Impaired mitochondrial function is abrogated by dexrazoxane in doxorubicin-treated childhood acute lymphoblastic leukemia survivors.

BACKGROUND: Impaired cardiac function in doxorubicin-treated childhood cancer survivors is partly mediated by the disruption of mitochondrial energy production. Doxorubicin intercalates into mitochondrial DNA (mtDNA) and disrupts genes encoding for polypeptides that make adenosine triphosphate. METHODS: This cross-sectional study examined mtDNA copy numbers per cell and oxidative phosphorylation (OXPHOS) in peripheral blood mononuclear cells (PBMCs) in 64 childhood survivors of high-risk acute lymphoblastic leukemia (ALL) who had been treated on Dana-Farber Cancer Institute childhood ALL protocols and had received doxorubicin alone (42%) or doxorubicin with the cardioprotectant dexrazoxane (58%). The number of mtDNA copies per cell and the OXPHOS enzyme activity of nicotinamide adenine dinucleotide dehydrogenase (complex I [CI]) and cytochrome c oxidase (complex IV [CIV]) were measured with quantitative real-time polymerase chain reaction immunoassays and thin-layer chromatography, respectively. RESULTS: At a median follow-up of 7.8 years after treatment, the median number of mtDNA copies per cell for patients treated with doxorubicin alone (1106.3) was significantly higher than the median number for those who had also received dexrazoxane (310.5; P = .001). No significant differences were detected between the groups for CI or CIV activity. CONCLUSIONS: Doxorubicin-treated survivors had an increased number of PBMC mtDNA copies per cell, and concomitant use of dexrazoxane was associated with a lower number of mtDNA copies per cell. Because of a possible compensatory increase in mtDNA copies per cell to maintain mitochondrial function in the setting of mitochondrial dysfunction, overall OXPHOS activity was not different between the groups. The long-term sustainability of this compensatory response in these survivors at risk for cardiac dysfunction over their lifespan is concerning.

Changes in fat mitochondrial DNA and function in subjects randomized to abacavir-lamivudine or tenofovir DF-emtricitabine with atazanavir-ritonavir or efavirenz: AIDS Clinical Trials Group study A5224s, substudy of A5202.

BACKGROUND: The effect of nonthymidine nucleoside reverse-transcriptase inhibitors (NRTIs) on fat mitochondrial DNA (mtDNA) content and function is unclear. METHODS: A5202 randomized antiretroviral therapy-naive human immunodeficiency virus-infected subjects to abacavir-lamivudine (ABC/3TC) versus tenofovir DF-emtricitabine (TDF/FTC) with efavirenz (EFV) or atazanavir-ritonavir (ATV/r). A5224s, substudy of A5202, enrolled 269 subjects with fat measurements by dual-energy x-ray absorptiometry and computed tomography. A subset of subjects underwent fat biopsies at baseline and week 96 for mtDNA content (real-time polymerase chain reaction) and oxidative phosphorylation nicotinamide adenine dinucleotide (reduced) dehydrogenase (complex I) and cytochrome c oxidase (complex IV) activity levels (immunoassays). Intent-to-treat analyses were performed using analysis of variance and paired t tests. RESULTS: Fifty-six subjects (87% male; median age, 39 years) were included; their median body mass index, CD4 cell count, and fat mtDNA level were 26 kg/m(2), 227 cells/µL, and 1197 copies/cell, respectively. Fat mtDNA content decreased within the ABC/3TC and TDF/FTC groups (combining EFV and ATV/r arms; median change, -341 [interquartile range, -848 to 190; P = .03] and -400 [-661 to -221; P < .001] copies/cell, respectively), but these changes did not differ significantly between the 2 groups (P = .57). Complex I and IV activity decreased significantly in the TDF/FTC group (median change, -12.45 [interquartile range, -24.70 to 2.90; P = .003] and -8.25 [-13.90 to -1.30; P < .001], optical density × 10(3)/µg, respectively) but not the ABC/3TC group. Differences between the ABC/3TC and TDF/FTC groups were significant for complex I (P = .03). CONCLUSIONS: ABC/3TC and TDF/FTC significantly and similarly decreased fat mtDNA content, but only TDF/FTC decreased complex I and complex IV activity levels. CLINICAL TRIALS REGISTRATION: NCT00118898.

Longitudinal changes in mitochondrial-associated measures and insulin resistance in youth with perinatally-acquired HIV in the U.S.

