215 research outputs found
Uncoupling protein 3 attenuates generation of reactive oxygen species by interacting with thioredoxin 2 in the mitochondrial intermembrane space
Katsuya Hirasaka1*, Edward M Mills2, Shohei Kohno1, Tomoki Abe1, Chika Ikeda1, Tasuku Maeda1, Shigetada Kondo1, Ayako Maita1, Yuushi Okumura1 and Takeshi Nikawa1
Author Affiliations
1 Department of Nutritional Physiology, Institute of Health Biosciences, University of Tokushima, Tokushima, 770-8503, Japan
2 Division of Pharmacology/Toxicology, University of Texas at Austin, Austin, TX 78712, USAPoster presentation
Uncoupling protein 3 (UCP3) is primarily expressed in the inner membrane of skeletal muscle mitochondria. It has been proposed that UCP3 reduces production of reactive oxygen species (ROS) and oxidative damage. However, the mechanisms by which UCP3 attenuates ROS production are not well understood. Here we report that UCP3 interacts with the non-processed form of thioredoxin 2 (Trx2), a redox protein that is localized in mitochondria, but not processed Trx2, which is involved in cellular responses to ROS. The hydrophilic sequences within the N-terminal tail of UCP3, which faces the intermembrane space, are necessary for binding to Trx2. In addition, Trx2 directly associated with UCP3 through a mitochondrial targeting signaling sequence, was processed in the intermembrane space, and thereby allowing redox reactions. A bimolecular fluorescence complementation analysis demonstrated that the interaction of these proteins occurs in the mitochondrial intermembrane space. Furthermore, increased UCP3 expression significantly attenuated ROS production in isolated mitochondrial without effects on membrane potential, however this effect is lost by Trx2 knock down. These results suggest that UCP3 binds to Trx2 in the mitochondrial intermembrane space and attenuates ROS production.Pharmac
地域課題解決学習による児童の挑戦する意欲と社会的有効性意識の向上 : 総合的な学習の時間のマネジメントと授業実践を通して
The purpose of this study is to examine the effects of teachers’ the period for the Period of Integrated Study management and class practice, which mainly focuses on solving the problems of the community, on children’s willingness to take on challenges and awareness of social effectiveness in elementary schools. A graduate student who is also an elementary school teacher managed the Period of Integrated Study and practiced the lesson for about one year, mainly focusing on solving the problems of the community for 4th to 6th graders. A questionnaire survey was conducted before and after the practice to measure the children’s willingness to take on challenges and awareness of social effectiveness. As a result, under certain conditions, it was found that, in elementary schools, teachers’ the Period of Integrated Study management and class practice, which mainly focuses on solving the problems of the community can increase children’s willingness to take on challenges and a sense of social effectiveness. The condition is that the children have the experience of directly changing to solve the problems of the community continuously together with the residents who work to solve the problems of the community
N -Ethyl- N -Nitrosourea Induces Retinal Photoreceptor Damage in Adult Rats
Seven-week-old male Lewis rats received a single intraperitoneal injection of N-ethyl-N-nitrosourea (ENU) (100, 200, 400 or 600 mg/kg), and retinal damage was evaluated 7 days after the treatment. Sequential morphological features of the retina and retinal DNA damage, as determined by a TUNEL assay and phospho-histone H2A.X (γ-H2AX), were analyzed 3, 6, 12, 24 and 72 hr, 7 days, and/or 30 days after 400 mg/kg ENU treatment. Activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) was analyzed immunohistochemically by poly (ADP-ribose) (PAR) expression in response to DNA damage of the retina. All rats that received ≥ 400 mg/kg of ENU developed retinal degeneration characterized by the loss of photoreceptor cells in both the central and peripheral retina within 7 days. In the 400 mg/kg ENU-treated rats, TUNEL-positive signals were only located in the photoreceptor cells and peaked 24 hr after ENU treatment. The γ-H2AX signals in inner retinal cells appeared at 24 hr and peaked at 72 hr after ENU treatment, and the PAR signals selectively located in the photoreceptor cell nuclei appeared at 12 hr and peaked at 24 hr after ENU treatment. However, degeneration was restricted to photoreceptor cells, and no degenerative changes in inner retinal cells were seen at any time points. Retinal thickness and the photoreceptor cell ratio in the central and peripheral retina were significantly decreased, and the retinal damage ratio was significantly increased 7 days after ENU treatment. In conclusion, ENU induced retinal degeneration in adult rats that was characterized by photoreceptor cell apoptosis through PARP activity
EVALUATION OF ACCELERATED STABILIZATION OF LANDFILL BY MONITORING FUNCTIONAL MICROBES
Joint Research on Environmental Science and Technology for the Eart
Chronic Orofacial Pain in Dental Patients: Retrospective Investigation over 12 years
Orofacial pain is often difficult to diagnose and treat. However, there have been few reports on the clinical observation of dental patients with orofacial pain. We retrospectively investigated the characteristics of 221 dental patients who had suffered from persistent orofacial pain. Data were collected from the outpatient medical records in our clinic over the past 12 years. More than half of the patients (53.8%) had suffered with pain for more than 6 months from pain onset until the first visit to our clinic. The main diagnoses were neuropathic pain (30.3%), myofascial pain (23.5%), psychogenic pain (20.4%), odontogenic toothache (17.2%), and others (7.7%) such as temporomandibular disorders and glossitis. The treatments included pharmacotherapy, splint therapy, and others such as nerve block, dental treatment, physiotherapy, and/or psychotherapy. Excluding the patients (52 of 221 initially enrolled patients) with unknown responses to treatment, 65.7% showed remission or a significant improvement in pain in response to treatment. Although only a small group of patients had odontogenic toothache, the rate of improvement was highest for this disorder. In conclusion, early consultation with a dentist is useful to prevent chronicity of odontogenic pain and to make a differential diagnosis in patients with orofacial pain
Hepatomegaly Associated with Non-Obstructive Sinusoidal Dilation in Experimental Visceral Leishmaniasis.
