scholarly journals Increase of mitochondria and mitochondrial DNA in response to oxidative stress in human cells

2000 ◽  
Vol 348 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Hsin-Chen LEE ◽  
Pen-Hui YIN ◽  
Ching-You LU ◽  
Chin-Wen CHI ◽  
Yau-Huei WEI
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Mitochondrial Dna ◽  
Copy Number ◽  
Human Cells ◽  
Dependent Manner ◽  
Mtdna Copy Number ◽  
Human Lung Fibroblast ◽  
Mitochondrial Mass ◽  
Enhanced Production

Mitochondrial respiratory function is impaired in the target tissues of patients with mitochondrial diseases and declines with age in various human tissues. It is generally accepted that respiratory-chain defects result in enhanced production of reactive oxygen species and free radicals in mitochondria. Recently, we have demonstrated that the copy number of mitochondrial DNA (mtDNA) is increased in the lung tissues of elderly human subjects. The mtDNA copy number was suggested to be increased by a feedback mechanism that compensates for defects in mitochondria harbouring mutated mtDNA and a defective respiratory system. However, the detailed mechanism remains unclear. In this study, we treated a human lung fibroblast cell line, MRC-5, with H2O2 at concentrations of 90-360 μM. After the treatment for 24-72 h, we found that cells were arrested at G0 and G1 phases but that mitochondrial mass and mtDNA content were significantly increased in a concentration- and time-dependent manner. Moreover, the oxidative stress induced by buthionine sulphoximine was also found to cause an increase in mitochondrial mass of the treated cells. Increased uptake of a vital mitochondrial dye Rhodamine 123 and enhanced tetrazolium [MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] reduction revealed that the mitochondria increased by H2O2 treatment were functional. In addition, the increase in the mitochondrial mass was also observed in cell-cycle-arrested cells induced by mimosine, lovastatin and genistein. Taken together, these findings suggest that the increase in mitochondrial mass and mtDNA content are the early molecular events of human cells in response to endogenous or exogenous oxidative stress through cell-cycle arrest.

Biomarker for Benzopyrene Exposure Is Mitochondrial Mass and Mitochondrial DNA Copy in Blood Cells and Hematopoietic Tissues

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4889-4889
Author(s):  
Myung-Geun Shin ◽  
Hye-Ran Kim ◽  
Hyun-Jung Choi ◽  
Hwan-Young Kim ◽  
Dong-Kyun Han ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Mitochondrial Dna ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Copy Number ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Mtdna Copy Number ◽  
Mitochondrial Mass ◽  
Dose Dependent

Abstract Abstract 4889 Benzopyrenes are well known pollutants and carcinogens. They can intercalate into DNA and interfere transcriptions, resulting in causing various human diseases. However, biomarkers of benzopyrene toxicity have not been comprehensively studied in blood and leukemia cells. The current study was investigated to discover biomarkers for benzopyrene exposure in blood cells and leukemia cell lines. Peripheral blood, peripheral blood hematopoietic stem cell and leukemia cells (THP-1, K562, Molt-4 and HL-60) were cultured in RPMI 1640 media with adding 0, 50, 100 and 200μM of benzopyrene. Viability and apoptosis were assessed by tryptophan blue dye exclusion test and flowcytometry using annexin V. Hydrogen peroxide was measured using enzyme immunoassay. Mitochondrial mass, membrane potential and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green, Red probes and real time PCR, respectively. The number of cell remained constant for three weeks culture. Viability of four cell lines disclosed significant decrease after two weeks of benzopyrene treatment. Apoptosis was increased in time- and dose-dependent manner after two weeks of benzopyrene treatment. Mitochondrial contents and membrane potentials were dramatically increased in three-week culture at dose dependent manner. Hydrogen peroxide level was significantly elevated after two weeks treatment of benzopyrene compared to non-benzopyrene treatment group. The number of mtDNA copy increased gradually after exposure to benzopyrene. These results indicated that increased mitochondrial mass and mtDNA copy number were biomarkers for direct exposure of benzopyrene in blood cells and hematopoietic tissues. Disclosures: No relevant conflicts of interest to declare.

