Treatment with chondroitin sulfate to modulate inflammation and atherogenesis in obesity

Osteoarthritic patients treated with high doses of chondroitin sulfate (CS) have a lower incidence of coronary heart disease--but the mechanistic aspects of these beneficial effects of CS remain undefined. We examined how CS treatment affects the formation of atheroma via interaction with endothelial cells and monocytes.

We characterized arterial atheromatous plaques by multiphoton microscopy and serum pro-inflammatory cytokines by immunoenzymatic techniques in obese mice receiving CS (1 g/kg/day, i.p.) or vehicle for 6 days. Effects of CS on signaling pathways, cytokine secretion and macrophage migration were evaluated in cultures of human coronary endothelial cells and in a monocyte cell line stimulated with TNF-α by Western blot, immunoenzymatic techniques and transwell migration assays.

Treatment of obese mice with CS reduced the extension of foam cell coverage in atheromatous plaques of arterial bifurcations by 62.5%, the serum concentration of IL1β by 70%, TNF-α by 82% and selected chemokines by 25-35%. Cultures of coronary endothelial cells and monocytes stimulated with TNF-α secreted less pro-inflammatory cytokines in the presence of CS (P < 0.01). CS reduced the activation of the TNF-α signaling pathway in endothelial cells (pErk 36% of reduction, and NFκB 33% of reduction), and the migration of activated monocytes to inflamed endothelial cells in transwells (81 ± 6 vs. 13 ± 2, P < 0.001).

CS interferes with the pro-inflammatory activation of monocytes and endothelial cells driven by TNF-α thus reducing the propagation of inflammation and preventing the formation of atherosclerotic plaques.