Ultrastructural Remodeling of Cardiomyocytes in Postinfarction Myocardium of Rats in the Late Stages of the Disease.

Identifying factors that contribute to the transition to the dilated phase in cardiac ischemia is a critical challenge in heart failure treatment. Currently, no effective therapies exist for this ischemic complication, and the mechanisms driving left ventricular dilatation during chronic post-infarction remodeling remain poorly understood. One potential pathological process leading to ventricular dilatation involves specific compensatory rearrangements in the border zone adjacent to the infarct, which isolates the intact myocardium from inflammation at the scar edge.

STIM1 ablation impairs exercise-induced physiological cardiac hypertrophy and dysregulates autophagy in mouse hearts.

Cardiac stromal interaction molecule 1 (STIM1), a key mediator of store-operated Ca entry (SOCE), is a known determinant of cardiomyocyte pathological growth in hypertrophic cardiomyopathy. We examined the role of STIM1 and SOCE in response to exercise-dependent physiological hypertrophy. Wild-type (WT) mice subjected to exercise training (WT-Ex) showed a significant increase in exercise capacity and heart weight compared with sedentary (WT-Sed) mice.

NaV1.6 dysregulation within myocardial T-tubules by D96V calmodulin enhances proarrhythmic sodium and calcium mishandling.

Calmodulin (CaM) plays critical roles in cardiomyocytes, regulating Na+ (NaV) and L-type Ca2+ channels (LTCCs). LTCC dysregulation by mutant CaMs has been implicated in action potential duration (APD) prolongation and arrhythmogenic long QT (LQT) syndrome. Intriguingly, D96V-CaM prolongs APD more than other LQT-associated CaMs despite inducing comparable levels of LTCC dysfunction, suggesting dysregulation of other depolarizing channels.

Distributed synthesis of sarcolemmal and sarcoplasmic reticulum membrane proteins in cardiac myocytes.

It is widely assumed that synthesis of membrane proteins, particularly in the heart, follows the classical secretory pathway with mRNA translation occurring in perinuclear regions followed by protein trafficking to sites of deployment. However, this view is based on studies conducted in less-specialized cells, and has not been experimentally addressed in cardiac myocytes. Therefore, we undertook direct experimental investigation of protein synthesis in cardiac tissue and isolated myocytes using single-molecule visualization techniques and a novel proximity-ligated in situ hybridization approach for visualizing ribosome-associated mRNA molecules for a specific protein species, indicative of translation sites.

Genetically Independent Tetranucleotide to Hexanucleotide Core Motif SSR Markers for Identifying Cultivars.

For the purpose of protecting the rights of breeders, we developed a new simple sequence repeat (SSR) marker set consisting only of genetically independent tetranucleotide or longer core motifs. Using available genome sequences for five strains, we designed primers for 13 SSR markers that amplified polymorphic sequences in 20  cultivars. We evaluated the independence of every possible marker pair based on genotype data.

Enhancement of Cardiac Store Operated Calcium Entry (SOCE) within Novel Intercalated Disk Microdomains in Arrhythmic Disease.

Store-operated Ca entry (SOCE), a major Ca signaling mechanism in non-myocyte cells, has recently emerged as a component of Ca signaling in cardiac myocytes. Though it has been reported to play a role in cardiac arrhythmias and to be upregulated in cardiac disease, little is known about the fundamental properties of cardiac SOCE, its structural underpinnings or effector targets. An even greater question is how SOCE interacts with canonical excitation-contraction coupling (ECC).

Rat Left Ventricular Cardiomyocytes Characterization in the Process of Postinfarction Myocardial Remodeling.

Ischemic lesions of the heart, including myocardial infarction, are the most common pathologies of human cardiovascular system. Despite all the research and achievements of medicine in this field, the mortality from this disease remains heavy. Therefore, studying of processes occurring in the myocardium in the early and late postinfarction periods remains important.

[DNA CONTENT IN INDIVIDUAL CHROMOSOMES OF NORMAL CHINESE HAMSTER KARYOTYPE AND CHROMOSOMES OF CONSTANT HAMSTER CELL LINES CHL V-79 RJK AND Vebr-5].