Increased Mitochondrial Mass and Mitochondrial DNA Copy Number Are Biomarkers for Benzene Exposure in Hematopoietic Tissue and Leukemia Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4426-4426
Author(s):  
Myung-Geun Shin ◽  
Ha-Young Eom ◽  
Hye-Ran Kim ◽  
Aerin Kwon ◽  
Dong kyun Han ◽  
...  
Keyword(s):  
Copy Number ◽  
Bone Marrow Cells ◽  
Leukemia Cell ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Hematopoietic Tissue ◽  
Mtdna Copy Number ◽  
Mitochondrial Mass ◽  
Benzene Exposure ◽  
Leukemia Cell Lines

Abstract Abstract 4426 Background Exposure to benzene and its metabolites increases risk of marrow failure disorders, leukemia and other hematological diseases. However, biomarkers of benzene toxicity have not been comprehensively studied in hematopoietic cells and leukemia cells. We previously reported that benzene metabolites may impair electron chain transport and mitochondrial function (3rd WHO Conference on Children's Health and the Environment, 7-10 June 2009). Therefore, we hypothesized that alterations in mitochondrial mass and mitochondrial DNA (mtDNA) may occur in bone marrow cells and leukemia cells after benzene exposure to compensate for damaged mitochondria. Materials and Methods Total bone marrow cells from healthy individuals and leukemia cell lines (THP-1, Kasumi-1, K562, Molt-4 and HL-60) were cultured in RPMI media containing 10% fetal bovine serum for 5 days. Benzene was added in cell culture media with 0, 1 and 10mM concentration at 24 hour interval. Cell count was performed using an automated blood cell analyzer (ADVIA120, Siemens, Germany). Viability and apoptosis were assessed by tryptophan blue dye exclusion test and flowcytometry based annexin V staining protocol. Hydrogen peroxide content is measured using the commercial kit (Bioxytech® H2O2-560TM, OXIS International) according to the manufacturer's instructions. Mitochondrial mass, membrane potential and mtDNA copy number were measured using MitoTracker Green, MitoTracker Red probes (Invitrogen), and real time PCR using the QuantiTect SYBR Green PCR kit (Qiagen) and Rotor-Gene 3000 (Corbett Research), respectively. Results The number of cells were gradually increased regardless of concentration of benzene in day 3, and then steadily maintained during 3 weeks culture. Interestingly, the growth of K562 cells showed no growth inhibition effect (three fold increase) after 5-day exposure to benzene. Overall viability of five leukemia cell lines disclosed significant decrease after two week treatment of benzene (about 60% of viability was observed in 3- week suspension culture). The proportion of apoptosis was increased in time and dose dependent manner after 2-week treatment of benzene. Interestingly, mitochondrial contents and membrane potentials were dramatically increased in 3-week suspension culture after benzene exposure at dose dependent manner. The level of hydrogen peroxide significantly elevated after two week treatment of benzene (4.4 ± 1.9 μM/mg protein) compared with non-benzene treatment group (1.2 ± 1.0 μM/mg protein; P = 0.001). The average mtDNA copy number was gradually increased after exposure to benzene. Conclusions Benzene exposure caused increased mitochondrial mass and mtDNA copy number in response to oxidative stress induced by benzene. So, these mitochondrial changes can be used for biomarkers of benzene toxicity in hematopoietic tissue and leukemia cell. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Oxidative Stress Induces Mitochondrial Compromise in CD4 T Cells From Chronically HCV-Infected Individuals

2021 ◽  
Vol 12 ◽  
Author(s):  
Madison Schank ◽  
Juan Zhao ◽  
Ling Wang ◽  
Lam Ngoc Thao Nguyen ◽  
Dechao Cao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
Mitochondrial Dna ◽  
Cd4 T Cells ◽  
Hcv Infection ◽  
Cellular Respiration ◽  
Peroxisome Proliferator ◽  
Mtdna Copy Number ◽  
Mitochondrial Mass ◽  
Mitochondrial Functions

