title: A brief overview of mechanisms of mitochondrial toxicity from NRTIs.
abstract: Nucleoside reverse transcriptase inhibitors (NRTIs) in combinations with other antiretrovirals (highly active antiretroviral therapy, HAART) are the cornerstones of AIDS therapy, turning HIV infection into a manageable clinical entity. Despite the initial positive impact of NRTIs, therapeutic experience revealed serious side effects that appeared to originate in the mitochondria and which ultimately manifested as dysfunction of that organelle. It may be reasonable to consider that as the AIDS epidemic continues and as survival with HIV infection is prolonged by treatment with HAART, long-term side effects of NRTIs may become increasingly common. This consideration may be underscored in children who are born to HIV-infected mothers who received NRTI therapy in utero during gestation. The long-term effect of that NRTI exposure in utero is not clear yet. This review examines some proposed mechanisms of NRTI mitochondrial toxicity, including genetic predisposition, defects in mitochondria DNA replication, the encompassing "DNA pol-gamma hypothesis," the relationship between mitochondrial nucleotide and NRTI pools, mitochondrial DNA mutation and dysfunction, and oxidative stresses related to HIV infection and NRTIs. Mechanisms of mitochondrial toxicity are reviewed with respect to key cell biological, pathological, and pharmacological events.
authors.affiliation: Department of Pathology, Emory University, Atlanta, Georgia.
authors.forename: James J
authors.initials: JJ
authors.lastname: Kohler
authors.forename: William
authors.initials: W
authors.lastname: Lewis
mesh_terms: D000818:Animals; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000627:therapeutic use; D000074002:DNA Polymerase gamma; D004261:DNA Replication / Q000187:drug effects; D004272:DNA, Mitochondrial / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D015658:HIV Infections / Q000188:drug therapy / Q000517:prevention & control*; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D009705:Nucleosides / Q000009:adverse effects* / Q000627:therapeutic use; D009711:Nucleotides / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D019380:Anti-HIV Agents; D004272:DNA, Mitochondrial; D009705:Nucleosides; D009711:Nucleotides; D018894:Reverse Transcriptase Inhibitors; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; C413027:POLG protein, human