Visceral leishmaniasis (VL) is the most severe form of leishmaniasis caused by protozoan parasites of the genus Leishmania. Hepatomegaly is one of the most frequent clinical manifestations of VL, whereas immunopathology of the symptom has not been well investigated. Using our chronic model of experimental VL, we examined the influence of Leishmania donovani infection on the liver by clinical, histological, and biochemical analyses. The infected mice showed increased liver weight 24 weeks post-infection. Although an increase in serum ALT and inflammatory cell accumulation were observed in the livers of infected mice, no apparent parenchymal necrosis or fibrosis was observed. Tissue water content analyses demonstrated that increased liver weight was predominantly due to an increase in water weight. Together with the finding of hepatic sinusoidal dilation, these results suggested that edema associated with sinusoidal dilation causes hepatomegaly in L. donovani infection. Immunostaining of platelets and erythrocytes showed no thrombus formation or damage to the sinusoidal endothelium in the liver of infected mice. Taken together, these results suggest that hepatomegaly during experimental VL is caused by non-obstructive sinusoidal dilation
Functional impairment of Tax-specific but not CMV-specific CTLs in a minor population of asymptomatic HTLV-1-carriers
Functional impairment of Tax-specific but not cytomegalovirus-specific CD8+ T lymphocytes in a minor population of asymptomatic human T-cell leukemia virus type 1-carriers
<p>Abstract</p> <p>Background</p> <p>Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in a small percentage of infected individuals. ATL is often associated with general immune suppression and an impaired HTLV-1-specific T-cell response, an important host defense system. We previously found that a small fraction of asymptomatic HTLV-1-carriers (AC) already showed impaired T-cell responses against the major target antigen, Tax. However, it is unclear whether the impaired HTLV-1 Tax-specific T-cell response in these individuals is an HTLV-1-specific phenomenon, or merely reflects general immune suppression. In this study, in order to characterize the impaired HTLV-1-specific T-cell response, we investigated the function of Tax-specific CD8<sup>+ </sup>T-cells in various clinical status of HTLV-1 infection.</p> <p>Results</p> <p>By using tetramers consisting of HLA-A*0201, -A*2402, or -A*1101, and corresponding Tax epitope peptides, we detected Tax-specific CD8<sup>+ </sup>T-cells in the peripheral blood from 87.0% of ACs (n = 20/23) and 100% of HAM/TSP patients (n = 18/18) tested. We also detected Tax-specific CD8<sup>+ </sup>T-cells in 38.1% of chronic type ATL (cATL) patients (n = 8/21), although its frequencies in peripheral blood CD8<sup>+ </sup>T cells were significantly lower than those of ACs or HAM/TSP patients. Tax-specific CD8<sup>+ </sup>T-cells detected in HAM/TSP patients proliferated well in culture and produced IFN-γ when stimulated with Tax peptides. However, such functions were severely impaired in the Tax-specific CD8<sup>+ </sup>T-cells detected in cATL patients. In ACs, the responses of Tax-specific CD8<sup>+ </sup>T-cells were retained in most cases. However, we found one AC sample whose Tax-specific CD8<sup>+ </sup>T-cells hardly produced IFN-γ, and failed to proliferate and express activation (CD69) and degranulation (CD107a) markers in response to Tax peptide. Importantly, the same AC sample contained cytomegalovirus (CMV) pp65-specific CD8<sup>+ </sup>T-cells that possessed functions upon CMV pp65 peptide stimulation. We further examined additional samples of two smoldering type ATL patients and found that they also showed dysfunctions of Tax-specific but not CMV-specific CD8<sup>+ </sup>T-cells.</p> <p>Conclusions</p> <p>These findings indicated that Tax-specific CD8<sup>+ </sup>T-cells were scarce and dysfunctional not only in ATL patients but also in a limited AC population, and that the dysfunction was selective for HTLV-1-specifc CD8<sup>+ </sup>T-cells in early stages.</p
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