Using cytometry and an microfluorimetry, we have determined the genome size in Chinese hamster Cricetulus griseus, as well as absolute and relative DNA content of its individual chromosomes and of chromosomes in the transformed Chinese hamster cell lines V-79 RJK and Vebr-5 after prolonged cultivation. It has been shown that the genome size in male and female Chinese hamster is 6.660 and 6.

[Rat heat structural and functional characteristics and gas exchange parameters after experimental myocardial infarction].

Rat heart structural and functional changes and gas exchange parameters were investigated in six months after experimental myocardial infarction. Left ventricular end-systolic and end-diastolic dimensions in rats with chronic heart failure were 78 and 30% higher than in control respectively. Left ventricle cavity volume in systole and diastole were 5 and 2 times increased respectively.

[STEM CELLS PLAY NO CONSIDERABLE ROLE IN CARDIOMYOCYTE REPOPULATION OF ADULT HUMAN HEART].

There are two viewpoints concerning cardiac regeneration. One assumes that the myocardium of an adult human heart has a weak regenerative capacity. According to another, myocardium can renew at a high rate due to the presence of resident stem cells.

Sphingosine-1-phosphate: distribution, metabolism and role in the regulation of cellular functions.

The role of sphingosine-1-phosphate (S1P) in regulation of cellular functions and cell protection is reviewed. S1P, along with other sphingolipid metabolites, is believed to act as an intracellular second messenger and as an extracellular mediator molecule. S1P chemistry, production and metabolism are described.

Conserved SAMS function in regulating egg-laying in C. elegans.

S-adenosyl-L-methionine (SAM) is an intermediate metabolite of methionine and serves as the methyl donor for many biological methylation reactions. The synthesis of SAM is catalyzed by SAM synthetase (SAMS), which transfers the adenosyl moiety of adenosine-5'-triphosphate to methionine. In the nematode Caenorhabditis elegans, four sams family genes, sams-1, -3, -4 and -5, are predicted to encode SAMS proteins.

[DNA image-fluorimetry of individual human chromosomes].

Mucrofluorimetric method for the determination of DNA content in individual human chromosomes has been developed. The method is based on a preliminary identification of chromosomes with Hoechst 33258, followed by staining of the chromosomes with Feulgen reaction using Schiffs reagent type ethidium bromide-SO2, then measuring the fluorescence intensity of the chromosomes using an image analyzer. The method allows to determine the DNA content of individual chromosomes with accuracy up to 4.

Heterogeneity of left ventricular cardiomyocytes from rat heart.

Contractile cardiomyocytes in various parts of the heart differ in shape, size, ploidy, and other parameters. However, it is not known whether their population is heterogeneous within each heart chamber. In this paper, dry weight and ploidy of cardiomyocytes were estimated in different parts of rat left ventricle.

[Regeneration of the liver of Chinese hamster Cricetulus griseus].

Using cytofluorimetry and interferometry, hepatocyte DNA, dry mass and distribution of hepatocyte ploidy classes were measured in hamsters Cricetulus griseus in 1 month after partial hepatoctomy. Ploidy of normal liver hepatocyte was 2.35 +/- 0.

[Cellular mechanisms of regeneration of rats' liver after experimental myocardial infarction].

Morphological changes and regeneration activity of the rats' liver after an experimental myocardial infarction (MI), caused by a permanent left coronary artery occlusion, were investigated. It has been shown that in 6 months after MI there were considerable changes of the rats' liver circulatory system: the quantity of vessels per unit of area increased by 118%, thickness of their walls by 19%, and the average square of vessels lumens by 159%. The percentage of connective tissue in 6 months after MI increased more than in one and a half time in comparison with control.

Major chondroitin sulfate proteoglycans identified in L6J1 myoblast culture.

The major proteoglycans from L6J1 rat myoblast culture were identified. The proteoglycans were isolated from different constituents of cell culture: culture medium, extracellular matrix (ECM), and myoblasts. To identify their core proteins, the proteoglycans were treated with enzymes specifically digesting chondroitin/dermatan sulfates or chondroitin sulfates.

