Mitochondrial Transfer to Host Cells from Ex Vivo Expanded Donor Hematopoietic Stem Cells.

Mitochondrial dysfunction is observed in various conditions, from metabolic syndromes to mitochondrial diseases. Moreover, mitochondrial DNA (mtDNA) transfer is an emerging mechanism that enables the restoration of mitochondrial function in damaged cells. Hence, developing a technology that facilitates the transfer of mtDNA can be a promising strategy for the treatment of these conditions. Here, we utilized an ex vivo culture of mouse hematopoietic stem cells (HSCs) and succeeded in expanding the HSCs efficiently. Upon transplantation, sufficient donor HSC engraftment was attained in-host. To assess the mitochondrial transfer via donor HSCs, we used mitochondrial-nuclear exchange (MNX) mice with nuclei from C57BL/6J and mitochondria from the C3H/HeN strain. Cells from MNX mice have C57BL/6J immunophenotype and C3H/HeN mtDNA, which is known to confer a higher stress resistance to mitochondria. Ex vivo expanded MNX HSCs were transplanted into irradiated C57BL/6J mice and the analyses were performed at six weeks post transplantation. We observed high engraftment of the donor cells in the bone marrow. We also found that HSCs from the MNX mice could transfer mtDNA to the host cells. This work highlights the utility of ex vivo expanded HSC to achieve the mitochondrial transfer from donor to host in the transplant setting.

Role of the ST6GAL1 sialyltransferase in regulating ovarian cancer cell metabolism.

The ST6GAL1 sialyltransferase, which adds α2-6-linked sialic acids to N-glycosylated proteins, is upregulated in many malignancies including ovarian cancer. Through its activity in sialylating select surface receptors, ST6GAL1 modulates intracellular signaling to regulate tumor cell phenotype. ST6GAL1 has previously been shown to act as a survival factor that protects cancer cells from cytotoxic stressors such as hypoxia. In the present study, we investigated a role for ST6GAL1 in tumor cell metabolism. ST6GAL1 was overexpressed (OE) in OV4 ovarian cancer cells, which have low endogenous ST6GAL1, or knocked-down (KD) in ID8 ovarian cancer cells, which have high endogenous ST6GAL1. OV4 and ID8 cells with modulated ST6GAL1 expression were grown under normoxic or hypoxic conditions, and metabolism was assessed using Seahorse technology. Results showed that cells with high ST6GAL1 expression maintained a higher rate of oxidative metabolism than control cells following treatment with the hypoxia mimetic, desferrioxamine (DFO). This enrichment was not due to an increase in mitochondrial number. Glycolytic metabolism was also increased in OV4 and ID8 cells with high ST6GAL1 expression, and these cells displayed greater activity of the glycolytic enzymes, hexokinase and phosphofructokinase. Metabolism maps were generated from the combined Seahorse data, which suggested that ST6GAL1 functions to enhance the overall metabolism of tumor cells. Finally, we determined that OV4 and ID8 cells with high ST6GAL1 expression were more invasive under conditions of hypoxia. Collectively, these results highlight the importance of sialylation in regulating the metabolic phenotype of ovarian cancer cells.

Mitochondrial DNA Variations Modulate Alveolar Epithelial Mitochondrial Function and Oxidative Stress in Newborn Mice Exposed to Hyperoxia.

Oxidative stress is an important contributor to bronchopulmonary dysplasia (BPD), a form of chronic lung disease that is the most common morbidity in very preterm infants. Mitochondrial functional differences due to inherited and acquired mutations influence the pathogenesis of disorders in which oxidative stress plays a critical role. We previously showed using mitochondrial-nuclear exchange (MNX) mice that mitochondrial DNA (mtDNA) variations modulate hyperoxia-induced lung injury severity in a model of BPD. In this study, we studied the effects of mtDNA variations on mitochondrial function including mitophagy in alveolar epithelial cells (AT2) from MNX mice. We also investigated oxidant and inflammatory stress as well as transcriptomic profiles in lung tissue in mice and expression of proteins such as PINK1, Parkin and SIRT3 in infants with BPD. Our results indicate that AT2 from mice with C57 mtDNA had decreased mitochondrial bioenergetic function and inner membrane potential, increased mitochondrial membrane permeability and were exposed to higher levels of oxidant stress during hyperoxia compared to AT2 from mice with C3H mtDNA. Lungs from hyperoxia-exposed mice with C57 mtDNA also had higher levels of pro-inflammatory cytokines compared to lungs from mice with C3H mtDNA. We also noted changes in KEGG pathways related to inflammation, PPAR and glutamatergic signaling, and mitophagy in mice with certain mito-nuclear combinations but not others. Mitophagy was decreased by hyperoxia in all mice strains, but to a greater degree in AT2 and neonatal mice lung fibroblasts from hyperoxia-exposed mice with C57 mtDNA compared to C3H mtDNA. Finally, mtDNA haplogroups vary with ethnicity, and Black infants with BPD had lower levels of PINK1, Parkin and SIRT3 expression in HUVEC at birth and tracheal aspirates at 28 days of life when compared to White infants with BPD. These results indicate that predisposition to neonatal lung injury may be modulated by variations in mtDNA and mito-nuclear interactions need to be investigated to discover novel pathogenic mechanisms for BPD.

