Effect of 2-Aminoethoxydiphenyl Borate on the State of Skeletal Muscles in Dystrophin-Deficient Mice.

Objective: Ca overload of muscle fibers is one of the factors that secondarily aggravate the development of Duchenne muscular dystrophy (DMD). The purpose of this study is to evaluate the effects of the Ca channel modulator 2-aminoethoxydiphenyl borate (APB) on skeletal muscle pathology in dystrophin-deficient mice.

Methods: Mice were randomly divided into six groups: wild type (WT), WT+3 mg/kg APB, WT+10 mg/kg APB, , +3 mg/kg APB, +10 mg/kg APB.

Correction: Belosludtsev et al. Alisporivir Treatment Alleviates Mitochondrial Dysfunction in the Skeletal Muscles of C57BL/6NCrl Mice with High-Fat Diet/Streptozotocin-Induced Diabetes Mellitus. 2021, , 9524.

The original publication [...

Reduction of Mitochondrial Calcium Overload via MKT077-Induced Inhibition of Glucose-Regulated Protein 75 Alleviates Skeletal Muscle Pathology in Dystrophin-Deficient Mice.

Duchenne muscular dystrophy is secondarily accompanied by Ca excess in muscle fibers. Part of the Ca accumulates in the mitochondria, contributing to the development of mitochondrial dysfunction and degeneration of muscles. In this work, we assessed the effect of intraperitoneal administration of rhodacyanine MKT077 (5 mg/kg/day), which is able to suppress glucose-regulated protein 75 (GRP75)-mediated Ca transfer from the sarcoplasmic reticulum (SR) to mitochondria, on the Ca overload of skeletal muscle mitochondria in dystrophin-deficient mice and the concomitant mitochondrial dysfunction contributing to muscle pathology.

ANT-Mediated Inhibition of the Permeability Transition Pore Alleviates Palmitate-Induced Mitochondrial Dysfunction and Lipotoxicity.

Hyperlipidemia is a major risk factor for vascular lesions in diabetes mellitus and other metabolic disorders, although its basis remains poorly understood. One of the key pathogenetic events in this condition is mitochondrial dysfunction associated with the opening of the mitochondrial permeability transition (MPT) pore, a drop in the membrane potential, and ROS overproduction. Here, we investigated the effects of bongkrekic acid and carboxyatractyloside, a potent blocker and activator of the MPT pore opening, respectively, acting through direct interaction with the adenine nucleotide translocator, on the progression of mitochondrial dysfunction in mouse primary lung endothelial cells exposed to elevated levels of palmitic acid.

Glucocorticoid Deflazacort Normalizes the Ultrastructure of Skeletal Muscles and the State of the Colon Microbiota in Dystrophin-Deficient Mice.

We studied the effect of enteral administration of the glucocorticoid deflazacort (DFC, 1.2 mg/kg per day, 28 days) on the state of skeletal muscles and tissue ultrastructure, as well as the composition of the colon microbiota in dystrophin-deficient mdx mice. DFC has been shown to reduce the intensity of degeneration/regeneration cycles in muscle fibers of mdx mice.

Synthesis and comparative analysis of the cytotoxicity and mitochondrial effects of triphenylphosphonium and F16 maslinic and corosolic acid hybrid derivatives.

The cytotoxic profile and antiproliferative and mitochondrial effects of triterpene acid conjugates with mitochondriotropic lipophilic triphenylphosphonium (TPP) and F16 cations were evaluated. Maslinic and corosolic acids chosen as the investigation objects were synthesized from commercially available oleanolic and ursolic acids. Study of the cytotoxic activity of TPP and F16 triterpenoid derivatives against six tumor cell lines demonstrated a comparable synergistic effect in the anticancer activity, which was most pronounced in the case of MCF-7 mammary adenocarcinoma cells and Jurkat and THP-1 leukemia cells.

Pore-Forming VDAC Proteins of the Outer Mitochondrial Membrane: Regulation and Pathophysiological Role.

