Concentration of endogenous dipeptide carnosine in human muscle tissue reaches tens of millimoles. For more than 100 years of research, a lot of data concerning carnosine functions were accumulated, among which anti-aging effects are regarded most important. Heire, effect of carnosine in cell cultures was studied. It has been found that apart from the known action--an increase of the Hayflick limit and morphological rejuvenation--carnosine stimulates cell division in colony-forming assays and in the course of transition of cells to the quiescent state. The analysis of the transcriptome showed that carnosine-induced changes are mainly related to positive regulation of the cell cycle at all levels, from the onset of the DNA synthesis to chromosome condensation. One can suppose that the revealed stimulation of the cell cycle account for the carnosine-induced rejuvenation processes and a high concentration ofcarnosine in muscle tissue is required for the muscle recovery (regeneration) after excess loads.

Концентрация эндогенного дипептида карнозина в мышечной ткани человека достигает десятков миллимолей. За более чем 100 лет исследований накоплен огромный материал о самых разнообразных функциях карнозина, из которых основными считают действия, направленные против процессов старения. При исследовании действия карнозина на культуры клеток нами обнаружено, что помимо уже известных активностей: увеличения предела Хейфлика и морфологического омоложения клеток – карнозин стимулирует клеточные деления в тесте колониеобразования и тормозит процесс перехода клеток в состояние покоя. При анализе изменений в транскриптоме, происходящих под действием карнозина, выявлено, что основные сдвиги связаны с позитивной регуляцией клеточного цикла на всех уровнях – от начала синтеза ДНК до конденсации хромосом. Можно предположить, что именно способность карнозина стимулировать клеточный цикл лежит в основе его омолаживающего действия, а высокие концентрации этого дипептида в мышечной ткани играют роль не только физиологического буфера, но и необходимы для восстановления (регенерации) мышц после чрезмерных нагрузок.

Preparation stimulating hair growth (PSHG) was studied on mice of various strains (Balb/c, CBA, C57BI/6, and outbred). It was shown that a long-term (44 months) application of PSHG does not reliably affect the appearance of young healthy mice but does induce increase in the hair follicle size. No adverse consequences of the PSHG application were observed. Naturally occurring propagating regenerative hair waves peculiar to mice were preserved. In older mice (more than 2 years) with signs of alopecia, application of PSHG caused an overgrowing of bald patches within two months. Transcriptome analysis of the PSHG effect performed in fibroblast cell culture showed that PSHG stimulates processes of tissue development and remodeling. These observations together with previous findings showing that PSHG stimulates autophagy and induces death of cells subjected to oxidative stress may suggest that the mechanism of the PSHG effect involves stimulation of regeneration of skin and its derivatives owing to more efficient elimination of senescent and damaged follicle cells.

The expression of human telomerase catalytic subunit in HL-60 and HT-1080 malignant transformed cells and telomerized fibroblasts was studied by quantitative PCR. It was found that the number of transcripts of human telomerase catalytic subunit per cell in telomerized fibroblasts could be hundreds of times higher than in HL-60 and HT-1080 cells. Telomerized fibroblast cultures are suggested as experimental systems for selection of basal compounds for creation of anticancer drug prototypes, the molecular target of which is human telomerase catalytic subunit. The effects of human telomerase catalytic subunit expression on the fibroblast proteome are analyzed.

