127 research outputs found

    Calcium oscillation associated with reduced protein kinase C activities in ras-transformed NIH3T3 cells

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    AbstractWe show here novel intracellular Ca2+ oscillation in ν-K-ras-transformed NIH3T3 cells induced by mitogenic peptide hormones, bradykinin and bombesin, as well as fetal calf serum. Induction of the Ca2+ oscillation is strongly correlated with the malignant properties and inversely with PKC activities in vitro and in vivo. These results suggest that the mitogen-induced Ca2+ oscillation is negatively regulated by PKC, which modulates Ca2+ influx in ν-K-ras-transformed NIH3T3 cells

    Abnormal social behavior, hyperactivity, impaired remote spatial memory, and increased D1-mediated dopaminergic signaling in neuronal nitric oxide synthase knockout mice

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    <p>Abstract</p> <p>Background</p> <p>Neuronal nitric oxide synthase (nNOS) is involved in the regulation of a diverse population of intracellular messenger systems in the brain. In humans, abnormal NOS/nitric oxide metabolism is suggested to contribute to the pathogenesis and pathophysiology of some neuropsychiatric disorders, such as schizophrenia and bipolar disorder. Mice with targeted disruption of the nNOS gene exhibit abnormal behaviors. Here, we subjected nNOS knockout (KO) mice to a battery of behavioral tests to further investigate the role of nNOS in neuropsychiatric functions. We also examined the role of nNOS in dopamine/DARPP-32 signaling in striatal slices from nNOS KO mice and the effects of the administration of a dopamine D1 receptor agonist on behavior in nNOS KO mice.</p> <p>Results</p> <p>nNOS KO mice showed hyperlocomotor activity in a novel environment, increased social interaction in their home cage, decreased depression-related behavior, and impaired spatial memory retention. In striatal slices from nNOS KO mice, the effects of a dopamine D1 receptor agonist, SKF81297, on the phosphorylation of DARPP-32 and AMPA receptor subunit GluR1 at protein kinase A sites were enhanced. Consistent with the biochemical results, intraperitoneal injection of a low dose of SKF81297 significantly decreased prepulse inhibition in nNOS KO mice, but not in wild-type mice.</p> <p>Conclusion</p> <p>These findings indicate that nNOS KO upregulates dopamine D1 receptor signaling, and induces abnormal social behavior, hyperactivity and impaired remote spatial memory. nNOS KO mice may serve as a unique animal model of psychiatric disorders.</p

    Role of Heat Shock Protein 70 in Induction of Stress Fiber Formation in Rat Arterial Endothelial Cells in Response to Stretch Stress

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    We investigated the mechanism by which endothelial cells (ECs) resist various forms of physical stress using an experimental system consisting of rat arterial EC sheets. Formation of actin stress fibers (SFs) and expression of endothelial heat-shock stress proteins (HSPs) in response to mechanical stretch stress were assessed by immunofluorescence microscopy. Stretch stimulation increased expression of HSPs 25 and 70, but not that of HSP 90. Treatment with SB203580, a p38 MAP kinase inhibitor that acts upstream of the HSP 25 activation cascade, or with geldanamycin, an inhibitor of HSP 90, had no effect on the SF formation response to mechanical stretch stress. In contrast, treatment with quercetin, an HSP 70 inhibitor, inhibited both upregulation of endothelial HSP 70 and formation of SFs in response to tensile stress. In addition, treatment of stretched ECs with cytochalasin D, which disrupts SF formation, did not adversely affect stretch-induced upregulation of endothelial HSP 70. Our data suggest that endothelial HSP 70 plays an important role in inducing SF formation in response to tensile stress

    Effect of connective tissue growth factor (CCN2/CTGF) on proliferation and differentiation of mouse periodontal ligament-derived cells

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    Background: CCN2/CTGF is known to be involved in tooth germ development and periodontal tissue remodeling, as well as in mesenchymal tissue development and regeneration. In this present study, we investigated the roles of CCN2/CTGF in the proliferation and differentiation of periodontal ligament cells (murine periodontal ligament-derived cell line: MPL) in vitro. Results: In cell cultures of MPL, the mRNA expression of the CCN2/CTGF gene was stronger in sparse cultures than in confluent ones and was significantly enhanced by TGF-β. The addition of Recombinant CCN2/CTGF (rCCN2) to MPL cultures stimulated DNA synthesis and cell growth in a dose-dependent manner. Moreover, rCCN2 addition also enhanced the mRNA expression of alkaline phosphatase (ALPase), type I collagen, and periostin, the latter of which is considered to be a specific marker of the periosteum and periodontium; whereas it showed little effect on the mRNA expression of typical osteoblastic markers, e.g., osteopontin and osteocalcin. Finally, rCCN2/CTGF also stimulated ALPase activity and collagen synthesis. Conclusion: These results taken together suggest important roles of CCN2/CTGF in the development and regeneration of periodontal tissue including the periodontal ligament.</p

    Integrated education of gross anatomy and CT radiology for current advances in medicine

