Diacetylglycerol

Diacylglycerol, abbreviated as DAG, is a product that is formed during the enzymatic cleavage of the membrane lipid phosphatidylinositol-4,5-bisphosphate (PIP2) by phospholipase C (PLC). Phosphatidylinositol-4,5-bisphosphate is enzymatically cleaved into the cytosolic inositol trisphosphate (IP3) and into the membrane-bound diacylglycerol.

Diacyglycerol recruits enzymes to the cell membrane and anchors them there. Among other things, diacyglycerol is involved in the activation of protein kinase C (PKC). Protein kinase C phosphorylates enzymes in the cytosol and thus influences gene expression. Studies have shown that hyperglycaemia activates protein kinase C (PKC) and also triggers elevated diacylglycerol (DAG) levels (Koya D et al. 1988). This promotes the production of extracellular matrix and cytokines, increases the contractility and permeability of blood vessels, increases cell growth in blood vessels, activates phospholipase A2 and inhibits Na+/K+-ATPase. As a result, the retina of the eye, kidney and heart are damaged.

1. Koya D et al (1988) Protein kinase C activation and the development of diabetic complications. Diabetes 47:859-866.