The Influence of Myofibrils on the Proliferation and Differentiation of Myoblasts Cocultured with Macrophages.

We studied the effect of myofibrils on proliferation and differentiation of myoblasts cocultured with macrophages as well as the effect of incubation of macrophages with myofibrils on the expression by macrophages of the compounds that are cytokines for muscle cells. In the cocultures, macrophages stimulated the proliferation of myoblasts. Myofibrils greatly enhanced the stimulating effect of macrophages, whereas lipopolysaccharide (LPS) completely abolished it. The culture medium conditioned by macrophages activated the proliferation of myoblasts that were incubated with myofibrils but inhibited it when myoblasts were incubated with LPS. Possibly, myofibrils and their constituent proteins activate macrophages in an alternative pathway, enriching the population with M2-type macrophages.Z.

[Pathological fantasies in children]. / Patologicheskoe fantazirovanie u deteĭ.

AIM: To develop a clinical classification of pathological fantasies (fantasy syndrome) in children and adolescents regardless of nosological attribution. MATERIAL AND METHODS: We examined 109 patients, aged 3-16 years, using psychopathological and instrumental (EEG and MRI) methods. RESULTS AND CONCLUSION: Authors developed the clinical typology of pathological fantasies in children with different mental diseases and disorders. The following variants of fantasy syndromes were singled out: 1. fantasizing with sensorealization of mental images; 2. fantastic stories (subdivided into 5 different variants): 2.1 easily provoked fantasies with situation-conditioned content; 2.2. fantasizing with increased falsehood; 2.3. sexual allegations and self-accusations; 2.4. fantasizing about imaginary worlds; 2.5. fantasies about a fictional friend); 3. playing transformation; 4. fantasies with a predominance of specific hobbies.

Targeted delivery of siRNA to differentiated murine myotubes in culture by a conjugate of cationic oligopeptide with FS2 venom.

A conjugate of the ligand of FS2 venom dihydropyridine receptors with a cationic arginine-containing oligopeptide was synthesized. It was found that the conjugate provides siRNA delivery to murine myotubes differentiated in vitro. The effect of RNA interference with the use of siRNA complexes with the conjugate was observed when siRNA concentrations were an order of magnitude lower than those used in the case of siRNA complexes with a non-conjugated oligopeptide.

[Small interfering RNAs targeting human myostatin].

Ten human myostatin small interfering RNAs which sequence was found by two different software products were synthesized and tested for activity. It was found that three of them have pronounced biological activity and decrease myostatin mRNA level to 22-27% of control value. These small interfering RNAs stimulate human myoblast proliferation and decrease their differentiation reliably. The obtained small interfering RNAs can be used for development of new approaches for the treatment of sarcopenia and different myodystrophies.

siRNAs targeting mouse myostatin.

Eight different mouse myostatin small interfering RNA (siRNAs) were synthesized and tested. Five siRNAs showed a pronounced biological effect reducing myostatin mRNA content. For two of them, the myostatin mRNA level was reduced 3- and 4-fold, respectively. The obtained siRNAs can be used for study of biological effects of myostatin, both in vitro and in vivo.

Cytotoxic effects of macrophages and asbestos on transformed rat mesothelial cells.

Asbestos produced a cytotoxic effect on transformed cells of rat pleural mesothelium and on IAR2 epithelial cells and Rat1 fibroblasts transformed by ras oncogene, but not on normal cells of these strains under conditions of coculturing with peritoneal macrophages. Contact of mesothelioma cells, but not macrophages with asbestos was necessary and sufficient for attaining the cytotoxic effect. Macrophage-conditioned medium potentiated asbestos cytotoxicity for transformed mesothelial cells, but not for IARS-ras and Rat1-ras.

Inhibition of asbestos-induced transformation of rat pleural mesothelial cells in co-culture with rat macrophages.

