Isolation of lung lamellar bodies and their conversion to tubular myelin figures in vitro

1980 ◽  
Vol 198 (3) ◽  
pp. 485-501 ◽  
Author(s):  
Ronald L. Sanders ◽  
Robert J. Hassett ◽  
Albert E. Vatter
1962 ◽  
Vol 14 (3) ◽  
pp. 401-420 ◽  
Author(s):  
I. K. Buckley

Unfixed, compressed acinar cells of rat pancreas, isolated by mechanical and enzymatic means, were examined by phase microscopy and photomicrographed using 35 mm film and electronic flash illumination. Similarly, observations were made on Walker carcinoma cells; in addition, these cells were treated with solutions containing either phosphatidase A or enzyme inhibitors. Acinar cells contained, besides nuclei, perinuclear droplets and secretion granules, various membranous and vacuolar structures. The basal cytoplasm showed parallel dark lines interpreted as endoplasmic reticulum. In some cells, fragmentation of the reticulum was followed by the direct incorporation of fragments into simple myelin figures. In other cells it appeared that phase-lucent linear structures and vacuoles were derived by dilatation of cisternae of the endoplasmic reticulum. Perinuclear fluid collections arose either by dilation of the perinuclear cisternae of the endoplasmic reticulum or by fluid dilatation of the nuclear envelope. Phosphatidase A disrupted early vacuoles of Walker carcinoma cells. From this and the direct involvement of elements of the endoplasmic reticulum in myelin figures, it was concluded that the membranes limiting the endoplasmic reticulum incorporate phosphatides in continuous layers. While many severely injured cells formed large vacuoles, others developed concentrically laminated myelin figures; it was concluded that both types of structure derived from phosphatides liberated intracellularly, the vacuoles by vesicular myelin figure formation.


1991 ◽  
Vol 11 (3) ◽  
pp. 207-212 ◽  
Author(s):  
J. Thomas Hjelle ◽  
Barbara T. Golinska ◽  
Diane C. Waters ◽  
Kevin R. Steidley ◽  
David R. McCarroll ◽  
...  

The nature of intracytoplasmic lipid inclusions found in cultured rabbit and rat peritoneal mesothelial cells was examined by ultrastructural and biochemical techniques. Transmission electron microscopy also demonstrated extracellular release of these lipid bodies. Differential fixation with tannic acid revealed 2 types of inclusions, lamellated (lamellar bodies) and nonlamellated (homogeneous). The lamellar bodies were found near or in the Golgi apparatus and on the cell surface where occasionally they were observed in exocytotic pouches. The homogeneous inclusions were the predominant species being found primarily intracellularly. Lipid bodies obtained from the culture media over the cells displayed on electron microscopy the same morphological characteristics as those seen intracellularly. Exposure of confluent cultures of mesothelial cells to the vital lipid stain Nile Red caused the appearance of intensely fluorescent droplets in or on the cells at wave lengths consistent with staining for phosphatidylcholine-rich vesicles. Incubation of the cells with r4C)-choline an d subsequent analysis of phospholipid formation revealed high rates of r4C)-phosphatidylcholine addition to both intra and extracellular lipid pools. Taken together, mesothelial cells exhibit lipid bodies similar in ultrastructure to the surfactant containing organelles of Type II pneumocytes.


1988 ◽  
Vol 66 (7) ◽  
pp. 895-900 ◽  
Author(s):  
James B. Kirkland ◽  
Tammy M. Bray

Acute bovine pulmonary edema is a naturally occurring lung disease caused by 3-methylindole (3MI), a ruminal fermentation product of tryptophan. Morphological and in vitro studies have suggested that 3MI causes abnormalities in phospholipid synthesis. The present study was designed to investigate the effect of 3MI on the quantity and functional quality of surfactant using the goat as an experimental model. Following intravenous infusion of 3MI, goats were killed at 6-, 18-, and 30-h intervals. The lungs were removed and intracellular surfactant, in the form of lamellar bodies, and extracellular surfactant from alveolar lavage were quantified. 3MI treatment did cause modest changes in the lamellar body phospholipid pools, decreasing the quantity of phosphatidylcholine and the proportion of palmitate in this fraction. The quantity of lavage phospholipids was not significantly affected. There was an increase in the protein content of the lavage, reflecting the presence of edema. The functional quality of the surfactant isolated from the lavage fraction was tested in vitro using a pulsating bubble surfactometer. 3MI infusion decreased the ability of surfactant to lower the surface tension of an air bubble at maximum radius and during compression.


2016 ◽  
Vol 310 (6) ◽  
pp. L519-L531 ◽  
Author(s):  
Saket Ahuja ◽  
Lars Knudsen ◽  
Shashi Chillappagari ◽  
Ingrid Henneke ◽  
Clemens Ruppert ◽  
...  

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder, and some patients with HPS develop pulmonary fibrosis, known as HPS-associated interstitial pneumonia (HPSIP). We have previously reported that HPSIP is associated with severe surfactant accumulation, lysosomal stress, and alveolar epithelial cell type II (AECII) apoptosis. Here, we hypothesized that defective autophagy might result in excessive lysosomal stress in HPSIP. Key autophagy proteins, including LC3B lipidation and p62, were increased in HPS1/2 mice lungs. Electron microscopy demonstrated a preferable binding of LC3B to the interior of lamellar bodies in the AECII of HPS1/2 mice, whereas in wild-type mice it was present on the limiting membrane in addition to the interior of the lamellar bodies. Similar observations were noted in human HPS1 lung sections. In vitro knockdown of HPS1 revealed increased LC3B lipidation and p62 accumulation, associated with an increase in proapoptotic caspases. Overexpression of LC3B decreased the HPS1 knockdown-induced p62 accumulation, whereas rapamycin treatment did not show the same effect. We conclude that loss of HPS1 protein results in impaired autophagy that is restored by exogenous LC3B and that defective autophagy might therefore play a critical role in the development and progression of HPSIP.


