Plasticity of airway cell proliferation and gene expression after acute naphthalene injury

1995 ◽  
Vol 269 (6) ◽  
pp. L791-L799 ◽  
Author(s):  
B. R. Stripp ◽  
K. Maxson ◽  
R. Mera ◽  
G. Singh
Keyword(s):  
Epithelial Cells ◽  
Cellular Proliferation ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Acute Injury ◽  
Alveolar Type ◽  
Airway Epithelial ◽  
Clara Cells ◽  
Proliferating Cells ◽  
Sequence Of Events

The goal of this study was to determine the temporal and spatial sequence of events that accompany lung injury and repair after parenteral administration of the Clara cell-specific cytotoxicant, naphthalene. Changes in airway epithelial cells were evaluated by measuring alterations in the expression of markers for differentiated Clara cells (CYPIIF and Clara cell 10-kDa secretory protein, CC10), distal airway/alveolar type II cells (surfactant protein B; SP-B) and for cycling/proliferating cells (cyclin dependent kinase 1;CDK1). Naphthalene-induced Clara cell cytotoxicity resulted in the exfoliation of epithelial cells containing CC10 protein. This was accompanied by a dramatic reduction in the abundance of mRNA for CC10 and CYPIIF. Large numbers of CDK1 mRNA-positive cells were identified in and around bronchioles and terminal bronchioles 48 h after treatment. This cellular proliferation resulted in the population of airways by immature epithelial cells lacking normal levels of CC10 mRNA but overexpressing SP-B mRNA. Seventy-two hours after naphthalene treatment a reduction in CDK1 mRNA-positive cells was noted within bronchioles and terminal bronchioles at all locations, with the exception of airway bifurcations. At airway bifurcations CDK1 mRNA appeared to be more abundant at the 72-h time point than at 48 h. Comparison of these sections with serial sections probed for CC10 mRNA demonstrated a correlation between the expression of CDK1 and CC10 mRNA at bifurcations. Temporal increases in the abundance of CC10 mRNA observed at later time points were largely accounted for by the processive maturation of newly repopulated cells neighboring bifurcations in bronchioles. These studies identify spatially distinct populations of cells that act in concert to repopulate naphthalene-injured airways and support the notion that branch point cells play an important role in the maturation of newly regenerated airway epithelial cells after acute injury.

scholarly journals Subtype-specific expression patterns of inositol 1,4,5-trisphosphate receptors in rat airway epithelial cells.

1996 ◽  
Vol 44 (11) ◽  
pp. 1237-1242 ◽  
Author(s):  
T Sugiyama ◽  
M Yamamoto-Hino ◽  
K Wasano ◽  
K Mikoshiba ◽  
M Hasegawa
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelium ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Specific Cell ◽  
Airway Epithelial ◽  
Clara Cells ◽  
Ciliated Cells ◽  
Inositol 1,4,5 Trisphosphate

We investigated the immunohistochemical localization of inositol 1,4,5-trisphosphate receptor (IP3R) Types 1, 2, and 3 in rat airway epithelium using the monoclonal antibodies KM1112, KM1083, and KM1082 specific for each type of IP3R. The epithelium from trachea to distal intrapulmonary airways (bronchioles) showed positive immunoreactivity for all types of IP3R. However, cell type as well as subcellular site immunoreactivity for each type of IP3R varied. IP3R Type 1 was found only in the apical thin cytoplasmic area of ciliated cells throughout all airway levels. IP3R Type 2 was exclusively localized to the entire cytoplasm of ciliated cells from the trachea to bronchioles. IP3R Type 3 was expressed mainly in the supranuclear cytoplasm not only of ciliated cells at all airway levels but also in Clara cells of the bronchiolar epithelium. Double fluorescent staining using combinations of KM1083 and Wisteria floribunda lectin or anti-rat 10-KD Clara cell-specific protein antibody confirmed that the IP3R Type 2-positive cells were neither seromucous cells nor Clara cells. These results indicate that the expression of three types of IP3Rs in different cell types and subcellular sites may reflect diverse physiological functions of IP3Rs within airway epithelial cells. The double staining studies suggested that the anti-IP3R Type 2 monoclonal antibody KM1083 would be a specific cell marker for ciliated cells of the airway epithelium.