HIV infection and its treatment are associated with mitochondrial dysfunction and metabolic derangement. However, longitudinal changes in oxidative phosphorylation activities [Complex I (C1) and Complex IV (C4)], or venous lactate/pyruvate ratios (LPR), and their relationships with insulin resistance (IR), remain unclear in youth living with perinatally-acquired HIV (YPHIV). We measured venous LPR, C1, and C4 activities in blood cells and homeostatic model assessment for IR (HOMA-IR) over two years. Limited longitudinal differences in mitochondrial-related measures and IR were observed in YPHIV vs youth perinatally HIV-exposed but uninfected. There were no systematic differences in C1, C4, or HOMA-IR between the groups.

Subcutaneous Adipocyte Adenosine Triphosphate Levels in HIV Infected Patients.

Lipoatrophy, or fat wasting, remains a syndrome plaguing HIV+ patients receiving antiretroviral (ARV) therapy. Both HIV infection per se and certain ARV are associated with lowered adipose tissue mitochondrial deoxyribonucleic acid (mtDNA) and mitochondrial ribonucleic acid (mtRNA) levels, but effects on adenosine triphosphate (ATP) production are unclear. We hypothesized that such alterations would accompany lowering of ATP levels in fat of HIV+ patients and would be worse in those displaying lipoatrophy. Gluteal-fold, subcutaneous adipose tissue was obtained from HIV seronegative control patients, from HIV+ ARV-naive patients, and those on ARV with or without lipoatrophy. Cellular ATP was measured in isolated adipocytes and preadipocyte fraction cells by bioluminescence. mtDNA copies/cell and oxidative phosphorylation (OXPHOS) mtRNA transcripts were evaluated by quantitative polymerase chain reactions. ATP levels were consistently higher in preadipocyte fraction cells than adipocytes, but values strongly correlated with each other (r = 0.66, p < .001). ATP levels in adipocytes were higher in both ARV-naive and nonlipoatrophic HIV+ patients compared to seronegative controls, but significantly lower in adipocytes and preadipocytes of lipoatrophic versus other HIV+ patients. Fat mtDNA copies/cell and OXPHOS mtRNA transcripts were lower in lipoatrophic patient samples compared to HIV seronegative. The ratio of specific OXPHOS transcripts to each other was significantly higher in nonlipoatrophic patients versus all groups, and this ratio correlated significantly with ATP levels in adipocytes. Thus, HIV infection is associated with an increase in adipose tissue ATP stores. Decreases in adipose mtDNA and OXPHOS mtRNA are found in those with HIV on ARV; however, ATP level is effected only in patients displaying lipoatrophy.

Mitochondrial Dysfunction and Insulin Resistance in Pubertal Youth Living with Perinatally Acquired HIV.

Mitochondrial dysfunction (MD) is linked to cardiometabolic complications, such as obesity and insulin resistance (IR), the frequencies of which are higher in adults living with HIV infection and receiving combination antiretroviral therapies (ARV). ARV-treated youth living with perinatally acquired HIV infection (YLPHIV) may be especially susceptible to IR due to long-term exposure to both factors. Medical histories, fasting blood chemistry panels, and mitochondrial function in banked peripheral blood mononuclear cells (PBMCs) were assessed in eligible YLPHIV from the Pediatric HIV/AIDS Cohort Study (PHACS)/Adolescent Master Protocol (AMP) Mitochondrial Determinants Component cohort, stratified by Homeostatic Model Assessment of IR (HOMA-IR) score: case (score ≥4, n = 39) or control (score <4, n = 105). PBMCs were sources for mitochondrial (mt) DNA copies/cell; mtRNA transcript levels of oxidative phosphorylation (OXPHOS) subunits NADH dehydrogenases 1 and 6, and cytochrome B; and enzymatic activities of OXPHOS Complexes I (CI) and IV (CIV). Logistic regression models were fit to estimate the odds of IR case diagnosis, adjusted for sex, race/ethnicity, body mass index (BMI) z-score, and Tanner stage. IR cases were similar to controls by age, sex, and race/ethnicity. Cases had higher median levels of peak HIV viral load, lactate, pyruvate, triglycerides, and BMI z-scores. OXPHOS CI enzymatic activity was lower in cases (log10 1.62 vs. 1.70) and inversely correlated with HOMA-IR score (r = -0.157, p = .061), but did not associate with IR in adjusted models. Fully adjusted models indicated associations of nadir CD4% [odds ratio (OR) = 0.95, 95% confidence intervals (CIs) = 0.90-1.00] or peak HIV load (OR = 3.48, 95% CIs = 1.70-10.79) with IR. IR in YLPHIV was strongly associated with morphometrics, but early virologic and immunologic factors may also influence MD.

