Alveolar type II cells have multiple functions, including surfactant production and fluid clearance, which are critical for lung function. Differentiation of type II cells occurs in cultured fetal ...lung epithelial cells treated with dexamethasone plus cAMP and isobutylmethylxanthine (DCI) and involves increased expression of 388 genes. In this study, type II cells of human adult lung were isolated at approximately 95% purity, and gene expression was determined (Affymetrix) before and after culturing 5 days on collagen-coated dishes with or without DCI for the final 3 days. In freshly isolated cells, highly expressed genes included SFTPA/B/C, SCGB1A, IL8, CXCL2, and SFN in addition to ubiquitously expressed genes. Transcript abundance was correlated between fetal and adult cells (r = 0.88), with a subset of 187 genes primarily related to inflammation and immunity that were expressed >10-fold higher in adult cells. During control culture, expression increased for 8.1% of expressed genes and decreased for approximately 4% including 118 immune response and 10 surfactant-related genes. DCI treatment promoted lamellar body production and increased expression of approximately 3% of probed genes by > or =1.5-fold; 40% of these were also induced in fetal cells. Highly induced genes (> or =10-fold) included PGC, ZBTB16, DUOX1, PLUNC, CIT, and CRTAC1. Twenty-five induced genes, including six genes related to surfactant (SFTPA/B/C, PGC, CEBPD, and ADFP), also had decreased expression during control culture and thus are candidates for hormonal regulation in vivo. Our results further define the adult human type II cell molecular phenotype and demonstrate that a subset of genes remains hormone responsive in cultured adult cells.
In late gestation, morphological maturation of fetal lung includes septal thinning of potential airspaces, a process accelerated by exogenous glucocorticoids. Apoptosis occurs in normal fetal lung. ...Glucocorticoids increase apoptosis in several tissues. The authors hypothesized that exogenous glucocorticoids would increase apoptosis in fetal lung, primarily in the interstitium. They administered dexamethasone (DEX), 1 mg/kg, or vehicle (Control) to pregnant rats at 19 days of gestation. Fetuses were delivered at 3, 7, 12, or 24 hours post injection. DEX decreased fetal body weight and lung weight, DNA, and protein 12 hours post injection. Using the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) reaction to label apoptotic cells in lung, they calculated an apoptotic index (AI, apoptotic cells/1000 total cells) for each fetus. Average DEX AI (3.6 ± 2.6, mean ± SD) was greater than Control (1.7 ± 0.5) (P <.02). All DEX AIs were greater than Control AIs at 3, 7, and 12 hours, but were similar to Controls at 24 hours post injection. Apoptotic cells appeared to be interstitial, based on colocalization with vimentin staining. Presence of apoptotic cells was confirmed by electron microscopy and detection of the nucleosomal ladder pattern on DNA electrophoresis. The authors conclude that maternal administration of dexamethasone increases apoptosis in fetal lung, primarily in the interstitium. They speculate that apoptosis may contribute to morphological fetal lung maturation induced by endogenous glucocorticoids.
Carcinoembryonic cell adhesion molecule 6 (CEACAM6) is a glycosylated, glycophosphatidylinositol-anchored protein expressed in epithelial cells of various primate tissues. It binds gram-negative ...bacteria and is overexpressed in human cancers. CEACAM6 is associated with lamellar bodies of cultured type II cells of human fetal lung and protects surfactant function in vitro. In this study, we characterized CEACAM6 expression in vivo in human lung. CEACAM6 was present in lung lavage of premature infants at birth and increased progressively in intubated infants with lung disease. Of surfactant-associated CEACAM6, ∼80% was the fully glycosylated, 90-kDa form that contains the glycophosphatidylinositol anchor, and the concentration (3.9% of phospholipid for adult lung) was comparable to that for surfactant proteins (SP)-A/B/C. We examined the affinity of CEACAM6 by purification of surfactant on density gradient centrifugation; concentrations of CEACAM6 and SP-B per phospholipid were unchanged, whereas levels of total protein and SP-A decreased by 60%. CEACAM6 mRNA content decreased progressively from upper trachea to peripheral fetal lung, whereas protein levels were similar in all regions of adult lung, suggesting proximal-to-distal developmental expression in lung epithelium. In adult lung, most type I cells and ∼50% of type II cells were immunopositive. We conclude that CEACAM6 is expressed by alveolar and airway epithelial cells of human lung and is secreted into lung-lining fluid, where fully glycosylated protein binds to surfactant. Production appears to be upregulated during neonatal lung disease, perhaps related to roles of CEACAM6 in surfactant function, cell proliferation, and innate immune defense.
