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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/05/19 12:02:02」(JST)

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Integrin alphaXbeta2 (p150,95, CR4) is a complement receptor composed of CD11c and CD18.

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Integrin alphaXbeta2 at the US National Library of Medicine Medical Subject Headings (MeSH)

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1. 成人におけるステロイド抵抗性およびステロイド依存性の潰瘍性大腸炎に対するアプローチ approach to adults with steroid refractory and steroid dependent ulcerative colitis
2. 成人における重症または難治性クローン病の内科的マネージメントの概要 overview of the medical management of severe or refractory crohn disease in adults
3. 炎症の病因における白血球内皮細胞接着 leukocyte endothelial adhesion in the pathogenesis of inflammation
4. Leukocyte-adhesion deficiency
5. クローン病の内科的マネージメントにおける試験研究治療 investigational therapies in the medical management of crohn disease

English Journal

A cis-membrane FRET-based method for protein-specific imaging of cell-surface glycans.

Lin W1, Du Y, Zhu Y, Chen X.Author information 1Beijing National Laboratory for Molecular Sciences, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University , Beijing 100871, P.R. China.AbstractMetabolic labeling of glycans with chemical reproters (e.g., alkyne or azide) in conjunction with bioorthogonal chemistry is a powerful tool for imaging glycome; however, this method lacks protein-specificity and therefore is not applicable to imaging glycosylation of a specific protein of interest (POI). Here we report the development of a cis-membrane FRET-based methodology that allows protein-specific imaging of glycans on live cells. We exploit metabolic glycan labeling in conjunction with site-specific protein labeling to simultaneously install a FRET acceptor and a donor onto the glycans and the extracellular terminal of the protein of interest, respectively. The intramolecular donor-acceptor distance for the POI falls within the range for effective FRET, whereas the intermolecular FRET is disfavored since the excess acceptors on other proteins are distant from the donor. We demonstrated the capability of this cis-membrane FRET imaging method by visualizing the sialylation of several important cell surface receptors including integrin αXβ2, epidermal growth factor receptor, and transforming growth factor-beta receptor type I. Furthermore, our imaging experiments revealed that the sialylation might be important for β2 integrin activation. Our methodology should enable the live-cell studies on how glycosylation regulates the functions and dynamics of various cell-surface proteins.
Journal of the American Chemical Society.J Am Chem Soc.2014 Jan 15;136(2):679-87. doi: 10.1021/ja410086d. Epub 2014 Jan 1.
Metabolic labeling of glycans with chemical reproters (e.g., alkyne or azide) in conjunction with bioorthogonal chemistry is a powerful tool for imaging glycome; however, this method lacks protein-specificity and therefore is not applicable to imaging glycosylation of a specific protein of interest
PMID 24308457

The late endosomal adaptor molecule p14 (LAMTOR2) represents a novel regulator of Langerhans cell homeostasis.

Sparber F1, Scheffler JM, Amberg N, Tripp CH, Heib V, Hermann M, Zahner SP, Clausen BE, Reizis B, Huber LA, Stoitzner P, Romani N.Author information 1Department of Dermatology and Venereology, Innsbruck Medical University, Innsbruck, Austria;AbstractLangerhans cells (LCs) are dendritic cells (DCs) residing in epithelia, where they critically regulate immunity and tolerance. The p14 adaptor molecule is part of the late endosomal/LAMTOR (lysosomal adaptor and mitogen-activated protein kinase and mammalian target of rapamycin [mTOR] activator/regulator) complex, thereby contributing to the signal transduction of the extracellular signaling-regulated kinase (ERK) and the mTOR cascade. Furthermore, p14 represents an important regulator for endosomal sorting processes within the cell. Mutated, dysfunctional p14 leads to a human immunodeficiency disorder with endosomal/lysosomal defects in immune cells. Because p14 participates in the regulation of endosomal trafficking, growth factor signaling, and cell proliferation, we investigated the role of p14 in mouse DCs/LCs using a conditional knockout mouse model. p14-deficient animals displayed a virtually complete loss of LCs in the epidermis early after birth due to impaired proliferation and increased apoptosis of LCs. Repopulation analysis after application of contact sensitizer leads to the recruitment of a transient LC population, predominantly consisting of short-term LCs. The underlying molecular mechanism involves the p14-mediated disruption of the LAMTOR complex which results in the malfunction of both ERK and mTOR signal pathways. Hence, we conclude that p14 acts as a novel and essential regulator of LC homeostasis in vivo.
Blood.Blood.2014 Jan 9;123(2):217-27. doi: 10.1182/blood-2013-08-518555. Epub 2013 Oct 3.
Langerhans cells (LCs) are dendritic cells (DCs) residing in epithelia, where they critically regulate immunity and tolerance. The p14 adaptor molecule is part of the late endosomal/LAMTOR (lysosomal adaptor and mitogen-activated protein kinase and mammalian target of rapamycin [mTOR] activator/regu
PMID 24092934

Postprandial VLDL lipolysis products increase monocyte adhesion and lipid droplet formation via activation of ERK2 and NFκB.

den Hartigh LJ1, Altman R, Norman JE, Rutledge JC.Author information 1Department of Internal Medicine, Division of Endocrinology, Clinical Nutrition, and Vascular Medicine, University of California, Davis, California;AbstractPostprandial lipemia is characterized by a transient increase in circulating triglyceride-rich lipoproteins such as very low-density lipoprotein (VLDL) and has been shown to activate monocytes in vivo. Lipolysis of VLDL releases remnant particles, phospholipids, monoglycerides, diglycerides, and fatty acids in close proximity to endothelial cells and monocytes. We hypothesized that postprandial VLDL lipolysis products could activate and recruit monocytes by increasing monocyte expression of proinflammatory cytokines and adhesion molecules, and that such activation is related to the development of lipid droplets. Freshly isolated human monocytes were treated with VLDL lipolysis products (2.28 mmol/l triglycerides + 2 U/ml lipoprotein lipase), and monocyte adhesion to a primed endothelial monolayer was observed using a parallel plate flow chamber coupled with a CCD camera. Treated monocytes showed more rolling and adhesion than controls, and an increase in transmigration between endothelial cells. The increased adhesive events were related to elevated expression of key integrin complexes including Mac-1 [α(m)-integrin (CD11b)/β2-integrin (CD18)], CR4 [α(x)-integrin (CD11c)/CD18] and VLA-4 [α4-integrin (CD49d)/β1-integrin (CD29)] on treated monocytes. Treatment of peripheral blood mononuclear cells (PBMCs) and THP-1 monocytes with VLDL lipolysis products increased expression of TNFα, IL-1β, and IL-8 over controls, with concurrent activation of NFkB and AP-1. NFκB and AP-1-induced cytokine and integrin expression was dependent on ERK and Akt phosphorylation. Additionally, fatty acids from VLDL lipolysis products induced ERK2-dependent lipid droplet formation in monocytes, suggesting a link to inflammatory signaling pathways. These results provide novel mechanisms for postprandial monocyte activation by VLDL lipolysis products, suggesting new pathways and biomarkers for chronic, intermittent vascular injury.
American journal of physiology. Heart and circulatory physiology.Am J Physiol Heart Circ Physiol.2014 Jan 1;306(1):H109-20. doi: 10.1152/ajpheart.00137.2013. Epub 2013 Oct 25.
Postprandial lipemia is characterized by a transient increase in circulating triglyceride-rich lipoproteins such as very low-density lipoprotein (VLDL) and has been shown to activate monocytes in vivo. Lipolysis of VLDL releases remnant particles, phospholipids, monoglycerides, diglycerides, and fat
PMID 24163071