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Post by Max on Jun 30, 2005 7:42:38 GMT -5
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Post by Max on Jun 30, 2005 7:42:55 GMT -5
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Post by Max on Jun 30, 2005 7:43:14 GMT -5
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Post by Max on Jun 30, 2005 7:43:29 GMT -5
Mutat Res. 2004 Jul 13;551(1-2):199-211. Related Articles, Links
Molecular imaging of the transcription factor NF-kappaB, a primary regulator of stress response.
Carlsen H, Alexander G, Austenaa LM, Ebihara K, Blomhoff R.
Department of Nutrition, Faculty of Medicine, University of Oslo, P.O. Box 1046 Blindern, N-0316 Oslo, Norway.
A wide range of environmental stress and human disorders involves inappropriate regulation of NF-kappaB, including cancers and numerous inflammatory conditions. We have developed transgenic mice that express luciferase under the control of NF-kappaB, enabling real-time non-invasive imaging of NF-kappaB activity in intact animals. We show that, in the absence of stimulation, strong, intrinsic luminescence is evident in lymph nodes in the neck region, thymus, and Peyer's patches. Treating mice with stressors, such as TNF-alpha, IL-1alpha, or lipopolysaccharide (LPS) increases the luminescence in a tissue-specific manner, with the strongest activity observable in the skin, lungs, spleen, Peyer's patches, and the wall of the small intestine. Liver, kidney, heart, muscle, and adipose tissue exhibit less intense activities. Exposure of the skin to a low dose of UV-B radiation increases luminescence in the exposed areas. In ocular experiments, LPS- and TNF-alpha injected NF-kappaB-luciferase transgenic mice exhibit a 20-40-fold increase in lens NF-kappaB activity, similar to other LPS- and TNF-alpha-responsive organs. Peak NF-kappaB activity occurs 6h after injection of TNF-alpha and 12h after injection of LPS. Peak activities occur, respectively, 3 and 6h later than that in other tissues. Mice exposed to 360J/m(2) of UV-B exhibit a 16-fold increase in NF-kappaB activity 6h after exposure, characteristically similar to TNF-alpha-exposed mice. Thus, in NF-kappaB-luciferase transgenic mice, NF-kappaB activity also occurs in lens epithelial tissue and is activated when the intact mouse is exposed to classical stressors. Furthermore, as revealed by real-time non-invasive imaging, induction of chronic inflammation resembling rheumatoid arthritis produces strong NF-kappaB activity in the affected joints. Finally, we have used the model to demonstrate NF-kappaB regulation by manipulating the Vitamin A status in mice. NF-kappaB activity is elevated in mice fed a Vitamin A deficient (VAD) diet, and suppressed by surplus doses of retinoic acid (RA). We thus demonstrate the development and use of a versatile model for monitoring NF-kappaB activation both in tissue homogenates and in intact animals after the use of classical activators, during disease progression and after dietary intervention.
Publication Types:
Review
PMID: 15225593 [PubMed - indexed for MEDLINE]
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Post by Max on Sept 6, 2005 15:43:01 GMT -5
Arthritis Rheum. 2005 May;52(5):1381-91. Related Articles, Links
Elevated CXCL16 expression by synovial macrophages recruits memory T cells into rheumatoid joints.
van der Voort R, van Lieshout AW, Toonen LW, Sloetjes AW, van den Berg WB, Figdor CG, Radstake TR, Adema GJ.
Nijmegen Center for Molecular Life Sciences, University Medical Center St. Radboud, Nijmegen, The Netherlands.
OBJECTIVE: Directional migration of leukocytes is orchestrated by the regulated expression of chemokine receptors and their ligands. The receptor CXCR6 is abundantly expressed by Th1-polarized effector/memory lymphocytes accumulating at inflammatory sites. This study was undertaken to examine the presence of CXCR6+ T cells and of CXCL16, the only ligand for CXCR6, in the joints of patients with rheumatoid arthritis (RA). METHODS: Flow cytometry analysis of the expression of CXCR6 by peripheral blood and synovial fluid (SF) T cells. In addition, by performing conventional and real-time reverse transcriptase-polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay, we determined the expression of CXCL16 and its protease ADAM-10 within synovium and by cultured macrophages. SF T cell migration was studied with the Transwell system. RESULTS: Accumulation of CXCR6+ T cells within RA SF coincided with highly elevated levels of CXCL16+ macrophages. In vitro studies revealed that monocytes started to express CXCL16 upon differentiation into macrophages, and that RA SF and tumor necrosis factor (TNF) enhanced CXCL16 expression. Moreover, RA patients responding to anti-TNF therapy showed a strongly decreased CXCL16 expression, whereas nonresponding patients did not. Interestingly, ADAM-10, a recently identified protease of CXCL16, was abundantly expressed by CXCL16+ macrophages in vitro and in RA in vivo, which resulted in increased levels of cleaved CXCL16 in RA SF relative to controls. Finally, CXCR6+ T cells from RA SF were attracted by CXCL16. CONCLUSION: These data provide evidence that enhanced production of CXCL16 in RA synovia leads to recruitment of CXCR6+ memory T cells, thereby contributing to the inflammatory cascade associated with RA pathology.
PMID: 15880344 [PubMed - indexed for MEDLINE]
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Post by hgghghhh on Sept 7, 2018 19:39:53 GMT -5
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