Gene technique to stretch diseased arteries gives hope for heart health

Photo / Thinkstock

Auckland gene scientists have come up with a way to put new stretch into hardened, old arteries, an important advance that points the way to a radical new treatment for heart disease.

Cardiovascular disease, mainly heart disease and strokes, is New Zealand's biggest killer, accounting for around 40 per cent of deaths.

Associate Professor Mervyn Merrilees, of Auckland University, and colleagues in a six-country collaboration have treated arteries in an animal trial to make them more elastic and resistant to build-ups of cholesterol.

Their technique involves manipulating a gene called V3 which is present in humans and other mammals. By inserting it via a virus into blood vessel cells, the gene, which normally produces little V3 protein, is made to produce a lot.

The cells, injected into a neck artery, led to the formation of a new arterial lining rich in elastin, a protein which gives blood vessels, skin and other tissues their stretchiness.

As people age, they lose elastin. Along with the deposition of LDL or "bad" cholesterol, this contributes to arteries developing inflamed lesions that can crack, leading to little lumps breaking off. This in turn can cause the blockages that produce heart attacks and a type of stroke.

People at elevated risk of cardiovascular disease are advised to reduce bad cholesterol intake, to exercise and are typically prescribed a cholesterol-lowering statin medicine.

But Professor Merrilees and his colleagues are developing their discoveries with the hope of producing a new form of treatment for cardiovascular disease, possibly within a decade.

"There's no reason to believe it won't work [in humans]," he said yesterday. "We feel fairly confident that the same principles apply to humans as they do to other animals."

A United States Government health organisation last week approved a grant for laboratory experiments with V3 using human tissue.

"They plan to take the human saphenous vein [from the leg] that is used in bypass operations, to soak it with V3 protein, to see if we can get them to switch on the deposition of elastic fibres."

The technology has obvious potential for cosmetic surgery, including helping to remove wrinkles, but the researchers are not pursuing that, preferring to focus on killers such as cardiovascular disease.

Another angle being developed by Professor Merrilees is to try to increase the elastin content of skin grown in the lab which, starting with their own skin cells, could help burns patients or those with ulcers that don't heal.

GENE POWER

The gene - V3, present in humans and other mammals.
* Normally produces little V3 protein.

Gene inserted into a virus, and the virus into blood vessel cells from animals.
* Now produces a great deal of V3 protein.

Neck artery cells scraped internally by angioplasty.
* The experimental cells are injected into the artery.
* New arterial lining develops on scraped area.
* New lining is rich in elastin, a stretchy component in blood vessels and other tissues. Lining now resistant to deposition of cholesterol.