Simvastatin inhibits cytokine-stimulated Cyr61 expression in osteoblastic cells: a therapeutic benefit for arthritis.
OBJECTIVE
To examine the effects of proinflammatory cytokines on Cyr61 expression in osteoblastic cells and the modulatory action of simvastatin, to assess the role of CREB in Cyr61 induction, and to investigate the relationship of osteoblastic expression of Cyr61 to disease progression in experimental arthritis.


METHODS
Cyr61 expression and CREB phosphorylation at serine 133 were examined by Western blotting. Promoter activity of Cyr61 was assessed by luciferase assay with promoter deletion/mutagenesis and forced expression/gene silencing of CREB. Interaction between CREB and the Cyr61 promoter was evaluated by electrophoretic mobility shift assay and chromatin immunoprecipitation. CCL2 expression was examined by Northern blotting and enzyme-linked immunosorbent assay. In rats with collagen-induced arthritis (CIA), osteoblastic expression of Cyr61 was examined by immunohistochemistry, and disease progression was assessed by clinical, radiographic, and histologic examination.


RESULTS
In primary human osteoblasts and U2OS cells, Cyr61 expression stimulated by tumor necrosis factor α, interleukin-1β (IL-1β), oncostatin M (OSM), and other IL-6-family cytokines was suppressed by simvastatin. In U2OS cells, simvastatin inhibited OSM-induced CREB phosphorylation and CREB-DNA binding. Knockdown of CREB by short hairpin RNA reduced Cyr61 synthesis. OSM-induced Cyr61 promoter activation was dependent on CRE-CREB interaction and inhibited by simvastatin. Cyr61 enhanced CCL2 expression by U2OS cells. Intraarticular injection of simvastatin inhibited CIA progression and diminished the number of Cyr61+ osteoblasts and infiltrating macrophages.


CONCLUSIONS
Simvastatin inhibited cytokine-stimulated Cyr61 expression in osteoblastic cells and suppressed disease progression and osteoblastic expression of Cyr61 in inflammatory arthritis. This finding indicates that simvastatin may have potential as a therapeutic agent for inflammatory arthritis.
Kok
Sang-Heng
SH
National Taiwan University, Taipei, Taiwan.
Hou
Kuo-Liang
KL
Hong
Chi-Yuan
CY
Wang
Juo-Song
JS
Liang
Po-Chin
PC
Chang
Cheng-Chi
CC
Hsiao
Michael
M
Yang
Hsiang
H
Lai
Eddie Hsiang-Hua
EH
Lin
Sze-Kwan
SK
D000818:Animals; D000924:Anticholesteremic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D001169:Arthritis, Experimental / Q000188:drug therapy*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D055515:Cysteine-Rich Protein 61 / Q000378:metabolism*; D016207:Cytokines / Q000494:pharmacology*; D004195:Disease Models, Animal; D018450:Disease Progression; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019821:Simvastatin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D016896:Treatment Outcome
D000924:Anticholesteremic Agents; C501848:CCN1 protein, human; D018932:Chemokine CCL2; D017362:Cyclic AMP Response Element-Binding Protein; D055515:Cysteine-Rich Protein 61; D016207:Cytokines; D019821:Simvastatin