scholarly journals Role of hepatocyte nuclear factor-3α and hepatocyte nuclear factor-3β in Clara cell secretory protein gene expression in the bronchiolar epithelium

1995 ◽  
Vol 308 (1) ◽  
pp. 197-202 ◽  
Author(s):  
C D Bingle ◽  
B P Hackett ◽  
M Moxley ◽  
W Longmore ◽  
J D Gitlin

The 5′ flanking region of the Clara cell secretory protein (CCSP) gene contains two cis-acting elements which bind hepatocyte nuclear factor (HNF)-3 alpha and HNF-3 beta in vitro. To determine the role of these proteins in mediating CCSP gene expression in the bronchiolar epithelium, chimeric CCSP-reporter gene constructs containing various regions of the CCSP 5′ flanking region were co-transfected into H-441 cells with HNF-3 alpha or HNF-3 beta expression plasmids. These studies indicate that each of these transcription factors positively regulates CCSP gene expression and revealed that CCSP region I (-132 to -76) is sufficient to mediate this effect. Gel-mobility-shift assays with oligonucleotides corresponding to CCSP region I, nuclear extract from bronchiolar epithelial cells and HNF-3-specific antibodies indicate that HNF-3 alpha and HNF-3 beta are the only proteins in bronchiolar epithelial cells which directly interact with this region. Consistent with these observations, HNF-3 alpha and HNF-3 beta transcripts were found to be enriched in this cell population and in situ hybridization of adult lung revealed HNF-3 gene expression in non-ciliated bronchiolar epithelial cells expressing the CCSP gene. Finally, experiments with CCSP region I and a heterologous promoter indicate that this region acts in a promoter-specific context, suggesting that additional factors interacting via the minimal CCSP promoter region are essential in determining the effects of HNF-3 on cell-specific CCSP gene expression in the bronchiolar epithelium.

1993 ◽  
Vol 295 (1) ◽  
pp. 227-232 ◽  
Author(s):  
C D Bingle ◽  
J D Gitlin

To determine the mechanisms of cell-specific gene expression in the developing pulmonary epithelium the Clara cell secretory protein (CCSP) gene promoter was analysed by DNAase I footprinting. A prominent site of protein-DNA interaction was detected from nucleotides -132 to -76 using nuclear extract from mouse lung and human H441 cells. Mobility shift analysis revealed that an oligonucleotide corresponding to this region interacted with multiple proteins from lung and H441 cell nuclear extracts. Analysis of the nucleotide sequence of this region identified two potential binding sites for hepatocyte nuclear factor 3 (HNF-3), and consistent with this finding binding to this CCSP oligonucleotide was specifically competed for by an oligonucleotide corresponding to the HNF-3-binding site from the mouse transthyretin gene. Mobility shift of the CCSP oligonucleotide was supershifted using antisera specific to HNF-3 alpha and HNF-3 beta, and HNF-3 alpha and HNF-3 beta translated in vitro were found to bind specifically to this same oligonucleotide. Co-transfection of HNF-3 alpha- and HNF-3 beta-expression plasmids increased cell-specific reporter gene activity in H441 cells transfected with a CCSP-CAT gene chimeric construct containing this -132 to -76 region. Taken together, these results suggest a role for HNF-3 in mediating cell-specific CCSP gene expression within the bronchiolar epithelium. These findings support the hypothesis that members of the HNF-3 ‘forkhead’ family of transcription factors determine gene expression and cell fate in multiple cell lineages derived from the primitive gut endoderm.


1998 ◽  
Vol 274 (5) ◽  
pp. L864-L869 ◽  
Author(s):  
X. L. Yao ◽  
T. Ikezono ◽  
M. Cowan ◽  
C. Logun ◽  
C. W. Angus ◽  
...  