Mitochondrial haplotype modulates genome expression and mitochondrial structure/function in cardiomyocytes following volume overload.

Mitochondrial DNA (mtDNA) haplotype regulates mitochondrial structure/function and reactive oxygen species in aortocaval fistula (ACF) in mice. Here, we unravel the mitochondrial haplotype effects on cardiomyocyte mitochondrial ultrastructure and transcriptome response to ACF in vivo. Phenotypic responses and quantitative transmission electron microscopy (TEM) and RNA sequence at 3 days were determined after sham surgery or ACF in vivo in cardiomyocytes from wild-type (WT) C57BL/6J (C57n:C57mt) and C3H/HeN (C3Hn:C3Hmt) and mitochondrial nuclear exchange mice (C57n:C3Hmt or C3Hn:C57mt). Quantitative TEM of cardiomyocyte mitochondria C3HWT hearts have more electron-dense compact mitochondrial cristae compared with C57WT. In response to ACF, mitochondrial area and cristae integrity are normal in C3HWT; however, there is mitochondrial swelling, cristae lysis, and disorganization in both C57WT and MNX hearts. Tissue analysis shows that C3HWT hearts have increased autophagy, antioxidant, and glucose fatty acid oxidation-related genes compared with C57WT. Comparative transcriptomic analysis of cardiomyocytes from ACF was dependent upon mtDNA haplotype. C57mtDNA haplotype was associated with increased inflammatory/protein synthesis pathways and downregulation of bioenergetic pathways, whereas C3HmtDNA showed upregulation of autophagy genes. In conclusion, ACF in vivo shows a protective response of C3Hmt haplotype that is in large part driven by mitochondrial nuclear genome interaction.NEW & NOTEWORTHY The results of this study support the effects of mtDNA haplotype on nuclear gene expression in cardiomyocytes. Currently, there is no acceptable therapy for volume overload due to mitral regurgitation. The findings of this study could suggest that mtDNA haplotype activates different pathways after ACF warrants further investigations on human population of heart disease from different ancestry backgrounds.

Mesenchymal stem cell bioenergetics and apoptosis are associated with risk for bronchopulmonary dysplasia in extremely low birth weight infants.

Oxidant stress contributes significantly to the pathogenesis of bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants. Mitochondrial function regulates oxidant stress responses as well as pluripotency and regenerative ability of mesenchymal stem cells (MSCs) which are critical mediators of lung development. This study was conducted to test whether differences in endogenous MSC mitochondrial bioenergetics, proliferation and survival are associated with BPD risk in ELBW infants. Umbilical cord-derived MSCs of ELBW infants who later died or developed moderate/severe BPD had lower oxygen consumption and aconitase activity but higher extracellular acidification-indicative of mitochondrial dysfunction and increased oxidant stress-when compared to MSCs from infants who survived with no/mild BPD. Hyperoxia-exposed MSCs from infants who died or developed moderate/severe BPD also had lower PINK1 expression but higher TOM20 expression and numbers of mitochondria/cell, indicating that these cells had decreased mitophagy. Finally, these MSCs were also noted to proliferate at lower rates but undergo more apoptosis in cell cultures when compared to MSCs from infants who survived with no/mild BPD. These results indicate that mitochondrial bioenergetic dysfunction and mitophagy deficit induced by oxidant stress may lead to depletion of the endogenous MSC pool and subsequent disruption of lung development in ELBW infants at increased risk for BPD.

Hedgehog Signaling Regulates Metabolism and Polarization of Mammary Tumor-Associated Macrophages.

