220 research outputs found

    Modulation of oxidative phosphorylation of human kidney 293 cells by transfection with the internal rotenone-insensitive NADH–quinone oxidoreductase (NDI1) gene of Saccharomyces cerevisiae

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    AbstractIn contrast to the mitochondrial proton-translocating NADH–quinone oxidoreductase (complex I), which consists of at least 43 different subunits, the internal rotenone-insensitive NADH–quinone oxidoreductase (Ndi1) of Saccharomyces cerevisiae is a single polypeptide enzyme. The NDI1 gene was stably transfected into the human embryonal kidney 293 (HEK 293) cells. The transfected NDI1 gene was then transcribed and translated in the HEK 293 cells to produce the functional enzyme. The immunochemical and immunofluorescence analyses indicated that the expressed Ndi1 polypeptide was located to the inner mitochondrial membranes. The expression of Ndi1 did not alter the content of existing complex I in the HEK 293 mitochondria, suggesting that the expressed Ndi1 enzyme does not displace the endogenous complex I. The NADH oxidase activity of the NDI1-transfected HEK 293 cells was not affected by rotenone but was inhibited by flavone. The ADP/O ratios coupled to NADH oxidation were lowered from 2.4 to 1.8 by NDI1-transfection while the ADP/O ratios coupled to succinate oxidation (1.6) were not changed. The NDI1-transfected HEK 293 cells were able to grow in media containing a complex I inhibitor such as rotenone and 1-methyl-4-phenylpyridinium ion. The potential usefulness of incorporating the Ndi1 protein into mitochondria of human cells is discussed

    Lack of complex I activity in human cells carrying a mutation in MtDNA-encoded ND4 subunit is corrected by the Saccharomyces cerevisiae NADH-quinone oxidoreductase (NDI1) gene

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    The gene for the single subunit, rotenone-insensitive, and flavone-sensitive internal NADH-quinone oxidoreductase of Saccharomyces cerevisiae (NDI1) can completely restore the NADH dehydrogenase activity in mutant human cells that lack the essential mitochondrial DNA (mtDNA)-encoded subunit ND4. In particular, the NDI1 gene was introduced into the nuclear genome of the human 143B.TK cell line derivative C4T, which carries a homoplasmic frameshift mutation in the ND4 gene. Two transformants with a low or high level of expression of the exogenous gene were chosen for a detailed analysis. In these cells the corresponding protein is localized in mitochondria, its NADH-binding site faces the matrix compartment as in yeast mitochondria, and in perfect correlation with its abundance restores partially or fully NADH-dependent respiration that is rotenone-insensitive, flavone-sensitive, and antimycin A-sensitive. Thus the yeast enzyme has become coupled to the downstream portion of the human respiratory chain. Furthermore, the P:O ratio with malate/glutamate-dependent respiration in the transformants is approximately two-thirds of that of the wild-type 143B.TK cells, as expected from the lack of proton pumping activity in the yeast enzyme. Finally, whereas the original mutant cell line C4T fails to grow in medium containing galactose instead of glucose, the high NDI1-expressing transformant has a fully restored capacity to grow in galactose medium. The present observations substantially expand the potential of the yeast NDI1 gene for the therapy of mitochondrial diseases involving complex I deficiency

    No Immune Responses by the Expression of the Yeast Ndi1 Protein in Rats

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    Background: The rotenone-insensitive internal NADH-quinone oxidoreductase from yeast, Ndi1, has been shown to work as a replacement molecule for complex I in the respiratory chain of mammalian mitochondria. In the so-called transkingdom gene therapy, one major concern is the fact that the yeast protein is foreign in mammals. Long term expression of Ndi1 observed in rodents with no apparent damage to the target tissue was indicative of no action by the host’s immune system. Methodology/Principal Findings: In the present study, we examined rat skeletal muscles expressing Ndi1 for possible signs of inflammatory or immune response. In parallel, we carried out delivery of the GFP gene using the same viral vector that was used for the NDI1 gene. The tissues were subjected to H&E staining and immunohistochemical analyses using antibodies specific for markers, CD11b, CD3, CD4, and CD8. The data showed no detectable signs of an immune response with the tissues expressing Ndi1. In contrast, mild but distinctive positive reactions were observed in the tissues expressing GFP. This clear difference most likely comes from the difference in the location of the expressed protein. Ndi1 was localized to the mitochondria whereas GFP was in the cytosol. Conclusions/Significance: We demonstrated that Ndi1 expression did not trigger any inflammatory or immune response in rats. These results push forward the Ndi1-based molecular therapy and also expand the possibility of using foreign protein

    Hepatic infarction following abdominal interventional procedures.

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    To clarify the incidence, background, and progress of hepatic infarction following interventional procedures, cases of hepatic infarction following interventional procedures at our department during the last decade were identified by reviewing the clinical records of 1982 abdominal angiography and interventional procedures and records of abdominal CT. Nine episodes (0.5%) in 8 patients were identified as hepatic infarction following an interventional procedure. Five episodes were preceded by embolization of the hepatic or celiac artery at emergency angiography for postoperative bleeding with hemorrhagic shock. Three episodes followed the elected interventional procedure for hepatocellular carcinoma, and the remaining episode occurred after 12 months of chemoinfusion through an indwelling catheter in the hepatic artery and portal vein. Hepatic arterial occlusion in all episodes and portal venous flow abnormality in 5 episodes were observed on angiography. Four patients whose liver function was initially impaired died of hepatic infarction, although the extent of the disease on CT did not appear to be related to the mortality. Multiple risk factors, including arterial insufficiency, were observed in each patient. The incidence of hepatic infarction following interventional procedures in this series was low but sometimes fatal, and occurred most frequently in emergency embolization in hemorrhagic shock.</p