Systemic Mitochondrial Oxidative Phosphorylation Protein Levels Correlate with Neuroimaging Measures in Chronically HIV-Infected Individuals.

Few studies have examined systemic mitochondrial function in conjunction with brain imaging in human immunodeficiency virus (HIV) disease. Oxidative phosphorylation enzyme protein levels of peripheral blood mononuclear cells were measured in association with neuroimaging indices in 28 HIV+ individuals. T1-weighted magnetic resonance imaging yielded volumes of seven brain regions of interest; diffusion tensor imaging determined fractional anisotropy (FA) and mean diffusivity (MD) in the corpus callosum (CC). Higher nicotinamide adenine dinucleotide dehydrogenase levels correlated with lower volumes of thalamus (p = .005) and cerebral white matter (p = .049) and, in the CC, with lower FA (p = .011, body; p = .005, genu; p = .009, total CC) and higher MD (p = .023, body; p = .035, genu; p = .019, splenium; p = .014, total CC). Greater cytochrome c oxidase levels correlated with lower thalamic (p = .034) and cerebellar gray matter (p = .021) volumes. The results indicate that systemic mitochondrial cellular bioenergetics are associated with brain health in HIV.

Mitochondrial function, morphology and metabolic parameters improve after switching from stavudine to a tenofovir-containing regimen.

OBJECTIVES: HIV-associated lipoatrophy has been associated with mitochondrial dysfunction induced by nucleoside reverse transcriptase inhibitor therapy. We hypothesize that lipid profiles and markers of mitochondrial function will improve in HIV-lipoatrophic patients switched to the nucleotide analogue tenofovir. METHODS: Ten patients receiving stavudine, lamivudine and lopinavir/ritonavir (Kaletra(R)) for over 6 years were switched from stavudine to tenofovir for 48 weeks. Subcutaneous fat tissue biopsies, fasting metabolic tests, HIV RNA, CD4 cell count and whole body dual energy X-ray absorptiometry (DEXA) scans were obtained at study entry and week 48. Mitochondrial DNA (mtDNA) copies/cell and mitochondrial morphology were assessed in adipose tissue biopsies, mtDNA 8-oxo-deoxyguanine in peripheral blood mononuclear cells, and glutathione (GSH) and F2-isoprostane in plasma. RESULTS: There was no change in limb fat mass by DEXA; however, trunk fat mass increased by 18.9% (P = 0.01). Fasting total cholesterol decreased by 33 mg/dL (P = 0.005) and serum glucose decreased by 4 mg/dL (P = 0.039). mtDNA copies/cell increased from 386 to 1537 (P < 0.001). Transmission electron microscopy showed that mitochondrial cristae were lacking or poorly defined at study entry, whereas mitochondrial inner structures were more well defined and outer membranes were intact at 48 weeks. Oxidative damage decreased in 8/10 patients, GSH increased and F2-isoprostane decreased. CONCLUSIONS: The results from this study demonstrate that systemic and peripheral fat mitochondria improve in patients switched to tenofovir following long-term exposure to stavudine, while continuing protease inhibitor therapy.

Subjective clinical lipoatrophy assessment correlates with DEXA-measured limb fat.

OBJECTIVES: Although physician- and patient-rated diagnoses of lipoatrophy are currently used as a basis for inclusion into clinical trials, few studies have compared physician- or patient-rated lipoatrophy severity with objective measures. We aim to assess the validity of physician- and patient-rated diagnoses of lipoatrophy by evaluating the correlation between clinical assessments of lipoatrophy and objective fat indices. METHODS: This cross-sectional study evaluated the association between clinical lipoatrophy scores and DEXA-measured limb fat (n = 154) and subcutaneous fat mitochondrial DNA (mtDNA) levels (n = 80) in HIV+ individuals. RESULTS: There was a significant negative correlation between DEXA-measured limb fat and lipoatrophy scores generated by either the patients (r = -0.27, p = .008) or the physician (r = -0.48, p < .0001). Also, a significant positive correlation was found between the patient-generated lipoatrophy score and the physician score (r = 0.68, p < .0001). However, there was no correlation between fat mtDNA levels and DEXA-measured limb fat (r = -0.09, p = .42) or between physician- or patient-generated lipoatrophy scores (r = -0.09, p = .43, and r = 0.04, p = .71, respectively). CONCLUSION: These results suggest that physician- and patient-rated lipoatrophy scores may be useful surrogates for more expensive measures of lipoatrophy, which could be reserved for research studies.

