Localization of acid phosphatase in lamellar bodies of tannic acid treated alveolar type II cells

1988 ◽  
Vol 89 (4) ◽  
pp. 391-395 ◽  
Author(s):  
M. Kalina
Respiration ◽  
1984 ◽  
Vol 46 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Sanae Shimura ◽  
Shinsaku Maeda ◽  
Tamotsu Takismima

1991 ◽  
Vol 260 (2) ◽  
pp. L129-L135 ◽  
Author(s):  
R. G. Eckenhoff ◽  
S. R. Rannels ◽  
A. B. Fisher

Morphological change and lamellar body loss suggests that alveolar type II cells rapidly de- or redifferentiate after several days of primary culture. To determine whether type II cells or lamellar body compositional changes precede these obvious morphological changes, we examined the in situ elemental composition of lamellar bodies and type II cells from intact lung and at different times after isolation using electron probe microanalysis (EPMA). Isolated cells were prepared by standard methods and plated on either tissue culture plastic or kept in suspension with stirrer flasks. Cell pellets obtained at 0, 3, 24, and 48 h after isolation were rapidly frozen, and thin freeze-dried cryosections were prepared and examined cold in a transmission electron microscope equipped for EPMA. Eight to ten type II cells from each of three to four different preparations for each time period were analyzed. A rapid, progressive, and sustained fall in lamellar body calcium and sulfur content occurred by 48 h of primary culture, suggesting rapid alteration in calcium and protein metabolism by type II cells and/or lamellar bodies after isolation. Also, marked changes in type II cell cytoplasmic Na and K occurred in freshly isolated cells, with incomplete normalization by 48 h. Culture on laminin-enriched Matrigel for 1 wk increased both lamellar body calcium or sulfur content, but 100 nM dexamethasone had no effect. Lamellar body calcium accumulation appears to be a very sensitive index of differentiated type II cell function.


2000 ◽  
Vol 278 (4) ◽  
pp. L830-L839 ◽  
Author(s):  
Joel F. Herbein ◽  
Jordan Savov ◽  
Jo Rae Wright

Alveolar type II cells secrete, internalize, and recycle pulmonary surfactant, a lipid and protein complex that increases alveolar compliance and participates in pulmonary host defense. Surfactant protein (SP) D, a collagenous C-type lectin, has recently been described as a modulator of surfactant homeostasis. Mice lacking SP-D accumulate surfactant in their alveoli and type II cell lamellar bodies, organelles adapted for recycling and secretion of surfactant. The goal of current study was to characterize the interaction of SP-D with rat type II cells. Type II cells bound SP-D in a concentration-, time-, temperature-, and calcium-dependent manner. However, SP-D binding did not alter type II cell surfactant lipid uptake. Type II cells internalized SP-D into lamellar bodies and degraded a fraction of the SP-D pool. Our results also indicated that SP-D binding sites on type II cells may differ from those on alveolar macrophages. We conclude that, in vitro, type II cells bind and recycle SP-D to lamellar bodies, but SP-D may not directly modulate surfactant uptake by type II cells.


1986 ◽  
Vol 251 (3) ◽  
pp. R470-R475 ◽  
Author(s):  
G. D. Massaro ◽  
L. Clerch ◽  
D. Massaro

We studied the perinatal development of rat alveolar type II cells. The volume density (Vv) of lamellar bodies increased twofold from gestational day 21.5 to postnatal day 1 and 1.6-fold between age 1 and 60 days. The Vv of glycogen areas fell sharply between late gestation and postnatal day 1; this decrease was greater in pups delivered from dexamethasone- compared with diluent-treated dams. In utero administration of glucagon to fetuses on gestational day 21.5 caused a decline in the Vv of glycogen areas within 4 h. Pups from dams underfed in late gestation had a higher Vv of glycogen areas and a lower Vv of lamellar bodies on the first 2 postnatal days compared with pups from dams allowed food ad libitum. We conclude that rat alveolar type II cells are somewhat immature at birth; prenatal maternal underfeeding slows the pre- and postnatal maturation of alveolar type II cells; and 3) exogenous glucagon causes a fall in the Vv of glycogen areas in type II cells of fetal rats at gestational day 21.5.


1975 ◽  
Vol 7 (3) ◽  
pp. 587-599 ◽  
Author(s):  
Una S. Ryan ◽  
J.W. Ryan ◽  
D.S. Smith

Lipids ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Avinash Chander ◽  
Namita Sen ◽  
Sandra Wadsworth ◽  
Alan R. Spitzer

1995 ◽  
Vol 312 (1) ◽  
pp. 175-181 ◽  
Author(s):  
H Sohma ◽  
N Matsushima ◽  
T Watanabe ◽  
A Hattori ◽  
Y Kuroki ◽  
...  

