Effect of pathological conditions on peritoneal macrophage glycosaminoglycans: Impact on cytoadherence

Glycosaminoglycans (GAGs) have a plethora of functions to play. They are widely present in extracellular matrix, cell surface and inside the cell. During pathological conditions remodeling of GAGs leads to modifications in their structure and functions. In the present work, peritoneal macrophages were isolated from normal, diabetic, and diet-induced hypercholesterolemic rats and evaluated in terms of GAGs and cytoadherence to various extracellular matrix (ECM) components. Peritoneal macrophages are known to play important roles in the control of infection and inflammation. Isolated GAGs were characterized as belonging to heparan sulfate/heparin class. There were quantitative changes in sulfated GAGs in diabetic and hypercholesterolemic groups when compared to normal rats. Dose-dependent changes in cytoadherence were observed only with respect to fibronectin in LPS-activated macrophages from diabetic animals but not with laminin and type IV collagen when compared to macrophages from normal rats. Cytoadherence was significantly decreased on treatment with heparinase indicating that cytoadherence was at least partly mediated by heparan sulfate/heparin class of GAGs. Global disaccharide composition analysis showed that GAGs from macrophages of diabetic animals had higher sulfation ratio when compared to that of control and hypercholesterolemic animals.