Osteoporosis is a widespread systemic disease characterized by a decrease in bone mass and an imbalance of the microarchitecture of bone tissue. Experimental and clinical studies devoted to investigating the main pathogenetic mechanisms of osteoporosis revealed the important role of estrogen deficiency, inflammation, oxidative stress, cellular senescence, and epigenetic factors in the development of bone resorption due to osteoclastogenesis, and decreased mineralization of bone tissue and bone formation due to reduced function of osteoblasts caused by apoptosis and age-depended differentiation of osteoblast precursors into adipocytes. The current review was conducted to describe the basic mechanisms of the development of osteoporosis at molecular and cellular levels and to elucidate the most promising therapeutic strategies of pathogenetic therapy of osteoporosis based on articles cited in PubMed up to September 2023.

The extracellular matrix (ECM) is the principal structure of bone tissue. Long-term spaceflights lead to osteopenia, which may be a result of the changes in composition as well as remodeling of the ECM by osteogenic cells. To elucidate the cellular effects of microgravity, human mesenchymal stromal cells (MSCs) and their osteocommitted progeny were exposed to simulated microgravity (SMG) for 10 days using random positioning machine (RPM). After RPM exposure, an imbalance of MSC collagen/non-collagen ratio at the expense of a decreased level of collagenous proteins was detected. At the same time, the secretion of proteases (cathepsin A, cathepsin D, MMP3) was increased. No significant effects of SMG on the expression of stromal markers and cell adhesion molecules on the MSC surface were noted. Upregulation of COL11A1, CTNND1, TIMP3, and TNC and downregulation of HAS1, ITGA3, ITGB1, LAMA3, MMP1, and MMP11 were detected in RPM exposed MSCs. ECM-associated transcriptomic changes were more pronounced in osteocommitted progeny. Thus, 10 days of SMG provokes a decrease in the collagenous components of ECM, probably due to the decrease in collagen synthesis and activation of proteases. The presented data demonstrate that ECM-associated molecules of both native and osteocommitted MSCs may be involved in bone matrix reorganization during spaceflight.

The mechanisms of pathogenesis of hypertrophic cardiomyopathy are associated with mutations in the sarcomere genes of cardiomyocytes and metabolic disorders of the cell, including mitochondrial dysfunction. Mitochondria are characterized by the presence of their own DNA and enzyme complexes involved in oxidative reactions, which cause damage to mitochondrial protein structures and membranes by reactive oxygen species. Mitochondrial dysfunctions can also be associated with mutations in the genes encoding mitochondrial proteins and lead to a violation of protective functions such as mitophagy, mitochondrial fusion, and fission. Mutations in myofibril proteins can negatively affect mitochondria through increased oxidative stress due to an increased need for ATP. Mitochondrial dysfunction is associated with impaired ATP synthesis and cardiac contractility, leading to clinical manifestations of hypertrophic cardiomyopathy. The current review was designed to characterize the role of mitochondria in the pathogenesis of hypertrophic cardiomyopathy based on published data; the search for publications was based on the analysis of articles including the keywords “hypertrophic cardiomyopathy, mitochondria, dysfunction” in the PubMed and Scopus databases up to January 2025.

The achievements of regenerative medicine are based on methods of controlling stem cell division and differentiation. Electromagnetic fields stimulate cell differentiation by means of affecting calcium channels and cellular signaling. However, only a small part of the mechanisms underlying electromagnetic field effect on cells has been studied. The prospect of their use in tissue engineering as an addition or alternative to biochemical effects becomes clear in the course of numerous experiments. Electromagnetic stimulation enhances the effect of biochemical differentiation inducers and can cause the secretion of exosomes of special properties, which may serve as a therapeutic tool. For example, it has been shown that EMFs at 15 Hz and 2 mT increased the expression of chondrogenic differentiation markers SOX9 and COL2 in human bone-marrow MSCs by up to 3-fold (based on Parate et al.). Optimizing EMF parameters (e.g., 15–50 Hz, 1–2 mT) for specific cells and pathologies remains a key challenge of the studies in the field of tissue engineering. This review describes the electromagnetic field effect on the chondrogenic and osteogenic differentiation of MSCs of various origins, which is important for the musculoskeletal tissue recovery, as well as on inflammatory diseases in model animals.

Cellular senescence of adipose tissue-derived mesenchymal stromal cells (AD-MSCs) is associated with chronic low-grade inflammation, metabolic dysfunction, and impaired adipogenesis contributing to the development of obesity, insulin resistance, and the progression of age-associated diseases. The aim of this study was to develop a model of cellular aging based on AD-MSCs to study the senolytic efficacy of the natural fisetin preparation for the subsequent development of geroprotective therapeutic strategies. The senescent markers SA-β-gal, SASP factors, and cell cycle arrest markers p16, p21, and p53 were assessed in models of replicative and stress-induced aging of AD-MSCs. H₂O₂ was identified as the most effective inducer of AD-MSC cellular senescence in comparison with LPS. It has been shown in the model of H₂O₂-induced senescence of AD-MSCs that the proportion of SA-β-gal+ cells was 2.0 (0.7)% in non-stimulated AD-MSCs, 81.7 (12.1)% in H₂O₂-stimulated AD-MSCs, and 19.1 (5.2)% and 13.0 (3.2)% after short-term (24 h) and long-term (7 days) fisetin treatment, respectively, indicating that fisetin treatment was associated with a lower proportion of SA-β-gal+ cells. Fisetin treatment resulted in a statistically significant decrease in the secretion of MCP-1, especially during long-term incubation. IL-1β showed a significant decrease after 7 days of fisetin treatment compared to H₂O₂, but the effect at 24 h was only significant in the group of 7 days of fisetin treatment. Fisetin treatment was also associated with higher p53 and p21 concentrations. Thus, in the present study, a model of H₂O₂-induced cellular senescence of AD-MSCs was developed, which can be used to evaluate the geroprotective potential of senotherapeutic preparations; fisetin warrants further evaluation as a potential senotherapeutic agent in this model.