Elevated infiltration of immunosuppressive alternatively polarized (M2) macrophages is associated with poor prognosis in patients with cancer. The tumor microenvironment remarkably orchestrates molecular mechanisms that program these macrophages. Here we identify a novel role for oncogenic Hedgehog (Hh) signaling in programming signature metabolic circuitries that regulate alternative polarization of tumor-associated macrophages. Two immunocompetent orthotopic mouse models of mammary tumors were used to test the effect of inhibiting Hh signaling on tumor-associated macrophages. Treatment with the pharmacologic Hh inhibitor vismodegib induced a significant shift in the profile of tumor-infiltrating macrophages. Mass spectrometry-based metabolomic analysis showed Hh inhibition induced significant alterations in metabolic processes, including metabolic sensing, mitochondrial adaptations, and lipid metabolism. In particular, inhibition of Hh in M2 macrophages reduced flux through the UDP-GlcNAc biosynthesis pathway. Consequently, O-GlcNAc-modification of STAT6 decreased, mitigating the immune-suppressive program of M2 macrophages, and the metabolically demanding M2 macrophages shifted their metabolism and bioenergetics from fatty acid oxidation to glycolysis. M2 macrophages enriched from vismodegib-treated mammary tumors showed characteristically decreased O-GlcNAcylation and altered mitochondrial dynamics. These Hh-inhibited macrophages are reminiscent of inflammatory (M1) macrophages, phenotypically characterized by fragmented mitochondria. This is the first report highlighting the relevance of Hh signaling in controlling a complex metabolic network in immune cells. These data describe a novel immunometabolic function of Hh signaling that can be clinically exploited. SIGNIFICANCE: These findings illustrate that Hh activity regulates a metabolic and bioenergetic regulatory program in tumor-associated macrophages that promotes their immune-suppressive polarization.

Vascular Endothelial Mitochondrial Function Predicts Death or Pulmonary Outcomes in Preterm Infants.

RATIONALE: Vascular endothelial mitochondrial dysfunction contributes to the pathogenesis of several oxidant stress-associated disorders. Oxidant stress is a major contributor to the pathogenesis of bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity that often leads to sequelae in adult survivors. OBJECTIVES: This study was conducted to identify whether differences in mitochondrial bioenergetic function and oxidant generation in human umbilical vein endothelial cells (HUVECs) obtained from extremely preterm infants were associated with risk for BPD or death before 36 weeks postmenstrual age. METHODS: HUVEC oxygen consumption and superoxide and hydrogen peroxide generation were measured in 69 infants. MEASUREMENTS AND MAIN RESULTS: Compared with HUVECs from infants who survived without BPD, HUVECs obtained from infants who developed BPD or died had a lower maximal oxygen consumption rate (mean ± SEM, 107 ± 8 vs. 235 ± 22 pmol/min/30,000 cells; P < 0.001), produced more superoxide after exposure to hyperoxia (mean ± SEM, 89,807 ± 16,616 vs. 162,706 ± 25,321 MitoSOX Red fluorescence units; P < 0.05), and released more hydrogen peroxide into the supernatant after hyperoxia exposure (mean ± SEM, 1,879 ± 278 vs. 842 ± 119 resorufin arbitrary fluorescence units; P < 0.001). CONCLUSIONS: Our results indicating that endothelial cells of premature infants who later develop BPD or die have impaired mitochondrial bioenergetic capacity and produce more oxidants at birth suggest that the vascular endothelial mitochondrial dysfunction seen at birth in these infants persists through their postnatal life and contributes to adverse pulmonary outcomes and increased early mortality.

Mitophagy and mitochondrial biogenesis in atrial tissue of patients undergoing heart surgery with cardiopulmonary bypass.

Mitophagy occurs during ischemia/reperfusion (I/R) and limits oxidative stress and injury. Mitochondrial turnover was assessed in patients undergoing cardiac surgery involving cardiopulmonary bypass (CPB). Paired biopsies of right atrial appendage before initiation and after weaning from CPB were processed for protein analysis, mitochondrial DNA/nuclear DNA ratio (mtDNA:nucDNA ratio), mtDNA damage, mRNA, and polysome profiling. Mitophagy in the post-CPB samples was evidenced by decreased levels of mitophagy adapters NDP52 and optineurin in whole tissue lysate, decreased Opa1 long form, and translocation of Parkin to the mitochondrial fraction. PCR analysis of mtDNA comparing amplification of short vs. long segments of mtDNA revealed increased damage following cardiac surgery. Surprisingly, a marked increase in several mitochondria-specific protein markers and mtDNA:nucDNA ratio was observed, consistent with increased mitochondrial biogenesis. mRNA analysis suggested that mitochondrial biogenesis was traniscription independent and likely driven by increased translation of existing mRNAs. These findings demonstrate in humans that both mitophagy and mitochondrial biogenesis occur during cardiac surgery involving CPB. We suggest that mitophagy is balanced by mitochondrial biogenesis during I/R stress experienced during surgery. Mitigating mtDNA damage and elucidating mechanisms regulating mitochondrial turnover will lead to interventions to improve outcome after I/R in the setting of heart disease.

