Antiretroviral nucleoside analogues suppress antibody synthesis in human B-lymphocytes.

Background: Some antiretroviral nucleoside reverse transcriptase inhibitors (NRTI) impair mitochondrial polymerase-γ and T-cell proliferation, possibly by pyrimidine depletion. We aimed to analyse NRTI effects on the content of mitochondrial DNA (mtDNA) and B-cells, and on their proliferation and antibody synthesis.

Methods: Peripheral blood B-lymphocytes from six healthy individuals were stimulated in vitro with interleukin-4 and Staphylococcus aureus superantigen in the presence or absence of NRTI in concentrations equivalent to, or fivefold exceeding, human peak plasma levels.

Skeletal muscle mitochondrial DNA content and aerobic metabolism in patients with antiretroviral therapy-associated lipoatrophy.

Objectives: To assess whether mitochondrial dysfunction in skeletal muscle characterizes antiretroviral therapy (ART)-associated lipoatrophy (LA).

Methods: A cross-sectional study comparing HIV-infected, antiretroviral-treated patients with LA (n = 5; LA+) and without LA (n = 5; non-LA) was conducted. Positron emission tomography was used to measure blood flow, oxygen extraction and oxygen consumption in quadriceps femoris muscle during rest and aerobic exercise.

Mitochondrial toxicity in HIV type-1-exposed pregnancies in the era of highly active antiretroviral therapy.

Background: The aim of this study was to determine the effects of HIV type-1 (HIV-1) infection and antiretroviral therapy (ART) on placental mitochondria.

Methods: HIV-1-infected pregnant women and HIV-1-uninfected controls were enrolled prospectively. Placental mitochondrial DNA (mtDNA) copy numbers were determined by quantitative PCR, subunits II and IV of cytochrome c oxidase (COX) were quantified by western blot and mitochondrial ultrastructure was evaluated by electron microscopy.

The gene-expression and phenotypic response of hFOB 1.19 osteoblasts to surface-modified titanium and zirconia.

The osteoblastic cell-line hFOB 1.19 with the potential to proliferate and differentiate revealed that cellular differentiation is not affected by material and roughness on newly developed zirconia implant materials. Materials under investigation were surfaces machined titanium (Ti-m), modified titanium (TiUnite, machined zirconia (TZP-A-m), modified zirconia (ZiUnitemachined alumina-toughened zirconia (ATZ-m) and modified alumina-toughened zirconia (ATZ-mod).

Pyrimidine nucleoside depletion sensitizes to the mitochondrial hepatotoxicity of the reverse transcriptase inhibitor stavudine.

Stavudine is a hepatotoxic antiretroviral nucleoside analogue that also inhibits the replication of mitochondrial DNA (mtDNA). To elucidate the mechanism and consequences of mtDNA depletion, we treated HepG2 cells with stavudine and either redoxal, an inhibitor of de novo pyrimidine synthesis, or uridine, from which pyrimidine pools are salvaged. Compared with treatment with stavudine alone, co-treatment with redoxal accelerated mtDNA depletion, impaired cell division, and activated caspase 3.

Mitochondrial toxicity of tenofovir, emtricitabine and abacavir alone and in combination with additional nucleoside reverse transcriptase inhibitors.

Background: Some nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) combinations cause additive or synergistic interactions in vitro and in vivo.

Methods: We evaluated the mitochondrial toxicity of tenofovir (TFV), emtricitabine (FTC) and abacavir as carbovir (CBV) alone, with each other, and in combination with additional NRTIs. HepG2 human hepatoma cells were incubated with TFV, FTC, CBV, didanosine (ddl), stavudine (d4T), lamivudine (3TC) and zidovudine (AZT) at concentrations equivalent to 1 and 10x clinical steady-state peak plasma levels (C(max)).

Uridine supplementation antagonizes zalcitabine-induced microvesicular steatohepatitis in mice.

Unlabelled: Zalcitabine is an antiretroviral nucleoside analogue that exhibits long-term toxicity to hepatocytes by interfering with the replication of mitochondrial DNA (mtDNA). Uridine antagonizes this effect in vitro. In the present study we investigate the mechanisms of zalcitabine-induced hepatotoxicity in mice and explore therapeutic outcomes with oral uridine supplementation.

The 6-maleimidocaproyl hydrazone derivative of doxorubicin (DOXO-EMCH) is superior to free doxorubicin with respect to cardiotoxicity and mitochondrial damage.

Doxorubicin causes a chronic cardiomyopathy in which genetic and functional lesions of mitochondria accumulate in the long-term and explain in part the delayed onset of heart dysfunction. DOXO-EMCH a 6-maleimidocaproyl hydrazone derivative of doxorubicin, is an albumin binding prodrug which has entered clinical trials because of its superior antitumor and toxicological profile. In the present work, we examined the chronic cardiotoxicity of DOXO-EMCH in direct comparison with doxorubicin.

Hepatocerebral mitochondrial DNA depletion syndrome caused by deoxyguanosine kinase (DGUOK) mutations.

Background: Autosomal recessive mutations in deoxyguanosine kinase (DGUOK) have been identified in the hepatocerebral form of mitochondrial DNA (mtDNA) depletion syndrome.

Objectives: To describe the clinical spectrum of DGUOK-related mtDNA depletion syndrome in 6 children and to summarize the literature.

Results: We identified pathogenic mutations in DGUOK in 6 children with the hepatocerebral form of mtDNA depletion syndrome.

Tissue-specific mtDNA lesions and radical-associated mitochondrial dysfunction in human hearts exposed to doxorubicin.

Doxorubicin causes a chronic cardiomyopathy. Although the exact pathogenesis is unknown, recent animal data suggest that somatically acquired alterations of mitochondrial DNA (mtDNA) and concomitant mitochondrial dysfunction play an important role in its onset. In this study, skeletal and myocardial muscles were examined from human autopsies.

Mitochondrial toxicity of nucleoside analogues in primary human lymphocytes.

Objective: To evaluate if nucleoside analogue reverse transcriptase inhibitors (NRTIs) and polymerase-gamma inhibitors deplete mitochondrial DNA (mtDNA) in cultured primary lymphocytes and if such depletion might be associated with functional defects.

Methods: Primary peripheral blood CD4 and CD8 lymphocytes were purified from six healthy humans (three male and three female), stimulated mitotically (CD3/CD28) and cultured for 10 days in the presence or absence of NRTIs. Lymphocyte proliferation, mtDNA content, the expression of mtDNA-encoded cytochrome c-oxidase II (COXII) and lactate production were assessed.

Depletion of mitochondrial DNA in liver under antiretroviral therapy with didanosine, stavudine, or zalcitabine.

The "D drug" HIV reverse-transcriptase inhibitors zalcitabine, didanosine, and stavudine are relatively strong inhibitors of polymerase-gamma compared with the "non-D drugs" zidovudine, lamivudine, and abacavir. D drugs deplete mitochondrial DNA (mtDNA) in cultured hepatocytes. This mtDNA depletion is associated with an increased in vitro production of lactate.

Mitochondrial DNA and its respiratory chain products are defective in doxorubicin nephrosis.

Background: Doxorubicin induces a self-perpetuating nephropathy characterized by early glomerular and late-onset tubular lesions in rats. We investigated the potential role of mitochondrial injury in the onset of these lesions.

Methods: Rats were treated with intravenous doxorubicin (1 mg kg(-1) week(-1)) for 7 weeks and were sacrificed either 1 week ('short-term') or 30 weeks ('long-term') following the last dose.

Time-dependent and tissue-specific accumulation of mtDNA and respiratory chain defects in chronic doxorubicin cardiomyopathy.

Background: Doxorubicin causes a chronic cardiomyopathy of unknown pathogenesis. We investigated whether acquired defects in mitochondrial DNA (mtDNA) and interconnected respiratory chain dysfunction may represent a molecular mechanism for its late onset.

Methods And Results: Rats were treated weekly with intravenous doxorubicin (1 mg/kg) for 7 weeks, starting at 11 weeks of age (group B).

Increased long-term mitochondrial toxicity in combinations of nucleoside analogue reverse-transcriptase inhibitors.

Background: Some nucleoside analogue reverse transcriptase inhibitors (NRTI) may cause depletion of mitochondrial (mt) DNA in liver by inhibiting polymerase-gamma. mtDNA depletion may contribute to lactic acidosis, steatohepatitis and liver failure.

Objective: To evaluate the long-term mitochondrial toxicity of NRTI combinations.

Evidence of nucleoside analogue reverse transcriptase inhibitor--associated genetic and structural defects of mitochondria in adipose tissue of HIV-infected patients.

To investigate if possible mitochondrial injury can be found in adipose tissue of nucleoside analogue reverse transcriptase inhibitor (NRTI)-treated patients, subcutaneous fat was taken from the buttocks of 24 HIV-positive patients and 8 HIV-negative controls. The content of mitochondrial DNA (mtDNA) was quantified using a Southern blot technique. Fat biopsies were examined by electron microscopy and screened by restriction fragment length polymorphism analysis for the presence of the nt 8344 and 3243 mtDNA point mutations.