Abstract Background Congenital diaphragmatic hernia (CDH) is associated with significant neonatal morbidity and mortality. Although prenatal complete tracheal occlusion (cTO) causes hypoplastic CDH ...lungs to enlarge, improved lung function has not been demonstrated. Furthermore, cTO interferes with the dynamic pressure change and fluid flow associated with fetal breathing. Purpose The purpose of the study was to assess a novel dynamic tracheal occlusion (dTO) device that preserves pressure changes and fluid flow. Methods In this pilot study, CDH was created in fetal lambs at 65 days of gestational age (GA). At 110 days GA, a cTO device (n = 3) or a dTO device (n = 4) was placed in the fetal trachea. At 135 days GA, lambs were delivered and resuscitated. Unoperated lamb co-twins (n = 5), sham thoracotomy lambs (n = 2), and untreated CDH lambs (n = 3) served as controls. Results Tracheal opening pressure, lung volume, lung fluid total protein, and phospholipid were significantly higher in the cTO group than in the dTO and unoperated control groups. Maximal oxygenation and lung compliance were significantly lower in the cTO group when compared with the unoperated control and dTO groups. Conclusion Preliminary results suggest that in the fetal lamb CDH model, dTO restores normal lung morphometrics and function, whereas cTO leads to enlarged but less functional lungs.
Carcinoembryonic antigen‐related cell adhesion molecule 6 (CEACAM6) is expressed in the epithelium of various primate tissues, including lung airway and alveoli. In human lung, CEACAM6 is ...developmentally and hormonally regulated, protects surfactant function, has anti‐apoptotic activity and is dysregulated in cancers. We hypothesized that alveolar CEACAM6 expression increases in lung injury and promotes cell proliferation during repair. Studies were performed in CEABAC transgenic mice‐containing human CEACAM genes. The level of CEACAM6 in adult CEABAC lung was comparable to that in human infants; expression occurred in epithelium of airways and of some alveoli but rarely co‐localized with markers of type I or type II cells. Ten days after bleomycin instillation, both the number of CEACAM6+ cells and immunostaining intensity were elevated in injured lung areas, and there was increased co‐localization with type I and II cell markers. To specifically address type II cells, we crossed CEABAC mice with animals expressing EGFP driven by the SP‐C promoter. After bleomycin injury, partially flattened, elongated epithelial cells were observed that expressed type I cell markers and were primarily either EGFP+ or CEACAM6+. In cell cycle studies, mitosis was greater in CEACAM6+ non‐type II cells versus CEACAM6+/EGFP+ cells. CEACAM6 epithelial expression was also increased after hyperoxic exposure and LPS instillation, suggesting a generalized response to acute lung injuries. We conclude that CEACAM6 expression is comparable in human lung and the CEABAC mouse. CEACAM6 in this model appears to be a marker of a progenitor cell population that contributes to alveolar epithelial cell replenishment after lung injury.
Transgenic mice containing human Carcinoembryonic Cell Adhesion Molecule genes express CEACAM6 in selected, unidentified lung epithelial cells at levels comparable to the human infant. Expression is increased in three models of lung injury with some localization to epithelial cells expressing both type 1 and type 2 cell markers. We propose that CEACAM6 in this model is a marker of a progenitor cell population that contributes to alveolar epithelial cell replenishment after lung injury.
