Evidence of a role for galectin-1 in acute inflammation

Galectin-1 (Gal-1), a member of a family of beta-galactoside-binding protei ns, has been suggested to play key roles in immunological and inflammatory processes. The present study deals with the concept of an in vivo role for Gal-1 in acute inflammation by using the rat hind paw edema test. Local adm inistration of Gal-1 (0.5, 2, 4 and 8 mu g/ml) inhibited acute inflammation induced by bee Venom phospholipase A(2) (PLA(2)) when it was injected 30 m in before the enzyme or co-injected together with PLA,. The anti-inflammato ry effect was prevented by a specific antibody, but independent of its carb ohydrate-binding properties. In contrast, Gal-1 failed to inhibit histamine -induced edema. Histopathological studies showed a clear reduction of the i nflammatory process when Gal-1 was injected before PLA(2), evidenced by a d iminished number of infiltrated polymorphonuclear neutrophils and scarce de granulated mast cells. The anti-inflammatory effect was also assessed in vi tro, showing that Gal-1 treatment reduced prostaglandin E-2 secretion and a rachidonic acid release from stimulated peritoneal macrophages. Results pre sented here provide the first evidence for a role of Gal-1 in acute inflamm ation and suggest that the anti-inflammatory effect involves the inhibition of both soluble and cellular mediators of the inflammatory response.