Myocardial aging as a B lymphocyte dependent event
The world population is rapidly aging. According to the United Nations Populations Fund, “People aged 60 and older make up 12.3% of the global population, and by 2050, that number will rise to almost 22%.” While the increase in the average lifespan is clearly a great achievement of our times, it is associated with an increase in the frequency of age associated disease. The heart is one of the organs that is arguably most sensitive to aging. With aging, in fact, the heart gets thicker and stiffer, and elderly people are at a markedly increased risk of developing heart disease, especially heart failure.
B lymphocytes, a type of white blood cell also known as “B cells”, have been shown to play a critical role in processes that result in increased heart thickness and stiffness. We have recently shown that the heart harbors a heterogeneous population of B lymphocytes. Importantly, we have shown that: 1) the balance between subgroups of cardiac B cells has marked effects on heart function; 2) aging is associated with marked changes in certain subgroups of heart B cells; and 3) B cell deficient animals are protected from the increase in cardiac mass that is typically associated with aging.
We will test the innovative hypothesis that heart aging is caused by age-associated changes in heart B lymphocytes. Since there are several safe drugs to modulate the functions of B lymphocytes, the proposed work could pave the way for the rapid establishment of novel therapeutic options for the treatment of age associated heart disease.