Mitochondrial Genetics Regulate Breast Cancer Tumorigenicity and Metastatic Potential.

Current paradigms of carcinogenic risk suggest that genetic, hormonal, and environmental factors influence an individual's predilection for developing metastatic breast cancer. Investigations of tumor latency and metastasis in mice have illustrated differences between inbred strains, but the possibility that mitochondrial genetic inheritance may contribute to such differences in vivo has not been directly tested. In this study, we tested this hypothesis in mitochondrial-nuclear exchange mice we generated, where cohorts shared identical nuclear backgrounds but different mtDNA genomes on the background of the PyMT transgenic mouse model of spontaneous mammary carcinoma. In this setting, we found that primary tumor latency and metastasis segregated with mtDNA, suggesting that mtDNA influences disease progression to a far greater extent than previously appreciated. Our findings prompt further investigation into metabolic differences controlled by mitochondrial process as a basis for understanding tumor development and metastasis in individual subjects. Importantly, differences in mitochondrial DNA are sufficient to fundamentally alter disease course in the PyMT mouse mammary tumor model, suggesting that functional metabolic differences direct early tumor growth and metastatic efficiency.

Bioenergetic programming of macrophages by the apolipoprotein A-I mimetic peptide 4F.

The apoA-I (apolipoprotein A-I) mimetic peptide 4F favours the differentiation of human monocytes to an alternatively activated M2 phenotype. The goal of the present study was to test whether the 4F-mediated differentiation of MDMs (monocyte-derived macrophages) requires the induction of an oxidative metabolic programme. 4F treatment induced several genes in MDMs that play an important role in lipid metabolism, including PPARγ (peroxisome-proliferator-activated receptor γ) and CD36. Addition of 4F was associated with a significant increase in FA (fatty acid) uptake and oxidation compared with vehicle treatment. Mitochondrial respiration was assessed by measurement of the OCR (oxygen-consumption rate). 4F increased basal and ATP-linked OCR as well as maximal uncoupled mitochondrial respiration. These changes were associated with a significant increase in ΔΨm (mitochondrial membrane potential). The increase in metabolic activity in 4F-treated MDMs was attenuated by etomoxir, an inhibitor of mitochondrial FA uptake. Finally, addition of the PPARγ antagonist T0070907 to 4F-treated MDMs reduced the expression of CD163 and CD36, cell-surface markers for M2 macrophages, and reduced basal and ATP-linked OCR. These results support our hypothesis that the 4F-mediated differentiation of MDMs to an anti-inflammatory phenotype is due, in part, to an increase in FA uptake and mitochondrial oxidative metabolism.

A method for assessing mitochondrial bioenergetics in whole white adipose tissues.

Obesity is a primary risk factor for numerous metabolic diseases including metabolic syndrome, type II diabetes (T2DM), cardiovascular disease and cancer. Although classically viewed as a storage organ, the field of white adipose tissue biology is expanding to include the consideration of the tissue as an endocrine organ and major contributor to overall metabolism. Given its role in energy production, the mitochondrion has long been a focus of study in metabolic dysfunction and a link between the organelle and white adipose tissue function is likely. Herein, we present a novel method for assessing mitochondrial bioenergetics from whole white adipose tissue. This method requires minimal manipulation of tissue, and eliminates the need for cell isolation and culture. Additionally, this method overcomes some of the limitations to working with transformed and/or isolated primary cells and allows for results to be obtained more expediently. In addition to the novel method, we present a comprehensive statistical analysis of bioenergetic data as well as guidelines for outlier analysis.

The Bioenergetic Health Index: a new concept in mitochondrial translational research.

