Peptides which can fix the heart

The new research of scientists from New York and Boston shows, that peptide-based drugs could be useful in stimulating the growth and proliferation of heart cells, so they could be a great help for patients who have suffered a damage on the heart.

New pharmacological approach

The research of peptides-based drugs, such as periostina, is a part of a research project aimed at identifying new pharmacological approaches for the treatment of cardiac patients. The human heart is capable of regeneration, the heart tissues of mature cells can even develop new cells, but the process is very slow.

Roger Hajjar, director of the Cardiovascular Research Center at the Mount Sinai School of Medicine in New York, and Bernhard Kuhn, cardiologist at Children's Hospital Boston are working on addressing the regenerative capacity of cells to a new therapeutic method for treating heart diseases.

The two doctors have formed CardioHeal, a start-up created to enable the development and research of new drugs based on peptides with the aim of stimulating the growth of new cells in the human heart.

Test on animal models

Researchers have identified two peptides that appear to be most promising for stimulating the  growth of new cells and thus for improving functions of the heart. The two peptides have showed good results on a mouse model and one of the two, the periostina, is being tested in the labs of the Mount Sinai School of Medicine on pigs with induced heart attacks. The heart of a pig is similar in size to the human heart so it´s a good model for testing new drugs before moving to humans.

Early results of the study show that the injection of the peptides-based drugs in the pericardium seems to improve the heart functions, although the damaged heart is not able to return completely to normal.

The researchers hope to find in the peptides an alternative approach for treatment of the heart diseases. Patients who have suffered a heart damage have some treatments available, including for example beta blockers which help the heart beat or surgeries which improve the functionality of the bloodstream. None of the treatments currently in use is able to restore the muscle tissue which has been lost because of the heart attack, but the peptides, if they prove safe and effective, could perform this ability in the future.

Stem cells could help

Besides the method with peptides, some research groups are working on developing a therapy based on stem cells. They are already testing it on human individuals. It is hoped that the implanted stem cells will be able to develop optimally and integrate with the rest of the tissue to restore a full cardiac function.

Researchers are working on several ways to find the best possibility to make the stem cells free in the part of the body which is supposed to be treated, in this case the heart, but clinical tests have showed ambiguous results. It also appears that the transplanted cells have difficulty integrating and surviving in the damaged tissues.

The potential benefits of the transplantation of these cells come from the ability to stimulate the growth of the tissue and fix the damage to the heart that the patient has undergone. The start of the process of growth through the use of peptides could be a simple way to deal with certain kinds of cardiomyopathies with a high degree of effectiveness.

Many tests needed

Before considering the start of testing the peptides on humans it is necessary to perform many tests to answer a series of questions including what is the best way to release the peptides in the heart of patients and which is the best time for treatment after a heart attack, what is the optimal dose and if it is necessary to use it just once or more times.

The researchers report that so far there haven´t been seen side effects in animals subjected to tests, but there haven´t been available safety controls large enough to rule out any problems.

If the periostina has the ability to stimulate the growth of cells to restore the function of the heart, the downside could be the formation of tumors or non-cardiac muscle tissue.

The periostina, a protein of the extracellular matrix, appears to be involved in cell adhesion and tumor formation. This protein is overexpressed in some human cancers such as breast, prostate and thyroid cancer or neuroblastoma.

The role of the periostina in the promotion or suppression of tumors is still controversial: some studies reveal a correlation between the level of protein expression and the degree of malignancy of the tumor, while others showed a decrease in expression of this protein in some tumors, for example in lung and bladder cancer.

Překlad: Pavla Čermáková

Zdroj: www.sciencenews.it