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C D Bingle

Publications and source records attributed to C D Bingle.

29 records · Page 2Linked to original sources
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↗
PubMed1995

Role of hepatocyte nuclear factor-3 alpha and hepatocyte nuclear factor-3 beta in Clara cell secretory protein gene expression in the bronchiolar epithelium.

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.

Animals↗
PubMed1993

Identification of hepatocyte nuclear factor-3 binding sites in the Clara cell secretory protein gene.

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.

Animals↗
PubMed1993

Interaction of CCAAT/enhancer-binding protein alpha and beta with the rat caeruloplasmin gene promoter.

To determine the mechanisms of expression of the rat caeruloplasmin gene, the promoter region was analysed by DNAase I footprinting. Using nuclear extract from rat liver, a prominent site of protein-DNA interaction was detected from -93 to -48 upstream of the caeruloplasmin gene transcription start and sequence analysis of this region revealed three potential CCAAT/enhancer-binding protein (C/EBP) consensus elements. Mobility-shift analysis using an oligonucleotide encoding this region identified specific binding of proteins from rat liver nuclear extract, and some of these complexes were supershifted using antisera to the C/EBP alpha and beta family members. Mobility-shift studies using a polypeptide encoding the DNA-binding domain of C/EBP alpha also revealed a specific interaction with this region of the caeruloplasmin promoter, and DNAase I footprinting using this polypeptide protected the identical region from -93 to -48. Co-transfection of expression plasmids encoding C/EBP alpha or a related leucine-zipper factor D-binding protein (DBP) revealed a C/EBP-specific increase in reporter gene activity in HepG2 cells transfected with caeruloplasmin-chloramphenicol acetyltransferase containing the -93 to -48 region. A similar result was obtained when these constructs were co-transfected into mouse L cells which were shown not to express the endogenous caeruloplasmin gene. Taken together, these data indicate a role for C/EBP alpha and beta in mediating transcription from the caeruloplasmin gene promoter and suggest that this region of the promoter is not responsible for tissue-specific expression.

Animals↗
PubMed1992

Induction of hepatic and pulmonary caeruloplasmin gene expression in developing guinea pigs following premature delivery.

We have previously shown that mRNA for caeruloplasmin, the serum copper-binding protein, is not expressed in guinea-pig liver prior to birth and expression increases rapidly following parturition. To further study the regulation of caeruloplasmin in neonatal animals we have used 3-day preterm guinea pigs, delivered by caesarean section, to investigate mRNA expression in liver and lung. Within 12 h of premature birth, hepatic caeruloplasmin mRNA levels are significantly increased and remain elevated by 72 h. This induction of expression is accompanied by an increase in circulating levels of holoprotein. Even greater induction of caeruloplasmin mRNA was observed in premature animals maintained in 95% oxygen for 72 h, confirming an acute-phase response in prematurity. Studies of lung RNA showed that caeruloplasmin mRNA is expressed throughout development, with highest levels observed in adult lung. In the premature animals levels were significantly elevated 12 h after delivery, but then fell by 72 h to below those seen in normal term lung. Hyperoxia did not influence the pulmonary mRNA levels.

Age Factors↗
PubMed1992

Copper metabolism in hypercupremic human livers. Studies of its subcellular distribution, association with binding proteins and expression of mRNAs.

In the present study we have used differential centrifugation, size exclusion chromatography, Western and Northern blotting to investigate the subcellular distribution of hepatic copper, the association of the metal with hepatic copper binding proteins and the expression of specific mRNAs for copper binding proteins in liver tissue from two patients with Wilson's disease, two patients with chronic liver disease and two patients with normal hepatic copper levels. Unlike previous studies the present results fail to show any gross differences in subcellular distribution of copper between the livers, with most of the copper being found in the soluble supernatant where it is associated with metallothionein. Caeruloplasmin mRNA levels were reduced in the two patients with Wilson's disease and also in a patient with fulminant hepatic failure. It remains to be confirmed if the reduction of caeruloplasmin mRNA is specific for Wilson's disease. Levels of mRNAs for copper zinc superoxide dismutase and metallothionein were variable and not related to liver copper.

Blotting, Northern↗
PubMed1991

Hepatic caeruloplasmin-gene expression during development in the guinea-pig. Correlation with changes in hepatic copper metabolism.

Decreased amounts of the serum copper-binding protein caeruloplasmin (hypocaeruloplasminaemia) are one of the characteristic abnormalities of copper metabolism that are found in all neonatal mammals. In the present study we have investigated the mechanism responsible for hypocaeruloplasminaemia found in neonatal guinea pigs. Northern-blot analysis of guinea-pig liver RNA revealed the presence of two caeruloplasmin mRNA species. A marked developmental change in expression was observed, with no detectable mRNA before birth, when hepatic copper is elevated. Expression was initiated soon after birth, when copper levels in the liver are falling, and was closely linked to the rise in enzymic activity and protein levels in serum. There was no differential regulation of the two mRNA species; however, a marked inter-animal variation in mRNA levels was observed. Using gel-filtration chromatography we were able to show that, before birth, serum copper was associated with a low-molecular-mass species and that, with the advent of expression of the caeruloplasmin gene after birth, copper was increasingly associated with caeruloplasmin.

Adult↗
PubMed1990

Developmental changes in hepatic copper proteins in the guinea pig.

We have suggested that Wilson's disease is caused by failure to adapt from the fetal to adult mode of copper metabolism and that the study of liver copper ontogeny might provide clues to the pathogenesis of Wilson's disease. This study traces the developmental changes in hepatic copper binding proteins in the guinea pig. During the last trimester, as fetal hepatic copper increases, metallothionein is the major copper binding peak in both the soluble and particulate supernatant fractions. After birth this peak decreases in parallel with the fall in liver copper. Metallothionein is absent from adult soluble supernatant and copper is associated with superoxide dismutase and a high molecular weight protein. A novel low molecular weight copper binding component is present in the particulate supernatant of neonatal liver, but is absent from the adult. Unlike many other animals, but similar to man, the switch from the fetal to adult mode of copper metabolism occurs at birth. Comparison of the copper protein profiles of the fetus and neonate with Wilson's disease are required to test the hypothesis that Wilson's disease is caused by developmental arrest of copper ontogeny.

Animals↗
PubMed1988

Neonatal and adult copper-64 metabolism in the pig and the possible relationship between the ontogeny of copper metabolism and Wilson's disease.

The copper profiles of neonatal mammals differ from those of the adult; in man they are similar to those found in people with Wilson's disease (WD). WD patients handle an intravenous bolus of radioactive copper in a characteristic manner which aids diagnosis. In view of the similarity between neonatal mammals and WD patients, we have studied the fate of an intravenous bolus of 64Cu injected into neonatal and adult pigs. In adult pigs, plasma 64Cu activity fell for 10 h and then slowly increased over the next 14 h as newly synthesised caeruloplasmin was secreted. In the neonate a secondary rise in 64Cu activity was not observed. Gel filtration of the soluble supernatant revealed significant differences in the association of 64Cu with hepatic copper proteins. In adults 64Cu associated predominantly with superoxide dismutase whilst in the neonate the 64Cu associated with metallothionein and a protein of high molecular weight. This study indicates that 64Cu export from the neonatal pig liver is in many ways similar to that found in WD. Additionally, there are similarities in the profile of hepatic 64Cu-binding proteins.

Animals↗