Andrey A. Mozhaev

Arterial hypertension and diabetes mellitus frequently coexist and synergistically accelerate adverse left ventricular remodeling through mitochondrial dysfunction, sterile inflammation, and extracellular matrix disorganization. Heat shock protein 60 (HSP60) is a mitochondrial chaperone involved in proteostasis and stress adaptation, but it remains unclear whether cardiomyocyte-restricted augmentation of HSP60 can modulate myocardial remodeling and influence systemic immune-cell bioenergetics. Male spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto (WKY) rats were studied with or without streptozotocin-induced diabetes. Animals were assigned to WKY, SHR, WKY+HSP60, SHR+HSP60, WKY + DM+HSP60, and SHR + DM+HSP60 groups. HSP60 was delivered using an adeno-associated virus serotype 9 (AAV9) vector under the cardiac troponin T promoter. Myocardial remodeling was assessed by histomorphometry and Masson’s trichrome staining, myocardial signaling by immunohistochemistry and RT-qPCR, and peripheral blood mononuclear cell (PBMC) mitochondrial membrane potential by JC-1 flow cytometry. Cardiac HSP60 delivery showed a context-dependent pattern. In hypertensive diabetic rats, this pattern included altered NLRP3 subcellular localization, modulation of mitochondrial regulatory and inflammatory-fibrotic transcripts, and increased PBMC mitochondrial membrane potential. PBMC polarization inversely correlated with myocardial fibrosis. Normotensive and single-pathology groups did not show a comparable integrated response profile. These findings indicate that cardiomyocyte-targeted HSP60 overexpression is associated with remodeling-related changes in myocardium and peripheral immune-cell bioenergetics under combined hypertensive and diabetic stress. PBMC mitochondrial membrane potential may represent a candidate peripheral indicator of myocardial state in this preclinical setting.

Mitochondria serve as an essential component in the maintenance of cardiac function, and targeting them may represent a promising approach to handling heart failure (HF). HF in this review refers to various etiologies, including ischemic cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy, unless otherwise specified. Mitochondrial dysfunction, a distinctive feature of HF, leads to a progressive decrease in bioenergetic reserves due to switching of energy production from oxidation of fatty acids in mitochondria to glycolytic pathways. The main problem in developing methods to improve mitochondrial function lies in the fact that protein preparations injected through the bloodstream cannot enter cells through the plasma membrane. Modern gene therapy involving the delivery of missing genes to cells using adeno-associated virus (AAV) vectors has the potential to improve the function of cardiomyocytes (CMCs). This type of therapy aims to target proteins that have been lost, damaged, or altered due to pathological conditions in the myocardium. This review summarizes pathophysiological mechanisms associated with mitochondrial dysfunction, which is mainly caused by increased oxidative stress and impaired mitochondrial biodynamics under HF progression. It also addresses possible ways to modulate these processes using gene therapy. Special attention is paid to modern characteristics of AAVs that can be used as vectors for the efficient delivery of desired genes to CMCs.

This review critically examines the evolving landscape of genetic animal models for investigating cardiovascular diseases (CVDs). We analyze established models, including spontaneously hypertensive rats, Watanabe hyperlipidemic rabbits, etc., and transgenic models that have advanced our understanding of essential and secondary hypertension, atherosclerosis, and non-ischemic diseases of the heart. This review systematically evaluates the translational strengths and physiological limitations of these approaches across species barriers. Particular attention is paid to emerging technologies—AAV-mediated gene delivery, CRISPR-Cas9 editing, and chemogenetic tools—that enable unprecedented precision in manipulating cardiac-specific gene expression to study pathophysiological mechanisms. We address persistent challenges including off-target effects and transgene expression variability, while highlighting innovations in synthetic vectors and tissue-specific targeting strategies. This synthesis underscores how evolving genetic technologies are revolutionizing cardiovascular research paradigms, offering refined disease models and optimized therapeutic interventions that pave the way toward personalized medicine approaches for the world’s leading cause of mortality.

