The aim of this study was to determine the effects of extremely low frequency electromagnetic field (ELF-EMF) on energy metabolism and oxidative stress in Caenorhabditis elegans (C. elegans). Worms in three adult stages (young adult stage, egg-laying stage and peak egg-laying stage) were investigated under 50 Hz, 3 mT ELF-EMF exposure. ATP levels, ATP synthase activity in vivo, reactive oxygen species (ROS) content, and changes of total antioxidant capacity (TAC) were detected, and worms' oxidative stress responses were also evaluated under ELF-EMF exposure. The results showed that ATP levels were significantly increased under this ELF-EMF exposure, and mitochondrial ATP synthase activity was upregulated simultaneously. In young adult stage, worms' ROS level was significantly elevated, together with upregulated TAC but with a decreased ROS-TAC score indicated by principal component analysis. ROS level and TAC of worms had no significant changes in egg-laying and peak egg-laying stages. Based on these results, we concluded that ELF-EMF can enhance worm energy metabolism and elicit oxidative stress, mainly manifesting as ATP and ROS level elevation together with ATP synthase upregulation and ROS-TAC score decrease in young adult C. elegans.
Adenosine Triphosphate ; metabolism ; Animals ; Caenorhabditis elegans ; radiation effects ; Electromagnetic Radiation ; Energy Metabolism ; Mitochondrial Proton-Translocating ATPases ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; analysis

Recent studies indicate that mitochondria are an important source of reactive oxygen species (ROS) in the spinal dorsal horn. In our previous study, application of malate, a mitochondrial electron transport complex I substrate, induced a membrane depolarization, which was inhibited by pretreatment with ROS scavengers. In the present study, we used patch clamp recording in the substantia geletinosa (SG) neurons of spinal slices, to investigate the cellular mechanism of mitochondrial ROS on neuronal excitability. DNQX (an AMPA receptor antagonist) and AP5 (an NMDA receptor antagonist) decreased the malate-induced depolarization. In an external calcium free solution and addition of tetrodotoxin (TTX) for blockade of synaptic transmission, the malateinduced depolarization remained unchanged. In the presence of DNQX, AP5 and AP3 (a group I metabotropic glutamate receptor (mGluR) antagonist), glutamate depolarized the membrane potential, which was suppressed by PBN. However, oligomycin (a mitochondrial ATP synthase inhibitor) or PPADS (a P2 receptor inhibitor) did not affect the substrates-induced depolarization. These results suggest that mitochondrial substrate-induced ROS in SG neuron directly acts on the postsynaptic neuron, therefore increasing the ion influx via glutamate receptors.
Animals ; Calcium ; Electron Transport Complex I ; Glutamic Acid ; Membrane Potentials ; Membranes ; Mitochondria ; Mitochondrial Proton-Translocating ATPases ; N-Methylaspartate ; Neurons* ; Oligomycins ; Rats* ; Reactive Oxygen Species ; Receptors, AMPA ; Receptors, Glutamate ; Receptors, Metabotropic Glutamate ; Spinal Cord Dorsal Horn ; Substantia Gelatinosa* ; Synaptic Transmission ; Tetrodotoxin

Cardiomyopathy, Dilated ; genetics ; DNA, Mitochondrial ; genetics ; Humans ; Hypertension ; genetics ; Mitochondrial Diseases ; genetics ; Mitochondrial Proton-Translocating ATPases ; genetics ; Point Mutation ; genetics

BACKGROUNDCardiovascular diseases, including dilated cardiomyopathy (DCM) and hypertension, are the leading cause of death worldwide. The role of mitochondrial DNA (mtDNA) in the pathogenesis of these diseases has not been completely clarified. In this study, we evaluate whether A8701G mutation is associated with maternally inherited hypertension and DCM in a Chinese pedigree of a consanguineous marriage.

METHODSFourteen subjects in a three-generation Han Chinese family with hypertension and DCM, in which consanguineous marriage was present in the parental generation, were interviewed. We divided all the family members into case (7 maternal members) and control group (7 nonmaternal members) for comparison. Clinical evaluations and sequence analysis of mtDNA were obtained from all participants. Frequency differences between maternal and nonmaternal members were tested to locate the disease-associated mutations.

RESULTSThe majority of the family members presented with a maternal inheritance of hypertension and DCM. Sequence analysis of mtDNA in this pedigree identified eight mtDNA mutations. Among the mutations identified, there was only one significant mutation: A8701G (P = 0.005), which is a homoplasmic mitochondrial missense mutation in all the matrilineal relatives. There was no clear evidence for any synergistic effects between A8701G and other mutations.

CONCLUSIONSA8701G mutation may act as an inherited risk factor for the matrilineal transmission of hypertension and DCM in conjunction with genetic disorders caused by consanguineous marriage.

Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Cardiomyopathy, Dilated ; genetics ; DNA, Mitochondrial ; genetics ; Female ; Genetic Predisposition to Disease ; Humans ; Hypertension ; genetics ; Male ; Middle Aged ; Mitochondrial Proton-Translocating ATPases ; genetics ; Mutation ; genetics ; Pedigree ; Risk Factors

OBJECTIVETo report on clinical, genetic and molecular characterization of two Chinese families with Leber's hereditary optic neuropathy.

