TY - JOUR
T1 - Orphan nuclear receptor NR4A2 induces synoviocyte proliferation, invasion, and matrix metalloproteinase 13 transcription
AU - Mix, Kimberlee S.
AU - McMahon, Kevin
AU - McMorrow, Jason P.
AU - Walkenhorst, Dana E.
AU - Smyth, Aisling M.
AU - Petrella, Brenda L.
AU - Gogarty, Martina
AU - Fearon, Ursula
AU - Veale, Douglas
AU - Attur, Mukundan G.
AU - Abramson, Steven B.
AU - Murphy, Evelyn P.
N1 - Copyright © 2012 by the American College of Rheumatology.
PY - 2012/7
Y1 - 2012/7
N2 - OBJECTIVE: To address the role of the nuclear receptor 4A (NR4A) family of orphan nuclear receptors in synoviocyte transformation, hyperplasia, and regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in models of inflammatory arthritis.METHODS: NR4A messenger RNA levels in synovial tissue and primary synoviocytes were measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). NR4A2 was stably overexpressed in normal synoviocytes, and cell proliferation, survival, anchorage-independent growth, migration, and invasion were monitored in vitro. MMP and TIMP expression levels were analyzed by quantitative RT-PCR, and MMP-13 promoter activity was measured using reporter assays. Stable depletion of endogenous NR4A levels was achieved by lentiviral transduction of NR4A short hairpin RNA (shRNA), and the effects on proliferation, migration, and MMP-13 expression were analyzed.RESULTS: NR4A2 was expressed at elevated levels in normal, OA, and RA synovial tissue and in primary RA synoviocytes. Tumor necrosis factor α (TNFα) rapidly and selectively induced expression of NR4A2 in synoviocytes. Ectopic expression of NR4A2 in normal synoviocytes significantly increased proliferation and survival, promoted anchorage-independent growth, and induced migration and invasion. MMP-13 gene expression was synergistically induced by NR4A2 and TNFα, while expression of TIMP-2 was antagonized. NR4A2 directly transactivated the proximal MMP-13 promoter, and a point mutation in the DNA binding domain of NR4A2 abolished transcriptional activation. Depletion of endogenous NR4A receptors with shRNA reduced synoviocyte proliferation, migration, and MMP-13 expression.CONCLUSION: The orphan nuclear receptor NR4A2 is a downstream mediator of TNFα signaling in synovial tissue. NR4A2 transcriptional activity contributes to the hyperplastic and invasive phenotype of synoviocytes that leads to cartilage destruction, suggesting that this receptor may show promise as a therapeutic target in inflammatory arthritis.
AB - OBJECTIVE: To address the role of the nuclear receptor 4A (NR4A) family of orphan nuclear receptors in synoviocyte transformation, hyperplasia, and regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in models of inflammatory arthritis.METHODS: NR4A messenger RNA levels in synovial tissue and primary synoviocytes were measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). NR4A2 was stably overexpressed in normal synoviocytes, and cell proliferation, survival, anchorage-independent growth, migration, and invasion were monitored in vitro. MMP and TIMP expression levels were analyzed by quantitative RT-PCR, and MMP-13 promoter activity was measured using reporter assays. Stable depletion of endogenous NR4A levels was achieved by lentiviral transduction of NR4A short hairpin RNA (shRNA), and the effects on proliferation, migration, and MMP-13 expression were analyzed.RESULTS: NR4A2 was expressed at elevated levels in normal, OA, and RA synovial tissue and in primary RA synoviocytes. Tumor necrosis factor α (TNFα) rapidly and selectively induced expression of NR4A2 in synoviocytes. Ectopic expression of NR4A2 in normal synoviocytes significantly increased proliferation and survival, promoted anchorage-independent growth, and induced migration and invasion. MMP-13 gene expression was synergistically induced by NR4A2 and TNFα, while expression of TIMP-2 was antagonized. NR4A2 directly transactivated the proximal MMP-13 promoter, and a point mutation in the DNA binding domain of NR4A2 abolished transcriptional activation. Depletion of endogenous NR4A receptors with shRNA reduced synoviocyte proliferation, migration, and MMP-13 expression.CONCLUSION: The orphan nuclear receptor NR4A2 is a downstream mediator of TNFα signaling in synovial tissue. NR4A2 transcriptional activity contributes to the hyperplastic and invasive phenotype of synoviocytes that leads to cartilage destruction, suggesting that this receptor may show promise as a therapeutic target in inflammatory arthritis.
KW - Arthritis, Rheumatoid/genetics
KW - Cell Movement/genetics
KW - Cell Proliferation
KW - Humans
KW - Matrix Metalloproteinase 13/genetics
KW - Nuclear Receptor Subfamily 4, Group A, Member 2/genetics
KW - Signal Transduction/genetics
KW - Synovial Membrane/cytology
KW - Tissue Inhibitor of Metalloproteinases/genetics
KW - Transcription, Genetic
UR - https://www.mendeley.com/catalogue/3751f344-6080-3248-a42a-82955eadf5b7/
U2 - 10.1002/art.34399
DO - 10.1002/art.34399
M3 - Article
C2 - 22275273
SN - 2326-5191
VL - 64
SP - 2126
EP - 2136
JO - Arthritis and Rheumatism
JF - Arthritis and Rheumatism
IS - 7
ER -