Understanding the molecular mechanisms underlying cell death during the development of pathological heart conditions is a critical task for modern research in biology and medicine, including the search for effective cardioprotective drugs. Despite the large amount of experimental data, studies of metabolic changes remain challenging, particularly concerning reactions involving highly reactive intermediates.

Genetically encoded fluorescent biosensors have taken biomedical research to a new level. These biosensors, being protein molecules by nature, enable the monitoring of biochemical parameters in living systems of varying complexity — from individual cellular compartments to tissues of whole organisms in vivo.

Within this project, we investigate the dynamics of acidosis and oxidative stress in rat heart tissues during ischemia-reperfusion injury and myocardial infarction. To achieve this, the genes encoding the biosensors SypHer3s (for pH monitoring) and HyPer7 (for H₂O₂ detection) will be delivered to cardiac tissues using viral particles. The physiological responses under simulated pathological conditions will then be recorded using intravital two-photon fluorescence microscopy. The platform developed through this project, based on genetically encoded biosensors, can later be applied to a wide range of studies of cardiac tissue function under normal and pathological conditions.

Technologies enabling control of cellular activity are indispensable for studying the cellular bases of complex physiological processes. Over the past two decades, classical methods of chemical and electrical stimulation have been complemented and, in some areas, replaced by genetic approaches such as chemogenetics, optogenetics, and thermogenetics. Thermogenetics is a technology that allows selective control of cells expressing thermosensitive proteins by heating or cooling them within the physiological temperature range.

Cardiac rhythm and conduction disorders represent a major medical and social issue. For instance, in sick sinus syndrome, the sinoatrial pacemaker fails to generate impulses at a sufficient rate, leading to decreased heart rate and pauses in cardiac activity. These pauses may cause fainting and pose a potential life-threatening risk. Other rhythm disturbances may lead to the sudden onset of ventricular fibrillation, resulting in death within minutes.

Presently, there is a pressing need for approaches that can safely and painlessly terminate life-threatening arrhythmias. As one such approach, we propose the use of thermogenetic control of cardiac rhythm based on thermosensitive ion channels. This method enables non-invasive heart stimulation through the delivery of genetic constructs containing a cardiomyocyte-specific promoter and a sequence encoding an ion channel from the TRP superfamily into myocardial tissue. Expression of these channels in cardiomyocytes allows the imposition of a desired heart rhythm in vivo through pulse infrared laser heating.

This project is entirely original and possesses a high degree of scientific novelty. Research in this field is undoubtedly of great relevance, and the expected scientific outcomes fully align with current trends in biomedicine. The results obtained will contribute to a deeper understanding of pathophysiological processes in cardiac tissues under cardiovascular diseases and will be valuable not only for elucidating fundamental mechanisms but also for developing new therapeutic approaches.