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991.
Noriko Isobe Tomomi Yonekawa Takuya Matsushita Katsuhisa Masaki Satoshi Yoshimura Jakub Fichna Shu Chen Jadwiga Furmaniak Bernard Rees Smith Jun-ichi Kira 《Neurochemical research》2013,38(5):997-1001
Neuromyelitis optica (NMO) is an inflammatory disease that selectively affects the optic nerves and spinal cord. The discovery of NMO-IgG targeting aquaporin-4 (AQP4) in NMO patients suggested that NMO is a distinct entity, with a fundamentally different etiology from that of multiple sclerosis (MS). Although NMO usually leads to grave disability because of the more severe tissue destruction compared with classical MS, there have been several reports describing a benign form of NMO over a long disease term. NMO-IgG/AQP4 antibodies show high specificity but medium sensitivity for NMO, while the clinical relevance of AQP4 antibody titers remains to be determined. We aimed to clarify the clinical relevance of AQP4 antibody levels determined by a bridging enzyme-linked immunosorbent assay in 38 patients with NMO or NMO spectrum disorder. The AQP4 antibody levels were higher in patients with optic neuritis (ON) than in those without ON (p = 0.0164). Among the 12 patients examined in a longitudinal study, four showed an increase in the ELISA values during some relapses, and eight showed no clear correlation between the ELISA values and relapse. Of the four patients who demonstrated a steady rise in the antibody levels over time, two patients had no concomitant relapses, despite elevation of the AQP4 antibody levels. We conclude that high AQP4 antibody levels are associated with the occurrence of ON, but that the antibody levels themselves are not closely correlated with the onset of relapse. 相似文献
992.
Tomoyo Kasumi Kohta Araki Tatsuya Ohyama Shingo Tsuji Eri Yoshikawa Hiroshi Kobayashi 《Molecular simulation》2013,39(10):769-779
Binding of urokinase-type plasminogen activator (uPA) to its receptor (uPAR) on the surface of a cancer cell is considered to be a trigger for starting cancer invasions. In addition, the somatomedin B (SMB) domain of vitronectin binds simultaneously to uPAR to construct a ternary complex of uPAR–uPA–SMB. Here we present stable structures of the solvated complexes of uPAR–uPA and uPAR–uPA–SMB obtained by classical molecular mechanics simulations, and the specific interactions between uPAR, uPA and SMB are investigated by ab initio fragment molecular orbital calculations. The result indicates that the SMB binding enhances the binding affinity between uPAR and uPA, although there is no direct contact between SMB and uPA. In particular, the specific interaction between uPAR and the Lys36 residue of uPA is significantly affected by the SMB binding. The positively charged Lys23, Lys46 and Lys61 residues of uPA have strong attractive interactions to uPAR in both the uPAR–uPA and uPAR–uPA–SMB complexes, demonstrating the importance of these residues in the specific binding between uPAR and uPA. The current results on the specific interactions are informative for proposing potent antagonists, which block the uPA and SMB bindings to uPAR. 相似文献
993.
Kizaki T Maegawa T Sakurai T Ogasawara JE Ookawara T Oh-ishi S Izawa T Haga S Ohno H 《Biochemical and biophysical research communications》2011,413(3):454-459
Chronic low-level inflammation is associated with obesity and a sedentary lifestyle, causing metabolic disturbances such as insulin resistance. Exercise training has been shown to decrease chronic low-level systemic inflammation in high-fat diet (HFD)-induced obesity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Ghrelin is a peptide hormone predominantly produced in the stomach that stimulates appetite and induces growth hormone release. In addition to these well-known functions, recent studies suggest that ghrelin localizes to immune cells and exerts an anti-inflammatory effect. The purpose of the current study was to investigate the role of ghrelin expressed in macrophages in the anti-inflammatory effects of voluntary exercise training. Expression of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein (MCP)-1 and F4/80 was increased in adipose tissue from mice fed a HFD (HFD mice) compared with mice fed a standard diet (SD mice), whereas the expression of these inflammatory cytokines was markedly decreased in mice performing voluntary wheel running during the feeding of a HFD (HFEx mice). The expression of TNF-α was also increased in peritoneal macrophages by a HFD and exercise training inhibited the increase of TNF-α expression. Interestingly, expression of ghrelin in peritoneal macrophages was decreased by a HFD and recovered by exercise training. Suppression of ghrelin expression by siRNA increased TNF-α expression and LPS-stimulated NF-κB activation in RAW264 cells, which is a macrophage cell line. TNF-α expression by stimulation with LPS was significantly suppressed in RAW264 cells cultured in the presence of ghrelin. These results suggest that ghrelin exerts potent anti-inflammatory effects in macrophages and functions as a mediator of the beneficial effects of exercise training. 相似文献
994.
