The heart adapts to the changing needs of each stage of life by adjusting its size. In this way the heart grows in line with the rest of our body, including during pregnancy, in a process called cardiac hypertrohpy. However, excessive physical exercise, hypertension and obesity can trigger excessive heart growth (pathological hypertrophy), a situation that can lead to a heart attack.
Understanding the molecular processes that regulate heart function and growth is, therefore, of immense importance. Researchers have now identified how two proteins control the growth of the heart and its adaptation to high blood pressure that can help design new strategies to treat heart failure caused by excessive growth of the heart.
The research, carried out by lead investigator Guadalupe Sabio from the National Center for Cardiovascular Research (CNIC) in Spain, shows for the first time that two proteins - p38 gamma and p38 delta - control heart growth.
Sabio's team found that p38 gamma and p38 delta regulate the growth of the left ventricle - the largest and strongest heart chamber - responsible for pumping oxygenated blood to the body.
The research team showed that the hearts of mice lacking these proteins are smaller than normal.
These hearts, although they function normally, are incapable of responding to external stimuli, such as high blood pressure.
The discovery advances understanding of the mechanisms through which heart cells grow and adapt.