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991.
Tomohiro Nakamura Piotr Cieplak Dong-Hyung Cho Adam Godzik Stuart A. Lipton 《Mitochondrion》2010,10(5):573-578
Neurons are known to use large amounts of energy for their normal function and activity. In order to meet this demand, mitochondrial fission, fusion, and movement events (mitochondrial dynamics) control mitochondrial morphology, facilitating biogenesis and proper distribution of mitochondria within neurons. In contrast, dysfunction in mitochondrial dynamics results in reduced cell bioenergetics and thus contributes to neuronal injury and death in many neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease, and Huntington’s disease. We recently reported that amyloid-β peptide, thought to be a key mediator of AD pathogenesis, engenders S-nitrosylation and thus hyperactivation of the mitochondrial fission protein Drp1. This activation leads to excessive mitochondrial fragmentation, bioenergetic compromise, and synaptic damage in models of AD. Here, we provide an extended commentary on our findings of nitric oxide-mediated abnormal mitochondrial dynamics. 相似文献
992.
Kuniko Akama Tomoe Horikoshi Atsushi Sugiyama Satoko Nakahata Aoi Akitsu Nobuyoshi Niwa Atsushi Intoh Yasutaka Kakui Michiko Sugaya Kazuo Takei Noriaki Imaizumi Takaya Sato Rena Matsumoto Hitoshi Iwahashi Shin-ichi Kashiwabara Tadashi Baba Megumi Nakamura Tosifusa Toda 《Biochimica et Biophysica Acta - Proteins and Proteomics》2010,1804(6):1272-1284
In mammalian spermiogenesis, sperm mature during epididymal transit to get fertility. The pig sharing many physiological similarities with humans is considered a promising animal model in medicine. We examined the expression profiles of proteins from boar epididymal caput, corpus, and cauda sperm by two-dimensional gel electrophoresis and peptide mass fingerprinting. Our results indicated that protein disulfide isomerase-P5 (PDI-P5) human homolog was down-regulated from the epididymal corpus to cauda sperm, in contrast to the constant expression of protein disulfide isomerase A3 (PDIA3) human homolog. To examine the functions of PDIA3 and PDI-P5, we cloned and sequenced cDNAs of pig PDIA3 and PDI-P5 protein precursors. Each recombinant pig mature PDIA3 and PDI-P5 expressed in Escherichia coli showed thiol-dependent disulfide reductase activities in insulin turbidity assay. Although PDIA3 showed chaperone activity to promote oxidative refolding of reduced denatured lysozyme, PDI-P5 exhibited anti-chaperone activity to inhibit oxidative refolding of lysozyme at an equimolar ratio. SDS-PAGE and Western blotting analysis suggested that disulfide cross-linked and non-productively folded lysozyme was responsible for the anti-chaperone activity of PDI-P5. These results provide a molecular basis and insights into the physiological roles of PDIA3 and PDI-P5 in sperm maturation and fertilization. 相似文献
993.
Akihiko Murai Kosuke Kurosaki Katsu Yamane Yoshihiko Nakamura 《Progress in biophysics and molecular biology》2010,103(2-3):310-317
In this paper, we present a system that estimates and visualizes muscle tensions in real time using optical motion capture and electromyography (EMG). The system overlays rendered musculoskeletal human model on top of a live video image of the subject. The subject therefore has an impression that he/she sees the muscles with tension information through the cloth and skin. The main technical challenge lies in real-time estimation of muscle tension. Since existing algorithms using mathematical optimization to distribute joint torques to muscle tensions are too slow for our purpose, we develop a new algorithm that computes a reasonable approximation of muscle tensions based on the internal connections between muscles known as neuronal binding. The algorithm can estimate the tensions of 274 muscles in only 16 ms, and the whole visualization system runs at about 15 fps. The developed system is applied to assisting sport training, and the user case studies show its usefulness. Possible applications include interfaces for assisting rehabilitation. 相似文献
994.
