[Diagnosis of fragility and age resilience from a dynamical systems perspective.]

The concepts of fragility and resilience are often used together to describe elderly people with reduced physical activity. While fragility, which develops with the aging of the body, is a biological syndrome of a decrease in the stressors response resulting from cumulative regression in many physiological systems, and age related a comprehensive assessment of the ability resistance to stress. In this regard, it is important to develop systems and scales for the identification groups of risk among the elderly. The complexity of the solution lies in the fact that the study of fragility and physical resilience is interdisciplinary, primarily related to the health and increase in the active life of older people. The review describes theories based on the mechanisms of physiological aging, among them the theory of a decrease in the ability to stress, in which stress-related to diseases. The cycles of the development of fragility and a decrease in physiological reserves are considered, and, as a consequence, a change in reactivity to stress, which leads to the development and progression of diseases. The article presents data on homeostatic dysregulation in the accumulation of cumulative deficiency and related changes in heart rate variability, which allows early diagnosis of stressors in the elderly. These data will be useful for the development and implementation of preventive measures aimed at improving the quality of life and resistance to stress factors in elderly and senile people.

[Age-related resilience as a manifestation of neurovegetative regulation of organism's functions.]

The concept of human resilience was created to search for new approaches to improving the well-being of middle-aged, elderly and old people. Resilience is based on the physiological mechanisms of maintaining homeostasis and the ability of organs and tissues to regenerate. Identifying the correlation between environmental factors and the level of reactivity of the body is an important aspect in assessing viability. It contributes to an increase in human life expectancy. Age-related resilience is based on neurophysiological mechanisms of protective processes at different levels, including neural networks and epigenetic mechanisms regulating the expression of MANF, TIMP-2, adropin, irisin, CCL2, CCLR2, ß2M genes. The study of medical, psychological, and social indicators of resilience will contribute to the development of new approaches to the correction of age-related pathology.

[Epigenetic regulation of adaptogenesis by pathology and aging.]

The organism adaptive possibilities by pathology and aging are discussed in account of the epigenetic. The organism adaptation to inner and external factors is carried out by organism unite humoral protective system, inclusive hypothalamus-hypophysis-pineal and hypothalamus-hypophysis-thymus axises. AEDG, AEDP, EDR, KED, EW, KE short peptides are the epigenetic regulators of gene expression and protein synthesis, which can be involve to the adaptation by stress and in the activation of hypothalamus-hypophysis-pineal and hypothalamus-hypophysis-thymus axises. These short peptides regulate the synthesis of proteins of heat shock, stress-protective proteins, cytocines, fibrinolysis and hemostasis factors and can participate in primary and tardive epigenetic regulation of adaptive response by stress, pathology and aging. The early functional diagnostic of element disturbances of organism unite humoral protective system by age-associative pathology can be usefull for the detection of deficient synchronization of epigenetic mechanisms, by wich the depletion and decrease of organism reserve possibilities occurs. The use of peptide can grade the adaptive syndrome manifestation by the stress and age pathology.

[Stimulating effect of water-soluble fraction from brown algae Fucus vesiculosus extract on cell proliferation in tissue culture of young and old rats.]

The influence of water-soluble fraction F-55 of brown algae extract Fucus vesiculosus on the development of organotypic tissue culture of different genesis, originating from three germ leaves in young and old rats was studied. The preparation F-55 has a stimulating effect on the processes of cell proliferation in the tissues of ecto-, ento- and mesodermal genesis (cerebral cortex, myocardium, spleen and liver), by regulating the processes of cell proliferation and apoptosis. The revealed strengthening of regeneration processes in explants from both young and old rats under the influence of F-55 preparation in the range of ultra-low concentrations of 10-100 ng/ml can serve as a basis for the creation of new medicinal cytoprotective substances that allow to enhance cell regeneration in various tissues in pathological conditions, including those associated with age.

The Effects of Weak Static Magnetic Field on the Development of Organotypic Tissue Culture in Rats.