Previous studies have shown that fibroblasts induced to migrate into an in vitro wound rapidly generate an array of stable, post-translationally detyrosinated microtubules (Glu MTs) oriented toward ...the direction of migration. To understand how cells generate a stable array of MTs at a specific location, we have analyzed the contribution of media components to the formation of oriented Glu MTs in wounded monolayers of 3T3 fibroblasts. When confluent monolayers were placed in serum-free medium (SFM) for 2 days before wounding, the cells contained virtually no Glu MTs or nocodazole-resistant MTs and were incapable of generating Glu MTs in response to wounding. Such SFM-treated monolayers were capable of generating oriented Glu MTs within 1 hour of wounding, if calf serum (CS) was added back to the medium. The Glu MTs in the CS refed cells were oriented toward the wound in cells at the wound edge, and were juxtanuclear in cells within the monolayer, demonstrating that CS restored the Glu MT array characteristic of each cell type. To determine the nature of the 'Glu MT-inducing' factor in CS, we subjected CS to different treatments and found that the CS factor was nondialyzable, resistant to heat, mild acid and trypsin, but inactivated by treatment with dithiothreitol. The factor was not absorbed by charcoal and was present in lipoprotein-deficient serum. These properties are consistent with the properties of a number of polypeptide growth factors, so we screened purified growth factors for their ability to induce Glu MTs in wounded SFM-treated monolayers. Of all the growth factors tested, only TGF-beta 1 and TGF-beta 2 induced a significant level (> or = 70% of the CS response) of oriented Glu MTs. The SFM-treated cells were exquisitely sensitive to TGF-beta 1, with significant induction of Glu MTs observed at 0.01 ng/ml TGF-beta 1. Induction of Glu MTs observed by immunofluorescence after CS or TGF-beta treatments were paralleled by increases in Glu tubulin detected on western blots. The Glu MTs formed after either CS or TGF-beta 1 treatment showed enhanced resistance to nocodazole, confirming that both treatments increased the level of stable MTs in cells. The TGF-beta 1 induction of stable MTs was slower than that of CS (2-4 hours onset versus 1 hour onset), but by 24 hours the level of MT stabilization in TGF-beta 1 was even greater than that in CS.
Venous thromboembolic events (VTEs) are a major cause of morbidity following abdominopelvic oncologic surgery. Enoxaparin, a subcutaneous injectable low molecular weight heparin, is commonly used for ...extended-duration VTE prophylaxis (EP), but has been associated with noncompliance. Newer direct oral anticoagulants have not been prospectively studied in the urologic oncology post-discharge setting. We aimed to improve compliance with EP following abdominopelvic oncologic surgery and secondarily test the hypothesis that apixaban is noninferior to enoxaparin for EP.
A single-center prospective quality improvement study measuring patient compliance and safety with EP was conducted between August 10, 2020 and September 21, 2021. Baseline data were continuously collected for 6 months, followed by a uniform departmental change from enoxaparin to apixaban. The duration of data collection was determined
using a noninferiority sample size estimation (145 per group). The primary outcome was compliance events (real or potential barriers to EP use). The secondary outcome was 30-day post-discharge safety events (symptomatic VTE or major bleed).
A total of 161 patients were discharged with enoxaparin (baseline period) and 154 with apixaban (intervention period). Safety events occurred in 3.1% vs 0% of patients receiving enoxaparin and apixaban, respectively. The absolute risk difference of 3.1% (95% CI: 0.043%-5.8%) met the prespecified noninferiority threshold (p=0.028 for apixaban superiority). Compliance events occurred in 33.5% of enoxaparin patients and 14.3% of apixaban patients (p=0.0001).
There were fewer compliance events using apixaban for EP than enoxaparin after urologic oncology surgery. Regarding safety, apixaban is noninferior to enoxaparin and may in fact have fewer associated major complications.
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