Raham Sher Khan Gunaratnam Thirukkumaran Ikuo Nakamura Masahiro Mii 《Plant Cell, Tissue and Organ Culture》2010,101(3):279-285
The presence of marker genes conferring antibiotic or herbicide resistance in transgenic plants has been a serious problem
for their public acceptance and commercialization. MAT (multi-auto-transformation) vector system has been one of the strategies
to excise the selection marker gene from transgenic plants. Agrobacterium
tumefaciens strain EHA105 harboring a rol-type MAT vector, pMAT101, was used to produce morphologically normal transgenic Petunia hybrida ‘Dainty Lady’ employing rol gene as the selection marker gene. LacZ gene was used as a model gene of interest. Infected explants were cultured on plant growth regulator (PGR)- and antibiotic-free
half-strength MS medium. Sixty-five percent of the infected explants produced hairy roots. The hairy roots were separated
and proliferated on 1/2 MS hormone-free medium. Shoots produced from the hairy roots on 1/2 MS medium supplemented with benzylaminopurine
(BA) and naphthalene acetic acid (NAA) exhibited hairy root syndrome (Ri syndrome) such as dwarfed, reduced apical dominance,
short internodes and increased rooting, but subsequently produced normal-looking marker-free shoots. Molecular analysis of
DNA from the hairy roots, shoots with Ri syndrome and morphologically normal shoots revealed that the normal shoots had only
LacZ gene, and the removable cassette consisting of rol, R (recombinase) and GUS genes was excised. From this study it can be concluded that the chimeric rol genes can be used as a selection marker for Agrobacterinum-mediated transformation of Petunia hybrida and that the production of marker-free normal transgenic plants is possible without using selective chemical agents employing
rol-type MAT vector. 相似文献
995.
Maya Shirakura Hidetaka Eguchi Hideaki Nakamura Keiko Hiyama Eiji Tanaka Takashi Takata 《Biochemical and biophysical research communications》2010,393(4):800-805
Vascular endothelial growth factor (Vegf) was previously shown to be expressed specifically in the condylar cartilage of temporomandibular joint-osteoarthritis (TMJ-OA) model rats. Here we demonstrate for the first time that hypoxia-inducible factor-1α (Hif-1α) is activated in mature chondrocytes of temporomandibular joint-osteoarthritis (TMJ-OA) model rat by mechanical overload, and that activated Hif-1 in chondrocytes can induce osteoclastogenesis via repression of osteoprotegerin (Opg) expression.In rat TMJs, degeneration of the condylar cartilage became prominent in proportion to the duration of overloading. Hif-1α expression was observed specifically in mature and hypertrophic chondrocytes, and Hif-1α-positivity, level of Vegf expression, and tartrate-resistant acid phosphatase (TRAP)-positive cell numbers all increased in the same manner. When ATDC5 cells induced differentiation by insulin were cultured under hypoxia, Hif-1α induction was observed in mature stage, but not in immature stage. Inductions of Hif-1-target genes showed a similar expression pattern. In addition, expression of Opg decreased in hypoxia, and Hif-1α played a role, in part, in its regulation. 相似文献
996.
Kyung-Duk Min Yulin Liao Hidetoshi Okazaki Kazunori Fujimoto Ayako Takahashi Satoru Yamazaki Shoji Sanada Atsushi Nakano Toshiaki Otsuka Tadashi Isomura Naoki Mochizuki 《Biochemical and biophysical research communications》2010,393(1):55-7396
Although various management methods have been developed for heart failure, it is necessary to investigate the diagnostic or therapeutic targets of heart failure. Accordingly, we have developed different approaches for managing heart failure by using conventional microarray analyses. We analyzed gene expression profiles of myocardial samples from 12 patients with heart failure and constructed datasets of heart failure-associated genes using clinical parameters such as pulmonary artery pressure (PAP) and ejection fraction (EF). From these 12 genes, we selected four genes with high expression levels in the heart, and examined their novelty by performing a literature-based search. In addition, we included four G-protein-coupled receptor (GPCR)-encoding genes, three enzyme-encoding genes, and one ion-channel protein-encoding gene to identify a drug target for heart failure using in silico microarray database. After the in vitro functional screening using adenovirus transfections of 12 genes into rat cardiomyocytes, we generated gene-targeting mice of five candidate genes, namely, MYLK3, GPR37L1, GPR35, MMP23, and NBC1. The results revealed that systolic blood pressure differed significantly between GPR35-KO and GPR35-WT mice as well as between GPR37L1-Tg and GPR37L1-KO mice. Further, the heart weight/body weight ratio between MYLK3-Tg and MYLK3-WT mice and between GPR37L1-Tg and GPR37L1-KO mice differed significantly. Hence, microarray analysis combined with clinical parameters can be an effective method to identify novel therapeutic targets for the prevention or management of heart failure. 相似文献
997.
