Oral potentially malignant disorders (OPMDs) are precursors of oral squamous cell carcinoma (OSCC). Deregulated cellular energy metabolism is a critical hallmark of cancer cells. Peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC1α) plays vital role in mitochondrial energy metabolism. However, the molecular mechanism of PGC1α on OPMDs progression is less unclear. Therefore, we investigated the effects of knockdown PGC1α on human dysplastic oral keratinocytes (DOKs) comprehensively, including cell proliferation, cell cycle, apoptosis, xenograft tumor, mitochondrial DNA (mtDNA), mitochondrial electron transport chain complexes (ETC), reactive oxygen species (ROS), oxygen consumption rate (OCR), extracellular acidification rate (ECAR), and glucose uptake. We found that knockdown PGC1α significantly inhibited the proliferation of DOKs in vitro and tumor growth in vivo, induced S-phase arrest, and suppressed PI3K/Akt signaling pathway without affecting cell apoptosis. Mechanistically, downregulated of PGC1α decreased mtDNA, ETC, and OCR, while enhancing ROS, glucose uptake, ECAR, and glycolysis by regulating lactate dehydrogenase A (LDHA). Moreover, SR18292 (an inhibitor of PGC1α) induced oxidative phosphorylation dysfunction of DOKs and declined DOK xenograft tumor progression. Thus, our work suggests that PGC1α plays a crucial role in cell proliferation by reprograming energy metabolism and interfering with energy metabolism, acting as a potential therapeutic target for OPMDs.
Humans ; Carcinoma, Squamous Cell/metabolism* ; Cell Proliferation ; DNA, Mitochondrial ; Energy Metabolism ; Glucose ; Mouth Neoplasms/metabolism* ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism* ; Phosphatidylinositol 3-Kinases ; Reactive Oxygen Species

Mitochondrial DNA is the mitochondria's own genetic material located within the mitochondrial matrix and is involved in cellular metabolism and energy supply. Mitochondrial DNA damage exacerbates oxidative stress by increasing the release of reactive oxygen species, while mitochondrial DNA release also triggers apoptosis and activates immune inflammatory responses through damage-related molecular patterns. Mitochondrial autophagy regulates mitochondrial DNA damage and release through a negative feedback mechanism to maintain intracellular homeostasis. Recent studies have shown that the occurrence and development of chronic liver disease are closely related to mitochondrial DNA-mediated immune inflammatory responses and oxidative stress.
Apoptosis ; Autophagy ; DNA, Mitochondrial/metabolism* ; Humans ; Liver Diseases ; Mitochondria ; Oxidative Stress ; Reactive Oxygen Species/metabolism*

OBJECTIVE: To explore the genetic etiology of a Chinese pedigree affected with infantile hepatitis syndrome. METHODS: Genes associated with liver diseases subjected to high-throughput sequencing. Candidate variants were validated by Sanger sequencing of the proband and his parents. The pathogenicity of the variants was analyzed through bioinformatic analysis. RESULTS: High-throughput sequencing revealed that the proband has harbored c.182T>C (p.F61S) and c.293C>T (p.P98L) variants of the MPV17 gene, which were verified by Sanger sequencing to be inherited from his parents. The variant c.182T>C (p.F61S) was unreported previously and predicted to be likely pathogenic by bioinformatic analysis. CONCLUSION The proband was caused by the compound heterozygous variations of MPV17 gene including c.182T>C (p.F61S) and c.293C>T (p.P98L). Discovery of the novel variant has enriched the spectrum of pathogenic variants of the MPV17 gene.
China ; DNA, Mitochondrial/genetics* ; Female ; Genetic Testing ; Humans ; Membrane Proteins/genetics* ; Metabolism, Inborn Errors/genetics* ; Mitochondrial Proteins/genetics* ; Mutation ; Pedigree ; Pregnancy ; Prenatal Diagnosis ; Syndrome

