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Park J, Baruch-Torres N, Yin YW. Structural and Molecular Basis for Mitochondrial DNA Replication and Transcription in Health and Antiviral Drug Toxicity. Molecules 2023; 28:1796. [PMID: 36838782 PMCID: PMC9961925 DOI: 10.3390/molecules28041796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Human mitochondrial DNA (mtDNA) is a 16.9 kbp double-stranded, circular DNA, encoding subunits of the oxidative phosphorylation electron transfer chain and essential RNAs for mitochondrial protein translation. The minimal human mtDNA replisome is composed of the DNA helicase Twinkle, DNA polymerase γ, and mitochondrial single-stranded DNA-binding protein. While the mitochondrial RNA transcription is carried out by mitochondrial RNA polymerase, mitochondrial transcription factors TFAM and TFB2M, and a transcription elongation factor, TEFM, both RNA transcriptions, and DNA replication machineries are intertwined and control mtDNA copy numbers, cellular energy supplies, and cellular metabolism. In this review, we discuss the mechanisms governing these main pathways and the mtDNA diseases that arise from mutations in transcription and replication machineries from a structural point of view. We also address the adverse effect of antiviral drugs mediated by mitochondrial DNA and RNA polymerases as well as possible structural approaches to develop nucleoside reverse transcriptase inhibitor and ribonucleosides analogs with reduced toxicity.
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Affiliation(s)
- Joon Park
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Noe Baruch-Torres
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Y. Whitney Yin
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
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Jao J, Jacobson DL, Russell JS, Wang J, Yu W, Gojanovich GS, Siminski S, Hyzy L, Geffner ME, Gerschenson M. Perinatally acquired HIV infection is associated with abnormal blood mitochondrial function during childhood/adolescence. AIDS 2021; 35:1385-1394. [PMID: 33730749 PMCID: PMC8243810 DOI: 10.1097/qad.0000000000002884] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE We assessed differences in mitochondrial function between youth living with perinatal HIV (YPHIV) and youth perinatally HIV-exposed but uninfected (YPHEU). DESIGN Cross-sectional analysis. METHODS We measured lactate and pyruvate values, as well as mitochondrial Complex I and Complex IV activity in peripheral blood mononuclear cells. Logistic or linear regression models were fit, as appropriate, to assess the association between PHIV status and each mitochondrial parameter, adjusted for confounders. We introduced interaction terms to assess effect modification of PHIV status on the relationship between anthropometric factors and each mitochondrial parameter. Among YPHIV, similar regression models were fit to assess the relationship between HIV-associated factors and each mitochondrial outcome. RESULTS A total of 243 YPHIV and 118 YPHEU were compared. On average, YPHIV had higher lactate/pyruvate ratio (β: 7.511, 95% confidence interval [95% CI]: 0.402, 14.620) and Complex IV activity (β: 0.037, 95% CI: 0.002, 0.072) compared to YPHEU, adjusted for confounders. Among YPHIV, body mass index Z score (BMIZ) and Complex I activity were inversely associated, whereas, among YPHEU, there was a positive association (β for interaction: -0.048, P = 0.003). Among YPHIV, current (β: -0.789, 95% CI: -1.174, -0.404) and nadir CD4+% (β: -0.605, 95% CI: -1.086, -0.125) were inversely associated with lactate/pyruvate ratio; higher current (4.491, 95% CI: 0.754, 8.229) and peak (7.978, 95% CI: 1.499, 14.457) HIV RNA levels were positively associated with lactate/pyruvate ratio in adjusted models. CONCLUSIONS Mitochondrial function and substrate utilization appear perturbed in YPHIV compared to YPHEU. Increasing immunosuppression and viremia are associated with mitochondrial dysfunction among YPHIV.
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Affiliation(s)
- Jennifer Jao
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Department of Medicine, Division of Adult Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Denise L Jacobson
- Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Jonathan S Russell
- Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY
| | - Jiajia Wang
- Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Wendy Yu
- Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Greg S Gojanovich
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI
| | - Sue Siminski
- Frontier Science and Technology Research Foundation, Amherst Office, NY
| | - Laurie Hyzy
- Frontier Science and Technology Research Foundation, Amherst Office, NY
| | - Mitchell E Geffner
- The Saban Research Institute of Children's Hospital Los Angeles, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Mariana Gerschenson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI
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A Comparison of Metabolic Outcomes Between Obese HIV-Exposed Uninfected Youth From the PHACS SMARTT Study and HIV-Unexposed Youth From the NHANES Study in the United States. J Acquir Immune Defic Syndr 2020; 81:319-327. [PMID: 30844997 DOI: 10.1097/qai.0000000000002018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Metabolic perturbations in HIV-exposed uninfected (HEU) obese youth may differ from those in the general obese pediatric population. METHODS Metabolic parameters of obese (body mass index Z-score >95th percentile) HEU youth in the Pediatric HIV/AIDS Cohort Study (PHACS) Surveillance Monitoring of ART Toxicities (SMARTT) study were compared with a matched sample of obese youth from the US National Health and Nutrition Examination Survey (NHANES). We evaluated systolic and diastolic hypertension (blood pressure ≥90th percentile for age, sex, and height), total cholesterol >200 mg/dL, high-density lipoprotein cholesterol <35 mg/dL, low-density lipoprotein cholesterol >130 mg/dL, triglycerides (TGs) >150 mg/dL, and Homeostatic Model Assessment-Insulin Resistance >4.0. Modified Poisson regression models were fit to quantify the prevalence ratio (PR) of each outcome comparing the 2 cohorts, adjusting for confounders. RESULTS The blood pressure outcome analytic subgroup included 1096 participants (n = 304 HEU), the total cholesterol and high-density lipoprotein cholesterol subgroup 1301 participants (n = 385 HEU), and the low-density lipoprotein cholesterol, TG, and Homeostatic Model Assessment-Insulin Resistance subgroup 271 (n = 83 HEU). After adjustment, obese HEU youth had a higher prevalence of systolic and diastolic hypertension [PR = 3.34, 95% confidence interval (CI): 2.48 to 4.50; PR = 2.04, 95% CI: 1.18 to 3.52, respectively], but lower prevalence of insulin resistance (PR = 0.67, 95% CI: 0.54 to 0.85) and hypercholesterolemia (PR = 0.67, 95% CI: 0.44 to 1.01) compared with obese NHANES youth. CONCLUSIONS In the United States, obese HEU youth seem to have an increased risk of hypertension, but lower risk of insulin resistance and hypercholesterolemia, compared with a general obese pediatric population. Monitoring for cardiovascular morbidity in adulthood may be warranted in HEU children.
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Jao J, Powis KM, Kirmse B, Yu C, Epie F, Nshom E, Abrams EJ, Sperling RS, Leroith D, Geffner ME, Kurland IJ, Côté HCF. Lower mitochondrial DNA and altered mitochondrial fuel metabolism in HIV-exposed uninfected infants in Cameroon. AIDS 2017; 31:2475-2481. [PMID: 28926411 PMCID: PMC5680102 DOI: 10.1097/qad.0000000000001647] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Evaluate blood mitochondrial DNA (mtDNA) content in HIV/antiretroviral-exposed uninfected (HEU) vs. HIV-unexposed uninfected (HUU) infants and investigate differences in mitochondrial-related metabolites by exposure group. DESIGN We enrolled a prospective cohort of HIV-infected and HIV-uninfected pregnant woman/infant pairs in Cameroon. METHODS Dried blood spot mtDNA : nuclear DNA ratio was measured by monochrome multiplex quantitative polymerase chain reaction in HEU infants exposed to in-utero antiretrovirals and postnatal zidovudine (HEU-Z) or nevirapine (HEU-N), and in HUU infants at 6 weeks of life. Acylcarnitines and branch-chain amino acids (BCAAs) were measured via tandem mass spectrometry and consolidated into seven uncorrelated components using principal component analysis. Linear regression models were fit to assess the association between in-utero/postnatal HIV/antiretroviral exposure and infant mtDNA, adjusting for confounders and principal component analysis-derived acylcarnitine/BCAA component scores. RESULTS Of 364 singleton infants, 38 were HEU-Z, 117 HEU-N, and 209 HUU. Mean mtDNA content was lowest in HEU-Z infants (140 vs. 160 in HEU-N vs. 174 in HUU, P = 0.004). After adjusting for confounders, HEU-Z infants remained at increased risk for lower mtDNA content compared with HUU infants (β: -4.46, P = 0.045), whereas HEU-N infants did not, compared with HUU infants (β: -1.68, P = 0.269. Furthermore, long-chain acylcarnitines were associated with lower (β: -2.35, P = 0.002) and short-chain and BCAA-related acylcarnitines were associated with higher (β: 2.96, P = 0.001) mtDNA content. CONCLUSION Compared with HUU infants, HEU infants receiving postnatal zidovudine appear to be at increased risk for decreased blood mtDNA content which may be associated with altered mitochondrial fuel utilization in HEU-Z infants.
