MMP9 and diabetic retinopathy: The proinflammatory LPA is a simple potent bioactive phospholipid with many important biological functions, such as mediating cell proliferation, migration and survival, suppression of apoptosis, angiogenesis, fibrosis and MMP-9, cytokine and chemokine secretion[6–8, 23] LPA is a potent activator of several transcription factors and signaling pathways which are known to be involved in the pathophysiology of diabetic retinopathy[24–28].