Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Expression of the pancreatitis-associated protein I (PAP I), an exocrine pancreatic protein, increases rapidly and strongly in acinar cells during the acute phase of pancreatitis. This is reminiscent of the response to stress of acute phase proteins. We have previously demonstrated that serum factors from rats with acute pancreatitis, but not from healthy rats, could induce endogenous PAP I gene expression in the acinar cell line AR-42J (Dusetti, N., Mallo, G., Dagorn, J.-C., Iovanna, J. L. (1994) Biochem. Biophys. Res. Commun. 204, 238-243). In the present work, we have evaluated the influence of several mediators of inflammation on rat PAP I gene transcription in these cells. Tumor necrosis factor alpha induced an increase in PAP I mRNA expression, and interferon gamma caused an even greater increase in PAP I mRNA level. These stimulations were antagonized by dexamethasone. Interleukin (IL)-1, IL-6, or dexamethasone alone were ineffective. Combinations of IL-1 with IL-6 or dexamethasone were also ineffective. IL-6 and dexamethasone together induced a marked stimulation of PAP I gene transcription, and this effect was slightly attenuated by IL-1. To analyze the cis-regulatory elements responsible for the induction of transcription, we fused a 1.2-kilobase segment of the rat PAP I promoter to the chloramphenicol acetyltransferase (CAT) gene as reporter. The resultant chimeric DNA was transfected into AR-42J cells. Addition of IL-6 or dexamethasone was ineffective, whereas their mixture increased the CAT activity 12 times. Progressive deletions of the PAP I promoter were then fused to the CAT gene, and the constructs were transfected to AR-42J cells. A 12-fold increase in CAT activity was seen upon IL-6/dexamethasone treatment with constructs containing more than 274 base pairs upstream from the cap site. In that region, two sequences are similar to the canonical IL-6 response element. Site-directed mutagenesis of these regions strongly decreased induction, showing that they were functional. PAP I should therefore be classified among acute phase proteins of class 2, whose expression is increased by IL-6 acting in combination with glucocorticoids.
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PMID:Pancreatitis-associated protein I (PAP I), an acute phase protein induced by cytokines. Identification of two functional interleukin-6 response elements in the rat PAP I promoter region. 754 77

The pancreatitis-associated protein I (PAP I) is a pancreatic secretory protein expressed in pancreas during acute pancreatitis but not in the healthy pancreas. The promoter of the PAP I gene thus represents a potential candidate to drive expression of therapeutic molecules to the diseased pancreas. In this work, we have constructed recombinant adenoviruses harboring the chloramphenicol acetyltransferase (CAT) gene driven by several fragments of the PAP I promoter and have characterized their properties in vitro and in vivo. In vitro studies showed that the transduction of the pancreatic cell line AR-42J with these adenoviruses led to low levels of CAT activity in basal conditions. After stimulation with a combination of interleukin-6 and dexamethasone or after induction of oxidative stress, CAT activity was strongly induced, a characteristic of the endogenous PAP I gene. Stimulation was maximal when constructs comprised 1253 base pairs of the PAP I promoter, upstream from initiation of transcription, and decreased with shorter fragments of 317, 180, 118 or 61 base pairs. The recombinant adenovirus containing the CAT gene under the control of the PAP I promoter fragment (-1253/+10) was also tested in vivo. Following administration by intravenous injection into mice, CAT activity was measured in several tissues 96 h later. In healthy animals, low but significant CAT activity was detected in pancreas, compared with near background values observed in the other tissues. When experimental acute pancreatitis was induced, CAT expression was strongly enhanced only in pancreas. In control experiments with adenoviruses in which the CAT gene was driven by the cytomegalovirus promoter, higher levels of expression were observed in all tissues. Expression was not modified after induction of acute pancreatitis. In conclusion, this study shows that (i) a recombinant adenovirus containing a fragment of the PAP I promoter allows specific targeting of a reporter gene to the mouse pancreas and (ii) expression of the reporter gene in pancreas is induced during acute pancreatitis. Adenovirus-mediated gene therapy of acute pancreatitis is therefore conceivable.
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PMID:The pancreatitis-associated protein I promoter allows targeting to the pancreas of a foreign gene, whose expression is up-regulated during pancreatic inflammation. 903 94

Production of inflammatory cytokines in the pancreas, lung, and liver is believed to play a major role in the development of severe pancreatitis. This tissue-specific production could lend itself to directed anti-cytokine gene therapy if an appropriate delivery system could be developed. This study was undertaken to examine a novel approach for the delivery of protein-based therapies to the tissues involved during acute pancreatitis. Healthy mice received an intraperitoneal injection of cationic liposomes and a DNA plasmid containing the chloramphenicol acetyltransferase (CAT) reporter gene. Animals were killed at 12 hours and 1, 2, 3, 7, and 14 days with serum, pancreas, lung, and liver harvested. Acute pancreatitis was induced (cerulein, 50 micrograms/kg/hr intraperitoneally x4) in additional mice before or after CAT transfection. The presence of pancreatitis was established in all animals by histologic scoring of pancreata and by serum amylase and lipase levels. CAT transfection efficiency was determined by quantitative CAT enzyme activity within tissue homogenates. Animals that received the liposome were successfully transfected with the CAT gene into the pancreas, lungs, and liver. Maximal transfection in each tissue occurred at 12 hours with decreasing CAT activity over the ensuing 14 days. No healthy animals receiving the CAT gene developed elevations in amylase, lipase, or any histologic parameter of pancreatitis. Transfection efficiency in the pancreas was markedly increased by preexisting or delayed induction of pancreatitis, whereas transfection of the lung and liver was increased to a lesser extent. Gene transfection into the pancreas, liver, and lungs is possible using a cationic liposome delivery system that does not induce pancreatitis or pancreatic inflammation. Pancreatic expression of the gene product is equal to or greater than that of the organs of the reticuloendothelial system and continues at very high efficiency rates during acute pancreatitis.
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PMID:Cationic liposome-mediated gene transfer during acute pancreatitis: tissue specificity, duration, and effects of acute inflammation. 984 74