Osteoarthritis (OA) is a degenerative articular disorder manifested by cartilage destruction, subchondral sclerosis, osteophytes, and synovitis, resulting in chronic joint pain and physical disability in the elderly. The purpose of this study was to investigate mitochondrial DNA copy number (mtDNA_CN) and inflammatory cytokines in primary knee OA patients and healthy volunteers. A total of 204 knee OA patients and 169 age-matched healthy volunteers were recruited. Their relative blood leukocyte mtDNA_CN was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), and ten inflammatory cytokines in their plasma were detected by multiplex immunoassay. Blood leukocyte mtDNA_CN in the OA group was significantly lower than that in the control group. Leukocyte mtDNA_CN in the control group was negatively correlated with their age (r=-0.380, P<0.0001), whereas mtDNA_CN in the OA group was positively correlated with their age (r=0.198, P<0.001). Plasma interleukin-4 (IL-4) and IL-6 were significantly higher in the knee OA group than in the control group. The plasma IL-6 level was positively correlated with blood leukocyte mtDNA_CN in the OA group (r=0.547, P=0.0014). IL-5 showed as a major factor (coefficient 0.69) in the second dimension of principle components analysis (PCA)-transformed data and was significantly higher in the OA group (P<0.001) as well as negatively correlated with mtDNA_CN (r=-0.577, P<0.001). These findings suggest that elevation of plasma IL-4 and IL-6 and a relative reduction in mtDNA_CN might be effective biomarkers for knee OA. IL-5 is a plausible factor responsible for decreasing blood leukocyte mtDNA_CN in knee OA patients.
Age Factors ; Aged ; Aged, 80 and over ; Cytokines/blood* ; DNA, Mitochondrial/blood* ; Female ; Gene Dosage ; Humans ; Leukocytes/metabolism* ; Male ; Middle Aged ; Osteoarthritis, Knee/metabolism* ; Principal Component Analysis

Ageratina adenophora is a noxious plant and it is known to cause acute asthma, diarrhea, depilation, and even death in livestock (Zhu et al., 2007; Wang et al., 2017). A. adenophora grows near roadsides and degraded land worldwide (He et al., 2015b). In the areas where it grows, A. adenophora is an invasive species that inhibits the growth of local plants and causes poisoning in animals that come in contact with it (Nie et al., 2012). In China, these plants can be found in Yunnan, Sichuan, Guizhou, Chongqing, and other southwestern areas (He et al., 2015a) and they have become a dominant species in these local regions. It threatens the native biodiversity and ecosystem in the invaded areas and causes serious economic losses (Wang et al., 2017). It has been reported that A. adenophora can grow in the northeast direction at a speed of 20 km per year in China (Guo et al., 2009). Because of the damage caused by A. adenophora, it ranks among the earliest alien invasive plant species in China (Wang et al., 2017).
Adenosine Triphosphatases/metabolism* ; Ageratina/toxicity* ; Animals ; Biodiversity ; Chemical and Drug Induced Liver Injury/pathology* ; China ; DNA, Mitochondrial/genetics* ; Ecosystem ; Introduced Species ; Liver/drug effects* ; Mice ; Microscopy, Electron, Transmission ; Mitochondria, Liver/pathology* ; Plant Extracts/toxicity*

Mitochondrial diseases are maternally inherited heterogeneous disorders that are primarily caused by mitochondrial DNA (mtDNA) mutations. Depending on the ratio of mutant to wild-type mtDNA, known as heteroplasmy, mitochondrial defects can result in a wide spectrum of clinical manifestations. Mitochondria-targeted endonucleases provide an alternative avenue for treating mitochondrial disorders via targeted destruction of the mutant mtDNA and induction of heteroplasmic shifting. Here, we generated mitochondrial disease patient-specific induced pluripotent stem cells (MiPSCs) that harbored a high proportion of m.3243A>G mtDNA mutations and caused mitochondrial encephalomyopathy and stroke-like episodes (MELAS). We engineered mitochondrial-targeted transcription activator-like effector nucleases (mitoTALENs) and successfully eliminated the m.3243A>G mutation in MiPSCs. Off-target mutagenesis was not detected in the targeted MiPSC clones. Utilizing a dual fluorescence iPSC reporter cell line expressing a 3243G mutant mtDNA sequence in the nuclear genome, mitoTALENs displayed a significantly limited ability to target the nuclear genome compared with nuclear-localized TALENs. Moreover, genetically rescued MiPSCs displayed normal mitochondrial respiration and energy production. Moreover, neuronal progenitor cells differentiated from the rescued MiPSCs also demonstrated normal metabolic profiles. Furthermore, we successfully achieved reduction in the human m.3243A>G mtDNA mutation in porcine oocytes via injection of mitoTALEN mRNA. Our study shows the great potential for using mitoTALENs for specific targeting of mutant mtDNA both in iPSCs and mammalian oocytes, which not only provides a new avenue for studying mitochondrial biology and disease but also suggests a potential therapeutic approach for the treatment of mitochondrial disease, as well as the prevention of germline transmission of mutant mtDNA.
Animals ; DNA, Mitochondrial ; genetics ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; MELAS Syndrome ; genetics ; Male ; Mice ; Microsatellite Repeats ; genetics ; Mitochondria ; genetics ; metabolism ; Mutation ; genetics