Voltage-dependent anion channels (VDAC1-3) of the outer mitochondrial membrane are a family of pore-forming β-barrel proteins that carry out controlled "filtration" of small molecules and ions between the cytoplasm and mitochondria. Due to the conformational transitions between the closed and open states and interaction with cytoplasmic and mitochondrial proteins, VDACs not only regulate the mitochondrial membrane permeability for major metabolites and ions, but also participate in the control of essential intracellular processes and pathological conditions. This review discusses novel data on the molecular structure, regulatory mechanisms, and pathophysiological role of VDAC proteins, as well as future directions in this area of research.

α-Ketoglutarate prevents hyperlipidemia-induced fatty liver mitochondrial dysfunction and oxidative stress by activating the AMPK-pgc-1α/Nrf2 pathway.

α-Ketoglutarate (AKG), a crucial intermediate in the tricarboxylic acid cycle, has been demonstrated to mitigate hyperlipidemia-induced dyslipidemia and endothelial damage. While hyperlipidemia stands as a major trigger for non-alcoholic fatty liver disease, the protection of AKG on hyperlipidemia-induced hepatic metabolic disorders remains underexplored. This study aims to investigate the potential protective effects and mechanisms of AKG against hepatic lipid metabolic disorders caused by acute hyperlipidemia.

Theoretical and Experimental Study of the Interaction of Protonophore Uncouplers and Decoupling Agents with Functionally Active Mitochondria.

The purpose of this work was to quantitatively characterize the effectiveness of oxidative phosphorylation uncouplers and decoupling agents in functionally active mitochondria, taking into account their content in the hydrophobic region of the inner membrane of these organelles. When conducting theoretical studies, it is accepted that uncouplers and decouplers occupy part of the volume of mitochondria to exhibit their activity, which is defined as the effective volume. The following quantities characterizing the action of these reagents are considered: (1) concentrations of reagents that cause double stimulation of mitochondrial respiration in state 4 ( ); (2) effective distribution coefficient ( ) - the ratio of the amount of reagents in the effective volume of mitochondria and the water volume; (3) the relative amount of reagents associated with the effective volume of mitochondria ( ); (4) specific activity of reagents localized in the effective volume of mitochondria ( ).

Effect of VBIT-4 on the functional activity of isolated mitochondria and cell viability.

VBIT-4 is a new inhibitor of the oligomerization of VDAC proteins of the outer mitochondrial membrane preventing the development of oxidative stress, mitochondrial dysfunction, and cell death in various pathologies. However, as a VDAC inhibitor, VBIT-4 may itself cause mitochondrial dysfunction in healthy cells. The article examines the effect of VBIT-4 on the functional activity of rat liver mitochondria and cell cultures.

Mitochondrial Transplantation Therapy Ameliorates Muscular Dystrophy in Mouse Model.

Duchenne muscular dystrophy is caused by loss of the dystrophin protein. This pathology is accompanied by mitochondrial dysfunction contributing to muscle fiber instability. It is known that mitochondria-targeted in vivo therapy mitigates pathology and improves the quality of life of model animals.

Protective Effect of Uridine on Structural and Functional Rearrangements in Heart Mitochondria after a High-Dose Isoprenaline Exposure Modelling Stress-Induced Cardiomyopathy in Rats.

The pyrimidine nucleoside uridine and its phosphorylated derivates have been shown to be involved in the systemic regulation of energy and redox balance and promote the regeneration of many tissues, including the myocardium, although the underlying mechanisms are not fully understood. Moreover, rearrangements in mitochondrial structure and function within cardiomyocytes are the predominant signs of myocardial injury. Accordingly, this study aimed to investigate whether uridine could alleviate acute myocardial injury induced by isoprenaline (ISO) exposure, a rat model of stress-induced cardiomyopathy, and to elucidate the mechanisms of its action related to mitochondrial dysfunction.

Uridine Administration Promotes Normalization of Heart Mitochondrial Function in Dystrophin-Deficient Mice and Decreases Tissue Fibrosis.