Kikukawa T Shimono K Tamogami J Miyauchi S Kim SY Kimura-Someya T Shirouzu M Jung KH Yokoyama S Kamo N 《Biochemistry》2011,50(41):8888-8898
Acetabularia rhodopsins are the first microbial rhodopsins discovered in a marine plant organism, Acetabularia acetabulum. Previously, we expressed Acetabularia rhodopsin II (ARII) by a cell-free system from one of two opsin genes in A. acetabulum cDNA and showed that ARII is a light-driven proton pump [Wada, T., et al. (2011) J. Mol. Biol. 411, 986-998]. In this study, the photochemistry of ARII was examined using the flash-photolysis technique, and data were analyzed using a sequential irreversible model. Five photochemically defined intermediates (P(i)) were sufficient to simulate the data. Noticeably, both P(3) and P(4) contain an equilibrium mixture of M, N, and O. Using a transparent indium tin oxide electrode, the photoinduced proton transfer was measured over a wide pH range. Analysis of the pH-dependent proton transfer allowed estimation of the pK(a) values of some amino acid residues. The estimated values were 2.6, 5.9 (or 6.3), 8.4, 9.3, 10.5, and 11.3. These values were assigned as the pK(a) of Asp81 (Asp85(BR)) in the dark, Asp92 (Asp96(BR)) at N, Glu199 (Glu204(BR)) at M, Glu199 in the dark, an undetermined proton-releasing residue at the release, and the pH to start denaturation, respectively. Following this analysis, the proton transfer of ARII is discussed. 相似文献
995.
Hidetatsu Outani Minoru Okada Kunihiko Hiramatsu Hideki Yoshikawa Noriyuki Tsumaki 《Biochemical and biophysical research communications》2011,(3):607
There is a significant need for cell sources for cartilage regenerative medicine. It has been reported that the combined transduction of two reprogramming factors (c-Myc and Klf4) and one chondrogenic factor (SOX9) directly induces chondrogenic cells from mouse dermal fibroblast (MDF) culture. To gain insights into the process by which cellular characteristics are altered by transduction of c-Myc, Klf4 and SOX9, we examined marker gene expression in the MDF culture at various time points after transduction. The expression of fibroblast-markers was reduced first, followed by an increase in the expression of a chondrocyte-marker. We detected no expression of pluripotent markers at any time point examined. To determine whether or not induced chondrogenic cells go through a pluripotent state after transduction, we analyzed MDFs prepared from Nanog-GFP transgenic mice by monitoring expression of the GFP-labeled pluripotent marker Nanog-GFP in the MDF culture, using time-lapse microscopic observation. Whole-well time-lapse observation revealed that none of the induced chondrogenic cells displayed GFP fluorescence during induction. These results indicate that cells do not undergo a pluripotent state during direct induction of chondrogenic cells from fibroblast culture by transduction of c-Myc, Klf4 and SOX9. 相似文献
996.
Kawabata K Yoshikawa H Saruwatari K Akazawa Y Inoue T Kuze T Sayo T Uchida N Sugiyama Y 《Biochimica et biophysica acta》2011,1814(10):1246-1252
It is well known that advanced glycation end products (AGEs) are formed in long-lived dermal proteins such as collagen, and that their formation is related to skin aging. To examine the distribution of AGEs in skin tissue, we performed immunofluorescence studies on the human skin using an anti-AGEs antibody. Interestingly, AGEs signals were observed not only in the dermis but also in the epidermis. The objectives of this study were to confirm the presence of N(ε)-(Carboxymethyl) lysine (CML), an AGE structure, in the epidermis and to characterize the CML-modified proteins. The presence of CML in the stratum corneum (SC) was examined using liquid chromatography-electrospray ionization time-of-flight mass spectrometry. Concordance between the retention times of a compound in the SC hydrolysate and authentic CML, as well as with the specific mass transition of CML, was detected. This result showed that CML is present in the epidermis. In order to characterize the CML-modified proteins in the epidermis, protein samples extracted from the SC were analyzed using two-dimensional electrophoresis followed by an amino acid sequence analysis. The clarified peptide sequences covered approximately 27% of the amino acid sequences of cytokeratin 10 (K10). In the immunoblotting experiment following the two-dimensional electrophoresis, where protein samples extracted from whole epidermis were used, the position of the major CML-positive spots corresponded to those of K10. Taken together these results showed that CML is present in the human epidermis, and suggest that K10 is one of the target molecules for CML modification in the epidermis. 相似文献
997.
