OBJECTIVETo study the clinical and enzymological characteristics of the children with mitochondrial respiratory chain complex III deficiency.

METHODThe clinical manifestations of five patients (3 males, 2 females) were summarized. Spectrophotometric assay was used for the analysis of respiratory chain complex I to V enzyme activity in peripheral blood leukocytes, after obtaining venous blood.

RESULT(1) Five patients were hospitalized at the age of 1 month to 15 years. Three patients had Leigh syndrome with progressive motor developmental delay or regression and weakness. One had severe liver damage and intrahepatic cholestasis. One presented muscle weakness. (2) Deficient complex I + III activity was identified in five patients. Their complex I + III activities in peripheral blood leukocytes were 3.0 to 14.2 nmol/min per mg mitochondrial protein (control: 84.4 ± 28.5 nmol/min per mg mitochondrial protein). The ratio of complex I + III to citrate synthase decreased to 3.5 to 22.9% (normal control 66.1 ± 14.7%). The activities of complex III decreased to 10.4 to 49.3% of the lowest control value, while complex I, II, IV and V activities were normal. The results supported the diagnosis of isolated respiratory chain complex III deficiency.

CONCLUSIONComplex III deficiency is a kind of disorder of energy metabolism with various manifestations. The complex I + III activities and the ratio of complex I + III to citrate synthase were lower than those of the control. The activities of complex I, II, IV and V were normal.

Adolescent ; Child ; Child, Preschool ; Electron Transport Complex I ; metabolism ; Electron Transport Complex II ; metabolism ; Electron Transport Complex III ; metabolism ; Female ; Humans ; Infant ; Leigh Disease ; Leukocytes, Mononuclear ; enzymology ; Male ; Mitochondrial Diseases ; diagnosis ; metabolism ; physiopathology

OBJECTIVETo investigate the mechanisms of Yinxing Pingchan recipe (YXPC) and its components, i.e. the components for detoxicating (A), for calming liver (B) and for dissolving blood stasis(C), in preventing and treating Parkinson's disease, and the path of its inhibition on nigrostriatal dopaminergic neuron (DAn) apoptosis in model mice of Parkinson's disease.

METHODSMale C57BL/6J mice were divided into the normal group, the model group and four Chinese medicinal groups, that is, the YXPC group, and Group A, B and C, treated with YXPC and its components A, B and C respectively. Mouse model of Parkinson's disease was established by intraperitoneal injection with 1-methl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP). All mice were sacrificed in 2 batches at the 14th and the 28th day respectively. The activity of mitochondrial enzyme complex I, II and IV (MEC I, II and IV) in the brain of mice were measured, respectively.

RESULTSAs compared with the normal group, the activity of MEC I and IV in brain was significantly lower (P < 0.05 or P < 0.01), and that of MEC II had no obvious change in the model group. As compared with the model group, the activity of MEC I was significantly higher in YXPC group and Group C at the 14th day (P < 0.05), while the activity of MECII in Group A at the 14th day, Group B at the 28th day and Group C at both 14th and 28th day was significantly lower (P<0.05 or P<0.01). Activity of MEC IV in the four Chinese medicinal groups at the 14th day all significantly increased (P<0.05 or P<0.01), and retained at high level in Group B and Group C at the 28th day (P<0.05).

CONCLUSIONYXPC and its components can maintain the mitochondrial function by partial inhibiting the activity of its enzyme complex, preventing DAn apoptosis to slow down the progress of Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Animals ; Brain ; enzymology ; Drugs, Chinese Herbal ; pharmacology ; Electron Transport Complex I ; metabolism ; Electron Transport Complex II ; metabolism ; Electron Transport Complex III ; metabolism ; Electron Transport Complex IV ; metabolism ; Enzyme Activation ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Mitochondria ; enzymology ; Parkinson Disease ; drug therapy ; enzymology ; etiology ; Random Allocation

No abstract available.
Apoferritins ; Ferritins ; Humans

O1igodendrocytes are known to be responsible for the synthesis and maintenance of myelin sheath in the central nervous system, and their functional disturbance leads to defect in myelination. But, the fine mechanism of myelination by oligodendrocytes is not yet known, and iron metabolism in central nervous system is suspected to be related with myelination process by oligodendrocytes. Carbonic anhydrase-II[CA-II], transfe-rrin, and ferritin are known to be present at oligodendrocytes and suspected to play a role in iron metabolism of central nervous system. In this study, demyelination and remyelination of ICR mouse brains were induced using cuprizone, the copper-chelating agent, and immunohistochemical changes of CA-II-, transferrin-, and ferritin-immunoreactive oligodendrocytes at corpus callosum were observed. During demyelination by cuprizone feeding, the numbers of CA-II- and transferrin-immunoreactive oligodendrocytes were decreased. Especially, the decrease ratio of CA-II-positive cells was great. In contrast, the number of ferritin-positive oligodendrocytes was increased during demyelination by cuprizone feeding. Cessation of cuprizone feeding leaded remyelination and the numbers of CA-II-, transferrin-, and ferritin-immunoreactive oligodendrocytes were returned to normal level. In conclusion, the derangement of iron metabolism in oligodendrocytes may be related to demyelination mechanism of central nervous system, and the CA-II is suspected to have an important role in iron metabolism of oligodenrocytes in relation to demyelination and remyelination induced with cuprizone.
Animals ; Brain ; Carbon* ; Central Nervous System ; Corpus Callosum ; Cuprizone* ; Demyelinating Diseases ; Ferritins ; Iron ; Iron-Binding Proteins* ; Metabolism ; Mice* ; Mice, Inbred ICR ; Myelin Sheath ; Oligodendroglia ; Transferrin

