Researchers are reporting for the first time that cardiovascular disease affects the blood vessels in the bone marrow and leads to increased production of white blood cells that drive inflammation, according to a study conducted in human bone marrow and in mice. The discovery could lead to new ways to prevent or treat heart disease, researchers say.
Researchers have known for some time that heart disease is associated with an accumulation of white blood cells, which normally fight infection. Many of these cells are found in plaque—the buildup of fats, cholesterol, and other substances in the blood vessel—where they arrive after being born in the bone marrow and migrating through the blood stream. But what leads to their increased bone marrow output is unclear, researchers say.
In the current study, researchers showed that three different cardiovascular diseases – heart attack, atherosclerosis, and hypertension—affect the bone marrow in a way that boosts white blood cell production. Each of these diseases can cause changes in the number of blood vessels in the bone marrow. They can also change the structure and function of the bone marrow vessels and affect the release of factors that regulate white blood cell production and migration, the researchers found. As a result, more white blood cell accumulation propels inflammation, including in the arteries and the heart. That can restrict blood supply and potentially trigger a heart attack, the researchers say.
“This study provides strong evidence that cardiovascular disease affects the bone marrow vasculature and consequently blood stem cell activity,” said Michelle Olive, Ph.D., a program officer in the NHLBI’s Division of Cardiovascular Sciences. “This work sheds new light on the important role played by the vascular bone marrow niche and how inflammation occurs. It could lead to new targets and treatments for heart disease, the leading cause of death.”
The study, partly funded by the NHLBI, appeared in Nature Cardiovascular Research.