Bioenergetics has become central to our understanding of pathological mechanisms, the development of new therapeutic strategies and as a biomarker for disease progression in neurodegeneration, diabetes, cancer and cardiovascular disease. A key concept is that the mitochondrion can act as the 'canary in the coal mine' by serving as an early warning of bioenergetic crisis in patient populations. We propose that new clinical tests to monitor changes in bioenergetics in patient populations are needed to take advantage of the early and sensitive ability of bioenergetics to determine severity and progression in complex and multifactorial diseases. With the recent development of high-throughput assays to measure cellular energetic function in the small number of cells that can be isolated from human blood these clinical tests are now feasible. We have shown that the sequential addition of well-characterized inhibitors of oxidative phosphorylation allows a bioenergetic profile to be measured in cells isolated from normal or pathological samples. From these data we propose that a single value-the Bioenergetic Health Index (BHI)-can be calculated to represent the patient's composite mitochondrial profile for a selected cell type. In the present Hypothesis paper, we discuss how BHI could serve as a dynamic index of bioenergetic health and how it can be measured in platelets and leucocytes. We propose that, ultimately, BHI has the potential to be a new biomarker for assessing patient health with both prognostic and diagnostic value.

Metastasis suppressor KISS1 seems to reverse the Warburg effect by enhancing mitochondrial biogenesis.

Cancer cells tend to utilize aerobic glycolysis even under normoxic conditions, commonly called the "Warburg effect." Aerobic glycolysis often directly correlates with malignancy, but its purpose, if any, in metastasis remains unclear. When wild-type KISS1 metastasis suppressor is expressed, aerobic glycolysis decreases and oxidative phosphorylation predominates. However, when KISS1 is missing the secretion signal peptide (ΔSS), invasion and metastasis are no longer suppressed and cells continue to metabolize using aerobic glycolysis. KISS1-expressing cells have 30% to 50% more mitochondrial mass than ΔSS-expressing cells, which are accompanied by correspondingly increased mitochondrial gene expression and higher expression of PGC1α, a master coactivator that regulates mitochondrial mass and metabolism. PGC1α-mediated downstream pathways (i.e., fatty acid synthesis and ß-oxidation) are differentially regulated by KISS1, apparently reliant upon direct KISS1 interaction with NRF1, a major transcription factor involved in mitochondrial biogenesis. Since the downstream effects could be reversed using short hairpin RNA to KISS1 or PGC1α, these data appear to directly connect changes in mitochondria mass, cellular glucose metabolism, and metastasis.

Mitochondrial genetics and obesity: evolutionary adaptation and contemporary disease susceptibility.

Obesity is a leading risk factor for a variety of metabolic diseases including cardiovascular disease, diabetes, and cancer. Although in its simplest terms, obesity may be thought of as a consequence of excessive caloric intake and sedentary lifestyle, it is also evident that individual propensity for weight gain can vary. The etiology of individual susceptibility to obesity seems to be complex-involving a combination of environmental-genetic interactions. Herein, we suggest that the mitochondrion plays a major role in influencing individual susceptibility to this disease via mitochondrial-nuclear interaction processes and that environmentally influenced selection events for mitochondrial function that conveyed increased reproductive and survival success during the global establishment of human populations during prehistoric times can influence individual susceptibility to weight gain and obesity.

Developmental exposure to second-hand smoke increases adult atherogenesis and alters mitochondrial DNA copy number and deletions in apoE(-/-) mice.

Cardiovascular disease is a major cause of morbidity and mortality in the United States. While many studies have focused upon the effects of adult second-hand smoke exposure on cardiovascular disease development, disease development occurs over decades and is likely influenced by childhood exposure. The impacts of in utero versus neonatal second-hand smoke exposure on adult atherosclerotic disease development are not known. The objective of the current study was to determine the effects of in utero versus neonatal exposure to a low dose (1 mg/m(3) total suspended particulate) of second-hand smoke on adult atherosclerotic lesion development using the apolipoprotein E null mouse model. Consequently, apolipoprotein E null mice were exposed to either filtered air or second-hand smoke: (i) in utero from gestation days 1-19, or (ii) from birth until 3 weeks of age (neonatal). Subsequently, all animals were exposed to filtered air and sacrificed at 12-14 weeks of age. Oil red-O staining of whole aortas, measures of mitochondrial damage, and oxidative stress were performed. Results show that both in utero and neonatal second-hand smoke exposure significantly increased adult atherogenesis in mice compared to filtered air controls. These changes were associated with changes in aconitase and mitochondrial superoxide dismutase activities consistent with increased oxidative stress in the aorta, changes in mitochondrial DNA copy number and deletion levels. These studies show that in utero or neonatal exposure to second-hand smoke significantly influences adult atherosclerotic lesion development and results in significant alterations to the mitochondrion and its genome that may contribute to atherogenesis.

Beyond retrograde and anterograde signalling: mitochondrial-nuclear interactions as a means for evolutionary adaptation and contemporary disease susceptibility.

