Keyword(s):  
T Cells ◽  
Epithelial Cell ◽  
Cell Injury ◽  
Alveolar Epithelial Cell ◽  
Pulmonary Inflammation ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Epithelial Cell Injury

ABSTRACT Patients with Pneumocystis pneumonia often develop respiratory failure after entry into medical care, and one mechanism for this deterioration may be increased alveolar epithelial cell injury. In vitro, we previously demonstrated that Pneumocystis is not cytotoxic for alveolar epithelial cells. In vivo, however, infection with Pneumocystis could increase susceptibility to injury by stressors that, alone, would be sublethal. We examined transient exposure to hyperoxia as a prototypical stress that does cause mortality in normal mice. Mice were depleted of CD4+ T cells and inoculated intratracheally with Pneumocystis. Control mice were depleted of CD4+ T cells but did not receive Pneumocystis. After 4 weeks, mice were maintained in normoxia, were exposed to hyperoxia for 4 days, or were exposed to hyperoxia for 4 days followed by return to normoxia. CD4-depleted mice with Pneumocystis pneumonia demonstrated significant mortality after transient exposure to hyperoxia, while all uninfected control mice survived this stress. We determined that organism burdens were not different. However, infected mice exposed to hyperoxia and then returned to normoxia demonstrated significant increases in inflammatory cell accumulation and lung cell apoptosis. We conclude that Pneumocystis pneumonia leads to increased mortality following a normally sublethal hyperoxic insult, accompanied by alveolar epithelial cell injury and increased pulmonary inflammation.

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