The effects of weak static magnetic field on the organotypic tissue culture of the rat cerebral cortex, liver, and spleen have been investigated. Exposure to a 200 µT static magnetic field induces tissue development, leading to the intensification of regeneration processes compared to the control explants.

[Effect of carboxylic acids and L-amino acids on the cellular proliferation in the organotypic culture of different genesis tissues in young and old rats.]

Effect of carboxylic acids - structurally related to amino acids, on the proliferation activity of the cells in organotypic cultures of brain cortex (ectodermal genesis) and liver (entodermal genesis) tissues was first studied in young and old rats. It was found that some aliphatic carboxylic acids have stimulating effects on proliferative activity of cells. Only acetic acid inhibited proliferation. In contrast many amino acids were able not only stimulate, but also inhibit cellular proliferation in the explants of young and old rats. This reflects the biological regularity, that the structure amplification leads to increase of the specificity. A decrease of number of active carboxylic acids and amino acids was observed in the explants of old rats. The carboxylic acids preserved the stimulating proliferation activity in the old rat. The data obtained create basis for the synthesis of new medicines, including the carboxylic acids, for increase of the regeneration processes by tissue pathology, also associated with aging.

[Effect of tryptophan and kynurenine on the cellular proliferation in the organotypic tissue culture of brain cortex in young and old rats.]

Metabolic disorders of L-kinurenin, which is an intermediate product of the breakdown of genetically encoded amino acid L-tryptophan, is one of the links in the development of a number of neuropathological processes. The influence of tryptophan and kynurenine on cell proliferation in organotypic tissue culture of the cerebral cortex in young and old rats was studied. Tryptophan in effective concentration (0,5 ng/ml) inhibited cellular proliferation of the cerebral cortex of young and old rats by 35 and 18%, respectively. However, under the action of kinurenin (1 ng/ml), stimulation of cell proliferation occurred, and more pronounced in the explants of the cerebral cortex of old rats-by 22% compared to the control. The data obtained about the ability of kynurenine to stimulate cellular proliferation in the cerebral cortex of old animals has the potential to create new drugs of nootropic drugs for diseases of the nervous system associated with age.

[Effect of genetically coded amino acids and their precursors carboxylic acids on the cellular proliferation in the organotypic culture of spleen in young and old rats].

Effect of carboxylic acids - structurally related to amino acids, on the proliferation activity of the cells in organotypic cultures of rat spleen was first studied. It was found that almost all aliphatic carboxylic acids have stimulating effects on proliferative activity of cells in young and old rats. In contrast only 3 from 14 active amino acids in young rats were able stimulate proliferation, but 11 amino acids inhibited it. In the old rats a number of the active amino acids was decreased until 4, an inhibiting effect was observed in 3 of them. Thus, the carboxylic acids are able to stimulate the regeneration processes in the immune tissue both in the young and old organisms. This fact can be a base for the research of new medical substances for the stimulation of the immunogenesis by the aging.

Low-molecular-weight components of the metabolome control the proliferative activity in cellular and bacterial cultures.

The effects of blood metabolites and model cell culture exometabolites found in the human and animal blood metabolomes have been assessed. Specifically, the influence of carboxylic acids that are structural analogues of amino acids and the drug Aktoflor-C have been studied. Methods of organotypic culturing of rat tissues and Escherichia coli bacterial culturing have been used. It has been found that all the tested compounds either stimulate or inhibit cell proliferation in tissue cultures and proliferation in bacterial cultures. The metabolites that are present in blood and interstitial fluids can exert regulation effects on the tissues of the body and intestinal microbiota.

Effect of Polypeptides on Cell Proliferation and Apoptosis during Aging.

Polypeptide complexes derived from the bronchi, blood vessels, muscles, kidneys, ovaries, testes, and retina stimulated the processes of cell renewal in organotypic cultures of the corresponding organs of young and old animals. A correlation between the intensity of regeneration and animal' age was revealed. The polypeptide complexes reduced the expression of apoptotic factors p53 and caspase 3 and increased the expression of proliferation protein Ki-67. These results provide the basis for further study of the polypeptide complexes as stimulators of regenerative processes in different tissues during ageing.