We have previously shown that chronic Hepatitis C virus (HCV) infection can induce DNA damage and immune dysfunctions with excessive oxidative stress in T cells. Furthermore, evidence suggests that HCV contributes to increased susceptibility to metabolic disorders. However, the underlying mechanisms by which HCV infection impairs cellular metabolism in CD4 T cells remain unclear. In this study, we evaluated mitochondrial mass and intracellular and mitochondrial reactive oxygen species (ROS) production by flow cytometry, mitochondrial DNA (mtDNA) content by real-time qPCR, cellular respiration by seahorse analyzer, and dysregulated mitochondrial-localized proteins by Liquid Chromatography-Mass Spectrometry (LC-MS) in CD4 T cells from chronic HCV-infected individuals and health subjects. Mitochondrial mass was decreased while intracellular and mitochondrial ROS were increased, expressions of master mitochondrial regulators peroxisome proliferator-activated receptor 1 alpha (PGC-1α) and mitochondrial transcription factor A (mtTFA) were down-regulated, and oxidative stress was increased while mitochondrial DNA copy numbers were reduced. Importantly, CRISPR/Cas9-mediated knockdown of mtTFA impaired cellular respiration and reduced mtDNA copy number. Furthermore, proteins responsible for mediating oxidative stress, apoptosis, and mtDNA maintenance were significantly altered in HCV-CD4 T cells. These results indicate that mitochondrial functions are compromised in HCV-CD4 T cells, likely via the deregulation of several mitochondrial regulatory proteins.

scholarly journals Mechanisms of Human Mitochondrial DNA Maintenance: The Determining Role of Primary Sequence and Length over Function

1999 ◽  
Vol 10 (10) ◽  
pp. 3345-3356 ◽  
Author(s):  
Carlos T. Moraes ◽  
Lesley Kenyon ◽  
Huiling Hao
Keyword(s):  
Mitochondrial Dna ◽  
Oxidative Phosphorylation ◽  
Copy Number ◽  
Human Cells ◽  
Mtdna Copy Number ◽  
Molecular Features ◽  
Mtdna Replication ◽  
Selection For ◽  
Dna Maintenance

Although the regulation of mitochondrial DNA (mtDNA) copy number is performed by nuclear-coded factors, very little is known about the mechanisms controlling this process. We attempted to introduce nonhuman ape mtDNA into human cells harboring either no mtDNA or mutated mtDNAs (partial deletion and tRNA gene point mutation). Unexpectedly, only cells containing no mtDNA could be repopulated with nonhuman ape mtDNA. Cells containing a defective human mtDNA did not incorporate or maintain ape mtDNA and therefore died under selection for oxidative phosphorylation function. On the other hand, foreign human mtDNA was readily incorporated and maintained in these cells. The suicidal preference for self-mtDNA showed that functional parameters associated with oxidative phosphorylation are less relevant to mtDNA maintenance and copy number control than recognition of mtDNA self-determinants. Non–self-mtDNA could not be maintained into cells with mtDNA even if no selection for oxidative phosphorylation was applied. The repopulation kinetics of several mtDNA forms after severe depletion by ethidium bromide treatment showed that replication and maintenance of mtDNA in human cells are highly dependent on molecular features, because partially deleted mtDNA molecules repopulated cells significantly faster than full-length mtDNA. Taken together, our results suggest that mtDNA copy number may be controlled by competition for limiting levels of trans-acting factors that recognize primarily mtDNA molecular features. In agreement with this hypothesis, marked variations in mtDNA levels did not affect the transcription of nuclear-coded factors involved in mtDNA replication.

scholarly journals Dihydromyricetin Improves Endothelial Dysfunction in Diabetic Mice via Oxidative Stress Inhibition in a SIRT3-Dependent Manner

