ErbB4 and STAT5A Directly Regulate Surfactant Protein B Expression in Fetal Type II Cells.

2009 ◽  
Author(s):  
K Zscheppang ◽  
A Schmiedl ◽  
T Dork ◽  
CE Dammann
Keyword(s):  
Surfactant Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Surfactant Protein B ◽  
Protein B

Processing of hydrophobic pulmonary surfactant protein B in rat type II cells

1989 ◽  
Vol 257 (2) ◽  
pp. L100-L108 ◽  
Author(s):  
T. E. Weaver ◽  
J. A. Whitsett
Keyword(s):  
Epithelial Cells ◽  
Surfactant Protein ◽  
Proteolytic Processing ◽  
Type Ii Cells ◽  
Type Ii ◽  
Proteolytic Fragment ◽  
Time Points ◽  
Surfactant Protein B ◽  
Extracellular Proteolysis ◽  
Protein B

The amino acid sequence of surfactant protein B (SP-B), derived from human genomic and cDNA sequences, indicates that the active polypeptide is contained within the sequence of a preproprotein of 381 residues. Synthesis of mature SP-B, which requires proteolytic processing at both the NH2- and COOH-termini of the proprotein, was studied in primary cultures of rat alveolar type II epithelial cells. Type II cells were pulse labeled with [35S]methionine-cysteine for 15-30 min and chased for 0-18 h. SP-B proprotein (Mr = 42,000) accumulated in the medium at early time points but declined at later time points suggesting extracellular proteolysis of the proprotein. In contrast, surfactant protein A (SP-A), another surfactant protein, continued to accumulate extracellularly during this time period. A proteolytic fragment of SP-B (Mr = 25,000) accumulated in the medium with a slightly slower time course, consistent with extracellular proteolysis of the proprotein. Intracellular processing of SP-B was also detected. SP-B polypeptides of Mr 8,000 and 12,000 were detected intracellularly and in the medium at late time points. These forms of SP-B (Mr = 8,000 and 12,000) comigrated in two-dimensional isoelectric-focusing sodium dodecyl sulfate-polyacrylamide gel electrophoresis with mature SP-B isolated from rat alveolar lavage fluid. The mature form of SP-B (Mr = 8,000), but not the Mr 42,000 and 25,000 SP-B precursors, was also detected in lamellar bodies isolated from rat lung homogenates. These experiments demonstrate complete proteolytic processing of prepro-SP-B to the alveolar Mr 8,000 form by type II epithelial cells in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, uptake, and localization of surfactant protein B in isolated rat alveolar type II cells

1992 ◽  
Vol 262 (6) ◽  
pp. L699-L707 ◽  
Author(s):  
J. S. Breslin ◽  
T. E. Weaver
Keyword(s):  
Surfactant Protein ◽  
Endocytic Pathway ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Coated Pits ◽  
Alveolar Type Ii Cells ◽  
Surfactant Protein B ◽  
Protein B

This study reports the ability of rat alveolar type II cells to internalize mature bovine surfactant protein B (SP-B) in vitro. Isolated type II cells were incubated with labeled SP-B, and binding and internalization were studied biochemically and morphologically. Biochemical analyses demonstrated a time-dependent association of 125I-labeled SP-B with type II cells; binding steadily increased through 4 h and then remained constant through 20 h of incubation. The association of [3H]SP-B with type II cells was characterized via light and electron microscopic autoradiography. Significant quantities of [3H]SP-B were found at the plasma membrane, in the endocytic pathway, and in lamellar bodies. The pathway of SP-B internalization was not altered by the presence of whole rat surfactant; however, the quantity of SP-B internalized into lamellar bodies was increased. 3[H]SP-B was not associated with coated pits and colocalized with horseradish peroxidase (HRP), consistent with receptor-independent internalization. Cell-associated SP-B was not degraded and was detected in lamellar bodies undergoing exocytosis. These results suggest that SP-B may follow a recycling pathway similar to that previously reported for surfactant phospholipids.

