scholarly journals Extracellular Regulation of Interleukin (IL)-1 β through Lung Epithelial Cells and Defective IL-1 Type II Receptor Expression

1999 ◽  
Vol 20 (5) ◽  
pp. 964-975 ◽  
Author(s):  
Kristin R. Coulter ◽  
Mark D. Wewers ◽  
Melissa P. Lowe ◽  
Daren L. Knoell
Keyword(s):  
Epithelial Cells ◽  
Receptor Expression ◽  
Lung Epithelial Cells ◽  
Type Ii ◽  
Lung Epithelial

scholarly journals In Vivo and In Vitro Analysis of Factor Binding Sites in Jaagsiekte Sheep Retrovirus Long Terminal Repeat Enhancer Sequences: Roles of HNF-3, NF-I, and C/EBP for Activity in Lung Epithelial Cells

2006 ◽  
Vol 80 (1) ◽  
pp. 332-341 ◽  
Author(s):  
Kathleen McGee-Estrada ◽  
Hung Fan
Keyword(s):  
Epithelial Cells ◽  
Long Terminal Repeat ◽  
Binding Site ◽  
Terminal Repeat ◽  
Lung Epithelial Cells ◽  
Type Ii ◽  
Jaagsiekte Sheep Retrovirus ◽  
Efficient System ◽  
Lung Epithelial

ABSTRACT Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma, a contagious lung cancer of sheep that arises from type II pneumocytes and Clara cells of the lung epithelium. Studies of the tropism of this virus have been hindered by the lack of an efficient system for viral replication in tissue culture. To map regulatory regions important for transcriptional activation, an in vivo footprinting method that couples dimethyl sulfate treatment and ligation-mediated PCR was performed in murine type II pneumocyte-derived MLE-15 cells infected with a chimeric Moloney murine leukemia virus driven by the JSRV enhancers (ΔMo+JS Mo-MuLV). In vivo footprints were found in the JSRV enhancers in two regions previously shown to be important for JSRV long terminal repeat (LTR) activity: a binding site for the lung-specific transcription factor HNF-3β and an E-box element in the distal enhancer adjacent to an NF-κB-like binding site. In addition, in vivo footprints were detected in two downstream motifs likely to bind C/EBP and NF-I. Mutational analysis of a JSRV LTR reporter construct (pJS21luc) revealed that the C/EBP binding site is critical for LTR activity, while the putative NF-I binding element is less important; elimination of these sites resulted in 70% and 40% drops in LTR activity, respectively. Electrophoretic mobility shift assays using nuclear extracts from MLE-15 murine Clara cell-derived mtCC1-2 cells with probes corresponding to the NF-I or C/EBP sites revealed several complexes. Antiserum directed against NF-IA, C/EBPα, or C/EBPβ supershifted the corresponding protein-DNA complexes, indicating that these isoforms, which are also important for the expression of several cellular lung-specific genes, may be important for JSRV expression in lung epithelial cells.

scholarly journals Rab38 targets to lamellar bodies and normalizes their sizes in lung alveolar type II epithelial cells

2011 ◽  
Vol 301 (4) ◽  
pp. L461-L477 ◽  
Author(s):  
Linghui Zhang ◽  
Kevin Yu ◽  
Kyle W. Robert ◽  
Kristine M. DeBolt ◽  
Nankang Hong ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Fluorescent Protein ◽  
Point Mutations ◽  
Lamellar Body ◽  
Lung Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii ◽  
Sprague Dawley ◽  
Lung Epithelial ◽  
Green Fluorescent

Rab38 is a rat Hermansky-Pudlak syndrome gene that plays an important role in surfactant homeostasis in alveolar type II (ATII) pneumocytes. We examined Rab38 function in regulating lamellar body (LB) morphology in ATII cells. Quantitative electron microscopy revealed that LBs in ATII cells were ∼77% larger in Rab38-null fawn-hooded hypertension (FHH) than control Sprague-Dawley (SD) rats. Rab38 protein expression was restricted in lung epithelial cells but was not found in primary endothelial cells. In SD ATII cells, Rab38 protein level gradually declined during 5 days in culture. Importantly, endogenous Rab38 was present in LB fractions purified from SD rat lungs, and transiently expressed enhanced green fluorescent protein (EGFP)-tagged Rab38 labeled only the limiting membranes of a subpopulation (∼30%) of LBs in cultured ATII cells. This selective targeting was abolished by point mutations to EGFP-Rab38 and was not shared by Rab7 and Rab4b, which also function in the ATII cells. Using confocal microscopy, we established a method for quantitative evaluation of the enlarged LB phenotype temporally preserved in cultured FHH ATII cells. A direct causal relationship was established when the enlarged LB phenotype was reserved and then rescued by transiently reexpressed EGFP-Rab38 in cultured FHH ATII cells. This rescuing effect was associated with dynamic EGFP-Rab38 targeting to and on LB limiting membranes. We conclude that Rab38 plays an indispensible role in maintaining LB morphology and surfactant homeostasis in ATII pneumocytes.

scholarly journals Carcinoembryonic cell adhesion molecule 6 in human lung: regulated expression of a multifunctional type II cell protein

2009 ◽  
Vol 296 (6) ◽  
pp. L1019-L1030 ◽  
Author(s):  
Venkatadri Kolla ◽  
Linda W. Gonzales ◽  
Nicole A. Bailey ◽  
Ping Wang ◽  
Sreedevi Angampalli ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Fetal Lung ◽  
Lung Epithelial Cells ◽  
Cell Protein ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Epithelial

