A large amount of energy is required for cardiomyocytes, muscle cells of the heart, to perform all of the vital functions of the heart, pumping blood and delivering nutrients and oxygen to the body tissues. Mitochondria provide the energy needed for these processes by metabolizing organic molecules like sugar, fatty acids, and amino acids. However, when a mitochondrial defect reduces the amount of energy cardiomyocytes receive for pumping blood, the heart can fail to deliver oxygen needed for the body to function.
Dilated cardiomyopathy (DCM) is a relatively common disorder that exhibits an inability of the heart to pump blood, because the "main pumping chamber" expands, weakens, and loses the ability to contract as needed (MedicineNet
). This week in a study published in Science
by scientists from Centro Nacional de Investigaciones Cardiovasculares Carloss III (CNIC) in Madrid and the Research Institute CECAD/Max Planck in Cologne, a team of researchers investigated the role of protein YME1 in the regulation of mitochondria.
When YME1 is missing, a mitochondrial defect is seen that leads to heart failure in cases of DCM. The team of scientists from Madrid and Cologne looked to reversing this defect to increase the lifespan of heart failure patients.
Unlike healthy people, patients with a mitochondrial defect causing DCM have cardiomyocytes that consume more sugars than fatty acids. Since fatty acids have more energy, DCM patients receive much less energy for powering the heart than healthy people do. During a study on reversing this effect, experimental mouse models of DCM were fed a high-fat diet in attempt to "force the heart cells to consume more fatty acids than sugars, and thus 'bypass' the mitochondrial defect,” explained Dr. Jaime Garcia-Prieto, one of two first authors of the study. The attempt was successful in overriding the mitochondrial defect, improving heart function, and increasing the lifespan of the experimental mice.
Although this study showed positive results, doctors are not yet jumping to feed all of their heart failure patients large amounts of fatty foods.
"We know that a diet rich in fats is a threat to health because it increases the incidence of atherosclerosis. The possibility that such a diet might be beneficial in certain cases of heart disease is very provocative and attractive. However, much translational research needs to be done before these results can be considered definitive,” said Valentin Fuster, MD, PhD, and General Director of the CNIC.
Watch the following video to learn more about cardiomyopathy under different circumstances.