Kazuhiro Sudo Jun Yasuda Yukio Nakamura 《Biochemical and biophysical research communications》2010,397(4):697-705
Human umbilical cord blood (UCB) cells are an alternative source of hematopoietic stem cells for treatment of leukemia and other diseases. It is very difficult to assess the quality of UCB cells in the clinical situation. Here, we sought to assess the quality of UCB cells by transplantation to immunodeficient mice. Cryopreserved CD34+ UCB cells from twelve different human donors were transplanted into sublethally irradiated NOD/shi-scid Jic mice. In parallel, the gene expression profiles of the UCB cells were determined from oligonucleotide microarrays. UCB cells from three donors failed to establish an engraftment in the host mice, while the other nine succeeded to various extents. Gene expression profiling indicated that 71 genes, including HOXB4, C/EBP-β, and ETS2, were specifically overexpressed and 23 genes were suppressed more than 2-fold in the successful UCB cells compared to those that failed. Functional annotation revealed that cell growth and cell cycle regulators were more abundant in the successful UCB cells. Our results suggest that hematopoietic ability may vary among cryopreserved UCB cells and that this ability can be distinguished by profiling expression of certain sets of genes. 相似文献
998.
Yasutoshi Kido Kosuke Nakamura Takashi Suzuki Hiroyuki Saimoto Daijiro Ohmori Shigeharu Harada 《BBA》2010,1797(4):443-450
The trypanosome alternative oxidase (TAO) functions in the African trypanosomes as a cytochrome-independent terminal oxidase, which is essential for their survival in the mammalian host and as it does not exist in the mammalian host is considered to be a promising drug target for the treatment of trypanosomiasis. In the present study, recombinant TAO (rTAO) overexpressed in a haem-deficient Escherichia coli strain has been solubilized from E. coli membranes and purified to homogeneity in a stable and highly active form. Analysis of bound iron detected by inductively coupled plasma-mass spectrometer (ICP-MS) reveals a stoichiometry of two bound iron atoms per monomer of rTAO. Confirmation that the rTAO was indeed a diiron protein was obtained by EPR analysis which revealed a signal, in the reduced forms of rTAO, with a g-value of 15. The kinetics of ubiquiol-1 oxidation by purified rTAO showed typical Michaelis-Menten kinetics (Km of 338 μM and Vmax of 601 μmol/min/mg), whereas ubiquinol-2 oxidation showed unusual substrate inhibition. The specific inhibitor, ascofuranone, inhibited the enzyme in a mixed-type inhibition manner with respect to ubiquinol-1. 相似文献
999.
? Premise of the study: The development of compound microsatellite markers was conducted in Neolitsea sericea to investigate genetic diversity and population genetic structure of this endangered insular species. ? Methods and Results: Using the compound microsatellite marker technique, 10 compound microsatellite markers that were successfully amplified showed polymorphism when assessed in 55 individuals from two populations in East China and Japan. Overall, the number of alleles ranged from 3 to 17, with an average of 7.9 alleles per locus. In addition, these primers could be easily amplified in Neolitsea aurata var. paraciculata and N. aurata var. chekiangensis. ? Conclusions: The highly polymorphic markers developed and characterized in this study will be useful for population genetic studies of N. sericea. 相似文献
1000.
Dynamics of large wood at the watershed scale: a perspective on current research limits and future directions 总被引:1,自引:0,他引:1
Recent research has elucidated the positive ecological roles of large wood (LW) in fish-bearing channels. However, where logjams
increase local flooding and bank erosion, LW has negative impacts on public safety and property protection. Although our understanding
of reach-scale processes and patterns has increased dramatically in recent years, only a few studies have integrated this
knowledge at the watershed scale. Here we review variations in LW dynamics along a gradient of watershed sizes. In small watersheds,
a massive amount of LW, resulting from forest dynamics and hillslope processes, remains on the valley floor. These pieces
may persist for several decades and are eventually transported during debris flows. In intermediate watersheds, LW is dominantly
recruited by bank erosion from adjacent riparian areas. These pieces are continuously transported downstream with LW pieces
that are supplied from the upstream watershed by floods because these channels have a greater width and depth than the length
and diameter of the pieces, as well as a high stream power. This leads to fragmentation of the LW pieces, which increases
their transportability. In large watersheds, LW pieces are frequently recruited at locations where the channel is adjacent
to riparian forests. Floated LW pieces can accumulate along channels with wide floodplains. Storage in floodplains can lead
to more rapid decay than in an anaerobic environment, resulting in the subsequent removal of LW pieces from the system. Our
review presents a generalized view of LW processing at the watershed scale, and is relevant to ecosystem management, disaster
prevention and the identification of knowledge gaps. 相似文献