Cell culture density is shown to alter the parameters characterizing phagocytic activity of cells in vitro. Phagocytosis index (PI, mean number of beads per cell in the bead-containing population) and phagocytosis percent (PP, percentage of bead-containing cells in cell population under study) for IC-21 macrophages incubated in the presence of non-opsonized 2-μm fluorescent latex beads were determined using fluorescent microscopy and ImageJ software specially adapted for the purpose. Under control conditions (DMEM without serum), increase in cell culture density was accompanied with a decrease of both parameters of the phagocytic activity. At a mean density of 4 cells/105 μm2 (9 cells per a viewfield) PI was 7.1 ± 0.2 beads/cell and at 20 cells/105 μm2 (40 cells per a viewfield) PI dropped to 4.6 ± 0.1 beads/cell. PP was less sensitive, varied in the range of 95–100% but also decreased as the cell density grew. At any density, PI was 1.5–2 times higher than the expected value (number of beads per µm2 × cell contour area); apparently this divergence can be accounted for by cell locomotion and capture of a larger number of beads than could drop onto a motionless cell with a constant contour area. Increase in cell density was also accompanied by a decrease of the cell contour area (S c), which amounted to 750 ± 16 μm2 at a density of 4 cells/105 μm2 and 346 ± 4 μm2 at a density of 20 cells/105 μm2. As the bead concentration was the same in all experiments, density-dependent decrease in PI and PP may be related with the observed decrease in cell contour area. Yet, the bead number per cell area unit (PI/S c) was bigger at higher density and PI/S c was higher in cells with smaller S c. Thus, individual (specific) activity of the cells did not lessen with an increase of the cell culture density in the range studied (4–20 cells/105 μm2). Reduction of the cell contour area may reflect alteration in cell adhesion to the substrate as well as competitive relations between adhesion and phagocytic processes. The data obtained imply that cell culture density has to be controlled as a factor notably altering the phagocytic activity parameters. The effects of serum, methyl-β-cyclodextrin, and carbenoxolon reported earlier [Golovkina et al. 2009. Biol membrany. 26 (5), 379–386] are re-evaluated and confirmed here.

Fetal bovine serum has been shown to considerably inhibit phagocytosis of non-opsonized 2-μm fluorescent latex beads by cultured macrophages IC-21. Phagocytic activity was assessed using fluorescent microscopy and specially devised ImageJ plugins. Phagocytosis percent, PP (percentage of the bead-containing cells in the cell population under study), and phagocytosis index, PI (mean number of beads per cell in the bead-containing population), were about 2 times lower in the cells incubated in the presence of 10% serum as compared to the respective parameters for the cells incubated in serum-free medium (55 ± 5% vs. 92 ± 1% and 2.0 ± 0.2 vs. 4.3 ± 0.2 beads/cell). The effect of serum was dose-dependent. Albumin (10 mg/ml) did not mimic the effect of serum, suggesting that fatty acid extraction was not the cause of the serum-induced inhibition. Serum is a source of exogenous cholesterol, therefore we checked if cholesterol removal could stimulate phagocytosis. Cholesterol-sequestering agent methyl-β-cyclodextrin (mβCD) in concentrations of 5–7 mM indeed caused an increase of the phagocytic activity but at 10 mM exerted an inhibitory effect in serum-free medium. Connexin channel blocker carbenoxolone (CBX, 250–500μM) in most cases inhibited phagocytosis; the presence of serum or mβCD modulated the CBX effects. The data indicate an important role of serum in regulation of the macrophage phagocytic activity. Stimulating effect produced by serum removal may partly be accounted for by a decrease of cholesterol concentration, which in turn may alter the functioning of integral proteins involved in the mechanisms of phagocytosis.

One of the earliest events of phagocytosis is the formation of lipid domains enriched with cholesterol and sphingomyelin in plasma membrane of a phagocyte. In these domain:;, there cluster phagocytic receptors and other integral proteins involved in the phagocytic signal cascade. Earlier we found that phagocytic receptor Fc gamma R and some ionic channels possess in their transmembrane region an amino-acid sequence analogous to the cholesterol-binding consensus of the peripheral-type benzodiazepine receptor (PBR). To check if this sequence is of functional significance, in this work we studied the effects of two synthetic peptides - a fragment of the PBR cholesterol-binding consensus, VLNYYVW, and its variation, LLVYPW, on the phagocytic activity of cultured macrophages IC-21. Phagocytosis was assessed by fluorescent microscopy, using 2-mu m non-opsonized fluorescent latex beads. Peptides were dissolved in DMSO, which turned to affect phagocytic activity by itself, in the presence of 0.5-1.3% DMSO the number of beads per cell was 20-30% lower than in the absence of DMSO. Peptide VLNYYVW (5-100 mu g/ml) augmented the inhibitory action of DMSO, while LLVYPW (20100 mu g/ml) exerted a differing effect. Our data suggest that the peptides studied may indeed interfere with the interactions between integral proteins and membrane cholesterol and thus affect the phagocytic process. The action of DMSO on phagocytosis found here may also be related to the disturbance in cholesterol-protein interactions. We propose that cholesterol-binding peptides can be used for the design of immunomodulating drugs.