Trafficking of newly synthesized surfactant protein B to the lamellar body in alveolar type II cells

2020 ◽  
Vol 381 (3) ◽  
pp. 427-438
Author(s):  
Kazuhiro Osanai ◽  
Shiro Mizuno ◽  
Hirohisa Toga ◽  
Keiji Takahashi
Keyword(s):  
Lamellar Body ◽  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Surfactant Protein B ◽  
Protein B

scholarly journals Surfactant Protein B (SP-B) −/− Mice Are Rescued by Restoration of SP-B Expression in Alveolar Type II Cells but Not Clara Cells

1999 ◽  
Vol 274 (27) ◽  
pp. 19168-19174 ◽  
Author(s):  
Sui Lin ◽  
Cheng-Lun Na ◽  
Henry T. Akinbi ◽  
Karen S. Apsley ◽  
Jeffrey A. Whitsett ◽  
...  
Keyword(s):  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Clara Cells ◽  
Alveolar Type Ii Cells ◽  
Surfactant Protein B ◽  
B Mice ◽  
Protein B

scholarly journals The ontogeny and distribution of surfactant protein B in human fetuses and newborns.

1992 ◽  
Vol 40 (10) ◽  
pp. 1471-1480 ◽  
Author(s):  
M T Stahlman ◽  
M E Gray ◽  
J A Whitsett
Keyword(s):  
Hyaline Membrane Disease ◽  
Surfactant Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Clara Cells ◽  
Lamellar Bodies ◽  
Gland Cells ◽  
Surfactant Protein B ◽  
Bronchial Gland ◽  
Protein B

The distribution of immunoreactive surfactant-associated protein B (IR-SP-B) was studied immunohistochemically in 120 subjects from 10 weeks of gestation to 7 postnatal months with a polyclonal antibody against human SP-B. Electron microscopy (EM) was done in 72 subjects to document the presence of Type II cells containing lamellar bodies. Fetuses of less than 18 weeks' gestation showed no immunostaining. Beginning at 18 weeks, non-mucous cells of tracheal glands immunostained in a few instances. Fetuses of 19 through 23 weeks showed progressive immunostaining of cells lining terminal airways. Infants 26-40 weeks who died with or without pulmonary pathology showed immunostaining of Type II cells and bronchioloalveolar (BA) portal cells of the respiratory bronchioles. In infants with hyaline membrane disease (HMD) who died less than 12 days after birth, occasional tracheal gland cells, BA portal cells, and mature and relining Type II cells immunostained. In bronchopulmonary dysplasia (BPD), BA portal cells, relining Type II cells, macrophages, and luminal material immunostained. Occasional tracheal and bronchial gland cells and Clara cells immunostained. The appearance of IR-SP-B at mid-gestation correlated with differentiation of Type II cells. There was good correlation of immunostaining with the presence of lamellar bodies on EM. Accelerated maturation of the lung was often associated with premature rupture of membranes (PROM).

Degradation of surfactant protein B by alveolar type II cells

1993 ◽  
Vol 265 (5) ◽  
pp. L448-L455 ◽  
Author(s):  
S. R. Bates ◽  
A. B. Fisher
Keyword(s):  
Degradation Products ◽  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Surfactant Protein B ◽  
The Media ◽  
Lag Period ◽  
Protein B

Surfactant protein B (SP-B) metabolism was studied in primary cultures of alveolar type II cells. Iodinated SP-B reconstituted with surfactant was incorporated rapidly into lung pneumocytes and degraded to trichloroacetic acid (TCA)-soluble products after a lag period of 1 h. Cellular degradation of SP-B occurred whether or not phospholipid liposomes or surfactant was added to the phospholipid-poor SP-B. Uptake and degradation of SP-B at 37 degrees C showed a linear increase up to 3 micrograms SP-B/ml after which the slope of the curve became less steep with increasing concentrations of SP-B in the media. After 4 h of incubation with SP-B, 35% of the SP-B processed was recovered as degradation products. Ninety-six percent of the degradation products were in the media and only 4% were recovered in the cell. The bulk of the breakdown of SP-B occurred inside the type II cells since degradation did not occur at 4 degrees C, showed a 1-h lag period, was proportional to the SP-B protein internalized by the cells, was inhibited 47% by ammonium chloride, was unaffected by the addition of protease inhibitors to the medium, and cell-conditioned medium produced only limited SP-B degradation. Alveolar macrophages also degraded SP-B, whereas other cell types degraded SP-B to a lesser extent. Thus the specificity of the metabolism of SP-B may be through the capability of lung cells to degrade SP-B.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding and uptake of surfactant protein B by alveolar type II cells