Yoshihiro Ojima Tomomi Sawabe Katsuya Konami Masayuki Azuma 《Biotechnology and bioengineering》2020,117(3):701-709
Outer membrane vesicles (OMVs) are extracellular vesicles released from the surface of Gram-negative bacteria, including Escherichia coli. Several gene-deficient mutants relating to envelope stress (nlpI and degP) and phospholipid accumulation in the outer leaflet of the outer membrane (mlaA and mlaE) increase OMV production. This study examined the combinatorial deletion of these genes in E. coli and its effect on OMV production. The nlpI and mlaE double-gene-knockout mutant (ΔmlaEΔnlpI) showed the highest OMV production. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis-based quantitative analysis showed that OMV production by strain ΔmlaEΔnlpI was ~30 times that by the wild-type (WT). In addition, to evaluate the protein secretion capacity of OMVs, a green fluorescent protein (GFP) fused with outer membrane protein W (OmpW) was expressed in OMVs. Western blot analysis showed that GFP secretion through OMVs reached 3.3 mg/L in the culture medium of strain ΔmlaEΔnlpI/gfp, 500 times that for the WT. Our approach using OMVs for extracellular protein secretion in E. coli is an entirely new concept compared with existing secretion systems. 相似文献
998.
Naoto Hirose Yuki Okamoto Makoto Yanoshita Yuki Asakawa Chikako Sumi Mami Takano Sayuri Nishiyama Shao‐Ching Su Tomomi Mitsuyoshi Ryo Kunimatsu Kazuo Tanne Kotaro Tanimoto 《Cell biology international》2020,44(4):966-974
Chondrocytes constantly receive external stimuli, which regulates remodeling. An optimal level of mechanical stress is essential for maintaining chondrocyte homeostasis, however, excessive mechanical stress induces inflammatory cytokines and protease, such as matrix metalloproteinases (MMPs). Therefore, excessive mechanical stress is considered to be one of the main causes to cartilage destruction leading to osteoarthritis (OA). Integrins are well‐known as cell adhesion molecules and act as receptors for extracellular matrix (ECM), and are believed to control intracellular signaling pathways both physically and chemically as a mechanoreceptor. However, few studies have focused on the roles and functions of integrins in inflammation caused by excessive mechanical stress. In this study, we examined the relationship between integrins (αVβ3 and αVβ5) and the expression of inflammatory factors under mechanical loading in chondrocytes by using an integrin receptor antagonist (cilengitide). Cilengitide suppressed the gene expression of interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), matrix metalloproteinase‐3 (MMP‐3), and MMP‐13 induced by excessive mechanical stress. In addition, the protein expression of IL1‐β and MMP‐13 was also inhibited by the addition of cilengitide. Next, we investigated the involvement of intracellular signaling pathways in stress‐induced integrin signaling in chondrocytes by using western blotting. The levels of p‐FAK, p‐ERK, p‐JNK, and p‐p38 were enhanced by excessive mechanical stress and the enhancement was suppressed by treatment with cilengitide. In conclusion, this study revealed that excessive mechanical stress may activate integrins αVβ3 and αVβ5 on the surface of chondrocytes and thereby induce an inflammatory reaction by upregulating the expression of IL‐1β, TNF‐α, MMP‐3, and MMP‐13 through phosphorylation of FAK and MAPKs. 相似文献
999.
Toshio Morikawa Kiyofumi Ninomiya Fengming Xu Naomichi Okumura Hisashi Matsuda Osamu Muraoka Takao Hayakawa Masayuki Yoshikawa 《Phytochemistry letters》2013,6(2):198-204
Two new acylated dolabellane-type diterpenes, nigellamines B3 (9) and D (10), were isolated from Nigella sativa (Ranunculaceae) seeds using column chromatography and preparative HPLC. Their structures were determined based on chemical and physicochemical evidence, and confirmed using previously isolated related compounds as reference. Of the seed constituents, nigellamines A2 (2), A3 (3), A5 (5), B1 (6), and B2 (7) had in vitro triglyceride metabolism-promoting activities in the high glucose-pretreated human liver carcinoma cell line, HepG2. 相似文献
1000.
Osamu Yoshikawa Yu Ebata Hiroyuki Tsuchiya Arisa Kawahara Chihiro Kojima Yoshito Ikeda Susumu Hama Kentaro Kogure Koichi Shudo Goshi Shiota 《Obesity (Silver Spring, Md.)》2013,21(1):E22-E25