METHODSOphthalmological examinations have revealed variable severity and age at onset of visual loss among the probands and other matrilineal relatives of both families. The entire mitochondrial genome of the two probands was amplified with PCR in 24 overlapping fragments using sets of oligonucleotide primers.

RESULTSThe ophthalmological examinations showed that penetrance was 12.5% and 30.0% respectively in the two families. Sequence analysis of the complete mitochondrial genomes in these pedigrees has identified unreported homoplasmic T8821G mutation in the ATPase 6 gene and distinct sets of polymorphisms belonging to haplogroups M10a. The T8821G mutation has occurred at the extremely conserved nucleotide (conventional position 99) of the ATPase6. Thus, this mutation may alter structural formation of ATPase6, thereby leading to failure in the synthesis of ATP involved in visual impairment.

CONCLUSIONAbove observations have suggested that the ATPase6 T8821G mutation may be involved in the pathogenesis of optic neuropathy in these families.

Adolescent ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; DNA, Mitochondrial ; genetics ; Female ; Humans ; Male ; Mitochondrial Proton-Translocating ATPases ; genetics ; Molecular Sequence Data ; Optic Atrophy, Hereditary, Leber ; enzymology ; genetics ; Pedigree ; Point Mutation ; Young Adult

OBJECTIVETo put the insight into the trichloroethylene (TCE)-induced effect on the differential expression of subcellular proteins in human normal liver cell line (L-02).

METHODSThe membrane proteins and nuclear proteins of TCE-treated (8.0 mmol/L) group and controls were extracted by subcellular proteome extraction kit, respectively. The TCE-induced differentially expressions were analyzed by a two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization tandem time-of-flight spectrometry (MALDI-TOF-MS). Bioinformatics analysis was used to reveal the biological processes and predict transmembrane domains of differential expressed proteins. The expression of ATP synthase subunit beta (ATP5B), heterogeneous nuclear ribonucleoprotein H2 (hnRNP H2) and far up steam element-binding protein 1 (FUBP1) were measured under TCE treatment by Western blot.

RESULTSAfter TCE treatment for 24 h in L-02 cells, 14 membrane proteins and 18 nuclear proteins were identified as differential expression. After treated with TCE in concentrations of 0, 2.0, 4.0 and 8.0 mmol/L for 24 h, the relative levels of ATP5B expression were 1.00±0.03, 1.21±0.14, 1.25±0.12 and 1.48±0.17 (F = 8.51, P = 0.007), the relative levels of hnRNP H2 expression were 1.00±0.09, 1.22±0.15, 1.43±0.21, 1.53±0.17 (F = 6.57, P = 0.015), respectively; the relative levels of FUBP1 expression were 1.00±0.11, 0.91±0.07, 0.73±0.04 and 0.67±0.03 (F = 15.81, P = 0.001), respectively, which were consistent with the results in proteomics. The bioinformatics analysis showed that the most dominant biological process were involved in RNA processing (10 proteins, P = 2.46×10(-6)), especially in RNA splicing (9 proteins, P = 1.77×10(-7)).

CONCLUSIONThe exposure of TCE could alter the expression of membrane proteins and nuclear proteins in L-02 cells. These abnormal expressed proteins involved in RNA splicing would provide novel clues for further understanding of TCE-induced hepatotoxicity.

Blotting, Western ; Cell Line ; DNA Helicases ; DNA-Binding Proteins ; Hepatocytes ; Heterogeneous-Nuclear Ribonucleoprotein Group F-H ; Humans ; Mitochondrial Proton-Translocating ATPases ; Proteome ; Proteomics ; RNA Processing, Post-Transcriptional ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Trichloroethylene

While the field of ATP synthase research has a long history filled with landmark discoveries, recent structural works provide us with important insights into the mechanisms that links the proton movement with the rotation of the Fo motor. Here, we propose a mechanism of unidirectional rotation of the Fo complex, which is in agreement with these new structural insights as well as our more general ΔΨ-driving hypothesis of membrane proteins: A proton path in the rotor-stator interface is formed dynamically in concert with the rotation of the Fo rotor. The trajectory of the proton viewed in the reference system of the rotor (R-path) must lag behind that of the stator (S-path). The proton moves from a higher energy site to a lower site following both trajectories simultaneously. The two trajectories meet each other at the transient proton-binding site, resulting in a relative rotation between the rotor and stator. The kinetic energy of protons gained from ΔΨ is transferred to the c-ring as the protons are captured sequentially by the binding sites along the proton path, thus driving the unidirectional rotation of the c-ring. Our ΔΨ-driving hypothesis on Fo motor is an attempt to unveil the robust mechanism of energy conversion in the highly conserved, ubiquitously expressed rotary ATP synthases.
Membrane Potentials ; physiology ; Membrane Proteins ; chemistry ; metabolism ; Mitochondrial Proton-Translocating ATPases ; chemistry ; metabolism ; Protein Conformation

OBJECTIVETo explore the mechanism of electroacupuncture on improving insulin resistance of rat from aspects of morphology and function of mitochondrial in quadriceps femoris.