Intracellular Ca2+ and regulation of ion transport across rabbit Clara cells

1992 ◽  
Vol 263 (1) ◽  
pp. L122-L127
Author(s):  
M. R. Van Scott ◽  
A. M. Paradiso
Keyword(s):  
Epithelial Cells ◽  
Ion Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Bathing Solution ◽  
Airway Epithelial ◽  
Clara Cells ◽  
Tracheal Cell

We investigated whether Ca2+ was involved in regulation of ion transport across rabbit distal airway epithelial cells by studying the effects that elevation of intracellular Ca2+ (Cai) had on the bioelectric properties of nonciliated bronchiolar (Clara) cell epithelia in culture. Exposure of Clara cells to 5 x 10(-7) M ionomycin increased Cai concentration and transepithelial short-circuit current (Isc). Changing extracellular Ca2+ concentration in the presence of ionomycin demonstrated that changes in Isc paralleled changes in Cai. Another ionophore, 4-bromo-A23187, also increased Cai and Isc. Ionomycin-induced changes in Isc were insensitive to amiloride and were inhibited greater than 50% by pretreating the cells with bumetanide or substituting gluconate for Cl- in the bathing solution. Bradykinin and carbachol, which increased Cai and caused an increase in Isc across tracheal cell cultures, had no effect on Cai or Isc in Clara cell preparations. These results support the hypothesis that changes in Cai are linked to regulation of Cl- secretion across bronchiolar epithelial cells, but physiological regulators of Cai in Clara cells remain to be defined.

Transgenic overexpression of β2-adrenergic receptors in airway epithelial cells decreases bronchoconstriction

2000 ◽  
Vol 279 (2) ◽  
pp. L379-L389 ◽  
Author(s):  
Dennis W. McGraw ◽  
Susan L. Forbes ◽  
Judith C. W. Mak ◽  
David P. Witte ◽  
Patricia E. Carrigan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelium ◽  
Adrenergic Receptors ◽  
Airway Epithelial Cells ◽  
Airway Responsiveness ◽  
Ozone Exposure ◽  
Clara Cell ◽  
Whole Body ◽  
Airway Epithelial

Airway epithelial cells express β2-adrenergic receptors (β2-ARs), but their role in regulating airway responsiveness is unclear. With the Clara cell secretory protein (CCSP) promoter, we targeted expression of β2-ARs to airway epithelium of transgenic (CCSP-β2-AR) mice, thereby mimicking agonist activation of receptors only in these cells. In situ hybridization confirmed that transgene expression was confined to airway epithelium, and autoradiography showed that β2-AR density in CCSP-β2-AR mice was approximately twofold that of nontransgenic (NTG) mice. Airway responsiveness measured by whole body plethysmography showed that the methacholine dose required to increase enhanced pause to 200% of baseline (ED200) was greater for CCSP-β2-AR than for NTG mice (345 ± 34 vs. 157 ± 14 mg/ml; P < 0.01). CCSP-β2-AR mice were also less responsive to ozone (0.75 ppm for 4 h) because enhanced pause in NTG mice acutely increased to 77% over baseline ( P < 0.05) but remained unchanged in the CCSP-β2-AR mice. Although both groups were hyperreactive to methacholine 6 h after ozone exposure, the ED200for ozone-exposed CCSP-β2-AR mice was equivalent to that for unexposed NTG mice. These findings show that epithelial cell β2-ARs regulate airway responsiveness in vivo and that the bronchodilating effect of β-agonists results from activation of receptors on both epithelial and smooth muscle cells.

Cell proliferation contributes to PNEC hyperplasia after acute airway injury

1997 ◽  
Vol 272 (3) ◽  
pp. L486-L493 ◽  
Author(s):  
T. P. Stevens ◽  
J. T. McBride ◽  
J. L. Peake ◽  
K. E. Pinkerton ◽  
B. R. Stripp
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
Metabolic Activation ◽  
Immunohistochemical Analysis ◽  
Airway Epithelial Cells ◽  
Neuroendocrine Cells ◽  
Clara Cells ◽  
Proliferating Cells ◽  
Airway Injury ◽  
Chronic Lung Diseases

