Potential "youth protein" is useful for heart diseases

Researchers from the USA and Norway, working under the guidance of Professor Peter Ganz from the University of California at San Francisco, have found that for people with a history of heart disease, the likelihood of developing heart failure, myocardial infarction or stroke, as well as death from these conditions is less in cases where their blood contains higher concentrations of two closely related proteins. 

One of these proteins – GDF-11, or tissue differentiation factor-11 – has recently attracted attention as a potential "source of youth", but laboratory research data do not yet allow us to unequivocally recognize this. A new study conducted not on mice, but on humans, adds fuel to the fire of scientific discussions.

For the first time, GDF-11 aroused the interest of specialists in 2013, when experiments on mice demonstrated its ability to rejuvenate an aging heart. Based on these observations, scientists have suggested that drugs that increase the level of this protein in the body can eliminate the physiological manifestations of aging, including those leading to the development of heart failure.

The new study involved 1,899 men and women with stable coronary artery disease, whose age ranged from 40 to 85 years (on average – 69 years). Due to the existing disease, in which blood flow to the heart decreases due to coronary artery damage, participants were at an increased risk of stroke, myocardial infarction, hospitalization for heart failure and death. Several hundred participants developed one or more of these conditions during almost 9 years of the study.

The authors used a laboratory test to assess the total blood content of GDF-11 and the protein myostatin, which is very close to it. The test did not allow us to estimate the number of these proteins separately due to the very high degree of structural and functional similarity of their molecules.

The results showed that for patients with a relatively high content of these two proteins in the blood (25% of patients with the highest rates) at the beginning of the study, the risk of death from any cause was more than twice lower compared to the risk for 25% of patients with the lowest levels of the GDF-11/myostatin combination. Patients with the highest values of the estimated parameter also developed unfavorable conditions associated with the underlying disease much less frequently.

In addition, the researchers found that the level of the studied combination of proteins in the human body progressively decreases with age, but the rate of this decrease is very individual. Examination of patients using standard clinical imaging techniques used to assess the degree of ventricular hypertrophy showed that patients with the lowest levels of GDF-11 and myostatin were more predisposed to thickening of the heart muscle. These observations are completely consistent with the results of earlier studies on mice.

The authors also note that fewer heart disease-related deaths among participants with high levels of GDF-11 and myostatin do not fully explain the lower mortality in this group. It is quite possible that these proteins also contribute to preventing death from any other causes unrelated to pathologies of the cardiovascular system.

The researchers believe that in addition to finding methods to increase the levels of GDF-11 and myostatin, specialists should pay attention to another approach that theoretically can improve people's health. This approach consists in blocking the activity of the FSTL3 protein circulating in the blood, or follistatin-like protein-3, which inhibits both GDF-11 and myostatin. The preliminary results obtained by the authors indicate that elevated levels of FSTL3 in the body are associated with an unfavorable prognosis for patients with heart disease. Professor Ganz notes that if the potential benefits of high levels of GDF-11 and myostatin exceed the possible risks, then getting rid of the inhibitor of these proteins may be much easier than increasing their low levels.

Article by Kristoff A. Olson et al. Association of growth differentiation factor 11/8, putative anti-aging factor, with cardiovascular outcomes and overall mortality in humans: analysis of the Heart and Soul and HUNT3 cohorts published in European Heart Journal.

Evgeniya Ryabtseva

Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of UC San Francisco:
Study of 'Fountain of Youth' Protein Points to Possible Human Health Benefit.