METHODSForty-eight 8-week Wistar rats (female and male in half) were randomly divided into a normal group (16 rats, group A), a model control group (16 rats, group B), a model plus electroacupuncture (EA) group (8 rats, group C) and a model plus sham acupoint EA group (8 rats, group D). Group A was given with basic diet while high-fat diet was applied in the group B, group C and group D for 8 weeks to establish model of insulin resistance. After the model establishment, "Guanyuan" (CV 4), "Zhongwan" (CV 12), "Zusanli" (ST 36) and "Fenglong" (ST 30) were selected according to acupoint combination of manifestation-root in the group C, while four points in non-meridian area where 1 to 2 mm next to the acupoints used in group C were selected in the group D. The treatment was given 15 min per time with 1 mA of intensity and 2 Hz in frequency, 5 times per week for totally 8 weeks. The transmission electron microscope was adopted to observe mitochondria structure, and chemical colorimetry was used to test the activity of adenosine triphosphate (ATP) synthase and phosphomolybdic acid colorimetry was applied to measure the content of ATP.

RESULTSAfter the treatment, the body mass was (401.63 +/- 109.81) g in the group B, which was significantly higher than (305.88 +/- 62.72) g in the group A (P < 0.05); morphological structure of mitochondrion was damaged, showing swelling and deformation; the activity of ATP synthase was decreased (P < 0.05) and the content of ATP in tissue of quadriceps femoris was also obviously lowered (P < 0.05). The body mass was (294.13 +/- 53.78) g in the group C, which was significantly lower than that in the group B (P < 0.05); the damaged mitochondrion was restored and merged among each other; the activity of ATP synthase was increased (P < 0.05); the content of ATP in tissue of quadriceps femoris was obviously lifted (P < 0.05). The results in group D were not different from those in group B.

CONCLUSIONThe electroacupuncture with manifestation-root acupoint combination could improve the recovery of damaged structure of mitochondrion and promote the merge among each other, which could enhance oxidizing capacity, lower body mass and improve synthetic rate of ATP.

Acupuncture Points ; Adenosine Triphosphate ; biosynthesis ; Animals ; Diabetes Mellitus, Type 2 ; metabolism ; therapy ; Electroacupuncture ; Female ; Humans ; Insulin ; metabolism ; Insulin Resistance ; Male ; Mitochondria ; enzymology ; metabolism ; ultrastructure ; Mitochondrial Proton-Translocating ATPases ; metabolism ; Quadriceps Muscle ; metabolism ; ultrastructure ; Rats ; Rats, Wistar

Mitochondrial adenosine triphosphate (ATP) synthase is the key enzyme of mitochondrial oxidative phosphorylation reaction. The down-regulation of the mitochondrial ATP synthase is a hallmark of most human carcinomas, which is the embodiment of the bioenergetic signature of cancer in the performance of the decreased oxidative phosphorylation and increased aerobic glycolysis. Combining with the bioenergetic signature of cancer, studies showed that mitochondrial ATP synthase and multidrug resistance and adverse prognosis of tumor were closely related. Its mechanisms are related to post-transcriptional regulation of the ATP synthase, the hypermethylation of the ATP synthase gene and the inhibitor peptide of the mitochondrial ATP synthase, called ATP synthase inhibitory factor 1 (IF1). In this review, we stress the biological characteristics of mitochondrial ATP synthase and the relationship between ATP synthase and multidrug resistance and prognosis of Malignant tumor, in order to find a new way for tumor therapy.
Adenosine Triphosphate ; Carcinoma ; enzymology ; Down-Regulation ; Energy Metabolism ; Humans ; Mitochondria ; enzymology ; Mitochondrial Proton-Translocating ATPases ; metabolism ; Neoplasms ; enzymology ; Nitric Oxide Synthase ; Oxidative Phosphorylation

The mammalian mitochondrial ATP synthase, also as known as mitochondrial respiratory chain complex V, is a large protein complex located in the mitochondrial inner membrane, where it catalyzes ATP synthesis from ADP, Pi, and Mg2+ at the expense of an electrochemical gradient of protons generated by the electron transport chain. Complex V is composed of 2 functional domains F0 and F1. The clinical features of patients are significantly heterogeneous depending on the involved organs. Most patients with complex V deficiency had clinical onset in the neonatal period with severe brain damage or multi-organ failure resulting in a high mortality. Neuromuscular disorders, cardiomyopathy, lactic acidosis and 3-methylglutaconic aciduria are common findings. Complex V consists of 16 subunits encoded by both mitochondrial DNA and nuclear DNA. On MT-ATP6, MT-ATP8, ATPAF2, TMEM70 and ATP5E gene of mitochondrial DNA, many mutations associated with Complex V deficiency have been identified. Here, the pathology, clinical features, diagnosis, treatment and molecular genetics of Complex V deficiency were summarized.
Mitochondrial Diseases ; complications ; etiology ; therapy ; Mitochondrial Proton-Translocating ATPases ; chemistry ; deficiency ; genetics ; physiology ; Prognosis