Pulmonary neuroendocrine cells (PNECs) are airway epithelial cells that are capable of secreting a variety of neuropeptides. PNECs are scattered throughout the bronchial tree either as individual cells or clusters of cells termed neuroepithelial bodies (NEBs). PNECs and their secretory peptides have been considered to play a role in fetal lung development. Although the normal physiological function of PNECs and neuropeptides in normal adult lungs and in repair from lung injury is not known, PNEC hyperplasia has been associated with chronic lung diseases, such as bronchopulmonary dysplasia, and with chronic exposures, such as hypoxia, tobacco smoke, nitrosamines, and ozone. To evaluate changes in PNEC number and distribution after acute airway injury, FVB/n mice were treated with either naphthalene or vehicle. Naphthalene is an aromatic hydrocarbon that, at the dose used in this study, selectively destroys nonciliated bronchial epithelial cells (Clara cells) through cytochrome P-450-mediated metabolic activation into cytotoxic epoxides. PNECs were identified by immunohistochemical analysis of calcitonin gene-related peptide-like immunoreactivity (CGRP-IR). Proliferating cells were marked with [(3)H]thymidine incorporation. Acute naphthalene toxicity results in PNEC hyperplasia that is detectable after 5 days of recovery. PNEC hyperplasia is characterized by increased numbers of NEBs without significant changes in the number of isolated PNECs and by increased [(3)H]thymidine labeling of CGRP-IR cells. These data show that cell proliferation contributes to PNEC hyperplasia after acute airway injury and suggest that PNECs may be capable of more rapidly increasing their number in response to injury than previously recognized.

Identification and isolation of mouse type II cells on the basis of intrinsic expression of enhanced green fluorescent protein

2003 ◽  
Vol 285 (3) ◽  
pp. L691-L700 ◽  
Author(s):  
Jason M. Roper ◽  
Rhonda J. Staversky ◽  
Jacob N. Finkelstein ◽  
Peter C. Keng ◽  
Michael A. O'Reilly
Keyword(s):  
Epithelial Cells ◽  
Fluorescent Protein ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Green Fluorescence ◽  
Experimental Conditions ◽  
Green Fluorescent

The unique morphology and cell-specific expression of surfactant genes have been used to identify and isolate alveolar type II epithelial cells. Because these attributes can change during lung injury, a novel method was developed for detecting and isolating mouse type II cells on the basis of transgenic expression of enhanced green fluorescence protein (EGFP). A line of transgenic mice was created in which EGFP was targeted to type II cells under control of the human surfactant protein (SP)-C promoter. Green fluorescent cells that colocalized by immunostaining with endogenous pro-SP-C were scattered throughout the parenchyma. EGFP was not detected in Clara cell secretory protein-expressing airway epithelial cells or other nonlung tissues. Pro-SP-C immunostaining diminished in lungs exposed to hyperoxia, consistent with decreased expression and secretion of intracellular precursor protein. In contrast, type II cells could still be identified by their intrinsic green fluorescence, because EGFP is not secreted. Type II cells could also be purified from single-cell suspensions of lung homogenates using fluorescence-activated cell sorting. Less than 1% of presorted cells exhibited green fluorescence compared with >95% of the sorted population. As expected for type II cells, ultrastructural analysis revealed that the sorted cells contained numerous lamellar bodies. SP-A, SP-B, and SP-C mRNAs were detected in the sorted population, but T1α and CD31 (platelet endothelial cell adhesion molecule) were not, indicating enrichment of type II epithelial cells. This method will be invaluable for detecting and isolating mouse type II cells under a variety of experimental conditions.

Airway epithelial Fas ligand expression: potential role in modulating bronchial inflammation

1998 ◽  
Vol 274 (3) ◽  
pp. L444-L449 ◽  
Author(s):  
Bernadette R. Gochuico ◽  
Kathleen M. Miranda ◽  
Edith M. Hessel ◽  
Joris J. De Bie ◽  
Antoon J. M. Van Oosterhout ◽  
...  
Keyword(s):  
Fas Ligand ◽  
Allergic Airway Inflammation ◽  
Inflammatory Cells ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Protective Mechanism ◽  
Airway Epithelial ◽  
Clara Cells ◽  
Inflammatory Conditions ◽  
Bronchial Inflammation

Epithelium-derived Fas ligand is believed to modulate inflammation within various tissues. In this paper, we report findings that suggest a similar immunoregulatory role for Fas ligand in the lung. First, Fas ligand was localized to nonciliated, cuboidal airway epithelial cells (Clara cells) throughout the airways in the normal murine lung by employing nonisotopic in situ hybridization and immunohistochemistry. Second, gldmutant mice, which express a dysfunctional Fas ligand protein, were noted to develop prominent infiltration of inflammatory cells in submucosal and peribronchial regions of the upper and lower airways. Third, during allergic airway inflammation induced by ovalbumin in mice, cell-associated staining for Fas ligand mRNA and protein was markedly reduced in the airway epithelium. These data suggest that Clara cell-derived Fas ligand may control immune activity in the airway; thus alterations in this protective mechanism may be involved in the pathogenesis of certain inflammatory conditions of the airway, such as asthma.