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Affiliation(s)
- Jennifer Jao
- aDepartment of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York bDepartment of Pediatrics and Internal Medicine, Massachusetts General Hospital cDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts dDepartment of Medical Genetics, University of Mississippi Medical Center, Jackson, Mississippi, USA eCameroon Baptist Convention Health Services, Bamenda, Cameroon fICAP, Mailman School of Public Health and College of Physicians and Surgeons, Columbia University gDepartment of Obstetrics, Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, New York hKeck School of Medicine of USC, The Saban Research Institute of Children's Hospital Los Angeles, Los Angeles, California iDepartment of Medicine, Stable Isotope and Metabolomics Core Facility, Albert Einstein College of Medicine, Bronx, New York, USA jDepartment of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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Jao J, Kirmse B, Yu C, Qiu Y, Powis K, Nshom E, Epie F, Tih PM, Sperling RS, Abrams EJ, Geffner ME, LeRoith D, Kurland IJ. Lower Preprandial Insulin and Altered Fuel Use in HIV/Antiretroviral-Exposed Infants in Cameroon. J Clin Endocrinol Metab 2015; 100:3260-9. [PMID: 26133363 PMCID: PMC4570172 DOI: 10.1210/jc.2015-2198] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Intrauterine HIV/antiretroviral (ARV) and postnatal ARVs are known to perturb energy metabolism and could have permanent effects on future metabolic health. Such maladaptive effects could be mediated by changes in mitochondrial function and intermediary metabolism due to fetal and early-life ARV exposure in HIV/ARV-exposed uninfected (HEU) infants. OBJECTIVE The objective of the study was to understand the relationship(s) between mitochondrial fuel use (assessed via acylcarnitines and branched chain amino acids) and preprandial insulin in infants exposed to in utero HIV/ARV plus postnatal zidovudine or nevirapine compared with HIV/ARV-unexposed uninfected (HUU) infants. DESIGN This was a prospective cohort study with the following three groups: 1) intrauterine HIV/ARV/postnatal zidovudine-exposed (HEU-A), 2) intrauterine HIV/ARV/postnatal nevirapine-exposed (HEU-N), and 3) HUU infants. Principal component analysis and linear regression modeling were performed to assess the association between in utero HIV/ARV exposure and infant insulin. SETTING The study was conducted at Cameroonian urban antenatal centers. PARTICIPANTS HIV-infected and -uninfected pregnant woman/infant dyads participated in the study. MAIN OUTCOME Preprandial insulin was the main outcome measured. RESULTS Of 366 infants, 38 were HEU-A, 118 HEU-N. Forty intermediary metabolites were consolidated into seven principal components. In a multivariate analysis, both HEU-A (β = -.116, P= .012) and HEU-N (β = -.070, P= .022) demonstrated lower insulin compared with HUU infants. However, at high levels of plasma metabolites, HEU-A (β = .027, P= .050) exhibited higher insulin levels than HEU-N or HUU infants. A unique array of short-chain acylcarnitines (β = .044, P= .001) and branched-chain amino acids (β = .033, P= .012) was associated with insulin. CONCLUSION HEU-A and HEU-N infants have lower preprandial insulin levels at 6 weeks of age and appear to use metabolic fuel substrates differently than HUU infants. Future studies are warranted to determine whether observed differences have lasting metabolic implications, such as later insulin resistance.
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Affiliation(s)
- Jennifer Jao
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Brian Kirmse
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Chunli Yu
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Yunping Qiu
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Kathleen Powis
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Emmanuel Nshom
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Fanny Epie
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Pius Muffih Tih
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Rhoda S Sperling
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Elaine J Abrams
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Mitchell E Geffner
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Derek LeRoith
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
| | - Irwin J Kurland
- Departments of Medicine (J.J.), Obstetrics, Gynecology, and Reproductive Science (J.J.), Genetics and Genomic Sciences (C.Y.), and Obstetrics, Gynecology, and Reproductive Science (R.S.S.), and Department of Medicine (D.L.), Division of Endocrinology, Icahn School of Medicine, Mt Sinai, New York, New York 10029; Department of Pediatrics (B.K.), Division of Genetics and Metabolism, Children's National Medical Center/George Washington University School of Medicine, Washington, DC 20037; Department of Medicine (Y.Q., I.J.K.), Division of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461; Departments of Pediatrics and Internal Medicine (K.P.), Massachusetts General Hospital, Boston, Massachusetts 02114; Cameroon Baptist Convention Health Services (E.N., F.E., P.M.T.), Bamenda, Cameroon; ICAP (E.J.A.), Mailman School of Public Health and College of Physicians and Surgeons, Columbia University, New York, New York 10032; and The Saban Research Institute of Children's Hospital Los Angeles (M.E.G.), Keck School of Medicine of University of Southern California, Los Angeles, California 90033
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Abstract
BACKGROUND Despite a wide body of literature supporting the use of antenatal antiretrovirals (ARV) for the prevention of mother-to-child transmission, there remains a need for continued monitoring as the intrauterine interval is a critical period during which fetal programming influences the future health and development of the child. METHODS We conducted a systematic review of the current literature addressing potential metabolic complications of in utero HIV and ARV exposure. We describe studies evaluating metabolic outcomes such as intrauterine and early postnatal growth, bone health and mitochondrial toxicity. RESULTS Overall, infants exposed to HIV/ARV do not appear to exhibit vastly compromised intrauterine or early postnatal growth. However, some studies on the effect of combination antiretroviral therapy on small for gestational age and low birth weight outcomes in low-middle income countries show a risk for small for gestational age/low birth weight while those in the United States do not. Postnatal growth to 1 year does not appear to be affected by intrauterine tenofovir exposure in African studies, but a US study found statistically significant differences in length for age z scores (LAZ) at 1 year. Little data exists on long-term bone health. Mitochondrial toxicity including abnormal mitochondrial morphology and DNA content, as well as neurologic deficits and death, have been demonstrated in HIV/ARV-exposed infants. CONCLUSION Although gross measures of metabolic well-being appear to be reassuring, careful vigilance of even small risks for potential serious adverse effects to infants exposed to intrauterine HIV/ARVs is warranted as intrauterine fetal metabolic programming may substantially impact the future health of the child.
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Timofeev V, Abramchik Y, Zhukhlistova N, Muravieva T, Fateev I, Esipov R, Kuranova I. 3'-Azidothymidine in the active site of Escherichia coli thymidine phosphorylase: the peculiarity of the binding on the basis of X-ray study. ACTA ACUST UNITED AC 2014; 70:1155-65. [PMID: 24699659 DOI: 10.1107/s1399004714001904] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022]
Abstract
The structural study of complexes of thymidine phosphorylase (TP) with nucleoside analogues which inhibit its activity is of special interest because many of these compounds are used as chemotherapeutic agents. Determination of kinetic parameters showed that 3'-azido-3'-deoxythymidine (3'-azidothymidine; AZT), which is widely used for the treatment of human immunodeficiency virus, is a reversible noncompetitive inhibitor of Escherichia coli thymidine phosphorylase (TP). The three-dimensional structure of E. coli TP complexed with AZT was solved by the molecular-replacement method and was refined at 1.52 Å resolution. Crystals for X-ray study were grown in microgravity by the counter-diffusion technique from a solution of the protein in phosphate buffer with ammonium sulfate as a precipitant. The AZT molecule was located with full occupancy in the electron-density maps in the nucleoside-binding pocket of TP, whereas the phosphate-binding pocket of the enzyme was occupied by phosphate (or sulfate) ion. The structure of the active-site cavity and conformational changes of the enzyme upon AZT binding are described in detail. It is found that the position of AZT differs remarkably from the positions of the pyrimidine bases and nucleoside analogues in other known complexes of pyrimidine phosphorylases, but coincides well with the position of 2'-fluoro-3'-azido-2',3'-dideoxyuridine (N3FddU) in the recently investigated complex of E. coli TP with this ligand (Timofeev et al., 2013). The peculiarities of the arrangement of N3FddU and 3'-azidothymidine in the nucleoside binding pocket of TP and correlations between the arrangement and inhibitory properties of these compounds are discussed.