Relationships Between Adipose Mitochondrial Function, Serum Adiponectin, and Insulin Resistance in Persons With HIV After 96 Weeks of Antiretroviral Therapy.

OBJECTIVE: Some antiretroviral therapy (ART) and HIV itself confer metabolic risk, perhaps through altered mitochondrial function and adipokines. In AIDS Clinical Trials Group study A5224s, adipose mitochondrial DNA (mtDNA) levels decreased on ART, and electron transport chain complex I (CI) and complex IV (CIV) activity decreased. Another study found decreased serum adiponectin on ART with mtDNA mutation m.10398A>G. We hypothesized that decreased adipose tissue mitochondrial function would be associated with lower adiponectin and insulin sensitivity on ART, and m.10398G would influence these changes. DESIGN: Retrospective analysis of an ART-naive substudy population from A5224s. METHODS: Analyses included adipose mtDNA levels, CI and CIV activity by immunoassay, visceral adipose tissue by computed tomography, and fasting serum glucose at week 0 and week 96 of ART. Fasting insulin and adiponectin were measured from cryopreserved serum using multiplex bead array. Homeostasis model assessment-2 (HOMA2)-IR and HOMA2-%B estimated insulin resistance and ß-cell function, respectively. The m.10398A>G mtDNA variant was available from existing genetic data. RESULTS: Thirty-seven participants had adipose biopsies at week 0 and week 96. Percent decreases in CIV activity and adiponectin were correlated (Spearman rho 0.41; P = 0.01); this association persisted after controlling for age, sex, body mass index, or visceral adipose tissue in single-covariate regression. HOMA2-IR correlated with decreased CIV (-0.44; P = 0.01) and CI (-0.34; P = 0.05) activity. Among 12 non-Hispanic white persons, m.10398G was associated with decreased adiponectin (P = 0.04). CONCLUSIONS: Decreased adipose mitochondrial activity correlated with changes in adiponectin and glucose homeostasis on ART. Previous findings that a mtDNA mutation modulates adiponectin levels in persons with HIV were replicated.

Mitochondrial RNA and DNA alterations in HIV lipoatrophy are linked to antiretroviral therapy and not to HIV infection.

BACKGROUND: The aim of this study was to assess the effect of antiretroviral therapy (ART) versus HIV on mitochondria in fat. METHODS: Subcutaneous fat was collected from 45 HIV-infected patients on ART with lipoatrophy, 11 HIV-infected ART-naive patients and nine healthy controls. Three mitochondrial transcripts: NADH dehydrogenase subunit 1 (ND1), cytochrome B (CYTB) and NADH dehydrogenase subunit 6 (ND6) genes were quantitated using TaqMan probes and normalized to nuclear-encoded ribosomal L13. RESULTS: ND1/L13 and CYTB/L13 were lower in HIV-positive patients on ART with lipoatrophy versus ART-naive patients (3.4 versus 7.2 [P=0.017] and 2.5 versus 4.6 [P=0.006], respectively). No difference was found between ART-naive patients and controls (P>0.70). ND6/L13 was similar between all groups. Dual-energy X-ray absorptiometry-measured limb fat and mitochondrial DNA in fat were also lower in HIV-positive patients on ART with lipoatrophy versus HIV-infected, ART-naive patients (4,382 versus 7,662 g [P=0.02] and 726 versus 1,372 copies/cell [P=0.03], respectively), but no difference was found between ART-naive and controls. In a multiple regression analysis, limb fat correlated with all three mitochrondrial RNA, whereas mitochondrial DNA did not correlate with mitochondrial RNA or limb fat. CONCLUSIONS: In contrast to ART-naive patients, HIV-positive patients on ART with lipoatrophy had significant depletion in mitochondrial DNA in fat and mitochondrial RNAs. This suggests that mitochondrial toxicity in lipoatrophy could be driven by ART and not by HIV itself. In addition, mitochondrial RNA abnormalities, and not mitochondrial DNA depletion, could be a key driving force behind lipoatrophy.

