Analysis of the Potential for N4-Hydroxycytidine To Inhibit Mitochondrial Replication and Function
| Autor: | Deborah G. Mitchell, Zachary M. Sticher, Joshua Marlow, Michael G. Natchus, Gregory R. Bluemling, Gaofei Lu, Levi Moellering, Alexander A. Kolykhalov, David B. Guthrie, George R. Painter |
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| Rok vydání: | 2019 |
| Předmět: |
Pharmacology
0303 health sciences Mitochondrial DNA POLRMT biology 030306 microbiology Chemistry RNA medicine.disease Molecular biology 03 medical and health sciences Mitochondrial toxicity chemistry.chemical_compound Infectious Diseases Cell culture RNA polymerase medicine biology.protein Pharmacology (medical) Cytotoxicity Polymerase 030304 developmental biology |
| Zdroj: | Antimicrobial Agents and Chemotherapy |
| ISSN: | 1098-6596 0066-4804 |
| DOI: | 10.1128/aac.01719-19 |
| Popis: | N 4-Hydroxycytidine (NHC) is an antiviral ribonucleoside analog that acts as a competitive alternative substrate for virally encoded RNA-dependent RNA polymerases. It exhibits measurable levels of cytotoxicity, with 50% cytotoxic concentration values ranging from 7.5 μM in CEM cells and up to >100 μM in other cell lines. The mitochondrial DNA-dependent RNA polymerase (POLRMT) has been shown to incorporate some nucleotide analogs into mitochondrial RNAs, resulting in substantial mitochondrial toxicity. NHC was tested in multiple assays intended to determine its potential to cause mitochondrial toxicity. NHC showed similar cytotoxicity in HepG2 cells incubated in a glucose-free and glucose-containing media, suggesting that NHC does not impair mitochondrial function in this cell line based on the Crabtree effect. We demonstrate that the 5'-triphosphate of NHC can be used by POLRMT for incorporation into nascent RNA chain but does not cause immediate chain termination. In PC-3 cells treated with NHC, the 50% inhibitory concentrations of mitochondrial protein expression inhibition were 2.7-fold lower than those for nuclear-encoded protein expression, but this effect did not result in selective mitochondrial toxicity. A 14-day incubation of HepG2 cells with NHC had no effect on mitochondrial DNA copy number or extracellular lactate levels. In CEM cells treated with NHC at 10 μM, a slight decrease (by ∼20%) in mitochondrial DNA copy number and a corresponding slight increase in extracellular lactate levels were detected, but these effects were not enhanced by an increase in NHC treatment concentration. In summary, the results indicate that mitochondrial impairment by NHC is not the main contributor to the compound's observed cytotoxicity in these cell lines. |
| Databáze: | OpenAIRE |
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