TDK conference 2024

One of the main challenges in modern cardiology is the regeneration of morphological or functional alterations resulting from various heart diseases, for which researchers are seeking solutions through stem cell-based therapies. The study of the telocyte cell population, described by Popescu and colleagues in 2005, is related to cardiac stem cell research. Until 2010, these cells were referred to as Cajal-type interstitial cells due to their similar morphological and immunohistochemical properties. Telocytes are connective tissue cells characterized by small cell bodies and long cytoplasmic extensions known as telopodes.

Functionally, they may play a role in intercellular signaling, impulse conduction, and the maintenance of stem cells. They may also have a mechanical role and participate in various immunoregulatory processes. Currently, immunohistochemical methods for detecting telocytes include CD34, CD117, CD28, vimentin, and PDGFR-α, but their presence must be confirmed using transmission electron microscopy. The presence of this cell population has been validated in numerous human and animal tissues in recent years. Cardiac telocytes have been identified in various regions of the heart in humans, horses, and pigs since 2015.

Changes in the morphology or depletion of telocytes have been described in human patients suffering from myocardial infarction, heart failure, cardiac amyloidosis, and various arrhythmias. In horses, the presence of telocytes has currently been confirmed in various tendons and areas of the pulmonary veins. Our research aims to confirm the presence of telocytes in the hearts of horses in different regions, particularly in areas frequently affected by diseases. Among the immunohistochemical markers used in human research, we successfully performed vimentin staining in horses. The electron microscopy examinations were carried out on the hearts of two healthy horses that were euthanized due to other non-toxic diseases. Sampling was conducted immediately after euthanasia. We excised samples from various heights of the wall and septal regions of the heart chambers, areas of the auricles, as well as from the mitral and tricuspid valves, and the structures of the impulse-generating and conduction system. After appropriate fixation and preparation, samples taken from different cardiac regions were examined using transmission electron microscopy. During our investigations, we confirmed the presence of telocytes in all the aforementioned areas and, for the first time, validated the relationship between telocytes and stem cells in horses. Based on our findings, a larger study can be planned to compare the number and morphological characteristics of telocytes in the hearts of healthy horses versus those suffering from various heart diseases.