41 research outputs found

    Oyygen uptake of adriamycin resistant cells of Ehrlich ascites tumor

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    エールリッヒ腹水癌細胞を用いアドリアマイシンに対する耐性細胞(ADR耐性細胞)を樹立した。電子顕微鏡を用い撮影写真から細胞質当たりのミトコンドリア(MT)の割合を面積比で求めた。親株に比較して1μg/ml ADR耐性細胞では1.32倍、10μg/ml ADR耐性細胞では1.47倍であった。これらの細胞の呼吸を測定した。耐性細胞の内発呼吸は親株に比較して増加していた。1μg/ml ADR耐性細胞では1.45倍、10μg/ml ADR耐性細胞では1.49倍であり、MTの増加量とほぼ同じ割合であった。これらのことから、細胞が耐性になるとエネルギー消費が高まるために細胞内MTが増加し、その結果呼吸(酸素消費)が増加することが推察された。Adriamycin-resistant cells of Ehrlich ascites tumor cells were established in our laboratory. Using electron microscope, the area of mitochondria (MT) per cytoplasm of ADR-resistant cells were measured with planimeter. The values of wild-type cells, 1μg/ml ADR-resistant cells and 10μg/ml ADR-resistant cells were 39.3, 51.8 and 57.7 μ(2) per 1,000 μ(2) of cytoplasm, respectively. Oxygen consumption of 1 μg/ml ADR-resistant cells and 10 μg/ml ADR-resistant cells were 1.45-fold and 1.49-fold compared to that of wild-type cells, respectively. These results indicate that ADR-resistant cells require more energy to work efflux pump than wild-type cells

    A Proteomic Approach for the Diagnosis of ‘Oketsu’ (blood stasis), a Pathophysiologic Concept of Japanese Traditional (Kampo) Medicine

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    ‘Oketsu’ is a pathophysiologic concept in Japanese traditional (Kampo) medicine, primarily denoting blood stasis/stagnant syndrome. Here we have explored plasma protein biomarkers and/or diagnostic algorithms for ‘Oketsu’. Sixteen rheumatoid arthritis (RA) patients were treated with keishibukuryogan (KBG), a representative Kampo medicine for improving ‘Oketsu’. Plasma samples were diagnosed as either having an ‘Oketsu’ (n = 19) or ‘non-Oketsu’ (n = 29) state according to Terasawa's ‘Oketsu’ scoring system. Protein profiles were obtained by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and hierarchical clustering and decision tree analyses were performed. KBG treatment for 4 or 12 weeks decreased the ‘Oketsu’ scores significantly. SELDI protein profiles gave 266 protein peaks, whose expression was significantly different between the ‘Oketsu’ and ‘non-Oketsu’ states. Hierarchical clustering gave three major clusters (I, II, III). The majority (68.4%) of ‘Oketsu’ samples were clustered into one cluster as the principal component of cluster I. The remaining ‘Oketsu’ profiles constituted a minor component of cluster II and were all derived from patients cured of the ‘Oketsu’ state at 12 weeks. Construction of the decision tree addressed the possibility of developing a diagnostic algorithm for ‘Oketsu’. A reduction in measurement/pre-processing conditions (from 55 to 16) gave a similar outcome in the clustering and decision tree analyses. The present study suggests that the pathophysiologic concept of Kampo medicine ‘Oketsu’ has a physical basis in terms of the profile of blood proteins. It may be possible to establish a set of objective criteria for diagnosing ‘Oketsu’ using a combination of proteomic and bioinformatics-based classification methods

    C/EBPβ Promotes Transition from Proliferation to Hypertrophic Differentiation of Chondrocytes through Transactivation of p57Kip2