Optogenetics and chemogenetics are relatively new biomedical technologies that emerged 20 years ago and have been evolving rapidly since then. This has been made possible by the combined use of genetic engineering, optics, and electrophysiology. With the development of optogenetics and thermogenetics, the molecular tools for cellular control are continuously being optimized, studied, and modified, expanding both their applications and their biomedical uses. The most notable changes have occurred in the basic life sciences, especially in neurobiology and the activation of neurons to control behavior. Currently, these methods of activation have gone far beyond neurobiology and are being used in cardiovascular research, for potential cancer therapy, to control metabolism, etc. In this review, we provide brief information on the types of molecular tools for optogenetic and thermogenetic methods─microbial rhodopsins and proteins of the TRP superfamily─and also consider their applications in the field of activation of non-neuronal tissues and mammalian cells. We also consider the potential of these technologies and the prospects for the use of optogenetics and thermogenetics in biomedical research.

Filamin C (FLNC) is a structural protein of muscle fibers. Mutations in the FLNC gene are known to cause myopathies and cardiomyopathies in humans. Here we report the generation by a CRISPR/Cas9 editing system injected into zygote pronuclei of two mouse strains carrying filamin C mutations—one of them (AGA) has a deletion of three nucleotides at position c.7418_7420, causing E>>D substitution and N deletion at positions 2472 and 2473, respectively. The other strain carries a deletion of GA nucleotides at position c.7419_7420, leading to a frameshift and a premature stop codon. Homozygous animals (Flnc^AGA/AGA and Flnc^GA/GA) were embryonically lethal. We determined that Flnc^GA/GA embryos died prior to the E12.5 stage and illustrated delayed development after the E9.5 stage. We performed histological analysis of heart tissue and skeletal muscles of heterozygous strains carrying mutations in different combinations (Flnc^GA/wt, Flnc^AGA/wt, and Flnc^GA/AGA). By performing physiological tests (grip strength and endurance tests), we have shown that heterozygous animals of both strains (Flnc^GA/wt, Flnc^AGA/wt) are functionally indistinguishable from wild-type animals. Interestingly, compound heterozygous mice (Flnc^GA/AGA) are viable, develop normally, reach puberty and it was verified by ECG and Eco-CG that their cardiac muscle is functionally normal. Intriguingly, Flnc^GA/AGA mice demonstrated better results in the grip strength physiological test in comparison to WT animals. We also propose a structural model that explains the complementary interaction of two mutant variants of filamin C.

Filamin C (FLNC) is a structural protein of muscle fibers. Mutations in the Flnc gene are known to cause myopathies and cardiomyopathies in humans. Here we report a generation of two mouse strains carrying filamin C mutations — one of them has a deletion of three nucleotides at position c.7418_7420, causing E>>;D substitution and N deletion at positions 2472 and 2473, respectively. The other strain carries a deletion of GA nucleotides at position c.7419_7420, leading to a frameshift and a premature stop-codon. We have shown that heterozygous animals of both strains are functionally and morphologically indistinguishable from wild type animals, while homozygosity is embryonically lethal. Interestingly, compound heterozygous mice are viable, develop normally, reach puberty and their cardiac muscle is functionally and histologically normal. We also propose a structural model that explains the complementary interaction of two mutant variants of filamin C.

The oligomeric state of the nucleoid-associated protein IHF (integration host factor) plays a significant role in the organization and compaction of the bacterial nucleoid and also in the evolution of bacterial resistance to unfavorable environmental conditions, in particular to antibiotics. Although IHF was identified more than 25 years ago, the molecular mechanisms of its participation in these processes are poorly understood. Using small-angle X-ray scattering, it was demonstrated for the first time that there are different oligomeric states of IHF in an aqueous medium depending on the presence of metal cations. It was found that the presence of Mg²⁺ and K⁺ ions hinders the formation of high-order oligomers of IHF. The results of this study may be useful in the development of strategies against bacterial resistance to drugs.

