The effect of high glucose and 100 units/ml of IFNγ on TIMP-1, TIMP-2, MMP-9 and IL-1β secretion by U937 macrophages. The conditioned medium from the above studies was also used in ELISA to quantify TIMP-1 and TIMP-2 (A), MMP-9 and IL-1β (B) as described in Methods. The Data presented are the representative of three independent experiments with the similar results. NG, normal glucose; HG, high glucose.