Disease modifying and antiangiogenic activity of 2-methoxyestradiol in a murine model of rheumatoid arthritis
Authors: Elizabeth G Moore
Steve J Strawn
William E Fogler
Carolyn F Sidor
Stacy M Plum
Eun J Park
Journal: BMC Musculoskeletal Disorders (2009)
Discipline: CLINICAL MEDICINE
Keywords: rheumatoid arthritis; neovascularization; 2-methoxyestradiol; anti-collagen monoclonal antibodies; synovitis
Affiliations: EntreMed, Inc, Rockville, MD 20850, USA. 

Abstract:  Background: A critical component of disease progression in rheumatoid arthritis (RA) involves neovascularization associated with pannus formation. 2-methoxyestradiol (2ME2) is a naturally occurring molecule with no known physiologic function, although at pharmacologic concentrations it has antiproliferative and antiangiogenic activities. We investigated the impact of orally administered 2ME2 on the initiation and development of proliferative synovitis using the anti-collagen monoclonal antibodies (CAIA) model. Methods: Severe polyarticular arthritis was induced in Balb/c female mice by administration of 2 mg of a monoclonal antibody cocktail intravenously into the tail vein of mice. Twenty-four hours following monoclonal antibody administration, mice were injected with 25 microg of LPS (E. coli strain 0111:B4) via the intraperitoneal route. Treatment with 2ME2 (100, 75, 50, 25, 10, 1 mg/kg, p.o., daily), or vehicle control began 24 hrs following LPS challenge and continued to day 21. Hind limbs were harvested, sectioned and evaluated for DMARD activity and general histopathology by histomorphometric analysis and immunohistochemistry (vWF staining). In a separate study, different dosing regimens of 2ME2 (100 mg/kg; q.d. vs q.w. vs q.w. x 2) were evaluated. The effect of treatment with 2ME2 on gene expression of inflammatory cytokines and angiogenic growth factors in the joint space was evaluated 5 and 14 days after the induction of arthritis. Results: Mice treated with 2ME2 beginning 24 hours post anti-collagen monoclonal antibody injection, showed a dose-dependent inhibition in mean arthritic scores. At study termination (day 21), blinded histomorphometric assessments of sectioned hind limbs demonstrated decreases in synovial inflammation, articular cartilage degradation, pannus formation, osteoclast activity and bone resorption. At the maximal efficacious dosing regimen (100 mg/kg/day), administration of 2ME2 resulted in total inhibition of the study parameters and prevented neovascularization into the joint. Examination of gene expression on dissected hind limbs from mice treated for 5 or 14 days with 2ME2 showed inhibition of inflammatory cytokine message for IL-1beta, TNF-alpha, IL-6 and IL-17, as well as the angiogenic cytokines, VEGF and FGF-2. Conclusion: These data demonstrate that in the CAIA mouse model of RA, 2ME2 has disease modifying activity that is at least partially attributable to the inhibition of neovascular development. Further, the data suggests new mechanistic points of intervention for 2ME2 in RA, specifically inhibition of inflammatory mediators and osteoclast activity. 

Retracted: No

PubPeer comments:
 image duplication, flipped vertical and horizontal ![file] Disclaimer: These potential image duplications have been detected automatically using ImageTwin http: dx.doi.org 10.1145 3019612.3019875 Although results have been curated, the automatic algorithm may have generated false positive results and cannot take into account all scientific explanations for apparent duplications like stripped and reprobed blots, time series, serial sections and reused controls. ,