Changes in lighting accompany modern urbanization trends and can lead to various pathologies based on circadian disturbances. In this study, we assessed the changes in the circadian rhythm of core body temperature (Tcore) and locomotor activity of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) following exposure to different lighting conditions: extended light phase of the day (16 h–8 h, 20 h–4 h, 24 h–0 h), light pollution, monochromatic light, and bright light therapy. The telemetry data was collected after experimental lighting conditions during periods with standard lighting (12 h of light and 12 h of darkness) and was processed using linear and cosinor analysis. The daily rhythms of rats’ parameters persisted in accordance with the standard lighting regime. Tcore changes were observed in both groups compared to the initial period: in WKY, a decrease in Tcore during the darkness and an increase during the light; in SHR, the opposite trend, with Tcore increased during the darkness and decreased during the light phase of the day. A relationship between Tcore and activity was observed with weak correlation. WKY exhibited more pronounced signs of adaptive variation and desynchronization compared to SHR, which could be associated with a wider range of functional capabilities of the organism without cardiovascular pathology.

Cardiac arrhythmias are common disorders that can be fatal. Modern methods of treating bradyarrhythmias include the implantation of pacemakers and cardioverter–defibrillators. However, implantable devices can cause various complications related to the electrodes installed inside the heart, including infection. Less invasive heart rhythm modulation could be beneficial for some cohorts of patients. Here, we demonstrate an alternative approach to heart pacing based on thermogenetics. We used adeno-associated viruses to deliver genetic human transient receptor potential subfamily V member 1 (TRPV1), a heat-sensitive cation channel, into isolated cardiomyocytes and the mouse heart. This allowed us to induce action potentials and control contractility using short heat pulses delivered by infrared laser illumination. Using this approach, we demonstrated the thermogenetic pacing of isolated cardiomyocytes in vitro and in the mouse heart in vivo . Our results demonstrate the potential of thermogenetics for developing therapeutic strategies for heart rhythm modulation.

Structure and function of bacterial nucleoid is controlled by the nucleoid-associated proteins (NAP). In any phase of growth, various NAPs, acting sequentially, condense nucleoid and facilitate formation of its transcriptionally active structure. However, in the late stationary phase, only one of the NAPs, Dps protein, is strongly expressed, and DNA–protein crystals are formed that transform nucleoid into a static, transcriptionally inactive structure, effectively protected from the external influences. Discovery of crystal structures in living cells and association of this phenomenon with the bacterial resistance to antibiotics has aroused great interest in studying this phenomenon. The aim of this work is to obtain and compare structures of two related NAPs (HU and IHF), since they are the ones that accumulate in the cell at the late stationary stage of growth, which precedes formation of the protective DNA–Dps crystalline complex. For structural studies, two complementary methods were used in the work: small-angle X-ray scattering (SAXS) as the main method for studying structure of proteins in solution, and dynamic light scattering as a complementary one. To interpret the SAXS data, various approaches and computer programs were used (in particular, the evaluation of structural invariants, rigid body modeling and equilibrium mixture analysis in terms of the volume fractions of its components were applied), which made it possible to determine macromolecular characteristics and obtain reliable 3D structural models of various oligomeric forms of HU and IHF proteins with ~2 nm resolution typical for SAXS. It was shown that these proteins oligomerize in solution to varying degrees, and IHF is characterized by the presence of large oligomers consisting of initial dimers arranged in a chain. An analysis of the experimental and published data made it possible to hypothesize that just before the Dps expression, it is IHF that forms toroidal structures previously observed in vivo and prepares the platform for formation of DNA–Dps crystals. The results obtained are necessary for further investigation of the phenomenon of biocrystal formation in bacterial cells and finding ways to overcome resistance of various pathogens to external conditions.