The role of cortisol metabolism in the realization of pathogenetic links in the development of osteoporosis – the rationale for the search for new pharmacotherapeutic targets (review)

Background: Osteoporosis is an important medical and social public health problem in an aging or elderly society. Osteoporosis is caused by an imbalance in bone remodeling, which is a continuous process of destruction of mature bone tissue by osteoclasts (bone resorption) and the formation of new bone tissue by osteoblasts (bone formation). The system of bone homeostasis that regulates the functional activity of osteoclasts and osteoblasts is represented by a wide range of molecules. The understanding of the molecular mechanisms of bone homeostasis achieved today makes it possible to significantly change and expand the paradigms of treatment and prevention of osteoporosis. The aim of the study: To consider the main pathogenetic pathways through which the effect of the cortisol metabolism system on the development of osteoporosis is realized and to identify ways to find new therapeutic approaches to the treatment and prevention of this pathology. Materials and methods: To achieve this goal, we analyzed the literature on the influence of cortisol metabolism on the development of osteoporosis published in the last 10 years. Results: To date, there are significant prerequisites in the literature for a direct connection of disorders of steroid hormone metabolism with the development of osteoporosis and a violation of osteoreparative processes. This literature review presents the main pathogenetic pathways that cause the processes leading to a decrease in bone density in disorders of cortisol metabolism. The enzyme 11b-hydroxysteroid dehydrogenase (11b-HSD), represented by two isoforms, performs the mutual conversion of cortisone and cortisol in tissues. Using the methods of reverse genetics, we have established the systemic consequences of knockout of both isoforms. Convincing evidence demonstrates that both enzymes are involved in the pathogenesis of osteoporosis. Since animals with type 11b-HSD deficiency are characterized by proinflammatory activation of the endothelium, we assume that further study of the interaction between the endothelium and bone tissue is of particular interest. Conclusion: The effects of glucocorticoids on eNOS expression seem to be significantly modulated by 11ß-HSD isoenzymes. The established relationship between 11ß-HSD and NO can be considered a promising pharmacotherapeutic target. In this regard, a pharmacotherapeutic approach aimed at restoring the balance of nitric oxide in bone and endothelial tissues, currently considered as one of the most relevant ways to correct osteoporosis, may also be relevant in case of cortisol metabolism disorders due to 11ß-HSD2 deficiency.