The work shows the effect of the metabolic modulator uridine on the functioning and ultrastructure of heart mitochondria in dystrophin-deficient mdx mice. Intraperitoneal administration of uridine (30 mg/kg/day for 28 days) improved K transport and increased its content in the heart mitochondria of mdx mice to the level of wild-type animals. This was accompanied by a significant decrease in the level of malondialdehyde and an increase in the number of mitochondria in the heart of mdx mice.

Mitochondrial Dyshomeostasis as an Early Hallmark and a Therapeutic Target in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal multisystem disease characterized by progressive death of motor neurons, loss of muscle mass, and impaired energy metabolism. More than 40 genes are now known to be associated with ALS, which together account for the majority of familial forms of ALS and only 10% of sporadic ALS cases. To date, there is no consensus on the pathogenesis of ALS, which makes it difficult to develop effective therapy.

Effects of the Long-Term Administration of Uridine on the Functioning of Rat Liver Mitochondria in Hyperthyroidism.

The effect of uridine (30 mg/kg for 7 days; intraperitoneally) on the functions of liver mitochondria in rats with experimentally induced hyperthyroidism (HT) (200 µg/100 g for 7 days, intraperitoneally) is studied in this paper. An excess of thyroid hormones (THs) led to an intensification of energy metabolism, the development of oxidative stress, a significant increase in the biogenesis, and changes in the content of proteins responsible for the fusion and fission of mitochondria. The injection of uridine did not change the concentration of THs in the blood of hyperthyroid rats (HRs) but normalized their body weight.

Modulators reducing the efficiency of oxidative ATP synthesis in mitochondria: protonophore uncouplers, cyclic redox agents, and decouplers.

This work considers the main indicators of the oxidative phosphorylation efficiency in mitochondria: the ADP/O and H/O ratios. Three groups of modulators that reduce the efficiency of oxidative phosphorylation are compared: protonophore uncouplers, cyclic redox compounds, and decouplers. It is noted that some of them are considered effective therapeutic agents.

Effect of Fusidic Acid and Some Nitrogen-Containing Derivatives on Liposomal and Mitochondrial Membranes.

The paper assesses the membranotropic action of the natural antibiotic fusidic acid (FA) and its derivatives. It was found that a FA analogue with ethylenediamine moiety (derivative 2), in contrast to native FA and 3,11-dioxime analogue (derivative 1), is able to increase the mobility of the lipid bilayer in the zone of lipid headgroups, as well as to induce permeabilization of lecithin liposome membranes. A similar effect of derivative 2 is also observed in the case of rat liver mitochondrial membranes.

Alterations in Mitochondrial Morphology and Quality Control in Primary Mouse Lung Microvascular Endothelial Cells and Human Dermal Fibroblasts under Hyperglycemic Conditions.

The effect of hyperglycemia on the morphology of individual mitochondria and the state of the mitochondrial network in primary mouse lung microvascular endotheliocytes and human dermal fibroblasts has been investigated. The cells were exposed to high (30 mM) and low (5.5 mM) glucose concentrations for 36 h.

Pharmacological and Genetic Suppression of VDAC1 Alleviates the Development of Mitochondrial Dysfunction in Endothelial and Fibroblast Cell Cultures upon Hyperglycemic Conditions.

Prolonged hyperglycemia related to diabetes and its complications leads to multiple cellular disorders, the central one being the dysfunction of mitochondria. Voltage-dependent anion channels (VDAC) of the outer mitochondrial membrane control the metabolic, ionic, and energy cross-talk between mitochondria and the rest of the cell and serve as the master regulators of mitochondrial functions. Here, we have investigated the effect of pharmacological suppression of VDAC1 by the newly developed inhibitor of its oligomerization, VBIT-4, in the primary culture of mouse lung endotheliocytes and downregulated expression of VDAC1 in human skin fibroblasts on the progression of mitochondrial dysfunction upon hyperglycemic stress.

Conjugation of Triterpenic Acids of Ursane and Oleanane Types with Mitochondria-Targeting Cation F16 Synergistically Enhanced Their Cytotoxicity against Tumor Cells.

