|
|
||||||||



* Department of Veterinary Biochemistry and Physiology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, and
Department of Rheumatology, St. Vincents University Hospital, Elm Park, Dublin, Ireland; and
Department of Rheumatology, Freeman Hospital, Newcastle upon Tyne, United Kingdom
Modulation by proinflammatory mediators indicate that NURR1 induction represents a point of convergence of distinct signaling pathways, suggesting an important common role for this transcription factor in mediating multiple inflammatory signals. The present study identifies NURR1 as a molecular target of methotrexate (MTX) action in human inflammatory joint disease and examines the mechanism through which MTX modulates NURR1 expression. MTX significantly suppresses expression of NURR1 in vivo in patients with active psoriatic arthritis (n = 10; p < 0.002) who were prescribed low-dose MTX for management of peripheral arthritis. Importantly, reduction in NURR1 levels correlate (n = 10; r = 0.57; p = 0.009) with changes in disease activity score (both clinical and laboratory parameters). MTX selectively modulates NURR1 levels induced by inflammatory stimuli and growth factors in resident cell populations of synovial tissue. In primary human synoviocytes and microvascular endothelial cells, we observe dose-dependent differential effects of MTX on steady-state and inducible NURR1 levels. Our data confirms that adenosine, and its stable analog 5'-N-ethylcarboxamideadenosine, can mimic the differential effects of MTX on NURR1 transcription. In addition, we verify that the inhibitory effect of low-dose MTX on NURR1 activation is mediated through the adenosine receptor A2. More specifically, our data distinguishes the selective involvement of the A2A receptor subtype in these responses. In summary, these findings establish the nuclear orphan receptor NURR1 as a molecular target of MTX action in human inflammatory joint disease and demonstrate that the immunomodulatory actions of MTX on NURR1 expression are mediated through adenosine release.
This article has been cited by other articles:
![]() |
G. Hasko and P. Pacher A2A receptors in inflammation and injury: lessons learned from transgenic animals J. Leukoc. Biol., March 1, 2008; 83(3): 447 - 455. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. M. Wessels, T. W. J. Huizinga, and H.-J. Guchelaar Recent insights in the pharmacological actions of methotrexate in the treatment of rheumatoid arthritis Rheumatology, March 1, 2008; 47(3): 249 - 255. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. S. Mix, M. G. Attur, H. Al-Mussawir, S. B. Abramson, C. E. Brinckerhoff, and E. P. Murphy Transcriptional Repression of Matrix Metalloproteinase Gene Expression by the Orphan Nuclear Receptor NURR1 in Cartilage J. Biol. Chem., March 30, 2007; 282(13): 9492 - 9504. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Ralph, D. Zocco, B. Bresnihan, O. FitzGerald, A. N. McEvoy, and E. P. Murphy A Role for Type 1{alpha} Corticotropin-Releasing Hormone Receptors in Mediating Local Changes in Chronically Inflamed Tissue Am. J. Pathol., March 1, 2007; 170(3): 1121 - 1133. [Abstract] [Full Text] [PDF] |
||||
![]() |
B N Cronstein Going with the flow: methotrexate, adenosine, and blood flow Ann Rheum Dis, April 1, 2006; 65(4): 421 - 422. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |