COX-2 Inhibition Prevents Insulin-Dependent Diabetes in Low-Dose Streptozotocin-Treated Mice

Abstract

Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease believed to be caused by an inflammatory process in the pancreas leading to selective destruction of the β cells. Inducible cyclooxygenase (COX-2) is expressed under inflammatory conditions and its product prostaglandin E2 (PGE2) is an important inflammation mediator. We report here that administration of the selective COX-2 inhibitor NS-398 prevents the onset of diabetes in mice brought on by multiple low-doses of streptozotocin (STZ). Histological observations indicated that STZ-mediated destruction of β cells was prevented by NS-398 treatment. Delayed (day 3) administration of NS-398 was also protective in this model. No protective effect was observed when NS-398 was administered prior to a high, toxic dose of STZ. These results demonstrate the critical importance of COX-2 activity in autoimmune destruction of β cells, and point to the fact that COX-2 inhibition can potentially develop into a preventive therapy against IDDM.