An essential role of alternative splicing of c-myc suppressor FUSE-binding protein-interacting repressor in carcinogenesis.

Elevated expression of c-myc has been detected in a broad range of human cancers, indicating a key role for this oncogene in tumor development. Recently, an interaction between FUSE-binding protein-interacting repressor (FIR) and TFIIH/p89/XPB helicase was found to repress c-myc transcription and might be important for suppressing tumor formation. In this study, we showed that enforced expression of FIR induced apoptosis. Deletion of the NH(2)-terminal repression domain of FIR rescued the cells from apoptosis as did coexpression of c-Myc with FIR; thus, repression of Myc mediates FIR-driven apoptosis. Surprisingly, a splicing variant of FIR unable to repress c-myc or to drive apoptosis was frequently discovered in human primary colorectal cancers but not in the adjacent normal tissues. Coexpression of this splicing variant with repressor-competent FIR, either in HeLa cells or in the colon cancer cell line SW480, not only abrogated c-Myc suppression but also inhibited apoptosis. These results strongly suggest the expression of this splicing variant promotes tumor development by disabling FIR repression and sustaining high levels of c-Myc and opposing apoptosis in colorectal cancer.

Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients.

Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51years; 81% with HIV RNA ≤50copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets.

Mitochondrial DNA levels of peripheral blood mononuclear cells and subcutaneous adipose tissue from thigh, fat and abdomen of HIV-1 seropositive and negative individuals.

Mitochondrial dysfunction has been demonstrated in subcutaneous adipose tissue from lipoatrophic HIV-1-infected patients treated with nucleoside reverse transcriptase inhibitors (NRTIs). To further assess mitochondrial toxicity, mitochondrial DNA (mtDNA) copies/cell were measured in subcutaneous fat from various sites. Peripheral adipose tissues were obtained from the abdominal wall near the umbilicus, anterior lateral thigh, and dorsal cervical region of the neck of individuals from four cohorts: 1) seven lipoatrophic HIV-1-infected patients receiving a regimen with nucleoside reverse transcriptase inhibitors (NRTIs) as part of highly active antiretroviral therapy (HAART) for > 6 months; 2) seven non-lipoatrophic HIV-1-infected patients receiving NRTIs-containing HAART; 3) five HIV-1-infected patients on antiretroviral therapy < 2 weeks (naive); 4) and five HIV-1-negative participants. Along with the adipose tissue samples, peripheral blood mononuclear cells (PBMC) were also obtained from each patient for mtDNA depletion examination. Total DNA was isolated and mtDNA copies/cell quantitated by competitive and real-time PCR. MtDNA copies/cell in abdomen, thigh, and neck fat were depleted in lipoatrophic HIV-1 seropositive compared to the seropositive naive and seronegative cohorts. MtDNA copies/cell in thigh and neck fat were also decreased in non-lipoatrophic subjects exposed to NRTIs compared with NRTI-naive and HIV seronegative controls. PBMC values did not differ among the cohorts and there was no correlation with lipoatrophy state or HIV-1 serostatus. Additionally, differences in mtDNA copies/cell were observed in the fat depots from seronegative subjects. Thigh fat mtDNA levels were 45-55% lower than abdomen and neck. These studies help demonstrate that mtDNA levels can vary in different subcutaneous adipose depots suggesting possible metabolic differences.

The role of HIV and monocytes/macrophages in adipose tissue biology.