Carcinoembryonic cell adhesion molecule 6 (CEACAM6) is a glycosylated, glycosylphosphatidylinositol (GPI)-anchored protein expressed in epithelial cells of various human tissues. It binds gram-negative bacteria and is overexpressed in cancers, where it is antiapoptotic and promotes metastases. To characterize CEACAM6 expression in developing lung, we cultured human fetal lung epithelial cells and examined responses to differentiation-promoting hormones, adenovirus expressing thyroid transcription factor-1 (TTF-1), and silencing of TTF-1 with small inhibitory RNA. Glucocorticoid and cAMP had additive stimulatory effects on CEACAM6 content, and combined treatment maximally increased transcription rate, mRNA, and protein ∼10-fold. Knockdown of TTF-1 reduced hormone induction of CEACAM6 by 80%, and expression of recombinant TTF-1 increased CEACAM6 in a dose-dependent fashion. CEACAM6 content of lung tissue increased during the third trimester and postnatally. By immunostaining, CEACAM6 was present in fetal type II cells, but not mesenchymal cells, and localized to both the plasma membrane and within surfactant-containing lamellar bodies. CEACAM6 was secreted from cultured type II cells and was present in both surfactant and supernatant fractions of infant tracheal aspirates. In functional studies, CEACAM6 reduced inhibition of surfactant surface properties by proteins in vitro and blocked apoptosis of electroporated cultured cells. We conclude that CEACAM6 in fetal lung epithelial cells is developmentally and hormonally regulated and a target protein for TTF-1. Because CEACAM6 acts as an antiapoptotic factor and stabilizes surfactant function, in addition to a putative role in innate defense against bacteria, we propose that it is a multifunctional alveolar protein.

scholarly journals IGFBP2 protects against pulmonary fibrosis through inhibiting P21-mediated senescence

2021 ◽  
Author(s):  
Chin Chiahsuan ◽  
John Lee ◽  
Ranjith Ravichandran ◽  
Timothy Fleming ◽  
Stephen Wheatcroft ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Type Ii ◽  
P21 Protein ◽  
Aged Mice ◽  
Protein Levels ◽  
Age Related ◽  
Lung Epithelial

AbstractAccumulation of senescent cells contributes to age related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) are evolutionarily conserved proteins that play a vital role in many biological processes. Overall, little is known about the functions of IGFBP2 in the epigenetic regulation of cellular senescence and pulmonary fibrosis. Here, we show that Igfbp2 expression was significantly downregulated at both mRNA and protein levels in a low-dose bleomycin-induced pulmonary fibrosis model of aged mice. Using the reduced representation of bisulfite sequencing technique, we demonstrated Igfbp2 downregulation is attributed to DNA methylation of CpG islands in fibrotic lungs of aged mice. Furthermore, Igfbp2 siRNA knockdown increased both P53 and P21 protein levels in mouse lung epithelial cells exposed to hypoxia treatment. Lentiviral mediated expression of Igfb2 decreased P21 protein levels and significantly reduced beta galactosidase activity in mouse lung epithelial cells challenged with a senescent drug (atazanavir) and hypoxia treatments. Using the RT2 Profiler PCR Array, we found that P21, PAI-1, IRF-5 and IRF-7, important regulators of senescence pathway, were significantly downregulated specifically in type-II alveolar epithelial cells (AECs) of aged human-Igfbp2 transgenic mice after bleomycin challenge. Finally, transgenic expression of human-Igfbp2 in type-II AECs from aged bleomycin challenged mice significantly decreased senescent associated secretory phenotype factors and also reduced extracellular matrix markers compared to aged wild-type mice challenged with bleomycin injury. Collectively, these findings reveal that epigenetic repression of Igfbp2 promotes pulmonary fibrosis and that restoring IGFBP2 in fibrotic lungs could prove effective in IPF treatment.

Ontogeny of surfactant proteins and lipid-synthesizing enzymes in cultured fetal lung epithelial cells

1994 ◽  
Vol 267 (4) ◽  
pp. L375-L383 ◽  
Author(s):  
C. Fraslon-Vanhulle ◽  
B. Chailley-Heu ◽  
J. J. Batenburg ◽  
R. Elfring ◽  
J. R. Bourbon
Keyword(s):  
Epithelial Cells ◽  
Phospholipid Composition ◽  
Lipid Synthesis ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Lung Epithelial Cells ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Epithelial

Fetal rat lung epithelial cells were isolated on gestational day 17 (term is 22), separated from fibroblasts, and cultured up to 6 days in a serum-free medium on a basement membrane matrix. Surfactant protein (SP) A, barely detectable by immunostaining at the beginning of the culture, considerably increased in cells and subsequently in the lumen of the epithelial cell clusters. SP-A mRNA, already detectable at culture initiation, progressively increased. By contrast, SP-B and its mRNA appeared after 2-3 days. SP-C mRNA appeared only after 4 days of culture. Cells cultured 6 days had a phospholipid composition similar to that of freshly isolated adult rat type II cells. The enhancement of lipid synthesis between the first and the sixth culture days, reported earlier to occur in these cells, was found to be accompanied by a two- to fivefold increase in amount of mRNAs of lipogenic enzymes and choline phosphate cytidylyltransferase. In conclusion, alveolar epithelial type II cells appear to be capable of full differentiation in vitro, and components of the surfactant system are all regulated developmentally at a pretranslational level.

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