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Blagov AV, Sukhorukov VN, Guo S, Zhang D, Popov MA, Orekhov AN. Impaired Mitochondrial Function in T-Lymphocytes as a Result of Exposure to HIV and ART. Cells 2023; 12:cells12071072. [PMID: 37048145 PMCID: PMC10093108 DOI: 10.3390/cells12071072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/29/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
Mitochondrial dysfunction is a described phenomenon for a number of chronic and infectious diseases. At the same time, the question remains open: is this condition a consequence or a cause of the progression of the disease? In this review, we consider the role of the development of mitochondrial dysfunction in the progression of HIV (human immunodeficiency viruses) infection and the onset of AIDS (acquired immunodeficiency syndrome), as well as the direct impact of HIV on mitochondria. In addition, we will touch upon such an important issue as the effect of ART (Antiretroviral Therapy) drugs on mitochondria, since ART is currently the only effective way to curb the progression of HIV in infected patients, and because the identification of potential side effects can help to more consciously approach the development of new drugs in the treatment of HIV infection.
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Affiliation(s)
- Alexander V. Blagov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow 125315, Russia
| | - Vasily N. Sukhorukov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow 125315, Russia
| | - Shuzhen Guo
- Diabetes Research Center, School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Dongwei Zhang
- Diabetes Research Center, School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Mikhail A. Popov
- Department of Cardiac Surgery, Moscow Regional Research and Clinical Institute (MONIKI), 61/2, Shchepkin Street, Moscow 129110, Russia
| | - Alexander N. Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow 125315, Russia
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Rahman MM, Young CKJ, Goffart S, Pohjoismäki JLO, Young MJ. Heterozygous p.Y955C mutation in DNA polymerase γ leads to alterations in bioenergetics, complex I subunit expression, and mtDNA replication. J Biol Chem 2022; 298:102196. [PMID: 35760101 PMCID: PMC9307957 DOI: 10.1016/j.jbc.2022.102196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 12/03/2022] Open
Abstract
In human cells, ATP is generated using oxidative phosphorylation machinery, which is inoperable without proteins encoded by mitochondrial DNA (mtDNA). The DNA polymerase gamma (Polγ) repairs and replicates the multicopy mtDNA genome in concert with additional factors. The Polγ catalytic subunit is encoded by the POLG gene, and mutations in this gene cause mtDNA genome instability and disease. Barriers to studying the molecular effects of disease mutations include scarcity of patient samples and a lack of available mutant models; therefore, we developed a human SJCRH30 myoblast cell line model with the most common autosomal dominant POLG mutation, c.2864A>G/p.Y955C, as individuals with this mutation can present with progressive skeletal muscle weakness. Using on-target sequencing, we detected a 50% conversion frequency of the mutation, confirming heterozygous Y955C substitution. We found mutated cells grew slowly in a glucose-containing medium and had reduced mitochondrial bioenergetics compared with the parental cell line. Furthermore, growing Y955C cells in a galactose-containing medium to obligate mitochondrial function enhanced these bioenergetic deficits. Also, we show complex I NDUFB8 and ND3 protein levels were decreased in the mutant cell line, and the maintenance of mtDNA was severely impaired (i.e., lower copy number, fewer nucleoids, and an accumulation of Y955C-specific replication intermediates). Finally, we show the mutant cells have increased sensitivity to the mitochondrial toxicant 2′-3′-dideoxycytidine. We expect this POLG Y955C cell line to be a robust system to identify new mitochondrial toxicants and therapeutics to treat mitochondrial dysfunction.
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Affiliation(s)
- Md Mostafijur Rahman
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Carolyn K J Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Steffi Goffart
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Jaakko L O Pohjoismäki
- Department of Environmental and Biological Sciences, University of Eastern Finland, 80101 Joensuu, Finland
| | - Matthew J Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901.
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Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation. Pharmaceutics 2022; 14:pharmaceutics14071313. [PMID: 35890211 PMCID: PMC9319223 DOI: 10.3390/pharmaceutics14071313] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 02/07/2023] Open
Abstract
Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.