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Affiliation(s)
- Vladimir Timofeev
- X-ray Analysis Methods and Synchrotron Radiation, Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333, Russian Federation
| | - Yulia Abramchik
- X-ray Analysis Methods and Synchrotron Radiation, Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333, Russian Federation
| | - Nadezda Zhukhlistova
- X-ray Analysis Methods and Synchrotron Radiation, Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333, Russian Federation
| | - Tatiana Muravieva
- Laboratory of Biotechnology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation
| | - Ilya Fateev
- Laboratory of Biotechnology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation
| | - Roman Esipov
- Laboratory of Biotechnology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation
| | - Inna Kuranova
- X-ray Analysis Methods and Synchrotron Radiation, Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333, Russian Federation
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Cooper DL, Lovett ST. Toxicity and tolerance mechanisms for azidothymidine, a replication gap-promoting agent, in Escherichia coli. DNA Repair (Amst) 2010; 10:260-70. [PMID: 21145792 DOI: 10.1016/j.dnarep.2010.11.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/16/2010] [Accepted: 11/16/2010] [Indexed: 01/13/2023]
Abstract
Azidothymidine (AZT, zidovudine) is used to treat HIV-AIDS and prevent maternal transmission to newborns. Because the azido group replaces the 3' OH of thymidine, AZT is believed to act as a chain terminator during reverse transcription of viral RNA into DNA, although other mechanisms of viral inhibition have been suggested. There is evidence that AZT is genotoxic, particularly to the mitochondria. In this study, we use the bacterium Escherichia coli to investigate the mechanism of AZT toxicity and the cellular mechanisms that aid survival. We show that that replication arrests quickly after treatment, accompanied by induction of the SOS DNA damage response. AZT appears to produce single-strand DNA gaps, as evident by RecF-dependent induction of the SOS response and visualization of single-strand DNA binding protein foci within the cell. Some of these gaps must be converted to breaks, since mutants in the RecBCD nuclease, required for recombinational double-strand break repair, are highly sensitive to AZT. Blocks in the late recombination functions, the RuvAB branch migration helicase and RuvC Holliday junction endonuclease, caused extreme AZT sensitivity that could be relieved by mutations in the early recombination functions, such as RecF, suggesting gaps engage in recombination reactions. Finally, our data suggest that the proofreading exonucleases of DNA polymerases play little role in AZT tolerance. Rather, Exonuclease III appears to be the enzyme that removes AZT: xthA mutants are highly AZT-sensitive, with a sustained SOS response, and overproduction of the enzyme protects wild-type cells. Our findings suggest that incorporation of AZT into human nuclear and mitochondrial DNA has the potential to promote genetic instability and toxicity through the production of ssDNA gaps and dsDNA breaks, and predicts that the human Exonuclease III ortholog, APE1, will be important for drug tolerance.
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Affiliation(s)
- Deani L Cooper
- Department of Biology, Brandeis University, Waltham, MA 02454-9110, USA
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Wińska P, Miazga A, Poznański J, Kulikowski T. Partial selective inhibition of HIV-1 reverse transcriptase and human DNA polymerases γ and β by thiated 3'-fluorothymidine analogue 5'-triphosphates. Antiviral Res 2010; 88:176-81. [PMID: 20739003 DOI: 10.1016/j.antiviral.2010.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/13/2010] [Accepted: 08/16/2010] [Indexed: 10/19/2022]
Abstract
3'-Deoxy-3'-fluorothymidine (FLT, alovudine(®)) belongs to the most potent agents inhibiting HIV-1 replication. Its 5'-triphosphate (FLTTP) is a potent inhibitor of HIV-1 reverse transcriptase (HIV RT). Unfortunately, FLT exerts substantial hematologic toxicity both in vitro and in vivo. It was suggested that this toxicity may be related to inhibition of human DNA polymerases, especially mitochondrial DNA polymerase γ, by nucleoside analogue 5'-triphosphates leading to termination of DNA synthesis and mitochondrial dysfunction. To decrease the toxicity of FLT, its thiated analogues, 4-SFLT and 2-SFLT, were previously synthesized and shown to be potent inhibitors of HIV-1 with low in vitro cytotoxicity. To explain this phenomenon in the present study the synthesis of 5'-triphosphates of thiated FLT analogues was undertaken and their interaction with recombinant HIV-1 RT and human DNA polymerases γ (pol γ) and β (pol β) was investigated. It was shown that 3'-deoxy-3'-fluoro-4-thiothymidine 5'-triphosphate (4-SFLTTP) and 3'-deoxy-3'-fluoro-2-thiothymidine 5'-triphosphate (2-SFLTTP) were, similarly to FLTTP, potent competitive inhibitors of HIV-1 RT, with K(i)(app) values of 0.091 and 0.022 μM respectively. It is of interest that 2-SFLTTP, a compound in an unusual syn conformation around the glycosidic bond was an uncompetitive inhibitor of human mitochondrial DNA pol γ with K(i)(app) of 0.174 μM, while 4-SFLTTP in anti conformation inhibited this enzyme similarly to FLTTP, i.e., non-competitively, with K(i)(app) of 0.055 μM. Both 4-SFLTTP and 2-SFLTTP were competitive inhibitors of human DNA pol β, with K(i)(app) values of 16.84 and 4.04 μM, respectively. The results point to partially selective inhibition of HIV RT by thiated 3'-fluorothymidine 5'-triphosphate analogues. Of special interest is that 2-SFLTTP, showing syn conformation, is a less potent inhibitor of human mitochondrial pol γ than 4-SFLTTP and FLTTP, both in the anti conformation, and has a higher inhibitory activity against HIV-1 RT than 4-SFLTTP. Moreover, the parent nucleoside 2-SFLT possessing the syn conformation shows a more potent anti-HIV-1 activity and a better selectivity index than its 4-thio isomer in the anti conformation (Matthes et al., 1989; Poopeiko et al., 1995), 2-SFLT is a potent and selective anti-HIV-1 agent with the selectivity index 4-fold higher than that of FLT. Findings regarding the mechanisms of antiviral and cytotoxic activities of FLT and its thioanalogues are discussed.
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Affiliation(s)
- Patrycja Wińska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawińskiego St., 02-106 Warszawa, Poland
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10
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Intranasal delivery of zidovudine by PLA and PLA–PEG blend nanoparticles. Int J Pharm 2010; 395:266-71. [DOI: 10.1016/j.ijpharm.2010.05.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 05/02/2010] [Accepted: 05/15/2010] [Indexed: 11/20/2022]
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Kohler JJ, Lewis W. A brief overview of mechanisms of mitochondrial toxicity from NRTIs. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2007; 48:166-72. [PMID: 16758472 DOI: 10.1002/em.20223] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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.
