PubMed Health⌕ Search

Biomedical subjects

C D Bingle

Publications and source records attributed to C D Bingle.

At least 19 recordsLinked to original sources
PubMed2003

Comparative analysis of the PLUNC (palate, lung and nasal epithelium clone) protein families.

PLUNC (palate, lung and nasal epithelium clone) is a small, secreted protein that is expressed in the oropharynx and upper airways of humans, mice and rats. We have described a family of at least 14 PLUNC genes localized on chromosome 20 (in humans), 2 (in mice) or 3 (in rats). These rapidly evolving proteins are structurally related to lipopolysaccharide-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI). In the present analysis we comment on the comparative aspects of this protein family, which may function to protect epithelial surfaces from pathogenic micro-organisms.

Amino Acid Sequence↗
PubMed2001

Genomic organization of the mouse plunc gene and expression in the developing airways and thymus.

Few genes have been isolated which display specific expression in the proximal airways. A recently identified mouse cDNA, plunc, appears to be confined to the upper airways and nasopharyngeal epithelium, and may prove a useful marker for these regions. We now report the genomic cloning and characterization of the mouse plunc gene as well as its developmental expression in the nasal and airway epithelium. We also report the novel finding that plunc is also expressed in the medullary compartment of the murine thymus. The mouse gene contains nine exons and the intron-exon boundaries are conserved with those in the human homologue. At e14.5 plunc is expressed in the nasal epithelium and several days later is seen in the thymic lobes, but not in the lining of the tracheobronchial tree. Expression in the trachea and main-stem bronchi first appears at 1--2 days after birth. Tracheobronchial expression persists at high levels throughout adulthood, as do regional areas of nasal and thymic expression. Finally, we show that the human homologue is expressed in bronchial epithelium, suggesting a transcript that is evolutionarily conserved in the mammalian airway.

Animals↗
PubMed2001

Cytokine-mediated induction of the human elafin gene in pulmonary epithelial cells is regulated by nuclear factor-kappaB.

Elafin, a low molecular-weight proteinase inhibitor, is a member of the recently described trappin gene family. These proteins are thought to play important roles in the regulation of inflammation and are expressed in multiple epithelia. Elafin is found within the lung, and its expression can be induced by inflammatory mediators. The molecular mechanisms that mediate its induction are not understood. In this study we investigated the transcriptional regulation of the elafin gene in pulmonary epithelial cell lines. Transfection of elafin promoter constructs into the elafin-expressing pulmonary epithelial cell line A549 identified a number of positive-acting elements. Cytokine-mediated inducibility of the elafin gene promoter was shown to occur through a nuclear factor (NF)-kappaB site present within the minimal promoter. This site was shown to bind to NF-kappaB proteins within nuclear extracts from cytokine stimulated cell lines as well as to in vitro-translated RelA. Cotransfection with both RelA and NF-kappaB-inducing kinase induced reporter gene activation via this site, and mutagenesis experiments confirmed that it was crucial for induction of elafin gene activity. These results clearly identify a role for elafin in the inflammatory response of the airway epithelium to pathogenic insult and show that this response is mediated by an NF-kappaB site within the proximal promoter.

Base Sequence↗
PubMed2000

Characterisation of the human plunc gene, a gene product with an upper airways and nasopharyngeal restricted expression pattern.

Here we report the cloning and characterization of the human homologue of plunc, a murine gene expressed specifically in the upper airways and nasopharyngeal regions. The human plunc cDNA codes for a leucine-rich protein of 256 amino acids which is 72% identical to the murine protein. RNA blot analysis suggests that expression of plunc is restricted to the trachea, upper airway, nasopharyngeal epithelium and salivary gland. The human plunc gene contains nine exons and is localised to chromosome 20q11.2. The unique expression pattern of the human plunc suggest that it may prove a useful model gene with which to study the regulatory mechanisms which direct expression of genes specifically to the upper airways.

Amino Acid Sequence↗
PubMed2000

Exon skipping in Mcl-1 results in a bcl-2 homology domain 3 only gene product that promotes cell death.