2020 ◽  
Vol 21 (18) ◽  
pp. 6699
Author(s):  
Yu-Yun Hua ◽  
Yue Zhang ◽  
Wei-Wei Gong ◽  
Yue Ding ◽  
Jie-Ru Shen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Dysfunction ◽  
Thoracic Aorta ◽  
Copy Number ◽  
Hba1c Level ◽  
Dependent Manner ◽  
Ros Production ◽  
Diabetic Mice ◽  
Mtdna Copy Number ◽  
Endothelium Dependent Relaxation

Dihydromyricetin (DHY), a flavonoid component isolated from Ampelopsis grossedentata, exerts versatile pharmacological activities. However, the possible effects of DHY on diabetic vascular endothelial dysfunction have not yet been fully elucidated. In the present study, male C57BL/6 mice, wild type (WT) 129S1/SvImJ mice and sirtuin 3 (SIRT3) knockout (SIRT3-/-) mice were injected with streptozotocin (STZ, 60 mg/kg/day) for 5 consecutive days. Two weeks later, DHY were given at the doses of 250 mg/kg by gavage once daily for 12 weeks. Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) level, endothelium-dependent relaxation of thoracic aorta, reactive oxygen species (ROS) production, SIRT3, and superoxide dismutase 2 (SOD2) protein expressions, as well as mitochondrial Deoxyribonucleic Acid (mtDNA) copy number, in thoracic aorta were detected. Our study found that DHY treatment decreased FBG and HbA1c level, improved endothelium-dependent relaxation of thoracic aorta, inhibited oxidative stress and ROS production, and enhanced SIRT3 and SOD2 protein expression, as well as mtDNA copy number, in thoracic aorta of diabetic mice. However, above protective effects of DHY were unavailable in SIRT3-/- mice. The study suggested DHY improved endothelial dysfunction in diabetic mice via oxidative stress inhibition in a SIRT3-dependent manner.

scholarly journals mtDNA in the Pathogenesis of Cardiovascular Diseases

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lili Wang ◽  
Qianhui Zhang ◽  
Kexin Yuan ◽  
Jing Yuan
Keyword(s):  
Heart Failure ◽  
Cardiovascular Disease ◽  
Mitochondrial Dna ◽  
Copy Number ◽  
Heart Diseases ◽  
Mtdna Copy Number ◽  
Cardiac Inflammation ◽  
Ischemic Heart Diseases ◽  
Metabolic Functions ◽  
Underlying Mechanisms

The incidence rate of cardiovascular disease (CVD) has been increasing year by year and has become the main cause for the increase of mortality. Mitochondrial DNA (mtDNA) plays a crucial role in the pathogenesis of CVD, especially in heart failure and ischemic heart diseases. With the deepening of research, more and more evidence showed that mtDNA is related to the occurrence and development of CVD. Current studies mainly focus on how mtDNA copy number, an indirect biomarker of mitochondrial function, contributes to CVD and its underlying mechanisms including mtDNA autophagy, the effect of mtDNA on cardiac inflammation, and related metabolic functions. However, no relevant studies have been conducted yet. In this paper, we combed the current research status of the mechanism related to the influence of mtDNA on the occurrence, development, and prognosis of CVD, so as to find whether these mechanisms have something in common, or is there a correlation between each mechanism for the development of CVD?

scholarly journals Targeting reduced mitochondrial DNA quantity as a therapeutic approach in pediatric high-grade gliomas

2019 ◽  
Vol 22 (1) ◽  
pp. 139-151 ◽  
Author(s):  
Han Shen ◽  
Man Yu ◽  
Maria Tsoli ◽  
Cecilia Chang ◽  
Swapna Joshi ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Glucose Metabolism ◽  
Mitochondrial Function ◽  
Copy Number ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Grade ◽  
Mtdna Copy Number ◽  
Mitochondrial Oxidation ◽  
High Grade Gliomas