OBJECTIVE: To assess the role of HIV and monocytes/macrophages in adipose tissue dysregulation. METHODS: Cross-sectional study in 5 groups: HIV seronegative, HIV+ antiretroviral therapy (ART)-naive, HIV+ nonlipoatrophic on zidovudine- and/or stavudine-containing ART, HIV+ lipoatrophic on similar ART, and HIV+ on abacavir- or tenofovir-containing ART. HIV DNA in circulating monocyte subsets was quantitated by real-time polymerase chain reaction. Biopsied subcutaneous fat was examined for macrophage content by CD68 staining. Isolated adipocytes and macrophages were cultured and the supernatant assayed for secretory products by Luminex multiplex cytokine technology. RESULTS: Sixty-nine subjects were enrolled. Lipoatrophic subjects had higher median HIV DNA levels (270.5 copies/10 cells) in circulating peripheral CD14CD16 co-expressing monocyte subsets compared with subjects who were ART-naive (25.0 copies), nonlipoatrophic (15.0 copies), or on abacavir/tenofovir (57.5 copies), P < 0.01. Group differences in adipocytes and adipose macrophage content were marginal. Although adipocyte secretory products were similar, HIV-infected subjects had higher adipose macrophage-derived interleukin (IL)-12p40, IL-6, IL-8, and monocyte inflammatory protein 1 alpha and lower eotaxin and interferon gamma levels than HIV seronegative subjects (P < 0.05). Within HIV-infected subjects, adipose macrophage secretory products were comparable between subjects naive with ART versus those on ART. CONCLUSIONS: Circulating HIV-infected and proinflammatory CD14CD16 monocyte subsets contribute to the pathogenesis of HIV-associated lipoatrophy. Among HIV-infected individuals, macrophages, rather than adipocytes, are the primary source of low-grade inflammation in subcutaneous adipose tissue. HIV infection modifies these macrophages to a more proinflammatory phenotype, and these changes are not substantially mitigated by the use of ART.

Epidermal nerve fiber density, oxidative stress, and mitochondrial haplogroups in HIV-infected Thais initiating therapy.

OBJECTIVE: We explored associations between mitochondrial DNA (mtDNA) haplogroups, epidermal nerve fiber density (ENFD), and HIV-associated sensory neuropathy (HIV-SN) in a randomized trial of Thai patients initiating antiretroviral therapy (ART). DESIGN: The South East Asia Research Collaboration with Hawaii 003 study evaluated toxicity of nucleoside reverse transcriptase inhibitors (stavudine vs. zidovudine vs. tenofovir). We present secondary analyses of mtDNA haplogroups and ENFD changes. METHODS: ENFD, peripheral blood mononuclear cell mitochondrial complex I and IV, and 8-oxo-deoxyguanine (8-oxo-dG) were quantified. Peripheral blood mononuclear cell mtDNA sequences were obtained for haplogroup determination. Multivariate regression of ENFD change was performed. RESULTS: Paired ENFD was available from 118 patients. Median age, CD4 cell count, and height at entry were 34 years, 172 cells/µl, and 162 cm, respectively. Major haplogroups included M (42%), F (21%), and B (16%). Baseline ENFD, CD4 cell count, randomized ART, and biomarkers did not differ by haplogroup. Haplogroup B patients were older (P=0.02) at baseline, and had an increase in median ENFD (+1.5 vs. -2.9 fibers/mm; P=0.03) and 8-oxo-dG break frequency (+0.05 vs. 0.00; P=0.05) compared to other haplogroups. In a multivariate model, haplogroup B was associated with increased ENFD (ß=3.5, P=0.009) at week 24, whereas older age (P=0.02), higher baseline CD4 cell count, (P=0.03), higher complex I level (P=0.03), and higher ENFD (P<0.001) at baseline were all associated with decreased ENFD. Three of the six HIV-SN cases were haplogroup B (P=0.05). CONCLUSIONS: Thai persons belonging to mtDNA haplogroup B had increased ENFD and 8-oxo-dG on ART, and were more likely to develop HIV-SN. These results suggest that mtDNA variation influences early oxidative damage and ENFD changes.

Mitochondrial function, inflammation, fat and bone in HIV lipoatrophy: randomized study of uridine supplementation or switch to tenofovir.