Despite overall reductions in heart disease prevalence, the risk of developing heart failure has remained 2-fold greater among people with diabetes. Growing evidence has supported that fluctuations in glucose level and uptake contribute to cardiovascular disease (CVD) by modifying proteins, DNA, and gene expression. In the case of glucose, clinical studies have shown that increased dietary sugars for healthy individuals or poor glycemic control in diabetic patients further increased CVD risk. Furthermore, even after decades of maintaining tight glycemic control, susceptibility to disease progression can persist following a period of poor glycemic control through a process termed "glycemic memory." In response to chronically elevated glucose levels, a number of studies have identified molecular targets of the glucose-mediated protein posttranslational modification by the addition of an O-linked N-acetylglucosamine to impair contractility, calcium sensitivity, and mitochondrial protein function. Additionally, elevated glucose contributes to dysfunction in coupling glycolysis to glucose oxidation, pentose phosphate pathway, and polyol pathway. Therefore, in the "sweetened" environment associated with hyperglycemia, there are a number of pathways contributing to increased susceptibly to "breaking" the heart of diabetics. In this review we will discuss the unique contribution of glucose to heart disease and recent advances in defining mechanisms of action.
Calcium ; Cardiomyopathies ; Cardiovascular Diseases ; Diabetic Cardiomyopathies* ; Dietary Sucrose ; Disease Progression ; DNA ; Gene Expression ; Glucose* ; Glycolysis ; Heart ; Heart Diseases ; Heart Failure ; Humans ; Hyperglycemia ; Metabolism ; Mitochondrial Proteins ; Pentose Phosphate Pathway ; Prevalence ; Protein Processing, Post-Translational

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a 2 × 2 factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), α-ketoglutarate dehydrogenase (α-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, α-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-1α, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, H+ transporting, mitochondrial F1 complex, β polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.
Adenosine Triphosphate ; Birth Weight* ; Citrate (si)-Synthase ; Diet ; DNA, Mitochondrial ; Energy Metabolism* ; Fetal Growth Retardation ; Leucine* ; Liver ; Malate Dehydrogenase ; Nuclear Respiratory Factor 1 ; Organelle Biogenesis* ; Oxidoreductases ; Parturition* ; Peroxisomes ; Pyruvic Acid ; Research Design ; RNA, Messenger ; Sirtuin 1 ; Transcription Factors

BACKGROUND: To the best of our knowledge, the association between pediatric AML and mitochondrial aberrations has not been studied. We investigated various mitochondrial aberrations in pediatric AML and evaluated their impact on clinical outcomes. METHODS: Sequencing, mitochondrial DNA (mtDNA) copy number determination, mtDNA 4,977-bp large deletion assessments, and gene scan analyses were performed on the bone marrow mononuclear cells of 55 pediatric AML patients and on the peripheral blood mononuclear cells of 55 normal controls. Changes in the mitochondrial mass, mitochondrial membrane potential, and intracellular reactive oxygen species (ROS) levels were also examined. RESULTS: mtDNA copy numbers were about two-fold higher in pediatric AML cells than in controls (P<0.0001). Furthermore, a close relationship was found between mtDNA copy number tertiles and the risk of pediatric AML. Intracellular ROS levels, mitochondrial mass, and mitochondrial membrane potentials were all elevated in pediatric AML. The frequency of the mtDNA 4,977-bp large deletion was significantly higher (P< 0.01) in pediatric AML cells, and pediatric AML patients harboring high amount of mtDNA 4,977-bp deletions showed shorter overall survival and event-free survival rates, albeit without statistical significance. CONCLUSIONS: The present findings demonstrate an association between mitochondrial genome alterations and the risk of pediatric AML.
Bone Marrow Cells/metabolism ; Case-Control Studies ; Child ; Cohort Studies ; DNA, Mitochondrial/chemistry/genetics/metabolism ; Female ; Flow Cytometry ; Gene Deletion ; Gene Dosage ; *Genome, Mitochondrial ; Humans ; Leukemia, Myeloid, Acute/genetics/mortality/*pathology ; Male ; Membrane Potential, Mitochondrial ; Minisatellite Repeats/genetics ; Odds Ratio ; Reactive Oxygen Species/metabolism ; Sequence Analysis, DNA ; Survival Rate

Mitochondrial diseases is a group of metabolic disorders caused by abnormal structure and dysfunction of mitochondrial DNA (mtDNA). Abnormalities of mtDNA include point mutations, deletions, and rearrangements and depletion of mtDNA. These may affect the ability of mitochondria to generate energy in cells of various tissues and organs. As many factors are involved in the regulation of mtDNA mutations, most mitochondrial diseases may manifest great genetic heterogeneity and a wide spectrum of clinical manifestations. On the other hand, for the low prevalence of single disease, these disorders may be easily missed or with delayed diagnosis. This review focuses on the pathological mutations and benign variations of mtDNA, and research progress on such disorders.
Biomedical Research ; methods ; trends ; DNA, Mitochondrial ; genetics ; Energy Metabolism ; genetics ; Genetic Heterogeneity ; Humans ; Mitochondria ; genetics ; metabolism ; Mitochondrial Diseases ; diagnosis ; genetics ; Mutation