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Affiliation(s)
- James J Kohler
- Department of Pathology, Emory University, Atlanta, Georgia
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12
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Abstract
The mechanisms of the mitochondrial toxicity of AZT (azidothymidine; zidovudine) are not clear. The two main contenders are the incorporation of phosphorylated AZT into the mtDNA (mitochondrial DNA) and the competitive inhibition of natural deoxynucleotide metabolism. We have built a computational model of AZT metabolism in mitochondria in order to better understand these toxicity mechanisms. The model includes the transport of non-phosphorylated and phosphorylated forms of AZT into mitochondria, phosphorylation, and incorporation into mtDNA. The model also includes the mitochondrial metabolism of the natural deoxynucleotides. We define three simulated cell types, i.e. rapidly dividing, slowly dividing and postmitotic cells. Our standard simulation indicates that incorporation of AZT into mtDNA is highest in rapidly dividing cells because of the higher mitochondrial AZTTP (3'-azidothymidine-5'-triphosphate)/dTTP ratio in this cell type. However, under these standard conditions the rate of incorporation into mtDNA is too low to be a major cause of toxicity. These simulations relied on the assumption that phosphorylated AZT is transported with the same kinetics as phosphorylated thymidine. In simulations with mitochondria set to have a limited ability to transport phosphorylated AZT, AZTTP accumulates to toxic levels in the mitochondria of postmitotic cells, while low levels are maintained in mitochondria from rapidly dividing cells. This result is more consistent with the tissue toxicities observed in patients. Our model also predicts that inhibition by AZT of mitochondrial deoxycytidine phosphorylation by thymidine kinase 2 may contribute to the mitochondrial toxicity, since in simulations using a typical peak plasma AZT level the mtDNA replication rate is decreased by 30% in postmitotic cell simulations.
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Affiliation(s)
- Patrick C. Bradshaw
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, U.S.A
| | - Jiaxin Li
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, U.S.A
| | - David C. Samuels
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, U.S.A
- To whom correspondence should be addressed (email )
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Lewis LD, Amin S, Civin CI, Lietman PS. Ex vivo zidovudine (AZT) treatment of CD34+ bone marrow progenitors causes decreased steady state mitochondrial DNA (mtDNA) and increased lactate production. Hum Exp Toxicol 2005; 23:173-85. [PMID: 15171568 DOI: 10.1191/0960327104ht437oa] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Haematopoietic suppression is one of the dose-limiting side effects of chronic zidovudine (AZT) therapy. We tested the hypothesis that AZT would reduce mitochondrial DNA (mtDNA) content in haematopoietic progenitors causing impaired haematopoiesis and mitochondrial dysfunction. We studied the effects of AZT 0-50 microM in vitro, on normal human CD34+ haematopoietic progenitor cells cultured ex vivo for up to 12 days. The mean AZT IC50 for granulocyte (phenotype CD15+/CD14-) and erythroid (phenotype glycophorin+/CD45-) cell proliferation was 2.5 microM (SD+/-0.7) and 0.023 microM (SD+/-0.005), respectively. In myeloid-rich cell cultures, the mean lactate content of the media, compared to untreated controls, increased by 86% (SD+/-23) at 10 microM AZT and in erythroid-rich cultures it increased by 134% (SD+/-24) in the presence of 0.5 microM AZT. In myeloid-rich cultures the AZT IC50 for the reduction in the mitochondrial/nuclear DNA content ratio was 5.6 microM, whereas in erythroid rich cultures this AZT IC50 was < 0.0005 microM. AZT produced concentration-dependent inhibition of CD34+ progenitor proliferation into both myeloid and erythroid lineages; erythropoiesis was more sensitive than myelopoiesis. Concurrently, AZT reduced steady state mtDNA content, while increasing lactate production. These findings support the hypothesis that mtDNA is one of the intracellular targets involved in the pathogenesis of AZT-associated bone marrow progenitor cell toxicity.
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Affiliation(s)
- L D Lewis
- Department of Medicine and Pharmacology and Molecular Sciences (Division of Clinical Pharmacology), The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Viganò A, Giacomet V. Nucleoside Analogues Toxicities Related to Mitochondrial Dysfunction: Focus on HIV-Infected Children. Antivir Ther 2005. [DOI: 10.1177/135965350501002s06] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
| | - Vania Giacomet
- Paediatrics, L Sacco Hospital, University of Milan, Italy
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16
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Ogedegbe AEO, Thomas DL, Diehl AM. Hyperlactataemia syndromes associated with HIV therapy. THE LANCET. INFECTIOUS DISEASES 2003; 3:329-37. [PMID: 12781504 DOI: 10.1016/s1473-3099(03)00654-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hyperlactataemia is seen in 8-18.3% of HIV-infected patients taking nucleoside-analogue reverse transcriptase inhibitors (NRTIs). Recent epidemiological studies suggest that most episodes are transient and subclinical. However, symptomatic and occasionally life-threatening cases accompanied by metabolic acidosis and hepatic steatosis (ie, lactic acidosis syndrome) have also been described. Though yet to be fully elucidated, the proposed mechanism is NRTI-induced inhibition of mitochondrial DNA polymerase culminating in derangements in oxidative phosphorylation and lactate homeostasis. Signs and symptoms range from mild hyperlactataemia accompanied by nausea, abdominal discomfort, and weight loss to severe, intractable lactic acidosis complicated by coma and multi-organ failure. Significant progress has recently been made with regard to the natural history of NRTI-related hyperlactataemia. However, other important aspects of the disorder, such as its pathogenesis, predisposing conditions, and management, remain poorly understood. This article reviews the current published work on these issues, identifies areas of controversy, and addresses directions for future research.
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17
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Lewis W. Mitochondrial DNA replication, nucleoside reverse-transcriptase inhibitors, and AIDS cardiomyopathy. Prog Cardiovasc Dis 2003; 45:305-18. [PMID: 12638094 DOI: 10.1053/pcad.2003.3b] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nucleoside reverse-transcriptase inhibitors (NRTIs) in combination with other antiretrovirals (HAART) are the cornerstones of current AIDS therapy, but extensive use brought mitochondrial side effects to light. Clinical experience, pharmacological, cell, and molecular biological evidence links altered mitochondrial (mt-) DNA replication to the toxicity of NRTIs in many tissues, and conversely, mtDNA replication defects and mtDNA depletion in target tissues are observed. Organ-specific pathological changes or diverse systemic effects result from and are frequently attributed to HAART in which NRTIs are included. The shared features of mtDNA depletion and energy depletion became key observations and related the clinical and in vivo experimental findings to inhibition of mtDNA replication by NRTI triphosphates in vitro. Subsequent to those findings, other observations suggested that mitochondrial energy deprivation is concomitant with or the result of mitochondrial oxidative stress in AIDS (from HIV, for example) or from NRTI therapy itself.
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Affiliation(s)
- William Lewis
- Department of Pathology, Emory University Atlanta, GA 30322, USA.
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18
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Lewis W. Defective mitochondrial DNA replication and NRTIs: pathophysiological implications in AIDS cardiomyopathy. Am J Physiol Heart Circ Physiol 2003; 284:H1-9. [PMID: 12485813 DOI: 10.1152/ajpheart.00814.2002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lewis W, Copeland WC, Day BJ. Mitochondrial dna depletion, oxidative stress, and mutation: mechanisms of dysfunction from nucleoside reverse transcriptase inhibitors. J Transl Med 2001; 81:777-90. [PMID: 11406640 DOI: 10.1038/labinvest.3780288] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- W Lewis
- Department of Pathology, Emory University, Atlanta, Georgia 30322, USA.
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Loveday C. International perspectives on antiretroviral resistance. Nucleoside reverse transcriptase inhibitor resistance. J Acquir Immune Defic Syndr 2001; 26 Suppl 1:S10-24. [PMID: 11264998 DOI: 10.1097/00042560-200103011-00003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) comprise the first class of drug with proven antiretroviral efficacy against HIV-1, and the first in which drug resistance was reported. Ongoing research in the area of NRTI resistance and cross-resistance contributes much to what we know about the failure of antiretroviral therapy. The genetic mutation patterns responsible for resistance to the available NRTIs have been well documented. This information is being used to plan rational drug therapy. Furthermore, it serves as the standard against which to evaluate response patterns to multiple-drug regimens, ultimately enabling more accurate prediction of outcome with combination therapies. Other features of NRTI resistance, such as the theoretic reversal of zidovudine resistance associated with the M184V mutation or the powerful influence of the Q151M multiple-drug resistance mutation, have revealed the unpredictable nature of HIV resistance and how much we still need to learn. Although NRTIs are the cornerstone of antiretroviral therapy at present and are used to control disease progression for extended periods, it is clear that eventually resistance occurs with all antiretroviral regimens. Future research into NRTI-resistance mutations, mutational interactions, treatment sequencing, and viral fitness and fidelity will continue to refine our understanding of drug resistance and improve our ability to delay or eliminate resistance and advance HIV control.