[POLYPEPTIDES INFLUENCE ON TISSUE CELL CULTURES REGENERATION OF VARIOUS AGE RATS].

A comparative study of polypeptides extracted from the tissues of calves: Cortexin (from brain cortex), Epinorm (from pineal gland), Ventvil (from liver), Prostatilen (from prostate), Thymalin (from thymus), Chelohart (from heart), Chondrolux (from cartilage) on the relevant organotypic tissue cultures of young and old rats, in concentration 0,01-100 ng/ml was performed. Polypeptides specifically stimulated "young" and "old" cell cultures growth in concentration 20-50 ng/ml. This effect correlates with increasing of PCNA and decreasing of p53 expression in brain cortex, pineal gland, liver, prostate, heart, cartilage. Moreover, Thymalin activated CD5, CD20 expression--markers of B-cells differentiation. These data show that polypeptides isolated from different tissues have selective molecular activity on the regeneration of suitable tissues in aging.

Peptide Regulation of Cells Renewal Processes in Kidney Tissue Cultures from Young and Old Animals.

Polypeptide complex isolated from calf kidneys stimulates the processes of cell renewal in organotypic kidney tissue cultures from young and old rats. The polypeptide complex enhances expression of proliferation marker Ki-67 and reduces expression of proapoptotic peptide p53 in kidney explants obtained from young and old animals. Short peptides T-31 (AED) and T-35 (EDL) also stimulate proliferation and reduce apoptosis of the kidney cells, but to a lesser degree than the polypeptide complex. The results provide the basis for further investigation of the polypeptide complex as a preparation for the therapy of kidney diseases, including age-related pathologies.

Role of peptide bond in the realization of biological activity of short peptides.

We performed a comparative analysis of biological activity of Lys-Glu peptide and its amino acid constituents. It was established that Lys-Glu stimulated proliferation of splenic cells in organotypic culture, while the mixture of glutamic acid and lysine inhibited culture growth. Using the method of molecular docking, we showed that glutamic acid, lysine, and Lys-Glu peptide can interact with different DNA sequences. The energy of interaction and the most beneficial localization of glutamic acid, lysine, and Lys-Glu peptide in DNA molecule was calculated. We demonstrated the interaction of the peptide and amino acids with DNA along the minor groove. The energy of DNA interaction with the peptide is higher than with individual amino acids. The peptide bonds increase the interaction of Lys-Glu peptide with DNA, which potentiates the biological effect on cell proliferation in organotypic culture of splenic cells.

[THE REGULATING EFFECT OF DIPEPTIDES ON CELL PROLIFERATION IN NERVE TISSUE CULTURE IN MAMMALS AND ON ASSOCIATIVE LEARNING IN INSECTS].

The effect of dipeptides AspPro and AspSer and of their composing amino acids (asparagine acid--Asp, proline--Pro, serin--Ser) on the proliferative activity in the explants of cortex and subcortical structures of the rat brain and on the functional activity of CNS of the honeybee was studied. The square index defined as a proportion of the whole explant square to the square of its central zone was determined. The number of bees responded with the conditional reaction (proboscis extension in the direction to aromatized solution) after 1 min (short-term memory) and 180 min (long-term memory) was detected after single learning procedure. Both dipeptides, as well as the asparagine acid, stimulated an increase of the growth zone of the subcortical structure explants in rats and of the number of honeybees with retention of conditional reaction in the short-term/long-term memory independently of the effect of the second member of the dipeptide. The unidirectionality of the effect suggests the existence of common mechanisms of reception and signal transduction established during evolution that require the further study.

[Short peptides stimulate skin cell regeneration during ageing].

The actual goal of gerontocosmetology is deal with the research of new effective and harmless low- molecular substances. The influence of LK and AEDG peptides in concentrations 0.05-2.00 ng/ml on organotypic skin cell cultures proliferation in young and old animals were investigated. Peptides stimulated skin fibroblasts proliferation on 29-45% in skin cell cultures of young and old rats. This effect was observed in smaller concentration diapason and level during skin ageing in old cell cultures as compared to young cell cultures. These data open new approach for creation cosmetology substances in the base of LKand AEDG peptides.