Clara cell secretory protein (CCSP) is an inhibitor of secretory phospholipase A2. It is produced by airway epithelial cells and is present in airway secretions. Because interferon (IFN)-γ can induce gene expression in airway epithelial cells and may modulate the inflammatory response in the airway, it was of interest to study the effect of this cytokine on epithelial cell CCSP mRNA expression and CCSP protein synthesis. A human bronchial epithelial cell line (BEAS-2B) was used for this study. CCSP mRNA was detected by ribonuclease protection assay. IFN-γ was found to increase CCSP mRNA expression in a time- and dose-dependent manner. The CCSP mRNA level increased after IFN-γ (300 U/ml) treatment for 8–36 h, with the peak increase at 18 h. Immunobloting of CCSP protein also demonstrated that IFN-γ induced the synthesis and secretion of CCSP protein in a time-dependent manner. Nuclear run-on, CCSP reporter gene activity assay, and CCSP mRNA half-life assay demonstrated that IFN-γ-induced increases in CCSP gene expression were mediated, at least in part, at the posttranscriptional level. The present study demonstrates that IFN-γ can induce increases in steady-state mRNA levels and protein synthesis of human CCSP protein in airway epithelial cells and may modulate airway inflammatory responses in this manner.


1992 ◽  
Vol 262 (4) ◽  
pp. L399-L404 ◽  
Author(s):  
B. P. Hackett ◽  
N. Shimizu ◽  
J. D. Gitlin

To determine the mechanisms of Clara cell secretory protein (CCSP) gene expression, a cDNA clone was isolated and used in RNA blot analysis. A single 600 bp CCSP specific transcript was detected in the developing rat lung on fetal day 18. This transcript increased in abundance during late fetal life such that adult levels were attained within 2 wk postpartum. CCSP gene expression was tissue specific, being confined to lung and trachea at all developmental stages. The abundance of CCSP mRNA in lung tissue was unchanged after the induction of lung injury in adult rats either with lipopolysaccharide or prolonged exposure to hyperoxia. In situ hybridization of lung tissue revealed that CCSP gene expression is localized to the nonciliated epithelial (Clara) cells of the bronchiolar epithelium throughout fetal and postnatal development. Taken together the results indicate that the gene for CCSP is abundantly expressed in a cell-specific fashion in the lung and suggest that analysis of such expression will be useful in elucidating the role of Clara cells in the growth and development of the bronchiolar epithelium.


2006 ◽  
Vol 84 (4) ◽  
pp. 345-345
Author(s):  
Yusuke Inoue ◽  
L. Luanne Peters ◽  
Sun Hee Yim ◽  
Junko Inoue ◽  
Frank J. Gonzalez

2018 ◽  
Author(s):  
Ian Huck ◽  
Sumedha Gunewardena ◽  
Regina Espanol-Suner ◽  
Holger Willenbring ◽  
Udayan Apte

AbstractHepatocyte Nuclear Factor 4 alpha (HNF4α) is critical for hepatic differentiation. Recent studies have highlighted its role in inhibition of hepatocyte proliferation and tumor suppression. However, the role of HNF4α in liver regeneration is not known. We hypothesized that hepatocytes modulate HNF4α activity when navigating between differentiated and proliferative states during liver regeneration. Western blot analysis revealed a rapid decline in nuclear and cytoplasmic HNF4α protein levels accompanied with decreased target gene expression within 1 hour after 2/3 partial hepatectomy (post-PH) in C57BL/6J mice. HNF4α protein expression did not recover to the pre-PH levels until day 3. Hepatocyte-specific deletion of HNF4α (HNF4α-KO) in mice resulted in 100% mortality post-PH despite increased proliferative marker expression throughout regeneration. Sustained loss of HNF4α target gene expression throughout regeneration indicated HNF4α-KO mice were unable to compensate for loss of HNF4α transcriptional activity. Deletion of HNF4α resulted in sustained proliferation accompanied by c-myc and cyclin D1 over expression and a complete deficiency of hepatocyte function after PH. Interestingly, overexpression of degradation-resistant HNF4α in hepatocytes did not prevent initiation of regeneration after PH. Finally, AAV8-mediated reexpression of HNF4α in hepatocytes of HNF4α-KO mice post-PH restored HNF4α protein levels, induced target gene expression and improved survival of HNF4α-KO mice post-PH. In conclusion, these data indicate that HNF4α reexpression following initial decrease is critical for hepatocytes to exit from cell cycle and resume function during the termination phase of liver regeneration. These results reveal the role of HNF4α in liver regeneration and have implications for therapy of liver failure.