1992 ◽  
Vol 263 (3) ◽  
pp. L333-L341 ◽  
Author(s):  
S. R. Bates ◽  
M. F. Beers ◽  
A. B. Fisher
Keyword(s):  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Surface Binding ◽  
Alveolar Type Ii Cells ◽  
Apparent Lack ◽  
High Affinity ◽  
Surfactant Protein B ◽  
Protein B

Surfactant protein B (SP-B, mol wt 9,000, reduced) is a low-molecular-weight hydrophobic protein found in organic extracts of lung surfactant. The interaction of iodinated bovine SP-B (125I-SP-B) and isolated rat alveolar type II cells was examined. The association of SP-B with the lung cells was time and temperature dependent; type II cells exhibited time-dependent binding (at 4 degrees C) and uptake (at 37 degrees C) of SP-B. Binding of phospholipid-poor 125I-SP-B was linearly related to the external SP-B concentration from 0.25 to 60 microgram/ml and was not inhibited by a 60-fold excess of unlabeled SP-B. However, the binding of 125I-SP-B reconstituted with bovine surfactant or with phospholipid-containing liposomes occurred through a high-affinity, saturable process and could be inhibited with unlabeled SP-B. By Scatchard analysis, half-maximum binding in the presence of surfactant occurred at 3.1 +/- 0.7 micrograms SP-B/ml. Saturable binding of SP-B reconstituted with surfactant also occurred with other cell types. The results indicate that SP-B was bound and internalized by type II cells. The apparent lack of specificity in the absence of phospholipid may have been due to the self-association of SP-B. The reconstitution of SP-B with phospholipid altered the binding of phospholipid-poor SP-B from a nonspecific process to a high-affinity process consistent with a cell surface binding site.

Partial SP-B deficiency perturbs lung function and causes air space abnormalities

2005 ◽  
Vol 288 (6) ◽  
pp. L1154-L1161 ◽  
Author(s):  
Lori L. Nesslein ◽  
Kristin R. Melton ◽  
Machiko Ikegami ◽  
Cheng-Lun Na ◽  
Susan E. Wert ◽  
...  
Keyword(s):  
Cell Sorting ◽  
Lamellar Body ◽  
Surfactant Protein ◽  
Cellular Heterogeneity ◽  
Type Ii Cells ◽  
Type Ii ◽  
Surfactant Protein B ◽  
Air Space ◽  
Partial Deficiency ◽  
Deficient Mice

Surfactant protein B (SP-B) is required for function of newborn and adult lung, and partial deficiency has been associated with susceptibility to lung injury. In the present study, transgenic mice were produced in which expression of SP-B in type II epithelial cells was conditionally regulated. Concentrations of SP-B were maintained at 60–70% of that normally present in control. Immunostaining for SP-B demonstrated cellular heterogeneity in expression of the protein. In subsets of type II cells in which SP-B staining was decreased, immunostaining for pro-SP-C was increased and lamellar body ultrastructure was disrupted, consistent with focal SP-B deficiency. Fluorescence-activated cell sorting analyses of freshly isolated type II cells identified a population of cells with low SP-B content and a smaller population with increased SP-B content, confirming nonuniform expression of the SP-B transgene. Focal air space enlargement, without cellular infiltration or inflammation, was observed. Pressure-volume curves indicated that maximal tidal volume was unchanged; however, hysteresis was modestly altered and residual volumes were significantly decreased in the SP-B-deficient mice. Chronic, nonuniform SP-B deficiency perturbed pulmonary function and caused air space enlargement.

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