Risk Factors and Mechanisms of Cardiovascular Diseases in Posttraumatic Stress Disorder Model in Wistar Rats as Dependent on Stress Resistance and Age.

The article focuses on the pathogenetic mechanisms of posttraumatic stress disorder (PTSD), which is associated with psychological stress because of the coronavirus pandemic. The molecular mechanisms responsible for disease susceptibility in some individuals and stress resistance in others are amongst crucial research interests of experimental and clinical medicine. Priority data were obtained to indicate that distortions of synthesis and metabolism and, most significantly, a switch between two energy transport forms, glucose and lipids, underlie myocardial dysfunction in young and old stress-sensitive Wistar rats in a PTSD model. Histochemistry and polarization microscopy showed energy deficit in cardiomyocytes and signs of ischemic and hypoxic areas emerging in the myocardium as a result of an accumulation of NADH and NADPH, which initiate excessive production of reactive oxygen species.

Horizons of Heparin Therapy in COVID-19 and Pandemic-Related Diseases.

The disease caused by the coronavirus SARS-CoV-2, named COVID-19, has been spread around the world at a high transmission rate. It was initially considered to be an acute respiratory distress syndrome. Recent clinical data has highlighted that COVID-19 is characterized by a vascular dysfunction and thrombosis, which are not typical for many other acute respiratory diseases. Thrombotic complications are markers of severe COVID-19 and are associated with multiple organ failure and increased mortality. The application of unfractionated and/or low-molecular-weight heparins as anticoagulant medications, significantly reduced the severity of the disease and COVID-19-induced mortality, since heparin is a multifunctional agent. The goal of this review is to summarize the literature data on the pathogenic mechanisms of SARS-CoV-2 and to characterize the properties of heparin, which allow inhibiting these mechanisms at any stage of pathogenesis. We proposed a vicious circle hypothesis of SARS-CoV-2 pathogenesis, as well as an original approach to low-dose heparin therapy beyond its anticoagulant properties. The analysis of a wide range of effects and mechanisms of action of heparin will help create an idea of current possibilities and future potential of applying this drug.

Therapeutic targets in COVID-19 coagulopathy

Virus-induced coagulopathy is a typical example of the tight connection between inflammation and thrombosis. These two reactions are linked by pro-inflammatory agents, generated by activated neutrophils and their neutrophil extracellular traps (NETs). Extracellular membrane nanobubbles (EMNs), formed by a wide variety of cell types, have recently been identified as new entrants that play a key role in coagulopathy. EMNs directly and indirectly activate coagulation systems that lead to the further upregulation of inflammation and life-threatening organ dysfunction and thrombosis. EMNs are known to be responsible for the secretion, exchange, and transmission of important active biomolecules in COVID-19. Indeed, EMNs represent an essential mechanism in intercellular communication, and the roles of EMNs in infection and thrombosis have been increasingly recognized. The extracellular microvesicles of viruses, virosomes, represent a new type of infectious agents, which determines new therapeutic goals in solving the problems of controlling viral infections. Understanding the biological nature of all these microvesicles when studying them in vivo is of paramount importance for the development of diagnostic and therapeutic methods. © Gemostaz i Reologia LLC, 2021.

Mast cells heparin — New information on the old component (review)

Mast cells (MC) are widely distributed throughout the body of animals and humans, mainly in barrier tissues. This review provides new information on the hematopoietic origin of MCs from early erythromyeloid progenitors (EMPs), late EMPs, and definitive hematopoietic stem cells. As well as information on the maturation of MSs and heparin synthesis already in the embryonic period. Many physiological functions of MCs are determined by the properties of heparin, which forms the basis of the matrix of granules, since the heparin molecule is a strong polyanion, capable to forming complexes with many biologically active substances and regulating their properties. In a new hypothesis about the participation of MCs in pathological processes, it is assumed that this is due to the depletion of the heparin pool. In such cases, injections of exogenous heparin can help replenish MCs heparin stores. As a result of the restoration of the physiological functions of MCs and the action of exogenous heparin, the pathological process will be converted into an adaptive one. In clinical practice, unfractionated heparin (UFH) obtained from natural sources and low molecular weight heparin (LMWH) obtained by the biochemical route are used. Most often, UFH and LMWH are used in the clinic only as anticoagulants. The worldwide spread of a disease named COVID-19 in 2020 showed that UFH and LMWH are multifunctional drugs that have saved many people. The pandemic caused by COVID-19 has been an unprecedented social and health emergency worldwide. Depression, anxiety and post-traumatic stress disorder (PTSD) have been reported in populations of many countries. This review provides new information on experimental studies on the successful treatment of pathology with low doses of UFH in modeling PTSD in animals. Consequently, heparin can be considered as a promising multifunctional drug for effective pharmacological correction of comorbid diseases under the influence of extreme factors.