Possible key protein for curing pulmonary hypertension found

A new study has found that oxidized lipids, may also contribute to pulmonary hypertension, a serious lung disease that narrows the small blood vessels in the lungs.

The researchers at UCLA demonstrated using a rodent model that a peptide mimicking part of the main protein in high-density lipoprotein (HDL), the so-called "good" cholesterol, may help reduce the production of oxidized lipids in pulmonary hypertension. They also found that reducing the amount of oxidized lipids improved the rodents' heart and lung function.

A rare progressive condition, pulmonary hypertension can affect people of all ages. The disease makes it harder for the heart to pump blood through these vital organs, which can lead to heart failure.

Although researchers have known that oxidized lipids played a role in the development of atherosclerosis and other vascular diseases, the UCLA team discovered higher-than-normal levels of oxidized proteins in rodents with pulmonary hypertension.

First author Dr. Salil Sharma said that the increased amounts of the oxidized lipids due to pulmonary hypertension keeps the expression of this molecule under check, which aggravates symptoms of the disease.

By restoring the expression of microRNA-193 to its full potential, the researchers reduced the amount of oxidized lipids in the animals with pulmonary hypertension.

One of the hallmarks of pulmonary hypertension was a proliferation of smooth muscle cells in the lungs, which was harmful because it narrowed the lungs' small blood vessels.

Additionally, the team found reduced levels of microRNA-193 in the blood and lung tissue of human patients with the disease and discovered that they could slow the proliferation of the smooth muscle cells by increasing levels of microRNA-193 in the cells that had been isolated from these patients' lungs.

The study is published in the online edition of the journal Circulation.