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Affiliation(s)
- C Loveday
- Department of Retrovirology, Royal Free & University College Medical School, London, United Kingdom
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Lewis W, Grupp IL, Grupp G, Hoit B, Morris R, Samarel AM, Bruggeman L, Klotman P. Cardiac dysfunction occurs in the HIV-1 transgenic mouse treated with zidovudine. J Transl Med 2000; 80:187-97. [PMID: 10701688 DOI: 10.1038/labinvest.3780022] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cardiomyopathy in AIDS is an increasingly important clinical problem. Mechanisms of AIDS cardiomyopathy were explored using AIDS transgenic mice that express replication-incompetent HIV-1 (NL4-3delta gag/pol). Transgenic and FVB/n mice (n = 3 to 6 per cohort) received water ad libitum with and without zidovudine (3'-azido-2',3'-deoxythymidine; AZT; 0.7 mg/ml) for 21 or 35 days. After 21 days, echocardiographic studies were performed and abundance of mRNA for cardiac sarcoplasmic reticulum calcium ATPase (SERCA2), sodium calcium exchanger (NCX1), and atrial natriuretic factor were determined individually using Northern analysis of extracts of left ventricles. After 35 days, contractile function and relaxation were analyzed in isolated work-performing hearts. Histopathological and ultrastructural (transmission electron microscopy) changes were identified. After 21 days, molecular indicators of cardiac dysfunction were found. Depressed SERCA2 and increased atrial natriuretic factor mRNA abundance occurred in left ventricles from AZT-treated transgenic mice. NCX1 abundance was unchanged. Eccentric left ventricle hypertrophy was determined echocardiographically. After 35 days, cardiac dysfunction was worst in AZT-treated and AZT-untreated transgenic mice. Decreases in the first derivative of the maximal change in left ventricle systolic pressure with respect to time (+dP/dt) occurred in transgenic mice with and without AZT. Increased half-time of relaxation and ventricular relaxation (-dP/dt) occurred in AZT-treated and -untreated transgenic mice. Increased time to peak pressure was found only in AZT-treated transgenic mice. In AZT-treated FVB/n mice, -dP/dt was decreased. Ultrastructurally, mitochondrial destruction was most pronounced in AZT-treated transgenic mice, but also was found in AZT-treated FVB/n mice. Transgenic mice that express HIV-1 demonstrate cardiac dysfunction. AZT treatment of FVB/n mice causes mitochondrial ultrastructural alterations that are similar to those in other species. In transgenic mice, AZT treatment worsens molecular and ultrastructural features of cardiomyopathy. HIV-1 constructs and AZT each contribute to cardiac dysfunction in this murine model of AIDS cardiomyopathy.
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Affiliation(s)
- W Lewis
- Department of Pathology, University of Cincinnati College of Medicine, Ohio, USA.
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Szabados E, Fischer GM, Toth K, Csete B, Nemeti B, Trombitas K, Habon T, Endrei D, Sumegi B. Role of reactive oxygen species and poly-ADP-ribose polymerase in the development of AZT-induced cardiomyopathy in rat. Free Radic Biol Med 1999; 26:309-17. [PMID: 9895221 DOI: 10.1016/s0891-5849(98)00199-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The short term cardiac side-effects of AZT (3'-azido-3'-deoxythymidine, zidovudine) was studied in rats to understand the biochemical events contributing to the development of AZT-induced cardiomyopathy. Developing rats were treated with AZT (50 mg/kg/day) for 2 wk and the structural and functional changes were monitored in the cardiac muscle. AZT treatment provoked a surprisingly fast appearance of cardiac malfunctions in developing animals characterized by prolonged RR, PR and QT intervals and J point depression. Electron microscopy showed abnormal mitochondrial structure but the cardiomyocyte had normal myofibers. The AZT treatment of rats significantly increased ROS and peroxynitrite formation in heart tissues as determined by the oxidation of nonfluorescent dihydrorhodamine123 and dichlorodihydro-fluorescein diacetate (H2DCFDA) to fluorescent dyes, and induced single-strand DNA breaks. Lipid peroxidation and oxidation of cellular proteins determined from protein carbonyl content were increased as a consequence of AZT treatment. Activation of the nuclear poly-ADP-ribose polymerase and the accelerated NAD+ catabolism were also observed in AZT-treated animals. Western blot analysis showed that mono-ADP-ribosylation of glucose regulated protein (GRP78/BIP) was enhanced by AZT treatment, that process inactivates GRP78. In this way moderate decrease in the activity of respiratory complexes was detected in the heart of AZT-treated animals indicating a damaged mitochondrial energy production. There was a significant decrease in creatine phosphate concentration resulting in a decrease in creatine phosphate/creatine ratio from 2.08 to 0.58. ATP level remained close to normal but the total extractable ADP increased with 45%. The calculated free ATP/ADP ratio decreased from 340 to 94 in the heart of AZT-treated rats as a consequence of increased free ADP concentration. It was assumed that the increased free ADP in AZT-treated cardiomyocyte may help cells to compensate the defective ATP production in damaged mitochondria by activating the ATP synthesis in undamaged mitochondria. Southern blot analysis did not show decreased quantity of mtDNA deriving from AZT-treated rat hearts indicating that under our experimental conditions AZT-induced heart abnormalities are not the direct consequence of the mtDNA depletion. These data show that ROS-mediated oxidative damages, activated ADP-ribosylation reactions and accelerated NAD+ catabolism play basic roles in the development of AZT-induced cardiomyopathy in our animal model and indicated that these ROS-mediated processes can be important factors in the development of myopathy and cardiomyopathy in zidovudine-treated AIDS patients.
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Affiliation(s)
- E Szabados
- Department of Biochemistry, University Medical School Pecs, Hungary
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Taube R, Avidan O, Hizi A. The fidelity of misinsertion and mispair extension throughout DNA synthesis exhibited by mutants of the reverse transcriptase of human immunodeficiency virus type 2 resistant to nucleoside analogs. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 250:106-14. [PMID: 9431997 DOI: 10.1111/j.1432-1033.1997.00106.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The AIDS-causing retroviruses, human immunodeficiency virus types 1 and type 2 (HIV-1 and HIV-2, respectively) undergo extensive genetic variations, which effect their pathogenesis and resistance to drug therapy. It was postulated that this genetic hypervariability results from high rates of viral replication in conjugation with a relatively low fidelity of DNA synthesis [typical to the reverse transcriptases (RT) of these retroviruses]. As part of studying structure/function relationship in HIV RT, mutational analyses were conducted to identify amino acid residues which are involved in affecting the fidelity of DNA synthesis. The formation of 3'-mispaired DNA due to nucleotide misinsertions, and the subsequent elongation of this mismatched DNA were shown to be major determinants in affecting those substitutions during DNA synthesis (exhibited in vitro by HIV RT). It was interesting to find a correlation between sensitivity to nucleoside analogs (due to the ability to incorporate or reject an incoming analog) and the fidelity of DNA synthesis (which depends on the capacity to incorporate and extend a wrong nucleotide). Such a connection has already been found for several drug-resistant mutants of HIV-1 RT, with an increased fidelity of DNA synthesis relative to the wild-type RT. In the present study we have examined the fidelity of DNA synthesis using the same parameters of misinsertion and mispair extension for five novel drug-resistant mutants of HIV-2 RT; i.e. the single mutants [Val74]RT, [Gly89]RT and [Tyr215]RT and the double mutants [Val74,Tyr215]RT and [Gly89, Tyr215]RT. This comparative study suggests that unlike the Val74 mutant of HIV-1 RT, which was shown earlier to display a substantially enhanced fidelity, the comparable mutant of HIV-2 RT has fidelity similar to that of the wild-type RT. Depending on the assay employed and the DNA sequences extended, most other mutants of HIV-2 RT display moderate effects on the enzyme, leading to mild increases in fidelity of DNA synthesis. This implies a more complex and less distinctive correlation between drug-resistance, misinsertion and mispair extension in HIV-2 RT in contrast to HIV-1 RT, providing evidence for potential biochemical differences between these two related RT.
