A high-molecular-weight alveolar glycoprotein in the cell-free culture medium of human fetal lung type II pneumocytes

Lung ◽  
1980 ◽  
Vol 158 (1) ◽  
pp. 143-150 ◽  
Author(s):  
S. C. Sahu ◽  
A. K. Tanswell ◽  
W. S. Lynn
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Culture Medium ◽  
Fetal Lung ◽  
Type Ii ◽  
Type Ii Pneumocytes ◽  
Human Fetal Lung

Differentiation of Type II Cells during Explant Culture of Human Fetal Lung Is Accelerated by Endogenous Prostanoids and Adenosine 3′,5′-Monophosphate*

Endocrinology ◽  
1991 ◽  
Vol 128 (6) ◽  
pp. 2916-2924 ◽  
Author(s):  
PHILIP L. BALLARD ◽  
LINDA W. GONZALES ◽  
MARY C. WILLIAMS ◽  
JAMES M. ROBERTS ◽  
MARK M. JACOBS
Keyword(s):  
Fetal Lung ◽  
Explant Culture ◽  
Type Ii Cells ◽  
Type Ii ◽  
Human Fetal Lung

Effect of tunicamycin on maturation of fetal mouse lung

1993 ◽  
Vol 265 (3) ◽  
pp. L250-L259
Author(s):  
E. H. Webster ◽  
S. R. Hilfer ◽  
R. L. Searls ◽  
J. Kornilow
Keyword(s):  
Extracellular Matrix ◽  
Fetal Lung ◽  
Mouse Lung ◽  
Type I ◽  
Type Ii ◽  
Fetal Mouse ◽  
Type Ii Pneumocytes ◽  
Separate Control ◽  
Normal Controls

The mesodermal capsule of the fetal lung plays a role in differentiation of the respiratory region. It has been proposed for other epithelial organs that the mesodermal capsule influences development by modifying the basal lamina or the extended extracellular matrix. The effect could be on deposition or turnover of collagens, proteoglycans, and/or glycoproteins. This study tests the role of glycoproteins in differentiation of respiratory endings by inhibiting their synthesis with the antibiotic tunicamycin (TM). Lungs at 16 and 18 days gestation and 3 days after birth were cultured with TM and examined for morphological and biochemical differences from normal controls. With TM, alveolar regions did not expand properly and formed fewer type I pneumocytes, although type II pneumocytes were unaffected. The epithelium of untreated respiratory regions showed greater incorporation of radioactive mannose than the airways region or mesenchyme. This incorporation was diminished in TM, but the pattern persisted. Comparison with the results obtained with beta-xyloside suggested that differentiation of type I and type II pneumocytes is under separate control.

scholarly journals The Type II Deiodinase Is Retrotranslocated to the Cytoplasm and Proteasomes via p97/Atx3 Complex

2013 ◽  
Vol 27 (12) ◽  
pp. 2105-2115 ◽  
Author(s):  
Rafael Arrojo e Drigo ◽  
Péter Egri ◽  
Sungro Jo ◽  
Balázs Gereben ◽  
Antonio C. Bianco
Keyword(s):  
Molecular Weight ◽  
Endoplasmic Reticulum ◽  
Thyroid Hormone ◽  
High Molecular Weight ◽  
20S Proteasome ◽  
Type I ◽  
Type Ii ◽  
Cell Models ◽  
Natural Substrate ◽  
Iodothyronine Deiodinase

The type II iodothyronine deiodinase (D2) is a type I endoplasmic reticulum (ER)-resident thioredoxin fold-containing selenoprotein that activates thyroid hormone. D2 is inactivated by ER-associated ubiquitination and can be reactivated by two ubiquitin-specific peptidase-class D2-interacting deubiquitinases (DUBs). Here, we used D2-expressing cell models to define that D2 ubiquitination (UbD2) occurs via K48-linked ubiquitin chains and that exposure to its natural substrate, T4, accelerates UbD2 formation and retrotranslocation to the cytoplasm via interaction with the p97-ATPase complex. D2 retrotranslocation also includes deubiquitination by the p97-associated DUB Ataxin-3 (Atx3). Inhibiting Atx3 with eeyarestatin-I did not affect D2:p97 binding but decreased UbD2 retrotranslocation and caused ER accumulation of high-molecular weight UbD2 bands possibly by interfering with the D2-ubiquitin-specific peptidases binding. Once in the cytosol, D2 is delivered to the proteasomes as evidenced by coprecipitation with 19S proteasome subunit S5a and increased colocalization with the 20S proteasome. We conclude that interaction between UbD2 and p97/Atx3 mediates retranslocation of UbD2 to the cytoplasm for terminal degradation in the proteasomes, a pathway that is accelerated by exposure to T4.

