deoxycholic-acid and Arthritis--Rheumatoid

Heparin has a potential regulatory role in inflammatory diseases. However, the anticoagulant activity and poor oral bioavailability of heparin limit its use as an anti-inflammatory agent. Conjugation of bis-deoxycholic acid to 6-O-desulfated low molecular weight heparin (6DSHbD) was efficiently internalized by activated endothelial cells via a 2-step model, in which heparin attaches to adhesion molecules that facilitate accessibility of the bile acid conjugate to membrane transporters. The critical role of P-selectin during endothelial cell uptake of 6DSHbD by arthritic tissue was confirmed in p-selectin(-/-) arthritic mice. Intracellular 6DSHbD inhibited transcellular diapedesis of T cells through activated endothelial cells and impaired both the formation of ICAM-1-rich docking structures at the T cell contact surface and subsequent cytoskeletal rearrangement. Furthermore, 6DSHbD blocked activation of RhoA-GTPase and phosphorylation of ezrin/radixin/moesin induced by ICAM-1 cross-linking on activated endothelial cells, thereby impairing lymphocyte transcellular transmigration. After oral administration 6DSHbD was preferentially delivered to inflamed joint tissue, particularly in and around post-capillary venular endothelium and inhibited effector T cell homing to arthritic joints. Aggravation of collagen-induced arthritis conferred by the transfer of effector T cells was suppressed by oral 6DSHbD. Thus, intracellular heparin exerts anti-inflammatory effects through the inhibition of RhoA-dependent transendothelial recruitment of T cells and may have applications in the treatment of chronic inflammatory arthritis.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Rheumatoid; Cell Culture Techniques; Cells, Cultured; Deoxycholic Acid; Disease Models, Animal; Drug Delivery Systems; Heparin; Human Umbilical Vein Endothelial Cells; Humans; Intercellular Adhesion Molecule-1; Mice, Inbred DBA; rhoA GTP-Binding Protein; T-Lymphocytes; Transendothelial and Transepithelial Migration

The regulation of angiogenesis is an interesting area to consider for novel therapeutic approaches to rheumatoid arthritis (RA). Chemically modified heparins have been developed as possible candidates for angiogenesis inhibitor; however, they have a major clinical drawback in exhibiting poor oral bioavailability. Here, orally absorbable O-desulfated low molecular weight heparin (ODS-LMWH) derivatives were newly synthesized by conjugating 2-O- or 6-O-desulfated LMWH with deoxycholic acid (DOCA) or bisDOCA (a dimer of DOCA), and their physicochemical properties, antiangiogenic potency and pharmacokinetic profiles were assessed. After selecting the best candidate among those derivatives, its therapeutic efficacy on arthritis was investigated in a murine collagen antibody-induced arthritis (CAIA) model. ODS-LMWH derivatives significantly inhibited the capillary-like tube formation of human umbilical vein endothelial cells (HUVECs) and basic fibroblast growth factor (bFGF)-induced angiogenesis in the Matrigel plug assay. Among all the compounds, 6ODS-LHbD showed the highest oral bioavailability in rats (19.3%). In the CAIA mouse model, 6ODS-LHbD (10 mg/kg, p.o., S.I.D.) significantly inhibited neovascularization in the joint, the increase of hind-paw thickness, and the structural damage in the bone. Therefore, 6ODS-LHbD would be a promising candidate for an orally active drug for the treatment of RA.

Topics: Administration, Oral; Angiogenesis Inhibitors; Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Bone Resorption; Deoxycholic Acid; Heparin, Low-Molecular-Weight; Human Umbilical Vein Endothelial Cells; Humans; Male; Mice; Mice, Inbred BALB C; Rats; Rats, Sprague-Dawley; Sulfur

Phospholipase A2 (PLA2) activity has now been identified in rheumatoid synovial fluids. This PLA2 is a calcium-requiring protein of MW 11,000 with a neutral pH optimum. Its activity was inhibited by high concentrations of Mg2+, and by the active site-directed histidine reagent p-bromophenacyl bromide. Ionic and nonionic detergents, or the sulfhydryl reagent dithiothreitol caused loss of enzyme activity. Synovial fluid PLA2 did not interact with sulphated mucopolysaccharides such as heparin or chondroitin sulphate. Release and sequestration of PLA2 in the joint space may contribute to the characteristic rheumatoid inflammatory changes.

Topics: Acetophenones; Arthritis, Rheumatoid; Calcium; Chondroitin Sulfates; Deoxycholic Acid; Dithiothreitol; Heparin; Hot Temperature; Humans; Hydrogen-Ion Concentration; Magnesium; Molecular Weight; Octoxynol; Phospholipases; Phospholipases A; Phospholipases A2; Polyethylene Glycols; Synovial Fluid

Topics: Adult; Aged; Arthritis, Rheumatoid; Bile Acids and Salts; Chenodeoxycholic Acid; Cholic Acids; Deoxycholic Acid; Female; Humans; Male; Middle Aged