Mcl-1 is a member of the Bcl-2 family that is regulated transcriptionally and post-transcriptionally, with expression of the full-length Mcl-1-encoded gene product resulting in enhanced cell survival. As reported here, the human Mcl-1 gene can also undergo differential splicing, which yields an internally deleted, death-inducing gene product, Mcl-1(s/Delta)(TM). Whereas full-length Mcl-1 derives from three coding exons (instead of the two present in Bcl-2 and other anti-apoptotic members of this family), the Mcl-1(s/Delta)(TM) splice variant results from the joining of the first and third exons with skipping of the central exon. Because of the skipped exon and a shift in the reading frame downstream, the Bcl-2 homology domain (BH3) remains intact, whereas the BH1-, BH2-, and transmembrane-encoding domains do not. Mcl-1(s/Delta)(TM) thus has features similar to BH3 only, pro-apoptotic Bcl-2 family members and, accordingly, was found to promote cell death. In addition to a variety of other types of regulation, the Mcl-1 gene appears ideally designed for the generation of either a Bcl-2-like viability promoting or, as reported here, a BH3 only death-inducing gene product.

Amino Acid Sequence↗
PubMed2000

The influence of mode of delivery, hormonal status and postnatal O2 environment on epithelial sodium channel (ENaC) expression in perinatal guinea-pig lung.

We have studied factors that potentially modulate the expression of mRNA coding for subunits of the amiloride-sensitive sodium channel, alphaENaC and betaENaC, in lungs of vaginally and Caesarean (CS)-delivered late gestation fetal guinea-pigs. Expression of alphaENaC and betaENaC mRNAs was developmentally regulated in the late gestation fetus, reaching peak levels at term (68 days post conception, PC) and postnatally, respectively. In animals delivered by CS at 65 days PC and term, alphaENaC mRNA expression was significantly increased by day 1 post partum, reaching levels greater than those normally achieved in vaginally delivered animals at term. In contrast, betaENaC mRNA levels remained significantly lower postnatally in animals delivered by CS at 65 days PC compared with those in vaginally and CS-delivered animals at term. Plasma cortisol and total triiodothyronine (T3) levels increased towards term, were higher 1 day after vaginal delivery but declined towards pre-term levels by day 3. Cortisol levels also increased rapidly in the CS-delivered animals, reaching levels similar to those in vaginally delivered animals at day 1. Plasma T3 levels at days 1 and 3 were significantly lower in animals delivered by CS at 65 days PC. The increase in alphaENaC mRNA paralleled the increase in plasma cortisol after delivery, but not T3, and inhibition of cortisol synthesis with 2-methyl-1,2-di-3-pyridyl-1-propanone (metyrapone) after CS delivery suppressed the increase in alphaENaC mRNA expression. Concomitant with the increase in alphaENaC mRNA expression after CS delivery at 65 days PC was an increase in the amiloride-blockable component of lung fluid clearance by day 3 postnatally. We conclude that in late gestation guinea-pigs delivered by CS there is a significant increase in lung alphaENaC expression postnatally, which is mediated, in part, by the postnatal rise in cortisol at delivery. This in turn leads to an increase in amiloride-sensitive lung fluid clearance, which is unrelated to labour.

Animals↗
PubMed2000

Inflammatory neutrophils retain susceptibility to apoptosis mediated via the Fas death receptor.

Apoptosis and clearance of neutrophils is essential for successful resolution of inflammation. Altered signaling via the Fas receptor could explain the observed prolongation of neutrophil lifespan and associated tissue injury at inflammatory sites. We therefore compared inflammatory neutrophils extracted from joints of rheumatoid arthritis patients, with peripheral blood neutrophils. Inflammatory neutrophils underwent constitutive apoptosis in culture more rapidly than peripheral blood neutrophils; this was not explained by changes in surface expression of Fas or by induction of Fas ligand. Inflammatory neutrophils remained sensitive to Fas-induced death, at levels comparable to those seen in peripheral blood neutrophils. Similarly, granulocyte-macrophage colony-stimulating factor reduced apoptosis but did not abolish signaling via Fas. These data provide evidence for the rate of apoptosis in inflammatory neutrophils being continually modulated by death and survival signals in the inflammatory milieu. This allows for rapid resolution of inflammation as levels of survival factors fall, and suggests new strategies for inducing resolution of inflammation.