Abstract Background Despite increased understanding of the genetic events underlying pediatric high-grade gliomas (pHGGs), therapeutic progress is static, with poor understanding of nongenomic drivers. We therefore investigated the role of alterations in mitochondrial function and developed an effective combination therapy against pHGGs. Methods Mitochondrial DNA (mtDNA) copy number was measured in a cohort of 60 pHGGs. The implication of mtDNA alteration in pHGG tumorigenesis was studied and followed by an efficacy investigation using patient-derived cultures and orthotopic xenografts. Results Average mtDNA content was significantly lower in tumors versus normal brains. Decreasing mtDNA copy number in normal human astrocytes led to a markedly increased tumorigenicity in vivo. Depletion of mtDNA in pHGG cells promoted cell migration and invasion and therapeutic resistance. Shifting glucose metabolism from glycolysis to mitochondrial oxidation with the adenosine monophosphate–activated protein kinase activator AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) or the pyruvate dehydrogenase kinase inhibitor dichloroacetate (DCA) significantly inhibited pHGG viability. Using DCA to shift glucose metabolism to mitochondrial oxidation and then metformin to simultaneously target mitochondrial function disrupted energy homeostasis of tumor cells, increasing DNA damage and apoptosis. The triple combination with radiation therapy, DCA and metformin led to a more potent therapeutic effect in vitro and in vivo. Conclusions Our results suggest metabolic alterations as an onco-requisite factor of pHGG tumorigenesis. Targeting reduced mtDNA quantity represents a promising therapeutic strategy for pHGG.

scholarly journals Twinkle overexpression prevents cardiac rupture after myocardial infarction by alleviating impaired mitochondrial biogenesis

2016 ◽  
Vol 311 (3) ◽  
pp. H509-H519 ◽  
Author(s):  
Takahiro Inoue ◽  
Masataka Ikeda ◽  
Tomomi Ide ◽  
Takeo Fujino ◽  
Yuka Matsuo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Mitochondrial Biogenesis ◽  
Copy Number ◽  
Cardiac Rupture ◽  
Mtdna Copy Number ◽  
Border Area ◽  
Frame Duplication ◽  
And Oxidative Stress

Cardiac rupture is a fatal complication after myocardial infarction (MI). However, the detailed mechanism underlying cardiac rupture after MI remains to be fully elucidated. In this study, we investigated the role of mitochondrial DNA (mtDNA) and mitochondria in the pathophysiology of cardiac rupture by analyzing Twinkle helicase overexpression mice (TW mice). Twinkle overexpression increased mtDNA copy number approximately twofold and ameliorated ischemic cardiomyopathy at day 28 after MI. Notably, Twinkle overexpression markedly prevented cardiac rupture and improved post-MI survival, accompanied by the suppression of MMP-2 and MMP-9 in the MI border area at day 5 after MI when cardiac rupture frequently occurs. Additionally, these cardioprotective effects of Twinkle overexpression were abolished in transgenic mice overexpressing mutant Twinkle with an in-frame duplication of amino acids 353–365, which resulted in no increases in mtDNA copy number. Furthermore, although apoptosis and oxidative stress were induced and mitochondria were damaged in the border area, these injuries were improved in TW mice. Further analysis revealed that mitochondrial biogenesis, including mtDNA copy number, transcription, and translation, was severely impaired in the border area at day 5. In contrast, Twinkle overexpression maintained mtDNA copy number and restored the impaired transcription and translation of mtDNA in the border area. These results demonstrated that Twinkle overexpression alleviated impaired mitochondrial biogenesis in the border area through maintained mtDNA copy number and thereby prevented cardiac rupture accompanied by the reduction of apoptosis and oxidative stress, and suppression of MMP activity.

scholarly journals Increase of mitochondria and mitochondrial DNA in response to oxidative stress in human cells

2000 ◽  
Vol 348 (2) ◽  
pp. 425 ◽  
Author(s):  
Hsin-Chen LEE ◽  
Pen-Hui YIN ◽  
Ching-You LU ◽  
Chin-Wen CHI ◽  
Yau-Huei WEI
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dna ◽  
Human Cells
Sign in / Sign up

Export Citation Format

Share Document