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Affiliation(s)
- R Taube
- Department of Cell Biology and Histology, Sackler School of Medicine, Tel Aviv University, Israel
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26
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Sailaja G, Nayak R, Antony A. Azidothymidine induces apoptosis in mouse myeloma cell line Sp2/0. Biochem Pharmacol 1996; 52:857-62. [PMID: 8781503 DOI: 10.1016/0006-2952(96)82183-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Azidothymidine (AZT), which has been extensively used as an antiviral agent in the treatment of AIDS, showed strong inhibition of growth of Sp2/0 cells in vitro. AZT-treated cells showed a decrease in viability in a dose-dependent manner. AZT specifically induced typical apoptotic cell death with DNA double-strand cleavage and subsequent formation of apoptotic bodies. The induction of DNA double-strand cleavage into the oligonucleosomal ladder by AZT was protected in the presence of thymidine or uridine. An increase in endonuclease activity from nuclear extract of AZT-treated cells was observed. The enzyme activity was found to be Ca(2+)-and Mg(2+)-dependent and was inhibited by zinc acetate. A marked enhancement of PARP activity was observed in AZT-treated cells. These observations show that AZT can trigger both morphological and biochemical changes typical of apoptosis in the mouse myeloma cell line Sp2/0.
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Affiliation(s)
- G Sailaja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
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27
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Hart DJ, Luo H, Garry RF. Biochemical characterization of the reverse transcriptase of a human intracisternal A-type particle (HIAP). AIDS Res Hum Retroviruses 1996; 12:1367-72. [PMID: 8891116 DOI: 10.1089/aid.1996.12.1367] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The discovery of novel human intracisternal A-type particle (HIAP) that may be associated with the autoimmune disease Sjŏgren's syndrome has been previously reported. Although the HIAP retrovirus has been shown to be antigenically related to HIV-1, the viruses were distinguishable by different hydrodynamic mobilities through a sucrose gradient by morphology and intracellular location, and by differing divalent cation requirements for their in vitro reverse transcriptase (RT) reactions. In this report, additional biochemical characteristics are provide that further differentiate the HIAP RT from HIV-1 RT. Data are also presented that distinguish the HIAP RT from the known cellular DNA polymerases.
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Affiliation(s)
- D J Hart
- Department of Psychiatry and Neurology, Tulane University School of Medicine, New Orleans, Louisiana 70112-2699, USA
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28
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Spedding G. A non-radioactive assay system for screening for inhibitors of RNA-dependent reverse transcriptase activity; an analysis using aurintricarboxylic acid and plant flavonoids. J Mol Recognit 1996; 9:499-502. [PMID: 9174931 DOI: 10.1002/(sici)1099-1352(199634/12)9:5/6<499::aid-jmr291>3.0.co;2-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ongoing and extensive screening for potentially selective and potent inhibitors of RNA-dependent DNA polymerases (reverse transcriptases) is important for the discovery of therapeutic agents active against retroviruses. Traditional systems for assaying the activity of reverse transcriptase enzymes have relied upon the use of radioactive nucleotides for monitoring complementary DNA (cDNA) synthesis. Moreover, such assays have also typically been programmed by the addition of synthetic template-primers. The recent trend, however, is towards the use of more natural nucleic acid template-primer-directed systems, which provides for a more realistic estimation of the activity of potential therapeutic anti-reverse transcriptase agents. A novel agarose gel-electrophoretic method originally developed to evaluate DNA polymerase activity during enzyme purification was adapted for screening purposes. The system was modified so that one can detect the synthesis of non-radioactively labeled cDNA synthesized in both DNA and RNA template-directed reverse transcription reactions. Such assays are programmed with either M13mp9 single-stranded DNA or rabbit globin mRNA as appropriate templates. Following incubation of reaction mixtures, agarose gels are used to determine the activity of the DNA-dependent DNA polymerase and RNA-dependent DNA polymerase activities of Maloney murine leukemia virus. This is done through a detection of the amount of double-stranded nucleic acid molecules (either DNA:DNA or RNA:DNA hybrids) generated by the enzyme in the presence and absence of various known enzyme inhibitors. The assay systems that have been developed will be useful in initial, general, rapid, inexpensive and safer screening programs for potential inhibitors of both the DNA- and RNA-dependent DNA-polymerase functions of reverse transcriptase enzymes. The system was tested and evaluated with potent inhibitors of reverse transcription, such as aurintricarboxylic acid and with several plant flavonoids known to be moderately potent inhibitors of reverse transcriptases. The details concerning the RNA-dependent DNA polymerizing system and some of our results are presented.
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Affiliation(s)
- G Spedding
- Department of Chemistry, Butler University, Indianapolis, Indiana 46208, USA
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29
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Lewis W, Levine ES, Griniuviene B, Tankersley KO, Colacino JM, Sommadossi JP, Watanabe KA, Perrino FW. Fialuridine and its metabolites inhibit DNA polymerase gamma at sites of multiple adjacent analog incorporation, decrease mtDNA abundance, and cause mitochondrial structural defects in cultured hepatoblasts. Proc Natl Acad Sci U S A 1996; 93:3592-7. [PMID: 8622980 PMCID: PMC39655 DOI: 10.1073/pnas.93.8.3592] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The thymidine analog fialuridine deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil (FIAU) was toxic in trials for chronic hepatitis B infection. One mechanism postulated that defective mtDNA replication was mediated through inhibition of DNA polymerase-gamma (DNA pol-gamma), by FIAU triphosphate (FIALTP) or by triphosphates of FIAU metabolites. Inhibition kinetics and primer-extension analyses determined biochemical mechanisms of FIAU, 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) -5-methyluracil (FAU), 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)uracil triphosphate (TP) inhibition of DNA pol-gamma. dTMP incorporation by DNA pol-gamma was inhibited competitively by FIAUTP, FMAUTP, and FAUTP (K1=0.015, 0.03, and 1.0 microM, respectively). By using oliginucleotide template-primers. DNA pol-gamma incorporated each analog into DNA opposite a single adenosine efficiently without effects on DNA chain elongation. Incorporation of multiple adjacent analogs at positions of consecutive adenosines dramatically impaired chain elongation by DNA pol-gamma. Effects of FIAU, FMAU, and FAU on HepG2 cell mmtDNA abundance and ultrastructure were determined. After 14 days, mtDNA decreased by 30% with 20 microM FIAU or 20 microM FMAU and decreased less than 10% with 100 microM FAU. FIAU and FMAU disrupted mitochondria and caused accumulation of intracytoplasmic lipid droplets. Biochemical and cell biological findings suggest that FIAU and its metabolites inhibit mtDNA replication, most likely at positions of adenosine tracts, leading to decreased mtDNA and mitochondrial ultrastructural defects.
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Affiliation(s)
- W Lewis
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Cincinnati, OH 45267-0529, USA
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30
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Dittmar MT, Cichutek K, Fultz PN, Kurth R. The U3 promoter region of the acutely lethal simian immunodeficiency virus clone smmPBj1.9 confers related biological activity on the apathogenic clone agm3mc. Proc Natl Acad Sci U S A 1995; 92:1362-6. [PMID: 7877983 PMCID: PMC42519 DOI: 10.1073/pnas.92.5.1362] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Infection with the acutely pathogenic molecular virus clone SIVsmmPBj1.9, cloned from isolate PBj14 of simian immunodeficiency virus (SIV) from sooty mangabey monkeys (Cercocebus atys), leads to acute viral and often lethal disease within days or weeks. SIVsmmPBj1.9 has the unique property of replicating in nonstimulated peripheral blood mononuclear cells from pig-tailed macaques. In contrast, molecular virus clone SIVagm3mc of SIV from African green monkeys (Cercopithecus aethiops), which is apathogenic in its natural host and in pig-tailed macaques, is unable to grow in nonstimulated peripheral blood cells. Chimeric proviruses were constructed by exchanging defined regions of SIVagm3mc against comparable regions of SIVsmmPBj1.9. Four of five hybrid viruses generated by transfection into the CD4-positive T-cell line C8166 replicated in T-cell lines permissive for SIVagm3mc replication and in stimulated peripheral blood cells from pig-tailed macaques and from African green monkeys. Three hybrid viruses displayed the distinct biological property of SIVsmmPBj14 to replicate in nonstimulated peripheral blood cells from pig-tailed macaques and from African green monkeys. Replication in nonstimulated peripheral blood cells was dependent on the presence of the U3 promoter region of SIVsmmPBj1.9 within the viral long terminal repeat.