The present work shows the cytotoxic effects of novel conjugates of ursolic, oleanolic, maslinic, and corosolic acids with the penetrating cation F16 on cancer cells (lung adenocarcinoma A549 and H1299, breast cancer cell lines MCF-7 and BT474) and non-tumor human fibroblasts. It has been established that the conjugates have a significantly enhanced toxicity against tumor-derived cells compared to native acids and also demonstrate selectivity to some cancer cells. The toxic effect of the conjugates is shown to be due to ROS hyperproduction in cells, induced by the effect on mitochondria.

Effect of Large-Conductance Calcium-Dependent K Channel Activator NS1619 on Function of Mitochondria in the Heart of Dystrophin-Deficient Mice.

Dystrophin-deficient muscular dystrophy (Duchenne dystrophy) is characterized by impaired ion homeostasis, in which mitochondria play an important role. In the present work, using a model of dystrophin-deficient mdx mice, we revealed decrease in the efficiency of potassium ion transport and total content of this ion in the heart mitochondria. We evaluated the effect of chronic administration of the benzimidazole derivative NS1619, which is an activator of the large-conductance Ca2+-dependent K+ channel (mitoBK), on the structure and function of organelles and the state of the heart muscle.

Ion Channels of the Sarcolemma and Intracellular Organelles in Duchenne Muscular Dystrophy: A Role in the Dysregulation of Ion Homeostasis and a Possible Target for Therapy.

Duchenne muscular dystrophy (DMD) is caused by the absence of the dystrophin protein and a properly functioning dystrophin-associated protein complex (DAPC) in muscle cells. DAPC components act as molecular scaffolds coordinating the assembly of various signaling molecules including ion channels. DMD shows a significant change in the functioning of the ion channels of the sarcolemma and intracellular organelles and, above all, the sarcoplasmic reticulum and mitochondria regulating ion homeostasis, which is necessary for the correct excitation and relaxation of muscles.

Comparative Study of Cytotoxic and Membranotropic Properties of Betulinic Acid-F16 Conjugate on Breast Adenocarcinoma Cells (MCF-7) and Primary Human Fibroblasts.

The present study evaluates the cytotoxicity of a previously synthesized conjugate of betulinic acid (BA) with the penetrating cation F16 on breast adenocarcinoma (MCF-7) and human fibroblast (HF) cell lines, and also shows the mechanism underlying its membranotropic action. It was confirmed that the conjugate exhibits higher cytotoxicity compared to native BA at low doses also blocking the proliferation of both cell lines and causing cell cycle arrest in the G/G phase. We show that the conjugate indeed has a high potential for accumulation in mitochondria, being visualized in these organelles, which is most pronounced in cancer cells.

BK Activator NS1619 Improves the Structure and Function of Skeletal Muscle Mitochondria in Duchenne Dystrophy.

Duchenne muscular dystrophy (DMD) is a progressive hereditary disease caused by the absence of the dystrophin protein. This is secondarily accompanied by a dysregulation of ion homeostasis, in which mitochondria play an important role. In the present work, we show that mitochondrial dysfunction in the skeletal muscles of dystrophin-deficient mice is accompanied by a reduction in K transport and a decrease in its content in the matrix.

Alisporivir Normalizes Mitochondrial Function of Primary Mouse Lung Endothelial Cells Under Conditions of Hyperglycemia.

Effect of alisporivir (a mitochondrial permeability transition pore inhibitor) on the development of mitochondrial dysfunction under hyperglycemic conditions in the primary culture of mouse lung endothelial cells was investigated in this work. We demonstrated that hyperglycemia (30 mM glucose for 24 h) leads to the decrease in viability of the pulmonary endotheliocytes, causes mitochondrial dysfunction manifested by the drop in membrane potential and increase in superoxide anion generation as well as facilitates opening of the mitochondrial permeability transition pore (MPT pore). Incubation of endothelial cells with 5 µM alisporivir under hyperglycemic conditions leads to the increase in cell viability, restoration of the membrane potential level and of the MPT pore opening activity to control values.