Animals ; Cell Respiration ; Electron Transport Complex III ; metabolism ; Humans ; Iron-Sulfur Proteins ; chemistry ; metabolism ; Mitochondria ; metabolism ; Peptide Fragments ; chemistry ; metabolism ; Protein Multimerization ; Protein Structure, Quaternary ; Protein Subunits ; chemistry

We present a case of a young female patient with fulminant hepatitis who showed an altered biodistribution of Ga-67, after being scanned twice at 10 month intevals. On initial scan, uptake of Ga-67 was increased in the liver, kidneys, and skeletons. Increased hepatic Ga-67 uptake may be explained by increased transferrin unbound Ga-67 that was taken up by the inflamed liver. The saturation of iron-binding proteins due to multiple transfusions may lead to increased renal and skeletal Ga-67 uptake. On follow-up scan hepatic Ga-67 uptake was markedly increased. Also increased Ga-67 uptake in the axial skeleton and normalized renal uptake were shown. The findings were consistent with iron deficiency anemia. This case demonstrates altered Ga-67 biodistribution associated with multiple transfusions, fulminant hepatitis, and iron deficiency anemia.
Anemia, Iron-Deficiency ; Female ; Follow-Up Studies ; Hepatitis ; Humans ; Iron-Binding Proteins ; Kidney ; Liver ; Skeleton ; Transferrin

Electron Transport ; Electron Transport Complex III ; deficiency ; Humans ; Mitochondria ; metabolism

No abstract available.
Ferritins*

DNA primase catalyzes de novo synthesis of a short RNA primer that is further extended by replicative DNA polymerases during initiation of DNA replication. The eukaryotic primase is a heterodimeric enzyme comprising a catalytic subunit Pri1 and a regulatory subunit Pri2. Pri2 is responsible for facilitating optimal RNA primer synthesis by Pri1 and mediating interaction between Pri1 and DNA polymerase α for transition from RNA synthesis to DNA elongation. All eukaryotic Pri2 proteins contain a conserved C-terminal iron-sulfur (Fe-S) cluster-binding domain that is critical for primase catalytic activity in vitro. Here we show that mutations at conserved cysteine ligands for the Pri2 Fe-S cluster markedly decrease the protein stability, thereby causing S phase arrest at the restrictive temperature. Furthermore, Pri2 cysteine mutants are defective in loading of the entire DNA pol α-primase complex onto early replication origins resulting in defective initiation. Importantly, assembly of the Fe-S cluster in Pri2 is impaired not only by mutations at the conserved cysteine ligands but also by increased oxidative stress in the sod1Δ mutant lacking the Cu/Zn superoxide dismutase. Together these findings highlight the critical role of Pri2's Fe-S cluster domain in replication initiation in vivo and suggest a molecular basis for how DNA replication can be influenced by changes in cellular redox state.
Amino Acid Sequence ; Cell Cycle ; Cell Proliferation ; Chromatin Immunoprecipitation ; Cysteine ; genetics ; metabolism ; DNA Primase ; genetics ; metabolism ; DNA Replication ; DNA, Fungal ; genetics ; DNA-Directed DNA Polymerase ; metabolism ; Immunoblotting ; Immunoprecipitation ; Iron ; metabolism ; Iron-Sulfur Proteins ; metabolism ; Molecular Sequence Data ; Mutation ; genetics ; Oxidative Stress ; Protein Binding ; Saccharomyces cerevisiae ; genetics ; growth & development ; metabolism ; Sequence Homology, Amino Acid ; Sulfur ; metabolism

Iron plays a key role in Parkinson s disease (PD). To illustrate the mechanism underlying the increase of iron in substantia nigra (SN) in PD, changes of the expression of divalent metal transporter 1 (DMT1) and iron content were examined in SN in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated mice using immunohistochemistry and histochemistry respectively. Following MPTP treatment for 3 d, elevated iron staining was found in SN. A further increase in iron content was observed after 7 d. In these lesioned animals, tyrosine hydroxylase-immunoreactive DA neurons exhibited a decrease in number and morphological changes as well. There were two isoforms of DMT1 expressed in SN of mice. After MPTP treatment, the expression of DMT1 without IRE form increased in either group, whereas DMT1 with IRE form increased only after 7 d of MPTP treatment. These observations suggest that DMT1 is possibly involved in the process of iron accumulation in SN of MPTP-treated mice, which might be responsible for the subsequent death of DA neurons.
Animals ; Cation Transport Proteins ; metabolism ; Dopamine ; metabolism ; Iron ; metabolism ; Iron-Binding Proteins ; metabolism ; Mice ; Mice, Inbred C57BL ; Parkinsonian Disorders ; metabolism ; Protein Isoforms ; metabolism ; Substantia Nigra ; metabolism ; Transferrin ; metabolism