[The effect of leucine and lysine dipeptides on the proliferation of the myocardium and spleen from young and old rats in organotypic culture].

The effect of new dipeptides consisting from leucine and lysine was investigated in organotypic tissue culture on the cell proliferation development in spleen and myocardium explants in 3- and 24-months old rats. Dipeptide L-Leu-Lys stimulated the cell proliferation in the young and old rats at concentrations 0,001-10 ng/ml and 0,01-1 ng/ml accordingly. Dipeptide L-Lys-Leu stimulated as well the cell proliferation in the young and old rats at some deviation of diapason of stimulating concentrations. The data obtained aboutthe new dipeptides with high biological activity create a basis for future research at the organism level for their application in geriatrics to enhance regenerative processes in lymphoid and myocard tissue.

[Molecular aspects of immunoprotective activity of peptides in spleen during the ageing process].

Vilon, Timogen, Crystagen and R-1 short peptides possess various immunoprotective effects in spleen during its ageing. Both R-1 and Vilon peptides activate T-helpers. The effect of Vilon is provided by decreased level of apoptosis, as well as the effect of R-1 peptide is provided by increased proliferation and differentiation processes. Timogen activates B-cells by decreasing apoptosis level and increasing the proliferation of spleen cells. Crystagen also activates B-cells of the immune system; however, the peptide doesn't cause cell renewal in spleen as it ages.

Biological activity of amino acids in organotypic tissue cultures.

We studied the effect of 20 standard L-amino acids on proliferation of the nervous, cardiovascular, urogenital, digestive, and immune system tissues from young and old animals in organotypic cultures. The effect of amino acids on tissue culture proliferation depended on their origin and animal age.

[The mechanisms of stimulation of cellular proliferation under the effect of L-amino acids in the tissue culture in young and old rats].

The statistical method of range correlation was used to analyse the correlation of individual characteristics of L-amino acids, as well as of the dipole moments of the first pair of the nucleotides of their codons to the biological activity of the amino acids, i.e. to the stimulation of the cellular proliferation. The experimental material was obtained in the organotypic tissues of ecto- and mesodermal genesis in young and old rats. It was demonstrated, that each of stimulating amino acids acts in the explants from old rats to 1,5-6 times rarely, as compared to the explants from young rats. The weak correlation was detected between the stimulation of the cellular proliferation and physical-chemical characteristics - hydrophobicity, dipole moment and isoelectrical point of the amino acids, - in many tissues, but high and moderate correlation was detected in the brain subcortical explants, cerebella and skin. However, the moderate close correlation was detected between the dipole moment of the first pair of the nucleotides of their codons and the stimulating activity for the explants of the brain subcortical structures (young and old rats), of cerebella and skin (young rats), Spearman correlation coefficient rS =0,52; 0,45; 0,60, 0,71 accordingly. The moderate close correlation was detected also for the explants of testis and cartilage. It can be suggested, that some physical-chemicaland biochemical characteristics of amino acids should correlate to their biological activity, especially in relation to the ectodermal tissue.

A method of creation a cell monolayer based on organotypic culture for screening of physiologically active substances.

We developed a method of culturing and phenotyping of a monolayer of cells of the retinal tissue, thymus and spleen on the basis of organotypic culture. All characteristic types of neurons and fibroblasts were found in their microenvironment in the retinal cell monolayer. Lymphocytes, macrophages, and fibroblasts were verified in the monolayer of thymus and spleen cells. Histological staining, immunocytochemistry, and electron microscopy demonstrated the possibility of assessing the differentiation degree and functional activity of the cell monolayer. The developed technique preserves cell-cell interactions and a variety of cell types characteristic of the examined organ in the monolayer. This opens up new prospects for its application in basic research and in screening of different physiologically active substances.