title: Oxygen-dependent regulation of in vivo replication of simian virus 40 DNA is modulated by glucose.
abstract: Simian virus 40 (SV40)-infected CV1 cells exposed to hypoxia show an inhibition of viral replication. Reoxygenation after several hours of hypoxia results in new initiations followed by a nearly synchronous round of SV40 replication. In this communication, we examined the effect of glucose on inhibition of viral DNA replication under hypoxia. We found that glucose stimulated SV40 DNA replication under hypoxia in two different ways. First, the rate of DNA synthesis, i.e. the fork propagation rate, increased. This effect seemed to be mediated by inhibition of mitochondrial respiration by glucose (Crabtree effect). Inhibition of mitochondrial respiration probably resulted in a higher intracellular oxygen concentration and an activation of oxygen-dependent ribonucleotide reductase, which provides the precursors for DNA synthesis. This glucose effect was consequently strongly dependent on the strength of hypoxia and the extent of intracellular respiration; hypoxic gassing with 10 ppm instead of 200-400 ppm O(2) or treatment of hypoxic cells with a mitochondrial uncoupler (carbonyl cyanide m-chlorophenylhydrazone) reduced the glucose effect on replication, whereas antimycin A, an inhibitor of respiration, increased it. The second effect of glucose concerned initiation, i.e. stimulation of unwinding of the viral origin. This effect was not influenced by the strength of hypoxia or the extent of cellular respiration and seemed, therefore, not to be mediated through a Crabtree effect. No evidence for a direct correlation between the cellular ATP concentration and the extent of SV40 replication under hypoxia was found. The effect of glucose on replication under hypoxia was not restricted to SV40-infected CV1 cells but was also detectable in HeLa cells. This suggests it to be a mechanism of more general validity.
authors.affiliation: Physiologisch-chemisches Institut der Universität Tübingen, Hoppe-Seyler-Strasse 4, D-72076 Tübingen, Germany. hans-joerg.riedinger@uni-tuebingen.de
authors.forename: H J
authors.initials: HJ
authors.lastname: Riedinger
authors.forename: M
authors.initials: M
authors.lastname: van Betteraey-Nikoleit
authors.forename: U
authors.initials: U
authors.lastname: Hilfrich
authors.forename: K H
authors.initials: KH
authors.lastname: Eisele
authors.forename: H
authors.initials: H
authors.lastname: Probst
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000968:Antimycin A / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology; D015139:Blotting, Southern; D001973:Bromodeoxyuridine / Q000378:metabolism; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D002586:Cesium / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D004261:DNA Replication / Q000187:drug effects; D004279:DNA, Viral; D004305:Dose-Response Relationship, Drug; D015967:Gene Expression Regulation, Viral; D005947:Glucose / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D000860:Hypoxia; D007476:Ionophores / Q000494:pharmacology; D009693:Nucleic Acid Hybridization; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D013539:Simian virus 40 / Q000235:genetics*; D013997:Time Factors; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D002712:Chlorides; D004279:DNA, Viral; D007476:Ionophores; D014475:Uncoupling Agents; D002586:Cesium; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000968:Antimycin A; D000255:Adenosine Triphosphate; D001973:Bromodeoxyuridine; C028019:cesium chloride; D005947:Glucose; D010100:Oxygen