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    It is essential to learn human anatomy in 3D for advanced medicine. We designed such an education system by integrating anatomy dissection with diagnostic CT radiology. Cadavers were scanned by CT, and students consulted the postmortem CT images while dissecting the cadaver to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld DICOM viewers at the bench-side (OsiriX on iPod touch). Students had lectures and workshops on diagnostic radiology, and study assignments where they discussed findings in anatomy labs in comparison with CT radiology. This teaching method for gross anatomy was used from 2009, and yielded positive students’ perspectives, and significant improvements in radiology skills at clinical courses.This is the pre-peer reviewed version of the following article: Tohru Murakami, Yuki Tajika, Hitoshi Ueno, Sachiko Awata, Satoshi Hirasawa, Maki Sugimoto, Yoshihiko Kominato, Yoshito Tsushima, Keigo Endo, and Hiroshi Yorifuji. An integrated teaching method of gross anatomy and computed tomography radiology. Anat Sci Educ, 2014, which has been published in final form at http://onlinelibrary.wiley.com/ doi/10.1002/ase.1430/abstract

    Phosphodiesterase Inhibitors Suppress Lactobacillus casei Cell-Wall-Induced NF-κB and MAPK Activations and Cell Proliferation through Protein Kinase A—or Exchange Protein Activated by cAMP-Dependent Signal Pathway

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    Specific strains of Lactobacillus have been found to be beneficial in treating some types of diarrhea and vaginosis. However, a high mortality rate results from underlying immunosuppressive conditions in patients with Lactobacillus casei bacteremia. Cyclic AMP (cAMP) is a small second messenger molecule that mediates signal transduction. The onset and progression of inflammatory responses are sensitive to changes in steady-state cAMP levels. L. casei cell wall extract (LCWE) develops arteritis in mice through Toll-like receptor-2 signaling. The purpose of this study was to investigate whether intracellular cAMP affects LCWE-induced pathological signaling. LCWE was shown to induce phosphorylation of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and cell proliferation in mice fibroblast cells. Theophylline and phosphodiesterase inhibitor increased intracellular cAMP and inhibited LCWE-induced cell proliferation as well as phosphorylation of NF-κB and MAPK. Protein kinase A inhibitor H89 prevented cAMP-induced MAPK inhibition, but not cAMP-induced NF-κB inhibition. An exchange protein activated by cAMP (Epac) agonist inhibited NF-κB activation but not MAPK activation. These results indicate that an increase in intracellular cAMP prevents LCWE induction of pathological signaling pathways dependent on PKA and Epac signaling

    Hand-assisted laparoscopic splenectomy for a huge splenic vascular lesion with aneurysms in a patient with impending Kasabach-Merritt syndrome-like phenomenon

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    Splenic vascular lesions are relatively rare and are usually found incidentally. However, the vascular lesions associated with Kasabach-Merritt syndrome, such as hemangioma, can be life-threatening. We herein describe the case of a young adult female patient with a huge splenic vascular lesion, aneurysms of the splenic artery, and increased plasma levels of fibrin/fibrinogen degradation products and D-dimers. Hand-assisted laparoscopic splenectomy was performed, after which the coagulopathy was drastically improved. Minimally invasive surgical intervention such as hand-assisted laparoscopic splenectomy should be considered as the first treatment choice in such a case

    The Lactic Acid Bacterium Pediococcus acidilactici Suppresses Autoimmune Encephalomyelitis by Inducing IL-10-Producing Regulatory T Cells

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    BACKGROUND: Certain intestinal microflora are thought to regulate the systemic immune response. Lactic acid bacteria are one of the most studied bacteria in terms of their beneficial effects on health and autoimmune diseases; one of which is Multiple sclerosis (MS) which affects the central nervous system. We investigated whether the lactic acid bacterium Pediococcus acidilactici, which comprises human commensal bacteria, has beneficial effects on experimental autoimmune encephalomyelitis (EAE), an animal model of MS. METHODOLOGY/PRINCIPAL FINDINGS: P. acidilactici R037 was orally administered to EAE mice to investigate the effects of R037. R037 treatment suppressed clinical EAE severity as prophylaxis and therapy. The antigen-specific production of inflammatory cytokines was inhibited in R037-treated mice. A significant increase in the number of CD4(+) Interleukin (IL)-10-producing cells was observed in the mesenteric lymph nodes (MLNs) and spleens isolated from R037-treated naive mice, while no increase was observed in the number of these cells in the lamina propria. Because only a slight increase in the CD4(+)Foxp3(+) cells was observed in MLNs, R037 may primarily induce Foxp3(-) IL10-producing T regulatory type 1 (Tr1) cells in MLNs, which contribute to the beneficial effect of R037 on EAE. CONCLUSIONS/SIGNIFICANCE: An orally administered single strain of P. acidilactici R037 ameliorates EAE by inducing IL10-producing Tr1 cells. Our findings indicate the therapeutic potential of the oral administration of R037 for treating multiple sclerosis
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