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Young MJ. Off-Target Effects of Drugs that Disrupt Human Mitochondrial DNA Maintenance. Front Mol Biosci 2017; 4:74. [PMID: 29214156 PMCID: PMC5702650 DOI: 10.3389/fmolb.2017.00074] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/31/2017] [Indexed: 12/17/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) were the first drugs used to treat human immunodeficiency virus (HIV) the cause of acquired immunodeficiency syndrome. Development of severe mitochondrial toxicity has been well documented in patients infected with HIV and administered NRTIs. In vitro biochemical experiments have demonstrated that the replicative mitochondrial DNA (mtDNA) polymerase gamma, Polg, is a sensitive target for inhibition by metabolically active forms of NRTIs, nucleotide reverse transcriptase inhibitors (NtRTIs). Once incorporated into newly synthesized daughter strands NtRTIs block further DNA polymerization reactions. Human cell culture and animal studies have demonstrated that cell lines and mice exposed to NRTIs display mtDNA depletion. Further complicating NRTI off-target effects on mtDNA maintenance, two additional DNA polymerases, Pol beta and PrimPol, were recently reported to localize to mitochondria as well as the nucleus. Similar to Polg, in vitro work has demonstrated both Pol beta and PrimPol incorporate NtRTIs into nascent DNA. Cell culture and biochemical experiments have also demonstrated that antiviral ribonucleoside drugs developed to treat hepatitis C infection act as off-target substrates for POLRMT, the mitochondrial RNA polymerase and primase. Accompanying the above-mentioned topics, this review examines: (1) mtDNA maintenance in human health and disease, (2) reports of DNA polymerases theta and zeta (Rev3) localizing to mitochondria, and (3) additional drugs with off-target effects on mitochondrial function. Lastly, mtDNA damage may induce cell death; therefore, the possibility of utilizing compounds that disrupt mtDNA maintenance to kill cancer cells is discussed.
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Affiliation(s)
- Matthew J Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States
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Paemanee A, Sornjai W, Kittisenachai S, Sirinonthanawech N, Roytrakul S, Wongtrakul J, Smith DR. Nevirapine induced mitochondrial dysfunction in HepG2 cells. Sci Rep 2017; 7:9194. [PMID: 28835669 PMCID: PMC5569014 DOI: 10.1038/s41598-017-09321-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 07/20/2017] [Indexed: 01/14/2023] Open
Abstract
Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor frequently used in combination with other antiretroviral agents for highly active antiretroviral therapy (HAART) of patients infected with the human immunodeficiency virus type 1 (HIV-1). However NVP can cause serious, life-threatening complications. Hepatotoxicity is one of the most severe adverse effects, particularly in HIV patients with chronic hepatitis C virus co-infection as these patients can develop liver toxicity after a relatively short course of treatment. However, the mechanism of NVP-associated hepatotoxicity remains unclear. This study sought to investigate the effect of NVP on protein expression in liver cells using a proteomic approach. HepG2 cells were treated or not treated with NVP and proteins were subsequently resolved by two-dimensional gel electrophoresis. A total of 33 differentially regulated proteins were identified, of which nearly 40% (13/33) were mitochondrial proteins. While no obvious differences were observed between NVP treated and untreated cells after staining mitochondria with mitotracker, RT-PCR expression analysis of three mitochondrially encoded genes showed all were significantly up-regulated in NVP treated cells. Mitochondrial dysfunction was observed in response to treatment even with slightly sub-optimal therapeutic treatment concentrations of NVP. This study shows that NVP induces mitochondrial dysregulation in HepG2 cells.
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Affiliation(s)
- Atchara Paemanee
- Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand.,Genome Technology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Wannapa Sornjai
- Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand
| | - Suthathip Kittisenachai
- Genome Technology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | | | - Sittiruk Roytrakul
- Genome Technology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Jeerang Wongtrakul
- Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.
| | - Duncan R Smith
- Institute of Molecular Biosciences, Mahidol University, Bangkok, Thailand.
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Leveraging increased cytoplasmic nucleoside kinase activity to target mtDNA and oxidative phosphorylation in AML. Blood 2017; 129:2657-2666. [PMID: 28283480 DOI: 10.1182/blood-2016-10-741207] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/06/2017] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial DNA (mtDNA) biosynthesis requires replication factors and adequate nucleotide pools from the mitochondria and cytoplasm. We performed gene expression profiling analysis of 542 human acute myeloid leukemia (AML) samples and identified 55% with upregulated mtDNA biosynthesis pathway expression compared with normal hematopoietic cells. Genes that support mitochondrial nucleotide pools, including mitochondrial nucleotide transporters and a subset of cytoplasmic nucleoside kinases, were also increased in AML compared with normal hematopoietic samples. Knockdown of cytoplasmic nucleoside kinases reduced mtDNA levels in AML cells, demonstrating their contribution in maintaining mtDNA. To assess cytoplasmic nucleoside kinase pathway activity, we used a nucleoside analog 2'3'-dideoxycytidine (ddC), which is phosphorylated to the activated antimetabolite, 2'3'-dideoxycytidine triphosphate by cytoplasmic nucleoside kinases. ddC is a selective inhibitor of the mitochondrial DNA polymerase γ. ddC was preferentially activated in AML cells compared with normal hematopoietic progenitor cells. ddC treatment inhibited mtDNA replication, oxidative phosphorylation, and induced cytotoxicity in a panel of AML cell lines. Furthermore, ddC preferentially inhibited mtDNA replication in a subset of primary human leukemia cells and selectively targeted leukemia cells while sparing normal progenitor cells. In animal models of human AML, treatment with ddC decreased mtDNA, electron transport chain proteins, and induced tumor regression without toxicity. ddC also targeted leukemic stem cells in secondary AML xenotransplantation assays. Thus, AML cells have increased cytidine nucleoside kinase activity that regulates mtDNA biogenesis and can be leveraged to selectively target oxidative phosphorylation in AML.