Interferon-γ stimulates human Clara cell secretory protein production by human airway epithelial cells

1998 ◽  
Vol 274 (5) ◽  
pp. L864-L869 ◽  
Author(s):  
X. L. Yao ◽  
T. Ikezono ◽  
M. Cowan ◽  
C. Logun ◽  
C. W. Angus ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Epithelial Cells ◽  
Secretory Protein ◽  
Airway Epithelial Cells ◽  
Clara Cell ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Clara Cell Secretory Protein ◽  
Ifn Γ

Clara cell secretory protein (CCSP) is an inhibitor of secretory phospholipase A2. It is produced by airway epithelial cells and is present in airway secretions. Because interferon (IFN)-γ can induce gene expression in airway epithelial cells and may modulate the inflammatory response in the airway, it was of interest to study the effect of this cytokine on epithelial cell CCSP mRNA expression and CCSP protein synthesis. A human bronchial epithelial cell line (BEAS-2B) was used for this study. CCSP mRNA was detected by ribonuclease protection assay. IFN-γ was found to increase CCSP mRNA expression in a time- and dose-dependent manner. The CCSP mRNA level increased after IFN-γ (300 U/ml) treatment for 8–36 h, with the peak increase at 18 h. Immunobloting of CCSP protein also demonstrated that IFN-γ induced the synthesis and secretion of CCSP protein in a time-dependent manner. Nuclear run-on, CCSP reporter gene activity assay, and CCSP mRNA half-life assay demonstrated that IFN-γ-induced increases in CCSP gene expression were mediated, at least in part, at the posttranscriptional level. The present study demonstrates that IFN-γ can induce increases in steady-state mRNA levels and protein synthesis of human CCSP protein in airway epithelial cells and may modulate airway inflammatory responses in this manner.

scholarly journals Contribution of Pulmonary CYP-mediated Bioactivation of Naphthalene to Airway Epithelial Injury in the Lung

2020 ◽  
Vol 177 (2) ◽  
pp. 334-346
Author(s):  
Nataliia Kovalchuk ◽  
Qing-Yu Zhang ◽  
Laura Van Winkle ◽  
Xinxin Ding
Keyword(s):  
Epithelial Cells ◽  
Cellular Proliferation ◽  
Inhalation Exposure ◽  
Airway Epithelial Cells ◽  
Air Pollutant ◽  
Null Mouse ◽  
Airway Epithelial ◽  
Cytochrome P450 Enzymes ◽  
Lactate Dehydrogenase Activity

Abstract Previous studies have established that cytochrome P450 enzymes (CYPs) in both liver and lung are capable of bioactivating naphthalene (NA), an omnipresent air pollutant and possible human carcinogen, in vitro and in vivo. The aim of this study was to examine the specific contribution of pulmonary CYPs in airway epithelial cells to NA-induced airway toxicity. We used a lung-Cpr-null mouse model, which undergoes doxycycline-induced, Cre-mediated deletion of the Cpr (a redox partner of all microsomal CYPs) gene specifically in airway epithelial cells. In 2-month-old lung-Cpr-null mice, Cpr deletion occurred in 75%–82% of epithelial cells of conducting airways. The extent of NA-induced acute lung toxicity (as indicated by total protein concentration and lactate dehydrogenase activity in bronchoalveolar lavage fluid collected at 24-h after initiation of a 4-h, nose-only, 10-ppm NA inhalation exposure) was substantially lower (by 37%–39%) in lung-Cpr-null mice, compared with control littermates. Moreover, the extent of cellular proliferation (as indicated by 5-bromo-2′-deoxyuridine incorporation) was noticeably lower in both proximal and distal airways (by 59% and 65%, respectively) of NA-treated lung-Cpr-null mice, compared with control littermates, at 2-day post-NA inhalation exposure. A similar genotype-related difference in the extent of postexposure cell proliferation was also observed in mice exposed to NA via intraperitoneal injection at 200 mg/kg. These results directly validate the hypothesis that microsomal CYP enzymes in airway epithelial cells play a large role in causing injury to airway epithelia following exposure to NA via either inhalation or intraperitoneal route.

Sign in / Sign up

Export Citation Format

Share Document