Protein enabling other drugs to increase body's HDL levels identified

Sydney: Researchers have identified a protein, known as ORP2, responsible for transporting cholesterol inside cells that opens the way for new drugs to increase the body's 'good cholesterol' levels.

ORP2 can increase the amount of cholesterol in cells, a process called cholesterol efflux. We think this pathway will be very important for the development of a drug to increase this good cholesterol, said Rob Yang, Professor from the University of New South Wales in Australia.

Until now, drugs including statins have targeted bad cholesterol (LDL) by inhibiting its synthesis in the liver in an effort to mitigate the risk of heart disease and stroke.

However, while statins are effective at lowering LDL levels, they do little to increase the levels of good cholesterol (HDL) and there is no other drug in use that can significantly boost the human body's HDL levels.

Up to 90 per cent of a cell's cholesterol is found at the cell's plasma membrane, said the study published in the journal Molecular Cell.

"Knowing the molecules that deliver cholesterol to the plasma membrane itself is a huge step forward. The transport of cholesterol to the plasma membrane is the key to the generation of HDL.

If such a drug could be developed, it would not replace statins, but would be used complementarily, with one drug used to reduce the bad cholesterol and the other to increase levels of the good, Yang suggested.

Importantly, ORP2 could also be targeted to fight cancer. 

The rampant and uncontrolled growth of cells that characterises cancer could be stopped in its tracks by reducing the amount of cholesterol produced.

ORP2 could offer a new strategic line of research and possibly succeed where the use of statins in this area hasn't, Yang noted.