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Obumneme-Anyim I, Ibeziako N, Emodi I, Ikefuna A, Oguonu T. Hematological Indices at Birth of Infants of HIV-Positive Mothers Participating in a Prevention of Mother-to-Child Transmission Program. J Trop Pediatr 2016; 62:3-9. [PMID: 26411560 PMCID: PMC4892384 DOI: 10.1093/tropej/fmv061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The mother-to-child transmission of HIV, which accounts for 90% of infections in children, has been reduced markedly through the use of antiretroviral drugs by pregnant women and their newborns. Changes to the World Health Organization guidelines support further extension of the prevention of mother-to-child transmission programs with increased risk of toxicity on the fetuses. AIM To determine the hematological indices at birth of infants exposed in utero to maternal antiretroviral drugs. METHOD A comparative analytical study of 126 neonates whose blood samples were analyzed to determine their hematological indices. RESULT The hemoglobin, hematocrit, the total white blood cell (WBC) count and absolute neutrophil count (ANC) were significantly lower in infants of HIV-positive mothers. The total WBC and ANC were also significantly lower in the highly active antiretroviral therapy. HAART group and those exposed to maternal drugs for <1 year. CONCLUSION There are significant changes in the hematological indices of infants of HIV-positive mothers at birth.
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Affiliation(s)
- Ijeoma Obumneme-Anyim
- Department of Paediatrics, University of Nigeria Teaching Hospital, Ituku-Ozalla Enugu, 402139, Nigeria, Enugu Campus,
| | - Ngozi Ibeziako
- Department of Paediatrics, University of Nigeria Teaching Hospital, Ituku-Ozalla Enugu, 402139, Nigeria, Enugu Campus
| | - Ifeoma Emodi
- Department of Paediatrics, College of Medicine, University of Nigeria, Enugu, 400241, Nigeria
| | - Anthony Ikefuna
- Department of Paediatrics, College of Medicine, University of Nigeria, Enugu, 400241, Nigeria
| | - Tagbo Oguonu
- Department of Paediatrics, College of Medicine, University of Nigeria, Enugu, 400241, Nigeria
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Setzer B, Walker UA. Antiretroviral nucleoside analogues suppress antibody synthesis in human B-lymphocytes. Antivir Ther 2012; 17:729-35. [PMID: 22414568 DOI: 10.3851/imp2086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2011] [Indexed: 10/28/2022]
Abstract
BACKGROUND Some antiretroviral nucleoside reverse transcriptase inhibitors (NRTI) impair mitochondrial polymerase-γ and T-cell proliferation, possibly by pyrimidine depletion. We aimed to analyse NRTI effects on the content of mitochondrial DNA (mtDNA) and B-cells, and on their proliferation and antibody synthesis. METHODS Peripheral blood B-lymphocytes from six healthy individuals were stimulated in vitro with interleukin-4 and Staphylococcus aureus superantigen in the presence or absence of NRTI in concentrations equivalent to, or fivefold exceeding, human peak plasma levels. We also tested the effects of uridine, a pyrimidine precursor, which has antagonized NRTI toxicities in other models. RESULTS During 9 days of culture, B-lymphocyte proliferation and vitality were not affected by NRTI. Didanosine and stavudine, but not zidovudine, dose-dependently induced mtDNA depletion. All three NRTI significantly and dose-dependently impaired the synthesis of all immunoglobulin classes. The lymphocytotoxic effects of the thymidine analogues zidovudine and stavudine on B-lymphocytes were antagonized by the addition of uridine. CONCLUSIONS Didanosine, stavudine and zidovudine induce mitochondrial toxicity in human B-lymphocytes and impair the immunoglobulin synthesis in vitro, warranting further studies on their in vivo effects.