BACKGROUND: Lipoatrophy modestly improves when the thymidine analogue nucleoside reverse transcriptase inhibitor (tNRTI) is removed. In vitro, uridine (NucleomaxX(®); Pharma Nord, Vojens, Denmark) reversed tNRTI mitochondrial toxicity. METHODS: All patients had lipoatrophy on a tNRTI-containing regimen with HIV RNA<400 copies/ml. A randomized 48-week study switched patients from tNRTI to tenofovir (TDF) or added uridine (continuing tNRTI). End points were changes in limb fat (DEXA), subcutaneous abdominal fat mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA), inflammation markers (soluble tumour necrosis factor receptors, high-sensitivity C reactive protein [hsCRP], interleukin-6 [IL-6], soluble vascular cell adhesion molecule 1), bone mineral density (BMD) of the hip and spine, HIV-1 RNA, CD4(+) T-cells and fasting metabolic parameters. RESULTS: Fifty patients were enrolled (n=24 TDF switch; n=26 uridine); median age 48 years; 54% white; 86% male; limb fat 4,494 g. Baseline characteristics were similar between groups. In the NucleomaxX(®) arm, mtRNA increased (all P<0.001), hsCRP and IL-6 increased (both P=0.02), whereas fat mtDNA decreased without changes in limb fat. In the TDF-switch arm, fat mtDNA and inflammation markers did not change; however, significant increases in mtRNAs (P<0.001), limb fat (409 g; IQR -59-1,155) and CD4(+) T-cell count (P=0.03), and decreases in total and hip BMD (median -3.3%; IQR -5.1-0; P=0.005) were observed. Between-group changes were significant for fat mtDNA, hsCRP, IL-6, limb fat and hip BMD. No correlation was found between changes in limb fat and those of fat mtRNA, inflammation markers or protease inhibitor duration. CONCLUSIONS: In HIV lipoatrophy, NucleomaxX(®) improved mtRNA, but worsened inflammation markers and fat mtDNA without changes in limb fat. Switching from a tNRTI to TDF for 48 weeks increased limb fat and fat mtRNA. Large decreases in total and hip BMD were seen after TDF switch.ClinicalTrials.gov identifier: NCT00119379.

Short communication: transplacental nucleoside analogue exposure and mitochondrial parameters in HIV-uninfected children.

Transplacental nucleoside analogue exposure can affect infant mitochondrial DNA (mtDNA). We evaluated mitochondria in peripheral blood mononuclear cells of children with and without clinical signs of mitochondrial dysfunction (MD) and antiretroviral (ARV) exposure. We previously identified 20 children with signs of MD (cases) among 1037 HIV-uninfected children born to HIV-infected women. We measured mtDNA copies/cell and oxidative phosphorylation (OXPHOS) NADH dehydrogenase (complex I) and cytochrome c oxidase (complex IV) protein levels and enzyme activities, determined mtDNA haplogroups and deletions in 18 of 20 cases with stored samples and in sex- and age-matched HIV-uninfected children, both ARV exposed and unexposed, (1) within 18 months of birth and (2) at the time of presentation of signs of MD. In specimens drawn within 18 months of birth, mtDNA levels were higher and OXPHOS protein levels and enzyme activities lower in cases than controls. In contrast, at the time of MD presentation, cases and ARV-exposed controls had lower mtDNA levels, 214 and 215 copies/cell, respectively, than ARV-unexposed controls, 254 copies/cell. OXPHOS protein levels and enzyme activities were lower in cases than exposed controls, and higher in cases than unexposed controls, except for complex IV activity, which was higher in cases. Haplotype H was less frequent among cases (6%) than controls (31%). No deletions were found. The long-term significance of these small but potentially important alterations should continue to be studied as these children enter adolescence and adulthood.

Mitochondrial oxidative phosphorylation protein levels in peripheral blood mononuclear cells correlate with levels in subcutaneous adipose tissue within samples differing by HIV and lipoatrophy status.

Depletion of mitochondrial DNA (mtDNA) and mtDNA-encoded respiratory chain proteins in subcutaneous (SC) fat from patients with HIV lipoatrophy have clearly demonstrated the role of mitochondrial dysfunction in this syndrome. Research in HIV lipoatrophy, however, has been severely hampered by the lack of a suitable surrogate marker in blood or other easily obtained clinical specimens as fat biopsies are invasive and mtDNA levels in peripheral blood mononuclear cells (PBMC) do not consistently correlate with the disease process. We used a simple, rapid, quantitative 2-site dipstick immunoassay to measure OXPHOS enzymes Complex I (CI) and Complex IV (CIV), and rtPCR to measure mtDNA in 26 matched SC fat and PBMC specimens previously banked from individuals on potent antiretroviral (ARV) therapy with HIV lipoatrophy, on similar ARV therapy without lipoatrophy, and in HIV seronegative controls. Significant correlations were found between the respective PBMC and fat levels for both CI (r = 0.442, p = 0.024) and for CIV (r = 0.507, p = 0.008). Both CI and CIV protein levels were also significantly reduced in both PBMCs and fat in lipoatrophic subjects compared to HIV seronegative controls (p < or = 0.05), while a comparative reduction in mtDNA levels in lipoatrophic subjects was observed only in fat. We conclude that CI and CIV levels in PBMCs correlate to their respective levels in fat and may have utility as surrogate markers of mitochondrial dysfunction in lipoatrophy.