Type II pneumocytes release chemoattractant activity for monocytes constitutively

1997 ◽  
Vol 272 (5) ◽  
pp. L830-L837 ◽  
Author(s):  
S. Koyama ◽  
E. Sato ◽  
H. Nomura ◽  
K. Kubo ◽  
S. Nagai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
A549 Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Type Ii ◽  
Tgf Beta ◽  
Lipoxygenase Inhibitors ◽  
Monocyte Chemoattractant ◽  
Type Ii Pneumocytes ◽  
Cell Supernatant

In the present investigation, we determined whether A549 cells, a type II pneumocyte cell line, might release mediators that are responsible for monocyte chemoattractant activity (MCA) constitutively. To test this hypothesis, A549 cell supernatant fluids were harvested and evaluated for monocyte chemotaxis. A549 cell supernatant fluids showed MCA in a time-dependent manner (P < 0.001). Checkerboard analysis of 24- and 72-h supernatant fluids showed that the activity was chemokinetic rather than chemotactic. Partial characterization of 24- and 72-h supernatant fluids revealed that the mediator was composed of lipid-soluble activity that was blocked by lipoxygenase inhibitors and trypsin-sensitive activity blocked by cycloheximide. Molecular sieve column chromatography identified four molecular weight peaks. Two of four peaks were blocked by anti-monocyte chemoattractant protein-1 (MCP-1) and anti-transforming growth factor-beta (TGF-beta) polyclonal antibodies. MCP-1 and TGF-beta were detected by enzyme-linked immunosorbent assay. Leukotriene B4 (LTB4) receptor antagonist attenuated the lowest-molecular-weight peak chemotactic response, and the concentration of LTB4 was high enough for chemotactic activity. These findings suggest that type II pneumocytes may modulate the recruitment of monocytes into the alveolar space by releasing MCP-1, TGF-beta, and LTB4 constitutively.

scholarly journals Characterization of the β-Adrenergic Receptor in Isolated Human Fetal Lung Type II Cells

1992 ◽  
Vol 32 (3) ◽  
pp. 350-355 ◽  
Author(s):  
Cynthia K Ewing ◽  
Diane M Duffy ◽  
James M Roberts
Keyword(s):  
Adrenergic Receptor ◽  
Fetal Lung ◽  
Type Ii Cells ◽  
Type Ii ◽  
Human Fetal Lung

A CRE-like element plays an essential role in cAMP regulation of human SP-A2 gene in alveolar type II cells

1996 ◽  
Vol 271 (2) ◽  
pp. L287-L299 ◽  
Author(s):  
P. P. Young ◽  
C. R. Mendelson
Keyword(s):  
Gene Expression ◽  
Lung Tissue ◽  
Fusion Gene ◽  
Fetal Lung ◽  
Inducible Expression ◽  
Nuclear Proteins ◽  
Type Ii Cells ◽  
Type Ii ◽  
Nuclear Extracts ◽  
Human Fetal Lung

The human has two genes encoding surfactant protein-A (SP-A), termed SP-A1 and SP-A2; the SP-A2 gene is more highly regulated by cAMP and during fetal development than is SP-A1. In this study, by use of primary cultures of human type II cells transfected with fusion genes containing various amounts of SP-A2 5'-flanking DNA linked to human growth hormone (hGH) structural gene, as reporter, we found that -296 bp of SP-A2 upstream sequence is sufficient to direct high basal and cAMP-inducible expression in type II cells, but not in other cell types. By use of competitive EMSA, we observed that nuclear proteins isolated from midtrimester human fetal lung tissue bind specifically to a cAMP response element (CRE)-like sequence, TGACCTTA, at -242 bp, which we have termed CRESP-A2. Binding activity of CRESP-A2 for nuclear proteins from human fetal lung tissue before culture was manifest as two complexes of different mobilities and equivalent intensity. By contrast, upon differentiation of the human fetal lung in culture in the presence of dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP), the higher mobility complex was decreased to undetectable levels. By UV cross-linking analysis, using nuclear extracts from midgestation human fetal lung before culture and radiolabeled CRESP-A2 as a probe, we observed binding of proteins of approximately 50, 36, and 30 kDa. When nuclear extracts from human fetal lung cultured in the presence of DBcAMP were analyzed, binding of only the 50- and 36-kDa proteins was apparent. On the other hand, when the canonical CRE (TGACGTCA) known to bind the transcription factor CREB (M(r) approximately 43,000) was used as a probe, binding of only a approximately 43-kDa protein was evident using nuclear extracts from human fetal lung before and after culture. In type II cells transfected with an SP-A2(-296):hGH fusion gene in which CRESP-A2 was mutated, there was a marked reduction of basal and cAMP-stimulated fusion gene expression. These findings indicate that CRESP-A2 serves an important role in mediating basal and cAMP-inducible expression of the human SP-A2 gene in type II cells, that the fetal lung nuclear proteins bound to CRESP-A2 differ from those bound to the canonical palindromic CRE, and that changes in the complex of nuclear proteins bound to CRESP-A2 accompany induction of SP-A gene expression.

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