The aim of this work was to investigate the influence of macrophages on the process of rat pleural mesothelium cells (RPMC) transformation in vitro. For this purpose prolonged many-passage co-cultivation of rat pleural mesothelial cells and rat peritoneal macrophages was performed both in the presence (to study macrophage influence on asbestos-induced morphologic transformation) and in the absence (to study spontaneous transformation) of asbestos. It was shown that spontaneous transformation of RPMC slightly accelerated in the co-cultures, whereas asbestos-induced transformation was strongly inhibited. For instance, RPMC acquired the ability to form multilayer cell growth foci and colonies in semisolid agar at 22-24 passages in the absence and at 14-16 passages in the presence of asbestos, while in co-culture with macrophages these signs of transformation appeared at 17-19 passages without asbestos treatment and were not observed at the 40th passage under exposure to asbestos. It was shown that the observed inhibition of transformation was caused by preferential depletion of transformed cells in co-cultures of mesothelium and macrophages in the presence of asbestos: when equal concentrations of macrophages and asbestos were taken, the viability of early-passage RPMC was greater as compared with late passages, and the viability of late-passage RPMC was greater than that of mesothelioma cells. The amount of late-passage RPMC and mesothelioma cells able to form colonies in semisolid media was also drastically decreased in these conditions. These findings suggest that though macrophages can influence the process of asbestos-induced mesothelium transformation by different ways, as a whole the inhibitory action appears to be the strongest.

Cytokine secreted by rat macrophages and inhibiting proliferation of mesothelial cells.

Rat peritoneal macrophages and human peripheral blood monocytes secrete a protein with a molecular weight of 450 kDa, which specifically inhibits proliferation of cultured rat pleural mesothelial cells, but not fibroblasts and epitheliocytes. Protein secretion does not depend on the activation of macrophages. This cytokine is not a cobalamin-binding protein and has no arginase activity.

Spontaneous and asbestos-induced transformation of mesothelial cells in vitro.

The processes of spontaneous and asbestos-induced transformation of rat mesothelium were studied using cell cultures obtained in the laboratory. The same changes in cell properties were established in both spontaneous and asbestos-induced transformation: change in epidermal growth factor (EGF) response, in some cases appearance of fibroblast-like cells instead of polygonal ones, appearance of multilayer cell growth foci, and ability to grow in semisolid agar. The response to fibroblast growth factor, insulin-like growth factor 1, and insulin did not change during transformation as well as the P450 system activity measured by benz(a)pyrene (BP) and 7,12-dimethylbenzanthracene (DMBA) cytotoxicity. The asbestos-induced transformation began earlier than the spontaneous one. EGF began to stimulate mesothelium proliferation instead of its inhibition at 6-7 passages in the case of asbestos-induced transformation, whereas during spontaneous transformation this change began at 9-10 passages. Elongated rather than polygonal cells appeared at 10-11 instead of 17-18 passages (this morphological change did not take place at all lines studied). The ability to grow in semisolid agar was found at 14-16 passages with asbestos and at 22-24 passages without it. The results allow us to propose the necessity of a positive EGF response for mesothelial cell transformation and the similarity of mechanisms of spontaneous and asbestos-induced transformation.

Monoclonal antibodies directed against two different corticotropin-releasing factor determinants.

Two hybridomas secreting monoclonal antibodies (mAbs) against human/rat corticotropin-releasing factor (CRF) have been produced by the cell fusion technique. Isotyping of the mAbs revealed that both belong to the IgG1 subclass. Human serum containing CRF-binding protein inhibits the binding protein inhibits the binding of CRF to both mAbs. Modification of lysine residue inhibits binding of the mAbs in a different manner. Affinity constants of binding with native and histidine-modified antigens have been determined by ELISA. The epitope specificity of the mAbs has been examined in competition experiments. No competition was detected, suggesting that the mAbs recognize different antigenic determinants. Two monoclonal antibodies can be employed in a two-site assay to measure CRF.