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    BACKGROUND: Although transition from proliferation to hypertrophic differentiation of chondrocytes is a crucial step for endochondral ossification in physiological skeletal growth and pathological disorders like osteoarthritis, the underlying mechanism remains an enigma. This study investigated the role of the transcription factor CCAAT/enhancer-binding protein beta (C/EBPbeta) in chondrocytes during endochondral ossification. METHODOLOGY/PRINCIPAL FINDINGS: Mouse embryos with homozygous deficiency in C/EBPbeta (C/EBPbeta-/-) exhibited dwarfism with elongated proliferative zone and delayed chondrocyte hypertrophy in the growth plate cartilage. In the cultures of primary C/EBPbeta-/- chondrocytes, cell proliferation was enhanced while hypertrophic differentiation was suppressed. Contrarily, retroviral overexpression of C/EBPbeta in chondrocytes suppressed the proliferation and enhanced the hypertrophy, suggesting the cell cycle arrest by C/EBPbeta. In fact, a DNA cell cycle histogram revealed that the C/EBPbeta overexpression caused accumulation of cells in the G0/G1 fraction. Among cell cycle factors, microarray and real-time RT-PCR analyses have identified the cyclin-dependent kinase inhibitor p57(Kip2) as the transcriptional target of C/EBPbeta. p57(Kip2) was co-localized with C/EBPbeta in late proliferative and pre-hypertrophic chondrocytes of the mouse growth plate, which was decreased by the C/EBPbeta deficiency. Luciferase-reporter and electrophoretic mobility shift assays identified the core responsive element of C/EBPbeta in the p57(Kip2) promoter between -150 and -130 bp region containing a putative C/EBP motif. The knockdown of p57(Kip2) by the siRNA inhibited the C/EBPbeta-induced chondrocyte hypertrophy. Finally, when we created the experimental osteoarthritis model by inducing instability in the knee joints of adult mice of wild-type and C/EBPbeta+/- littermates, the C/EBPbeta insufficiency caused resistance to joint cartilage destruction. CONCLUSIONS/SIGNIFICANCE: C/EBPbeta transactivates p57(Kip2) to promote transition from proliferation to hypertrophic differentiation of chondrocytes during endochondral ossification, suggesting that the C/EBPbeta-p57(Kip2) signal would be a therapeutic target of skeletal disorders like growth retardation and osteoarthritis

    The Kunitz-Like Modulatory Protein Haemangin Is Vital for Hard Tick Blood-Feeding Success

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    Ticks are serious haematophagus arthropod pests and are only second to mosquitoes as vectors of diseases of humans and animals. The salivary glands of the slower feeding hard ticks such as Haemaphysalis longicornis are a rich source of bioactive molecules and are critical to their biologic success, yet distinct molecules that help prolong parasitism on robust mammalian hosts and achieve blood-meals remain unidentified. Here, we report on the molecular and biochemical features and precise functions of a novel Kunitz inhibitor from H. longicornis salivary glands, termed Haemangin, in the modulation of angiogenesis and in persistent blood-feeding. Haemangin was shown to disrupt angiogenesis and wound healing via inhibition of vascular endothelial cell proliferation and induction of apoptosis. Further, this compound potently inactivated trypsin, chymotrypsin, and plasmin, indicating its antiproteolytic potential on angiogenic cascades. Analysis of Haemangin-specific gene expression kinetics at different blood-feeding stages of adult ticks revealed a dramatic up-regulation prior to complete feeding, which appears to be functionally linked to the acquisition of blood-meals. Notably, disruption of Haemangin-specific mRNA by a reverse genetic tool significantly diminished engorgement of adult H. longicornis, while the knock-down ticks failed to impair angiogenesis in vivo. To our knowledge, we have provided the first insights into transcriptional responses of human microvascular endothelial cells to Haemangin. DNA microarray data revealed that Haemangin altered the expression of 3,267 genes, including those of angiogenic significance, further substantiating the antiangiogenic function of Haemangin. We establish the vital roles of Haemangin in the hard tick blood-feeding process. Moreover, our results provide novel insights into the blood-feeding strategies that enable hard ticks to persistently feed and ensure full blood-meals through the modulation of angiogenesis and wound healing processes

    Akt1 in Osteoblasts and Osteoclasts Controls Bone Remodeling

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    Bone mass and turnover are maintained by the coordinated balance between bone formation by osteoblasts and bone resorption by osteoclasts, under regulation of many systemic and local factors. Phosphoinositide-dependent serine-threonine protein kinase Akt is one of the key players in the signaling of potent bone anabolic factors. This study initially showed that the disruption of Akt1, a major Akt in osteoblasts and osteoclasts, in mice led to low-turnover osteopenia through dysfunctions of both cells. Ex vivo cell culture analyses revealed that the osteoblast dysfunction was traced to the increased susceptibility to the mitochondria-dependent apoptosis and the decreased transcriptional activity of runt-related transcription factor 2 (Runx2), a master regulator of osteoblast differentiation. Notably, our findings revealed a novel role of Akt1/forkhead box class O (FoxO) 3a/Bim axis in the apoptosis of osteoblasts: Akt1 phosphorylates the transcription factor FoxO3a to prevent its nuclear localization, leading to impaired transactivation of its target gene Bim which was also shown to be a potent proapoptotic molecule in osteoblasts. The osteoclast dysfunction was attributed to the cell autonomous defects of differentiation and survival in osteoclasts and the decreased expression of receptor activator of nuclear factor-κB ligand (RANKL), a major determinant of osteoclastogenesis, in osteoblasts. Akt1 was established as a crucial regulator of osteoblasts and osteoclasts by promoting their differentiation and survival to maintain bone mass and turnover. The molecular network found in this study will provide a basis for rational therapeutic targets for bone disorders
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