Glucural (amigluracyl) improves survival of isolated rat hepatocytes in suspension.

Nonsteroid anti-inflammatory drug glucural (water-soluble N-methyl-D-glucosamine complex with 6-methyluracyl) improves survival of isolated rat hepatocytes stored in suspension. This effect of glucural is presumably explained by its membranotropism.

[Comparative morphofunctional analysis of rat hepatocyte cultures isolated from the normal and pathologically changed liver due to experimental toxic hepatitis].

The goal of the study was to examine the state of primary hepatocytes of rats with toxic hepatitis induced by combination of CCl4 and ethanol. Fluorescent immunocytochemical analysis demonstrated that normal and pathologic hepatocytes in culture formed actin cytoskeleton, cell-cell and cell-matrix contacts. To investigate morphology and localization of mitochondria the hepatocytes were stained with Rhodamine 123.

Superoxide anion production by the mitochondrial respiratory chain of hepatocytes of rats with experimental toxic hepatitis.

The progression of toxic hepatitis is accompanied by the activation of oxidative processes in the liver associated with an enhancement of the mitochondrial respiratory chain activity and superoxide anion production (O(2)(*-)). The purpose of this study was to examine our previously formulated assumption concerning the predominant contribution of the complex I to O(2)(*-) production increase by the mitochondrial respiratory chain of hepatocytes in toxic hepatitis (Shiryaeva et al. Tsitologiia, 49, 125-132 2007).

[Proteoglycans of L6J1 myoblast extracellular matrix. Characteristics and effect on myoblast adhesion].

Proteoglycans were isolated from extracellular matrix of L6J1 rat myoblasts and their influence on myoblast adhesion was studied. Proteoglycan digestion with chondroitinase AC and heparinase III degrading the polysaccharide moieties revealed that chondroitin sulfate proteoglycans are the main class of myoblast extracellular matrix proteoglycans. Electrophoresis of enzymatically processed proteoglycans was used to examine their core proteins.

[Effects of antimicrobial peptides of neutrophils on tumor and normal cells in culture].

We performed a comparative study of effects of two structurally different cationic antimicrobial peptides of cathelicidin family, porcine protegrin 1 (PG1) and caprine bactenecin 5 (Bac5) on selected tumor and normal mammalian cells in vitro. Protegrins are amphiphilic beta-hairpin molecules having broad-spectrum antimicrobial activity due to their marked membranolytic properties. Bac5 belongs to the group of proline-rich peptides, which adopt a polyproline type II extended helix and kill microorganisms rather by a non-lytic mechanism.

Hepatocyte mitochondrion electron-transport chain alterations in CCl(4) and alcohol induced hepatitis in rats and their correction with simvastatin.

The goal of this study was to examine the state of hepatocyte mitochondrial respiratory chain of rats with toxic hepatitis induced by CCl(4) and ethanol. Oxygen consumption by hepatocytes and mitochondria was determined. Endogenous oxygen consumption by pathological hepatocytes was 1.

[New protective effect of simvastatin in rats with experimental steatohepatitis].

The intragastric introduction of carbon tetrachloride (CCl4) (0.2 ml/kg in 50% oil suspension, twice a week) and ethyl alcohol (5% solution ad libitum as the only available drink) in rats over a period of four weeks results in the development of inflammation, fibrosis, and fatty dystrophy in the liver. Such a fast formation of liver damage is obviously caused by potentiating effect of alcohol in combination with CCl4.

Isolation and characterization of proteoglycans synthesized by rat myoblasts L6J1 in culture.

Proteoglycans synthesized by rat myoblasts L6J1 in culture were isolated using sorbent Q-Sepharose from culture medium, extracellular matrix (ECM), and cells. Elution of the sorbed material in a NaCl gradient separated proteoglycans from the bulk of proteins eluted at low concentration of the salt. Four fractions (fractions I-IV) were obtained for each component of the cell culture, including two proteoglycan fractions for the ECM and culture medium and one fraction for the myoblasts.