Apoptosis↗
PubMed2000

Cloning and expression of guinea pig TIMP-2. Expression in normal and hyperoxic lung injury.

Tissue inhibitors of metalloproteinases (TIMPs) play a key regulatory role in extracellular matrix remodeling. By screening a lung library with a human TIMP-2 cDNA probe, we have isolated the cDNA corresponding to guinea pig TIMP-2. The 3.5-kb cDNA presents an open reading frame that predicts a protein of 220 amino acids showing 97.2, 96.8, 97.2, and 77.3% overall identity with human, mouse, rat, and chicken TIMP-2, respectively. Guinea pig TIMP-2 cDNA was expressed in CHO-K1 cells, showing a protein with the expected molecular weight and activity. Northern blot analysis revealed TIMP-2 expression in brain, kidney, intestine, spleen, heart, and lung. Transforming growth factor-beta downregulated TIMP-2 mRNA in guinea pig lung fibroblasts, whereas a variety of other stimuli showed no effect. In normal and hyperoxia-exposed lungs, TIMP-2 mRNA was mainly localized in alveolar macrophages and epithelial cells. No quantitative differences were found by Northern blot. These results confirm that TIMP-2 is highly conserved in mammals and largely expressed in lungs.

Amino Acid Sequence↗
PubMed1998

The LEC rat possesses reduced hepatic selenium, contributing to the severity of spontaneous hepatitis and sensitivity to carcinogenesis.

The hepatic concentrations of copper, zinc, magnesium, calcium, and selenium were measured in LEC rats, which develop a spontaneous form of hepatitis at 3-4 months of age, and compared to trace metal concentrations in the LEA rat, its asymptomatic congenic strain. Consistent with results found by other groups, copper was found to accumulate within the liver of LEC rats to levels more than 50 times those measured in LEA rats. In addition, liver selenium concentration in LEC rats was found to be around 50% of that in LEA rats. The enzyme activity, and RNA for the selenium dependent enzyme, glutathione peroxidase, was also found to be reduced in LEC rat liver. These results indicate that hepatic selenium in the LEC rat is depleted and that, as a result of this, the capacity to protect cells from copper-induced free-radical damage is reduced.

Animals↗
PubMed1997

Thyroid transcription factor-1.

Thyroid transcription factor-1 (TTF-1) is a recently identified member of the homeodomain transcription factor family, which plays a role in regulating genes expressed within the thyroid, lung and brain, including thyroglobulin, thyroid peroxidase, Clara cell secretory protein and the surfactant proteins. Additional studies, including gene targeting experiments, have clearly shown that expression of TTF-1 is essential for morphogenesis of the thyroid, lung and ventral forebrain, as TTF-1 knockout mice lack these organs. In the light of these studies it seems possible that mutations in TTF-1 may underlie certain abnormalities either of organogenesis of, or of cellular function within, these organ systems. A recent example of such a defect is the identification of a patient with thyroglobulin deficiency due to decreased TTF-1 expression.

Animals↗
PubMed1997

Cloning of guinea pig surfactant protein A defines a distinct cellular distribution pattern within the lung.

A full-length cDNA to guinea pig pulmonary surfactant protein (SP) A was cloned by screening a newborn guinea pig lung cDNA library with a human SP-A cDNA probe. The full-length guinea pig SP-A cDNA consists of 1,839 bp and is highly conserved at both nucleotide and amino acid sequence levels with those from other species. As expected, guinea pig SP-A mRNA is abundantly expressed in adolescent lung tissue and is undetectable in nonpulmonary tissues. In situ hybridization studies clearly show a unique cellular distribution pattern of SP-A mRNA within the guinea pig lung. SP-A mRNA expression is confined to cells of the alveolar epithelium with no expression in the bronchiolar epithelial cells, whereas SP-B mRNA is expressed in both alveolar and bronchiolar epithelial cell populations. This distinct expression pattern suggests that the guinea pig lung will be a useful model in which to study expression of transcription factors implicated in the regulation of SP genes.

