Targeting Matrix Metalloproteinases for Diabetic Retinopathy: The Way Ahead?

Diabetic retinopathy (DR) is a severe sight-threatening complication of diabetes. It causes progressive damage to the retina and is the most common cause of vision impairment and blindness among diabetic patients. DR develops as a result of various changes in the ocular environment. Such changes include accelerated mitochondrial dysfunction, apoptosis, reactive oxygen species production, and formation of acellular capillaries. Matrix metalloproteinases (MMPs) are one of the major culprits in causing DR. Under physiological conditions, MMPs cause remodeling of the extracellular matrix in the retina, while under pathological conditions, they induce retinal cell apoptosis. This review focuses on the roles of various MMPs, primarily MMP-2 and MMP-9 in DR and also their participation in oxidative stress, mitochondrial dysfunction, and apoptosis, along with their involvement in various signaling pathways. This review also underscores different strategies to inhibit MMPs, thus suggesting that MMPs may represent a putative therapeutic target in the treatment of DR.