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Affiliation(s)
- Bernhard Setzer
- Department of Rheumatology and Clinical Immunology, Medizinische Universitätsklinik, Freiburg, Germany
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Maggiolo F, Roat E, Pinti M, Nasi M, Gibellini L, De Biasi S, Airoldi M, Ravasio V, Mussini C, Suter F, Cossarizza A. Mitochondrial changes during D-drug-containing once-daily therapy in HIV-positive treatment-naive patients. Antivir Ther 2010; 15:51-9. [DOI: 10.3851/imp1483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Venhoff N, Setzer B, Melkaoui K, Walker UA. Mitochondrial Toxicity of Tenofovir, Emtricitabine and Abacavir Alone and in Combination with Additional Nucleoside Reverse Transcriptase Inhibitors. Antivir Ther 2007. [DOI: 10.1177/135965350701200704] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Background Some nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) combinations cause additive or synergistic interactions in vitro and in vivo. Methods We evaluated the mitochondrial toxicity of tenofovir (TFV), emtricitabine (FTC) and abacavir as carbovir (CBV) alone, with each other, and in combination with additional NRTIs. HepG2 human hepatoma cells were incubated with TFV, FTC, CBV, didanosine (ddI), stavudine (d4T), lamivudine (3TC) and zidovudine (AZT) at concentrations equivalent to 1 and 10x clinical steady-state peak plasma levels (Cmax). NRTIs were also used in double and triple combinations. Cell growth, lactate production, intracellular lipids, mtDNA and the mtDNA-encoded respiratory chain subunit II of cytochrome c oxidase (COXII) were monitored for 25 days. Results TFV and 3TC had no or minimal toxicity. FTC moderately reduced hepatocyte proliferation independent of effects on mtDNA. ddI and d4T induced a time- and dose-dependent loss of mtDNA and COXII, decreased cell growth and increased levels of lactate and intracellular lipids. CBV and AZT strongly impaired hepatocyte proliferation and increased lactate and lipid production, but did not induce mtDNA depletion. The dual combination of TFV plus 3TC had only minimal toxicity; TFV plus FTC slightly reduced cell proliferation without affecting mitochondrial parameters. All other combinations exhibited more pronounced adverse effects on mitochondrial endpoints. Toxic effects on mitochondrial parameters were observed in all combinations with ddI, d4T, AZT or CBV. TFV and 3TC both attenuated ddI-related cytotoxicity, but worsened the effects of CBV and AZT. Conclusions The data demonstrate unpredicted interactions between NRTIs with respect to toxicological endpoints and provide an argument against the liberal use of NRTI cocktails without first obtaining data from clinical trials.
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Affiliation(s)
- Nils Venhoff
- Medizinische Universitätsklinik, Department of Rheumatology & Clinical Immunology, Freiburg, Germany
| | - Bernhard Setzer
- Medizinische Universitätsklinik, Department of Rheumatology & Clinical Immunology, Freiburg, Germany
| | - Kerstina Melkaoui
- Medizinische Universitätsklinik, Department of Rheumatology & Clinical Immunology, Freiburg, Germany
| | - Ulrich A Walker
- Medizinische Universitätsklinik, Department of Rheumatology & Clinical Immunology, Freiburg, Germany
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Côté HCF, Magil AB, Harris M, Scarth BJ, Gadawski I, Wang N, Yu E, Yip B, Zalunardo N, Werb R, Hogg R, Harrigan PR, Montaner JS. Exploring Mitochondrial Nephrotoxicity as a Potential Mechanism of Kidney Dysfunction among HIV-Infected Patients on Highly Active Antiretroviral Therapy. Antivir Ther 2006. [DOI: 10.1177/135965350601100108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background Tenofovir (TDF) exposure has been associated with renal dysfunction. Mitochondrial nephrotoxicity was investigated as an underlying mechanism. Given the interaction between TDF and didanosine (ddI), their concurrent use was also investigated. Design Relative kidney biopsy mitochondrial DNA (mtDNA) to nuclear DNA ratios were measured retrospectively. HIV+ individuals on TDF within 6 months preceeding the biopsy (HIV+/TDF+, n=21) were compared to HIV+ individuals who never received TDF (HIV+/TDF-, n=10) and to HIV uninfected controls (HIV–, n=22). Twelve of the HIV+/TDF+ individuals received concurrent ddI, 10 of those once at unadjusted ddI dosage. Tubular mitochondria morphology was also examined by electron microscopy. Statistical analyses were done on log-transformed mtDNA/nDNA, using non-parametric tests. Results Kidney mtDNA levels were different among the three groups ( P=0.046). mtDNA ratios were lower in HIV+/TDF+ subjects (7.5 [2.0–12.1]) than in HIV- ones (14.3 [6.0–16.5], P=0.014), but not lower than HIV+/TDF-controls (6.4 [2.8–11.9], P=0.82). Among HIV+ subjects, there was a difference between TDF-, TDF+/ddI- and TDF+/ddI+ ( P=0.005), with concurrent TDF/ddI use associated with lower mtDNA (2.1 [1.9–5.5], n=12) than