Knowledge on the involvement of spinal COX-1 and COX-2 in pain due to osteoarthritis could be useful for better understanding of its pathogenesis and therapy. In this study we have investigated a long-term pattern of expression and production of spinal COX-1 and COX-2 in the model of osteoarthritis induced in rats by injection of monoiodoacetate (MIA) into the knee joint. MIA injection produced thermal hyperalgesia (assessed by the plantar test) and tactile allodynia (measured with von Frey hairs). The pain measures reached maximum on the fifht day, then remained relatively stable. The expression of spinal COX-2 mRNA reached maximum on day 5 (5.2 times; P<0.001) and remained increased until day 31 (4.9 times; P<0.001). Expression of spinal COX-1 mRNA increased gradually reaching maximum on the day 31 (4.5 times; P<0.001) when the relative expression of both genes was almost equal. The production of both proteins was almost similar at the beginning of the experiment. The highest production of COX-2 protein was observed on day 5 after the induction of osteoarthritis (increased 3.9 times). The levels of COX-1 protein increased gradually with maximum on day 31 (3.4 times). The present findings indicate that not only expression of COX-2 mRNA but also that of COX-1 mRNA is significantly increased in the spine during osteoarthritis pain. Thus, in contrast to inflammatory pain, the upregulation of spinal COX-1 may be important in osteoarthritis pain.
- MeSH
- artróza kolenních kloubů enzymologie genetika chemicky indukované MeSH
- bolest epidemiologie genetika chemicky indukované MeSH
- časové faktory MeSH
- cyklooxygenasa 1 biosyntéza genetika MeSH
- cyklooxygenasa 2 biosyntéza genetika MeSH
- enzymová indukce MeSH
- financování organizované MeSH
- hyperalgezie enzymologie genetika chemicky indukované MeSH
- krysa rodu rattus MeSH
- kyselina jodoctová MeSH
- membránové proteiny biosyntéza genetika MeSH
- měření bolesti MeSH
- messenger RNA MeSH
- mícha enzymologie MeSH
- modely nemocí na zvířatech MeSH
- potkani Wistar MeSH
- práh bolesti MeSH
- reakční čas MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
Ellipticine is an antineoplastic agent, whose mode of action is based mainly on DNA intercalation, inhibition of topoisomerase II and formation of covalent DNA adducts mediated by cytochromes P450 and peroxidases. Here, the molecular mechanism of DNA-mediated ellipticine action in human neuroblastoma IMR-32, UKF-NB-3 and UKF-NB-4 cancer cell lines was investigated. Treatment of neuroblastoma cells with ellipticine resulted in apoptosis induction, which was verified by the appearance of DNA fragmentation, and in inhibition of cell growth. These effects were associated with formation of two covalent ellipticine-derived DNA adducts, identical to those formed by the cytochrome P450- and peroxidase-mediated ellipticine metabolites, 13-hydroxy- and 12-hydroxyellipticine. The expression of these enzymes at mRNA and protein levels and their ability to generate ellipticine-DNA adducts in neuroblastoma cells were proven, using the real-time polymerase chain reaction, Western blotting analyses and by analyzing ellipticine-DNA adducts in incubations of this drug with neuroblastoma S9 fractions, enzyme cofactors and DNA. The levels of DNA adducts correlated with toxicity of ellipticine to IMR-32 and UKF-NB-4 cells, but not with that to UKF-NB-3 cells. In addition, hypoxic cell culture conditions resulted in a decrease in ellipticine toxicity to IMR-32 and UKF-NB-4 cells and this correlated with lower levels of DNA adducts. Both these cell lines accumulated in S phase, suggesting that ellipticine-DNA adducts interfere with DNA replication. The results demonstrate that among the multiple modes of ellipticine antitumor action, formation of covalent DNA adducts by ellipticine is the predominant mechanism of cytotoxicity to IMR-32 and UKF-NB-4 neuroblastoma cells.
- MeSH
- adukty DNA metabolismus MeSH
- apoptóza účinky léků MeSH
- buněčný cyklus účinky léků MeSH
- cyklooxygenasa 1 biosyntéza MeSH
- cyklooxygenasa 2 biosyntéza MeSH
- elipticiny farmakologie MeSH
- financování organizované MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- peroxidasa biosyntéza MeSH
- protinádorové látky farmakologie MeSH
- systém (enzymů) cytochromů P-450 biosyntéza MeSH
- viabilita buněk účinky léků MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- lidé MeSH
Cyclooxygenase is the enzyme responsible for the production of prostaglandins (PGs). This cyclooxygenase exists in two isoforms: cyclooxygenase-1 (COX-1) and cyclooxygense-2 (COX-2). In humans and primates high levels of COX-2 are detected in the seminal vesicle. Further, the main source of PGs in the semen of these species is from the seminal vesicle. In rodents, the source of PGs in semen is from the vas deferens and abundant levels of COX-2 are detected. A direct relation is thought to exist between COX-2 levels and the source of PGs in semen. Moreover, the role of COX-1 and COX-2 in the seminal vesicle of rodents is obscure. The present study aims at localizing COX-1 and COX-2 in the seminal vesicle of mice. Immunohistochemical staining and COX activity assay revealed COX-1 as a dominant isoform in the mouse seminal vesicle. On treatment with nimesulide – a preferential COX-2 inhibitor - no change in staining intensity and COX activity was observed. The total PG levels also appeared to be unaltered following nimesulide treatment. This confirms that nimesulide had no effect on COX-1. The results presented here suggest COX-1 is the dominant isoform in the mouse seminal vesicle and is responsible for PG synthesis.
- MeSH
- cyklooxygenasa 1 biosyntéza chemie metabolismus MeSH
- cyklooxygenasa 2 biosyntéza chemie metabolismus MeSH
- interpretace statistických dat MeSH
- mastné kyseliny chemie MeSH
- metabolismus lipidů účinky léků MeSH
- myši MeSH
- prostaglandiny biosyntéza chemie metabolismus MeSH
- semenné váčky enzymologie metabolismus účinky léků MeSH
- sulfonamidy chemie metabolismus MeSH
- Check Tag
- myši MeSH