1991 ◽  
Vol 1 (2) ◽  
pp. 89-105 ◽  
Author(s):  
Roger G. Ulrich ◽  
Kenneth S. Kilgore ◽  
Elena L. Sun ◽  
Clay T. Cramer ◽  
Leonard C. Ginsberg

2000 ◽  
Vol 19 (7) ◽  
pp. 392-401 ◽  
Author(s):  
L van Bree ◽  
I MCM Rietjens ◽  
G M Alink ◽  
J AMA Dormans ◽  
M Marra ◽  
...  

To investigate the effects of repeated exposure to nitrogen dioxide (NO2) on antioxidant enzymes in lung tissue and isolated lung cells, rats were continuously exposed to 20 mg/m3 NO2 (10.6 ppm) for 4 days. The activities of glucose-6-phosphate dehydrogenase (G6PDH), glutathione reductase (GR), and glutathione peroxidase (GSHPx) were measured in the cytosolic fraction of lung tissue of both control and NO2-exposed rats as well as in isolated alveolar macrophages (AMs) and type II cells. Qualitative and quantitative changes in AM and type II cells were studied by electron microscopy and by morphometric analyses using enzyme and immunohistochemistry. NO2 exposure resulted in significantly increased pulmonary activities of G6PDH, GR, and GSHPx, both expressed per lung and per gram of lung weight. Morphometric data show that NO2 exposure significantly increased the number of type II cells, predominantly in the centriacinar region, indicating proliferation of epithelium following cellular injury. Type II cells in lungs of NO2-exposed rats had a squamous, less cuboidal appearance with more lamellar bodies compared to type II cells in lungs of control rats. Compared to control lungs, a higher number of macrophages could be isolated from NO2-exposed lungs, while numbers of type II cells isolated from lungs of control and NO2-exposed rats were the same. Isolated type II cells from control and NO2-exposed rats were polymorphic, with a small number of lamellar bodies and without polarity. Isolated macro-phages were rounded and contained many filopodia. NO2 exposure caused increases in the activities of G6PDH and GSHPx in isolated type II cells and of GSHPx in isolated macrophages, when expressed per number of cells. Macrophages and type II cells isolated from control and NO2-exposed rats and re-exposed in vitro to NO2, showed no differences in phagocytosis and viability features. Our results indicate that NO2-induced increases in pulmonary antioxidant enzymes are also reflected in isolated AM and type II cells. Since these lung cells do not display a decreased sensitivities toward an in vitro NO2 exposure, overall increase in antioxidant enzyme activities do not seem to play the most pivotal role in controlling cellular NO2 sensitivity and oxidant defence. Combined data from biochemical, morphological, and morphometric analyses of lungs and lung cells suggest that lung cell and tissue oxidant sensitivity and defence largely depends on the cell and tissue organisation, i.e., cell numbers and morphology as well as the ratio of surface area to cytoplasmic volume.


1989 ◽  
Vol 67 (1) ◽  
pp. 414-421 ◽  
Author(s):  
N. J. Gross ◽  
K. R. Narine

Mouse alveolar surfactant can be separated by equilibrium centrifugation on continuous sucrose gradients into three subtypes which we call “ultraheavy”, “heavy”, and “light” on the basis of their buoyant densities. We examined their metabolic relationship by in vivo labeling studies and by physical manipulation, cycling the surface area in vitro in an attempt to convert one subtype into another. Labeling studies indicated rapid quantitative progression of surfactant through ultraheavy, heavy, and light subtypes in sequence. To mimic the in vivo conversion of subtypes in vitro we “cycled” the surface area of surfactant in plastic tubes. Newly secreted surfactant obtained from incubated lungs, as well as surfactant obtained by alveolar lavage and lamellar bodies, exhibited conversion of material from heavier to lighter subtypes. The conversion between subtypes was quantal and was dependent on cycling, temperature, and time. We conclude that the three subtypes are discrete forms of alveolar surfactant that evolve from one into another. Cycling may provide a means to study the mechanisms of their interconversion in vitro.


1999 ◽  
Vol 86 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Margaret Oulton ◽  
Elizabeth Edwards ◽  
Kiren Handa

Conversion of heavy-aggregate alveolar surfactant (H) to a light-aggregate, nonsurface active form (L) is believed to involve the activity of an enzyme, namely, convertase. This conversion can be reproduced in vitro by the surface-area cycling technique. The purpose of the present study was to use this technique to investigate the developmental aspects of convertase activity in fetal, newborn, and adult rabbits. H was isolated from alveolar lavage from term [31-day gestation (31d)] fetal rabbit pups, 1-, 4-, and 7-day-old newborns, and adults, and the percent conversion to L was determined. To assess lamellar bodies (LB) as a potential source of activity in this species, these structures were isolated from lung tissue of 27-day-gestation (27d) and 31d fetuses, 1-, 4-, and 7-day-old newborns, and adults and were cycled the same as for H. LB contained considerable activity at each developmental stage i.e., ∼82% of a 27d LB preparation converted to L after 3 h of cycling. In the adult, this value was 78%. Very little conversion of H was obtained from fetal lung (i.e., <20% of the 31d fetal preparation converted to L), but, by postnatal day 4, this value was greatly increased (i.e., >80% conversion) and stayed elevated to adulthood. The activity for each H and LB fraction was temperature and concentration dependent and diminished with storage at 4°C. These data suggest the LB as the source of convertase activity in the rabbit and demonstrate dramatic developmental changes in this activity after release of the LB contents to the alveoli.


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