Although there is general agreement that most forms of common disease develop as a consequence of a combination of factors, including genetic, environmental and behavioural contributors, the actual mechanistic basis of how these factors initiate or promote diabetes, cancer, neurodegenerative and cardiovascular diseases in some individuals but not in others with seemingly identical risk factor profiles, is not clearly understood. In this respect, consideration of the potential role for mitochondrial genetics, damage and function in influencing common disease susceptibility seems merited, given that the prehistoric challenges were the original factors that moulded cellular function, and these were based upon the mitochondrial-nuclear relationships that were established during evolutionary history. These interactions were probably refined during prehistoric environmental selection events that, at present, are largely absent. Contemporary risk factors such as diet, sedentary lifestyle and increased longevity, which influence our susceptibility to a variety of chronic diseases were not part of the dynamics that defined the processes of mitochondrial-nuclear interaction, and thus cell function. Consequently, the prehistoric challenges that contributed to cell functionality and evolution should be considered when interpreting and designing experimental data and strategies. Although several molecular epidemiological studies have generally supported this notion, studies that probe beyond these associations are required. Such investigation will mark the initial steps for mechanistically addressing the provocative concept that contemporary human disease susceptibility is the result of prehistoric selection events for mitochondrial-nuclear function, which increased the probability for survival and reproductive success during evolution.

Mitochondrial oxidative stress significantly influences atherogenic risk and cytokine-induced oxidant production.

BACKGROUND: Oxidative stress associated with cardiovascular disease (CVD) risk factors contributes to disease development. However, less is known whether specific subcellular components play a role in disease susceptibility. In this regard, it has been previously reported that vascular mitochondrial damage and dysfunction are associated with atherosclerosis. However, no studies have determined whether altered mitochondrial oxidant production directly influences atherogenic susceptibility and response in primary cells to atherogenic factors such as tumor necrosis factor-α (TNF-α). OBJECTIVES: We undertook this study to determine whether increased mitochondrial oxidant production affects atherosclerotic lesion development associated with CVD risk factor exposure and endothelial cell response to TNF-α. METHODS: We assessed atherosclerotic lesion formation, oxidant stress, and mitochondrial DNA damage in male apolipoprotein E (apoE)-null mice with normal and decreased levels of mitochondrial superoxide dismutase-2 (SOD2; apoE(-/-) and apoE(-/-), SOD2(+/-), respectively) exposed to environmental tobacco smoke or filtered air. RESULTS: Atherogenesis, oxidative stress, and mitochondrial damage were significantly higher in apoE(-/-), SOD2(+/-) mice than in apoE(-/-) controls. Furthermore, experiments with small interfering RNA in endothelial cells revealed that decreased SOD2 activity increased TNF-α-mediated cellular oxidant levels compared with controls. CONCLUSIONS: Endogenous mitochondrial oxidative stress is an important CVD risk factor that can modulate atherogenesis and cytokine-induced endothelial cell oxidant generation. Consequently, CVD risk factors that induce mitochondrial damage alter cellular response to endogenous atherogenic factors, increasing disease susceptibility.

Perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in non-human primates.

Epidemiological studies suggest that events occurring during fetal and early childhood development influence disease susceptibility. Similarly, molecular studies in mice have shown that in utero exposure to cardiovascular disease (CVD) risk factors such as environmental tobacco smoke (ETS) increased adult atherogenic susceptibility and mitochondrial damage; however, the molecular effects of similar exposures in primates are not yet known. To determine whether perinatal ETS exposure increased mitochondrial damage, dysfunction and oxidant stress in primates, archived tissues from the non-human primate model Macaca mulatta (M. mulatta) were utilized. M. mulatta were exposed to low levels of ETS (1 mg/m(3) total suspended particulates) from gestation (day 40) to early childhood (1 year), and aortic tissues were assessed for oxidized proteins (protein carbonyls), antioxidant activity (SOD), mitochondrial function (cytochrome oxidase), and mitochondrial damage (mitochondrial DNA damage). Results revealed that perinatal ETS exposure resulted in significantly increased oxidative stress, mitochondrial dysfunction and damage which were accompanied by significantly decreased mitochondrial antioxidant capacity and mitochondrial copy number in vascular tissue. Increased mitochondrial damage was also detected in buffy coat tissues in exposed M. mulatta. These studies suggest that perinatal tobacco smoke exposure increases vascular oxidative stress and mitochondrial damage in primates, potentially increasing adult disease susceptibility.