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Affiliation(s)
- M T Dittmar
- Department of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
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31
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Thompson WL, Scovill JP, Pace JG. Drugs that show protective effects from ricin toxicity in in vitro protein synthesis assays. NATURAL TOXINS 1995; 3:369-77. [PMID: 8581322 DOI: 10.1002/nt.2620030508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We used an in-vitro, inhibition of protein synthesis assay (PSI) to test a wide variety of drugs for possible therapeutic use against ricin, a toxic glycoprotein that causes death in animals by inhibiting protein synthesis. Selection of test drugs was based on possible interference with ricin activity at different stages of the toxic process. Most of the drugs tested had no effect on ricin-induced PSI, were toxic when tested alone, or enhanced the toxicity of ricin. The only ones showing protection were galactose, lactose, and several derivatives of these sugars, Brefeldin A (BFA), 3'-azido-3'-deoxythymidine (AZT), and a purine derivative (BM33203). THe sugar derivatives provided 50% protection against a PSI ED99 of ricin (0.1 micrograms/ml). Concentrations of BFA greater than 0.5 micro M caused about 50% PSI by itself, but blocked any further inhibitory effects of ricin. AZT, at optimum concentrations, reached a maximum protection level of about 40% in the presence of an ED99 dose of ricin, while the nucleoside derivative, BM33203 and AZT appeared to have an additive effect, showing up to 80% protection from an ED99 dose of ricin. Drugs showing protection in the PSI cell assay showed no protection from ricin in a cell-free translation assay used to determine if they would block ricin at the protein synthesis site.
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Affiliation(s)
- W L Thompson
- Toxicology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA
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32
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Ennen J, Findeklee H, Dittmar MT, Norley S, Ernst M, Kurth R. CD8+ T lymphocytes of African green monkeys secrete an immunodeficiency virus-suppressing lymphokine. Proc Natl Acad Sci U S A 1994; 91:7207-11. [PMID: 7913749 PMCID: PMC44368 DOI: 10.1073/pnas.91.15.7207] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Following natural and experimental infection by simian immunodeficiency virus SIVagm of African green monkeys (AGMs), the natural host, there is no evidence for the development of an immunodeficiency. Within the framework of our studies on human immunodeficiency virus (HIV)/SIV pathogenesis, we investigated the influence of CD8 T lymphocytes on SIVagm replication in AGM CD4 T lymphocytes in vitro. The following observations were made: (i) Peripheral blood mononuclear cells from both seronegative and seropositive AGMs contained only a low proportion (i.e., 10%) of CD4+ lymphocytes, whereas a high proportion (80%) of CD8+ cells was detected. Even after persistent SIVagm infection, CD4 T lymphocytes do not decrease in number. (ii) The target of in vitro infection of peripheral blood cells is the CD4+ mononuclear cell (T lymphocytes, monocytes) and SIVagm infects by binding to the CD4 molecule. (iii) In both naturally and experimentally SIVagm-infected AGMs the CD4+ T cells and monocytes, but not the CD8+ T cells, harbor DNA provirus. (iv) Virus reisolation and virus replication of SIVagm in CD4 T lymphocytes from seropositive AGMs is suppressed in the presence of autologous CD8 T lymphocytes or a soluble factor produced by these cells. Taken together, one possible reason for the apathogenicity of the SIVagm infection in AGMs may be the suppression of virus replication by a soluble, yet unidentified factor secreted by CD8 lymphocytes quantitatively dominating among peripheral blood cell populations. We have tentatively termed this factor "immunodeficiency virus-suppressing lymphokine." In addition, we show that immunodeficiency virus-suppressing lymphokine from AGMs is able to suppress HIV-1 replication in human CD4+ T cells.
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Affiliation(s)
- J Ennen
- Paul-Ehrlich Institute, Langen, Germany
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33
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Lewis W, Simpson JF, Meyer RR. Cardiac mitochondrial DNA polymerase-gamma is inhibited competitively and noncompetitively by phosphorylated zidovudine. Circ Res 1994; 74:344-8. [PMID: 8293572 DOI: 10.1161/01.res.74.2.344] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Zidovudine (azidothymidine [AZT]) inhibits human immunodeficiency virus replication and reduces the severity of acquired immunodeficiency syndrome. A limiting side effect of AZT is a mitochondrial cardiac and skeletal myopathy in which the pharmacologically active derivative of AZT (AZT triphosphate) plays a critical role. The present study determined biochemical mechanisms of AZT-induced mitochondrial toxicity and identified AZT triphosphate as an inhibitor of DNA polymerase-gamma in vitro. Inhibition kinetics were defined using purified bovine cardiac mitochondrial DNA polymerase-gamma and AZT triphosphate in vitro. The Km for deoxythymidine triphosphate was 0.8 +/- 0.3 mumol/L. AZT triphosphate incubation with DNA polymerase-gamma in vitro resulted in mixed kinetics with a competitive Ki of 1.8 +/- 0.2 mumol/L and a noncompetitive Ki' of 6.8 +/- 1.7 mumol/L. These Ki and Ki' values were strikingly higher than values for retroviral reverse transcriptase but lower than values for other cellular DNA polymerases. These data support previous molecular and morphological findings in clinical AZT mitochondrial myopathy and in models of AZT myopathy in vivo. Biochemical findings suggest that inhibition of mitochondrial DNA polymerase-gamma may be integral to the pathogenesis of AZT-induced myopathy.
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Affiliation(s)
- W Lewis
- Department of Pathology and Laboratory Medicine, University of Cincinnati, College of Medicine, OH
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34
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Schinazi RF. Competitive inhibitors of human immunodeficiency virus reverse transcriptase. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf02171660] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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35
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36
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De Clercq E. Antiviral agents: characteristic activity spectrum depending on the molecular target with which they interact. Adv Virus Res 1993; 42:1-55. [PMID: 8430518 DOI: 10.1016/s0065-3527(08)60082-2] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The target protein (enzyme) with which antiviral agents interact determines their antiviral activity spectrum. Based on their activity spectrum, antiviral compounds could be divided into the following classes: (1) sulfated polysaccharides (i.e., dextran sulfate), which interact with the viral envelope glycoproteins and are inhibitory to a broad variety of enveloped viruses (i.e., retro-, herpes-, rhabdo-, and arenaviruses): (2) SAH hydrolase inhibitors (i.e., neplanocin A derivatives), which are particularly effective against poxvirus, (-)RNA viruses (paramyxovirus, rhabdovirus), and (+/-)RNA virus (reovirus); (3) OMP decarboxylase inhibitors (i.e., pyrazofurin) and CTP synthetase inhibitors (i.e., cyclopentenylcytosine), which are active against a broad range of DNA, (+)RNA, (-)RNA, and (+/-)RNA viruses; (4) IMP dehydrogenase inhibitors (i.e., ribavirin), which are also active against various (+)RNA and (-)RNA viruses and, in particular, ortho- and paramyxoviruses; (5) acyclic guanosine analogs (i.e., ganciclovir) and carbocyclic guanosine analogs (i.e., cyclobut-G), which are particularly active against herpesviruses (i.e., HSV-1, HSV-2, VZV, CMV); (6) thymidine analogs (i.e., BVDU, BVaraU), which are specifically active against HSV-1 and VZV because of their preferential phosphorylation by the virus-encoded thymidine kinase; (7) acyclic nucleoside phosphonates (i.e., HPMPA, HPMPC, PMEA, FPMPA), which, depending on the structure of the acyclic side chain, span an activity spectrum from DNA viruses (papova-, adeno-, herpes-, hepadna-, and poxvirus) to retroviruses (HIV); (8) dideoxynucleoside analogs (i.e., AZT, DDC), which act as chain terminators in the reverse transcriptase reaction and thus block the replication of retroviruses as well as hepadnaviruses; and (9) the TIBO, HEPT, and other TIBO-like compounds, which interact specifically with the reverse transcriptase of HIV-1 and thus block the replication of HIV-1, but not of HIV-2 or any other retrovirus.