    The ND2 subunit is labeled by a photoaffinity analogue of asimicin, a potent complex I inhibitor

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    AbstractNADH:ubiquinone oxidoreductase (complex I) is the entry enzyme of mitochondrial oxidative phosphorylation. To obtain the structural information on inhibitor/quinone binding sites, we synthesized [3H]benzophenone-asimicin ([3H]BPA), a photoaffinity analogue of asimicin, which belongs to the acetogenin family known as the most potent complex I inhibitor. We found that [3H]BPA was photo-crosslinked to ND2, ND1 and ND5 subunits, by the three dimensional separation (blue-native/doubled SDS–PAGE) of [3H]BPA-treated bovine heart submitochondrial particles. The cross-linking was blocked by rotenone. This is the first finding that ND2 was photo-crosslinked with a potent complex I inhibitor, suggesting its involvement in the inhibitor/quinone-binding

    Gene Expression Profiles of the Small Intestinal Mucosa of Dogs Repeatedly Infected with the Cestode \u3ci\u3eEchinococcus multilocularis\u3c/i\u3e

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    The data set presented in this article is related to a previous research article entitled, The timing of worm exclusion in dogs repeatedly infected with the cestode Echinococcus multilocularis (Kouguchi et al., 2016). This article describes the genes \u3e2 fold up- or down-regulated in the first- and repeated-infection groups compared to the healthy controls group. The gene expression profiles were generated using the Agilent-021193 Canine (V2) Gene Expression Microarray (GPL15379). The raw and normalized microarray data have been deposited with the Gene Expression Omnibus (GEO) database under accession number GSE105098

    Application of Single Prolonged Stress Induces Post-traumatic Stress Disorder-like Characteristics in Mice

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    We tried to clarify the applicability of a single prolonged stress (SPS) protocol as post-traumatic stress disorder (PTSD) model in mice. To investigate PTSD pathophysiology, we conducted hypothalamo-pituitary-adrenal (HPA) negative feedback testing at 1, 4, 8 and 12 weeks after the SPS by administrating a dexamethasone (DEX) suppression test. The SPS induced over-suppression of the HPA system by DEX treatment at 8 and 12 weeks. To investigate PTSD-like behavioral characteristics, we subjected mice to testing in a light/dark box (to assess anxiety), a Y-maze (working memory), a cliff avoidance (visual cognition), and an open field (locomotor activity) at 1, 4, 8 and 12 weeks after the SPS. In the light/dark box test, the SPS-applied mice spent significantly less time in the light box at 8 or 12 weeks. In the cliff avoidance test, the SPS-applied mice spent significantly less time in the open area at 1 week. However, in both the Y-maze test and the open field test, SPS-applied mice tended toward slight decreases in a time-dependent manner until 12 weeks. Therefore, SPS-applied mice may thus be useful for assessing characteristics relevant to PTSD that coincide with changes in the HPA axis

    Adult Worm Exclusion and Histological Data of Dogs Repeatedly Infected with the Cestode \u3ci\u3eEchinococcus multilocularis\u3c/i\u3e

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    The data presented in this article are related to a previously published research article titled The timing of worm exclusion in dogs repeatedly infected with the cestode Echinococcus multilocularis (Kouguchi et al. 2016). This data describe a comparison of worm exclusion in the early stage of infection (1 day and 6 days post-infection) between dogs infected for the first time (control group) and dogs repeatedly infected with the parasite 4 times (repeated infection groups). We observed that 6 days post reinfection, the number of adult worms in repeated-infection groups decreased by 88.7% compared with the control group. Histological analysis comparison of the small intestinal mucosa from healthy, first infected, and repeatedly infected dogs are also reported. We observed no clear pathological abnormality, except the shortening of microvillus in reinfected dogs. However, eosinophil accumulation and eosinophilic ulcers were observed in some reinfected dogs. This data could be useful as preliminary data to develop a final host vaccine for this parasite

    Successful treatment of unresectable advanced rectal cancer with liver metastases by hemostasis re-irradiation of the rectal cancer and palliative low-dose whole-liver radiation therapy: a case report.

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    A 72-year-old man was admitted to the hospital with fatigue. Colonoscopy revealed a 50 × 50 mm rectal tumor with bleeding. Based on close inspection, he was diagnosed with unresectable advanced rectal cancer with multiple liver metastases. Chemotherapy was administered as 10 cycles of bevacizumab + mFOLFOX6 and 7 cycles of bevacizumab + FOLFIRI. Nine months later, he presented with hematochezia and progression of anemia. It was difficult to stop the bleeding via endoscopy. He underwent radiation therapy (39 Gy in 13 fractions), and hemostasis was confirmed. Then, further chemotherapy was performed with 3 cycles of bevacizumab + FOLFIRI and 2 cycles of TAS102. However 14 months after the initial visit, he presented with right hypochondralgia and abdominal fullness due to the progression of multiple liver metastases. Palliative low-dose whole-liver radiation therapy (WLRT) (30 Gy in 10 fractions) was performed. He developed Grade 2 nausea, but his right hypochondralgia reduced, liver dysfunction improved, and he successfully completed radiotherapy. At approximately the same time his anemia progressed, and colonoscopy revealed recurrent bleeding from the tumor. Re-irradiation (15 Gy in 5 fractions) of the rectal tumor was carried out and a blood transfusion was performed for the bleeding. He was discharged after confirmation the anemia had not progressed. Few reports have been published on the use of both palliative re-irradiation to stop bleeding from rectal cancer and palliative low-dose WLRT. Based on our experience with this case, we believe that palliative radiotherapy can be useful in treating patients with a poor prognosis
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