Surfactant protein A (SP-A), a lung-specific glycoprotein in pulmonary surfactant, is synthesized and secreted from the alveolar type II cells. It has been shown that SP-A is a Ca(2+)-binding protein with several binding sites and that the high-affinity site(s) is located in the C-terminal region of SP-A. In the present study we isolated the proteins from bovine lung soluble fraction that bind to SP-A in a Ca(2+)-dependent manner using DEAE-Sephacel and SP-A-conjugated Sepharose 4B. At least three different protein bands with molecular masses of 24.5, 32, and 33 kDa were observed on SDS/PAGE. The main protein, with molecular mass of 32 kDa, was identified as annexin IV by the partial-amino-acid-sequence analyses and an immunoblot analysis with anti-(annexin IV) antiserum. We also found from the immunoblot analysis that the cytosolic fraction of isolated rat alveolar type II cells contains annexin IV. In addition, when rat lung cytosol was loaded on to the lung lamellar body-conjugated Sepharose 4B in the presence of Ca2+, two proteins, with molecular masses of 32 and 60 kDa on SDS/PAGE respectively, were eluted with EGTA. The 32 kDa protein was shown to be annexin IV by an immunoblot analysis with the antiserum against annexin IV. The lung annexin IV augmented the Ca(2+)-induced aggregation of the lung lamellar bodies from rats. However, the augmentation of aggregation of the lung lamellar bodies by annexin IV was attenuated when the lamellar bodies were preincubated with polyclonal anti-SP-A antibodies. SP-A bound to annexin IV under conditions where contaminated lipid was removed. These results suggest that SP-A bound to annexin IV based on protein-protein interaction, though both proteins are phospholipid-binding proteins. All these findings suggest that the interaction between SP-A and annexin IV may have some role in alveolar type II cells.


1993 ◽  
Vol 41 (1) ◽  
pp. 57-70 ◽  
Author(s):  
M Kalina ◽  
F X McCormack ◽  
H Crowley ◽  
D R Voelker ◽  
R J Mason

Pulmonary surfactant is thought to be internalized and processed for reuse by alveolar Type II cells. In the present study we followed the internalization and intracellular trafficking of purified surfactant protein A (SP-A) by primary cultures of alveolar Type II cells. Internalization of native rat SP-A was compared with that of recombinant rat and human SP-A isolated from a patient with alveolar proteinosis. All SP-A species were conjugated with colloidal gold for visualization by electron microscopy. The gold conjugates were biologically active, as demonstrated by inhibition of phospholipid secretion from alveolar Type II cells. The SP-A-gold conjugates were internalized to lamellar bodies (LB) via the endosomal system, which included both electron-lucent and -dense multivesicular bodies. Labeling of LB was time dependent, and after 7 hr 30-40% of these organelles were labeled. Alkylation of SP-A greatly reduced internalization, as did an excess of non-conjugated SP-A. No qualitative differences in uptake were observed with the three forms of SP-A. The percent of labeled LB was similar (30-40%) after 7 hr of internalization with the three species of SP-A. The recombinant SP-A produced using a baculovirus vector lacked hydroxyproline and had an altered oligosaccharide, but these features did not affect its internalization or the rate of LB labeling. Internalization of the gold-conjugated SP-A and endocytosis of the fluid-phase marker Lucifer Yellow were related to the shape of Type II cells. Both uptake of SP-A, which is receptor mediated, and fluid-phase endocytosis were found to be less active in the flattened than in the rounded cells. Therefore, cell shape and hence cytoskeletal organization may play an important role in SP-A recycling. However, it is possible that both morphology and decreased endocytosis are independent manifestations related to the loss of differentiated function of cultured Type II cells.


2003 ◽  
Vol 284 (6) ◽  
pp. L981-L989 ◽  
Author(s):  
Peter Rückert ◽  
Sandra R. Bates ◽  
Aron B. Fisher

We evaluated the contribution of endocytotic pathways to pulmonary uptake of surfactant lipids from the alveolar space. Resting and stimulated 8-bromoadenosine 3′,5′-cyclic monophosphate (8-Br-cAMP) uptake of unilamellar liposomes labeled with either [3H]dipalmitoylphosphatidylcholine ([3H]DPPC) or 1-palmitoyl-2-[12-(7-nitro-2–1,3-benzoxadiazol-4-yl) amino] dodecanoyl-phosphatidylcholine (NBD-PC) was studied in isolated perfused rat lungs and isolated type II cells. Amantadine and phenylarsine oxide, inhibitors of clathrin-mediated endocytosis, each decreased [3H]DPPC uptake under resting conditions by ∼40%; their combination had no additional effect. Cytochalasin D, an inhibitor of actin-dependent processes, reduced liposome uptake by 55% and potentiated the effect of either clathrin inhibitor alone. Relative inhibition for all agents was higher in the presence of 8-Br-cAMP. The effect of inhibitors was similar for liposomes labeled with [3H]DPPC or NBD-PC. By fluorescence microscopy, NBD-PC taken up by lungs was localized primarily to alveolar type II cells and was localized to lamellar bodies in both lungs and isolated cells. These studies indicate that both clathrin-mediated and actin-mediated pathways are responsible for endocytosis of DPPC-labeled liposomes by alveolar type II cells in the intact lung.


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