Amino Acid Sequence↗
PubMed1996

Oct-1 interacts with conserved motifs in the human thyroid transcription factor 1 gene minimal promoter.

The homeodomain containing thyroid transcription factor 1 (TTF-1) is a lung- and thyroid-enriched protein implicated in the regulation of a number of pulmonary specific genes. Within the lung TTF-1 is expressed within the epithelial cells. Although the molecular mechanisms that govern this tight cell-type-specific distribution are unclear, transient transfection studies have suggested that tissue specificity is conferred in part by regions of the proximal promoter. Further studies have shown that two functionally important regions (BS1 and BS2) are sites for activation of the TTF-1 gene by the homeodomain protein HoxB3, raising the possibility that Hox proteins might function in the regulation of TTF-1 in vivo. The different cellular distributions of the two proteins within the lung suggest, however, that proteins distinct from HoxB3 might be the mediators of expression through these sites. In the present study we have used gel-mobility-shift experiments to show that in a pulmonary adenocarcinoma cell line (NCI-H441) that expresses TTF-1, the same single protein binds to both of these sites. The binding of this protein is competed for specifically by the addition of oligonucleotides containing a range of octamer-binding sites but not by a variety of non-related binding sites. Using specific antiserum we have identified this protein as being the ubiquitously expressed POU-domain protein Oct-1. Reverse transcriptase-PCR performed with degenerated primers suggests that Oct-1 is the major POU-domain-containing protein expressed in H441 cells. These results suggest that BS1 and BS2 are functional octamer sites and might therefore be implicated in the basal rather than the tissue-restricted expression of the TTF-1 gene.

Adenocarcinoma↗
PubMed1996

Generation of a rat bronchiolar epithelial cell cDNA library: isolation of a proline rich protein highly enriched in bronchiolar epithelial cells.

As a tool for the identification of novel gene products expressed in rat bronchiolar epithelial (BE) cells we generated a cDNA library prepared from BE cells, enriched to contain > 40% Clara cells. Using a simple differential screening strategy we isolated and partially characterized 47 clones, 29 of which corresponded to gene products known to be expressed within the bronchiolar epithelium. A further 15 clones contained sequences which were not present in the EMBL database and therefore represented potential novel BE cell enriched clones. One of these clones, CC-4, was characterized further and shown by northern blotting to be highly enriched in the BE cell population. The deduced protein product of CC-4 is a proline rich protein of 29.5 kd. These studies suggest that this cDNA library may be a useful tool for the identification of novel lung restricted gene products.

Amino Acid Sequence↗
PubMed1996

Molecular cloning of the forkhead transcription factor HNF-3 alpha from a human pulmonary adenocarcinoma cell line.

We have cloned the human homologue of HNF-3 alpha from the pulmonary adenocarcinoma cell line NCI-H441. Full-length HNF-3 alpha which was found to be 2872 bp encoded a protein of 473 amino acids. The human protein is highly related to the rat and mouse homologues and the forkhead DNA binding domain is highly conserved between all species yet identified. Northern blotting with a variety of human-derived cell lines identified a single 3 kb mRNA species. RNA levels are > 10-fold higher in the H441 cells than in any of the others.

Adenocarcinoma↗
PubMed1996

The lung enriched transcription factor TTF-1 and the ubiquitously expressed proteins Sp1 and Sp3 interact with elements located in the minimal promoter of the rat Clara cell secretory protein gene.