2009 ◽  
Vol 46 (4) ◽  
pp. 604-613 ◽  
Author(s):  
P. Katavolos ◽  
C. A. Ackerley ◽  
L. Viel ◽  
M. E. Clark ◽  
X. Wen ◽  
...  

Horses are prone to recurrent airway obstruction (RAO), an inflammatory lung disease induced by repeated exposure to environmental mold, dust, and bacterial components. Active disease manifests with mucus hyperproduction, neutrophilic inflammation, bronchoconstriction, and coughing. Chronically affected animals have lung remodeling characterized by smooth muscle hyperplasia, collagen deposition, lymphoid hyperplasia, and impaired aerobic performance. Clara cell secretory protein (CCSP) counters inflammation in the lung, hence we hypothesized that CCSP depletion is a key feature of RAO in horses. Recombinant equine CCSP and specific antiserum were produced, and percutaneous lung biopsies were obtained from 3 healthy horses and from 3 RAO-affected horses before and after induction of RAO. CCSP relative gene expression in tissue, as well as protein concentration in lung lavage fluid, was determined. Immunocytochemical analysis, using both light and immunogold ultrastructural methods, demonstrated reduced CCSP staining in lung tissue of animals with RAO. Immunogold label in Clara cell granules was less in animals with chronic RAO than in normal animals, and absent in animals that had active disease. Median lung lavage CCSP concentration was 132 and 129 ng/ml in healthy horses, and 62 and 24 ng/ml in RAO horses before and after challenge, respectively. CCSP lung gene expression was significantly higher in healthy animals than in animals with chronic RAO. Together, these preliminary findings suggest that reduced production of CCSP and subcellular changes in Clara cells are features of chronic environmentally induced lung inflammation in horses.


2006 ◽  
Vol 291 (3) ◽  
pp. L502-L511 ◽  
Author(s):  
Robert J. Homer ◽  
Zhou Zhu ◽  
Lauren Cohn ◽  
Chun Gun Lee ◽  
Wendy I. White ◽  
...  

The mammalian chitinase family includes members both with and without enzymatic activity against chitin, a product of fungal cell walls, exoskeletons of crustaceans and insects, and the microfilarial sheaths of parasitic nematodes. Two members of that family, Ym1 and acidic mammalian chitinase (AMCase), are strongly upregulated in pulmonary T helper (Th) 2 inflammation but not in Th1 inflammation. The sites of expression of these products are incompletely known. We show here that, in two different models of Th2 inflammation, Ym1 and AMCase are mutually exclusively expressed in proximal vs. distal airway epithelium, respectively, whereas both are expressed in alveolar macrophages. This regional difference along the airway corresponds to the previously noted distinction between mucus positive proximal cells and mucus negative distal cells under the same conditions. Among distal cells, AMCase colocalizes with epithelial cells expressing the Clara cell marker Clara cell secretory protein. These AMCase-expressing cells retain expression of FOXA2, a transcription factor whose downregulation in association with IL-13 signaling has previously been associated with production of mucus in proximal airway epithelial cells. These results provide evidence that secretory cells of proximal and distal airways undergo fundamentally different gene expression programs in response to allergic inflammation. Furthermore, AMCase provides the first positive molecular marker of distal Clara cell secretory protein-expressing cells under these conditions.


Sign in / Sign up

Export Citation Format

Share Document