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Affiliation(s)
- E De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium
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37
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Baba M, Shigeta S, Tanaka H, Miyasaka T, Ubasawa M, Umezu K, Walker RT, Pauwels R, De Clercq E. Highly potent and selective inhibition of HIV-1 replication by 6-phenylthiouracil derivatives. Antiviral Res 1992; 17:245-64. [PMID: 1379423 DOI: 10.1016/0166-3542(92)90021-v] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- M Baba
- Department of Microbiology, Fukushima Medical College, Japan
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38
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Binninger D, Ennen J, Bonn D, Norley SG, Kurth R. Mutational analysis of the simian immunodeficiency virus SIVmac nef gene. J Virol 1991; 65:5237-43. [PMID: 1716690 PMCID: PMC249002 DOI: 10.1128/jvi.65.10.5237-5243.1991] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We are using site-directed mutagenesis of single viral genes to identify and analyze the genetic determinants of human and simian immunodeficiency virus pathogenicity. In a first approach, we have constructed a series of simian immunodeficiency virus SIVmac nef mutants by partial deletion and insertions in the nef gene, as this gene is a candidate gene for the establishment and maintenance of latency. nef insertion mutants replicated faster than wild-type SIVmac, suggesting that the nef gene product acts as a negative factor for replication. Surface phenotyping revealed that cultures permanently infected with nef mutants exhibit an enhanced expression of viral proteins on the outer cell surface. We have analyzed the properties of the mutant viruses in cell culture and intend to use rapidly replicating mutants (putatively unable to undergo latency) as model vaccine viruses in the rhesus monkey.
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39
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Borroto-Esoda K, Boone LR. Equine infectious anemia virus and human immunodeficiency virus DNA synthesis in vitro: characterization of the endogenous reverse transcriptase reaction. J Virol 1991; 65:1952-9. [PMID: 1705993 PMCID: PMC240025 DOI: 10.1128/jvi.65.4.1952-1959.1991] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The endogenous reverse transcriptase reaction of equine infectious anemia virus (EIAV) has been studied, and conditions allowing synthesis of full-length minus-strand DNA have been determined. In contrast to results reported for other retroviruses, synthesis of EIAV full-length minus-strand DNA was not impaired by high concentrations of Nonidet P-40, a nonionic detergent used to make the virion envelope permeable. All components of the reaction were titrated for maximum synthesis of complete minus strands, and a time course under the standardized conditions was determined. Minor subgenomic bands were observed in some cases, and both the size and proportion varied with reaction conditions. Conditions established for full-length EIAV DNA synthesis also allowed full-genome-length human immunodeficiency virus type 1 DNA synthesis. The human immunodeficiency virus type 1 DNA product contained a greater proportion of reverse transcripts that were shorter than the complete virus genome. Also in contrast to EIAV, the endogenous synthesis of high-molecular-weight human immunodeficiency virus type 1 DNA was drastically reduced at Nonidet P-40 concentrations above 0.02%. These results indicated that a detergent-stable core is not a property shared by all lentiviruses. The EIAV virion synthetic machinery is unusually stable and provides a convenient system for further in vitro study of reverse transcription.
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Affiliation(s)
- K Borroto-Esoda
- Division of Virology, Wellcome Research Laboratories, Burroughs Wellcome Co., Research Triangle Park, North Carolina 27709
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40
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Baba M, De Clercq E, Tanaka H, Ubasawa M, Takashima H, Sekiya K, Nitta I, Umezu K, Nakashima H, Mori S. Potent and selective inhibition of human immunodeficiency virus type 1 (HIV-1) by 5-ethyl-6-phenylthiouracil derivatives through their interaction with the HIV-1 reverse transcriptase. Proc Natl Acad Sci U S A 1991; 88:2356-60. [PMID: 1706522 PMCID: PMC51230 DOI: 10.1073/pnas.88.6.2356] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In the search for 1-[(2-hydroxyethoxy)-methyl]-6-(phenylthio)thymine (HEPT) derivatives, we have found several 5-ethyl-6-(phenylthio)uracil analogues to be highly potent and selective inhibitors of human immunodeficiency virus (HIV) type 1. 1-Benzyloxymethyl-5-ethyl-6-phenylthiouracil, the most potent congener of the series, inhibits HIV-1 replication in a variety of cell systems, including peripheral blood lymphocytes, at a concentration of 1.5-7.0 nM, which is lower by a factor of 10(3) than the 50% antivirally effective concentration of the parent compound HEPT. The 5-ethyl-6-(phenylthio)uracil analogues, like HEPT itself, do not inhibit HIV-2 replication but do inhibit replication of 3'-azido-3'-deoxythymidine-resistant mutants of HIV-1. 1-Benzyloxy-methyl-5-ethyl-6-phenylthiouracil and its congeners are targeted at the HIV-1 reverse transcriptase (RT). They do not inhibit HIV-2 RT. They do not need to be metabolized to exert their inhibitory effect on HIV-1 RT. Yet this inhibitory effect is competitive with the natural substrate dTTP. The HEPT derivatives represent a group of RT inhibitors with a unique mode of interaction with HIV-1 RT.
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Affiliation(s)
- M Baba
- Department of Bacteriology, Fukushima Medical College, Japan
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41
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Parker WB, White EL, Shaddix SC, Ross LJ, Buckheit RW, Germany JM, Secrist JA, Vince R, Shannon WM. Mechanism of inhibition of human immunodeficiency virus type 1 reverse transcriptase and human DNA polymerases alpha, beta, and gamma by the 5'-triphosphates of carbovir, 3'-azido-3'-deoxythymidine, 2',3'-dideoxyguanosine and 3'-deoxythymidine. A novel RNA template for the evaluation of antiretroviral drugs. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52360-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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42
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Kraus G, Behr E, Baier M, König H, Kurth R. Simian immunodeficiency virus reverse transcriptase. Purification and partial characterization. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 192:207-13. [PMID: 1698157 DOI: 10.1111/j.1432-1033.1990.tb19216.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Native reverse transcriptase from simian immunodeficiency virus was purified from virus with good recovery to near homogeneity. The optimum reaction conditions of the enzyme were determined with respect to divalent cations, pH and ionic strength. The enzyme was shown to possess both RNA-dependent and DNA-dependent DNA synthesis activity. In addition, we could demonstrate an associated RNase H activity. Employing novel assay conditions, activated DNA as a heteropolymeric substrate was used more efficiently than the homopolymeric substrate poly(rA).oligo(dT) which in turn was used twofold more effectively as the template primer than poly(dC).oligo(dG). Other homopolymeric substrates, including poly(rC).oligo(dG), were also tested but were found to be poorly used by the reverse transcriptase. The Miachaelis-Menten constants were determined for each of the four nucleotides needed to elongate a natural template primer. Simultaneously, using dideoxyadenosine triphosphate as nucleotide analogue, we could show that this compound acts as a competitive inhibitor with respect to dATP, whereas it acts as a non-competitive inhibitor with respect to the other nucleotides. Gel electrophoretic analysis showed the enzyme to consist of two polypeptides with apparent molecular masses of 64 and 48 kDa. Using activity gel electrophoresis, we were able to demonstrate that both subunits exhibit DNA synthesis activity.
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Affiliation(s)
- G Kraus
- Paul Ehrlich Institut, Langen/Frankfurt, FRG
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