The mechanisms that direct expression of the Clara cell secretory protein (CCSP) gene to the bronchiolar epithelial cells of the lung remain to be elucidated. Previous studies have identified a number of proteins which bind to a functionally important region (Region 1) located -132 to -76 bp from the transcription start site in the rat CCSP gene. Subsequently we have shown that while Region 1 is an important positive regulator of CCSP gene expression, sequences 3' of this region (-75 to +38) are sufficient to confer tissue-specific expression of a reporter gene. In the present study we have used transient transfections with a deletion series of CCSP-CAT reporter plasmids (where CAT is chloramphenicol acetyltransferase) and gel mobility shift assays with a series of overlapping oligonucleotides covering the whole minimal promoter region to study protein-DNA interactions within this region. These studies have identified a conserved functional binding site for the lung and thyroid enriched homeodomain transcription factor TTF-1, located between positions -51 and -42 from the transcription start site. CCSP-CAT chimaeric reporters containing this region are specifically activated by TTF-1 in co-transfection assays, and nuclear extracts from cells which express TTF-1 bind to this region, as does in vitro translated rat TTF-1. Three additional conserved regions were identified, and in further gel mobility shift studies with an oligonucleotide spanning the conserved region immediately 5' to the TTF-1 site we identified a binding site for the ubiquitously expressed zinc-finger-containing proteins Sp1 and Sp3. These studies suggest that cell-type-restricted and ubiquitous nuclear proteins may play a combined role in the regulation of the CCSP gene within the bronchiolar epithelium by interacting with the minimal promoter region.

Animals↗
PubMed1996

Differential patterns of antioxidant enzyme mRNA expression in guinea pig lung and liver during development.

cDNA clones for guinea pig antioxidant enzymes, copper-zinc (Cu-Zn) and manganese (Mn-) superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were isolated by reverse transcription (RT)-polymerase chain reaction (PCR) cloning, to explore the mechanism regulating the differential expression of antioxidant enzymes (AOEs) in guinea pig lung and liver, during development. Increases in MnSOD, CAT and GPx mRNA expression in lung and, MnSOD mRNA in liver, were seen during the final period of gestation, whereas CuZnSOD and CAT mRNA expression in liver, which was constant during gestation, increased in the postnatal period. In lung, CuZnSOD mRNA level decreased just prior to birth while in liver, GPx mRNA expression declined markedly over the last third of gestation. In lung, while the mRNA levels of MnSOD, CAT, and GPx increased pre-natally, they declined following birth. In contrast, the postnatal increase in mRNA for CuZnSOD and CAT and the prenatal increase in MnSOD mRNA expression in liver remained at least to adolescence. In adolescent guinea pigs, CuZnSOD and CAT mRNA were most abundantly expressed in liver, while MnSOD and GPx mRNA were most abundant in heart and spleen, respectively. These results demonstrate markedly different developmental patterns of AOEs expression in guinea pig lung and liver during both the pre- and post-natal period. The short-lasting, late-gestational increases of MnSOD, CAT, and GPx mRNA expression in lung, may be responsible for the temporary increases in the activity of these antioxidants in the late gestational period, whereas the steady increases of CuZnSOD, CAT mRNA following birth, and also the prenatal increases in MnSOD mRNA expression, are probably responsible for the higher postnatal activity of these antioxidants in liver.

Aging↗
PubMed1996

Mechanisms of gene expression and cell fate determination in the developing pulmonary epithelium.

The pulmonary epithelium is a derivative of the foregut endoderm. Proliferation and differentiation of the primitive pulmonary epithelium result in an array of epithelial cell phenotypes that determine lung function and the response of the lung to injury, infection, or neoplastic transformation. The establishment of a cell phenotype requires the presence of transcription factors that activate or repress expression of specific genes. Members of the forkhead family of transcription factors, in particular HNF-3 alpha, HNF-3 beta, HFH-4; the homeodomain protein TTF-1; and N-myc, are all expressed in the developing pulmonary epithelium and may play important regulatory roles during development. Two genes specific to the pulmonary epithelium, the surfactant protein A and Clara cell secretory protein genes, serve as useful paradigms for understanding the mechanisms regulating cell-specific gene expression in the pulmonary epithelium.

Amino Acid Sequence↗