TDF+/ddI- (13.8 [7.5–16.4], n=9, P=0.003). No TDF–/ddI+ biopsies were available. In regression analyses, only HIV infection ( P=0.03), and TDF/ddI use ( P=0.003) were associated with lower mtDNA. At the ultrastructural level, abnormal tubular mitochondria was more prevalent in HIV+/TDF+ biopsies than HIV+/TDF- and HIV- ones together ( P<0.001) but not more so in TDF+/ddI+ biopsies than TDF+/ddI- ones ( P=0.67). Conclusions Renal dysfunction in this population may be mediated through mitochondrial nephrotoxicity that involves more than one drug and/or pathogenesis. Kidney mtDNA depletion was associated with HIV infection and concurrent TDF/ddI therapy but not TDF use alone, while kidney ultrastructural mitochondrial abnormalities were seen with TDF use. The interaction between TDF and ddI may be relevant in the kidney where both drugs are cleared. The clinical relevance of our findings needs to be evaluated given the current recommendation for reduced doses of ddI when used in conjunction with TDF.
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Affiliation(s)
- Hélène CF Côté
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
- Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, B.C., Canada
| | - Alex B Magil
- Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, B.C., Canada
- St. Paul's Hospital, Providence Health Care, Vancouver, B.C. Canada
| | - Marianne Harris
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Brian J Scarth
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Izabelle Gadawski
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Nancy Wang
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Eugenia Yu
- Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, Vancouver, B.C., Canada
| | - Benita Yip
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Nadia Zalunardo
- St. Paul's Hospital, Providence Health Care, Vancouver, B.C. Canada
| | - Ron Werb
- St. Paul's Hospital, Providence Health Care, Vancouver, B.C. Canada
| | - Robert Hogg
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - P Richard Harrigan
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
| | - Julio S Montaner
- British Columbia Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, B.C. Canada
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Moyle G. Mechanisms of HIV and Nucleoside Reverse Transcriptase Inhibitor Injury to Mitochondria. Antivir Ther 2005. [DOI: 10.1177/135965350501002s05] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Graeme Moyle
- St Stephens HIV Research, Chelsea and Westminster Hospital, London, UK
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13
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Walker UA, Venhoff N. Uridine in the Prevention and Treatment of Nrti-Related Mitochondrial Toxicity. Antivir Ther 2005. [DOI: 10.1177/135965350501002s13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term side effects of antiretroviral therapy are attributed to the mitochondrial (mt) toxicity of nucleoside analogue reverse transcriptase inhibitors (NRTIs) and their ability to deplete mtDNA. Studies in hepatocytes suggest that uridine is able to prevent and treat mtDNA depletion by pyrimidine NRTIs [zalcitabine (ddC) and stavudine (d4T)] and to fully abrogate hepatocyte death, elevated lactate production and intracellular steatosis. Uridine was also found to improve the liver and haematopoietic toxicities of zidovudine (AZT), which are unrelated to mtDNA depletion, and to prevent neuronal cell death induced by ddC. Most recently, uridine was found to prevent the onset of a lipoatrophic phenotype (reduced intracellular lipids, increased apoptosis, mtDNA depletion and mt depolarization) in adipocytes incubated long-term with d4T and AZT. Various steps of mt nucleoside utilization may be involved in the protective effect, but competition of uridine metabolites with NRTIs at polymerase y or other enzymes is a plausible explanation. Pharmacokinetic studies suggest that uridine serum levels can be safely increased in humans to achieve concentrations which are protective in vitro (50–200 μM). Uridine was not found to interfere with the antiretroviral activity of NRTIs. Mitocnol, a sugar cane extract which effectively increases uridine in human serum, was beneficial in individual HIV patients with mt toxicity and is now being tested in placebo-controlled randomized trials. Until these data become available, the risk-benefit calculation of using uridine should be individualized. The current safety data justify the closely monitored use of uridine in individuals who suffer from mt toxicity but who cannot be switched to less toxic NRTIs.
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Affiliation(s)
- Ulrich A Walker
- Department of Rheumatology and Clinical Immunology, Medizinische Universitätsklinik, Freiburg, Germany
| | - Nils Venhoff
- Department of Rheumatology and Clinical Immunology, Medizinische Universitätsklinik, Freiburg, Germany
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