[KE peptide regulates SIRT1, PARP1, PARP2 gene expression and protein synthesis in human mesenchymal stem cells aging.]

It was shown that KE peptide (Lys-Glu, vilon) has immunomodulatory, oncostatic and geroprotective effects. The aim of this work is to evaluate the effect of the KE peptide on gene expression and protein synthesis of SIRT1, PARP1, PARP2 during aging of human mesenchymal stem cells (MSC). The KE peptide increased gene expression and synthesis of the SIRT1 protein in «young¼ MSCs by 6 and 8,2 times, respectively. The KE peptide reduced gene expression and PARP1 protein synthesis during MSC aging by 2,1 and 5,3 times, respectively; and also reduced gene expression and PARP2 protein synthesis by 2,1 and 4,7 times, respectively. According to molecular modeling data, the KE peptide can interact with the GCGG sequence of double-stranded DNA (dsDNA) in the classical B-form and with the GGGC sequence of the curved dsDNA nucleosome. The indicated dsDNA sequences were found in the promoters of the human SIRT1, PARP1, PARP2 genes. Thus, the KE peptide regulates gene expression and synthesis of SIRT1, PARP1, PARP2 proteins in human mesenchymal stem cells during replicative ageing, which underlies the biological activity and geroprotective effect of this peptide.

[Chondrocytes secretory phenotype associated with aging: role in the pathogenesis of osteoarthritis and prospects for peptide bioregulation.]

Osteoarthritis (OA) is a socially significant age-associated disease, for the treatment of which a search for new effective drugs is underway. The development of OA correlates with the development of the aging-associated secretory chondrocyte phenotype (SASP). The purpose of the review is to analyze the pool of signaling molecules that form SASP of chondrocytes in OA and substantiate the possibility of peptide chondroprotection. It has been established that SASP of chondrocytes is characterized by a decrease in the synthesis of sirtuins, impaired remodeling of the extracellular matrix, and activation of cytokine production. Sigumir, a polypeptide complex of cartilage and bone tissues of young animals, and the AED tripeptide (Kartalax) have shown high efficacy in animal models of OA and oral administration in patients with OA of older age groups. These peptide substances regulate the synthesis of proapoptotic and proliferotropic molecules that form the SASP of chondrocytes.

[The influence of peptides on the chondrogenic differentiation of human mesenchymal stem cells during replicative aging.]

Osteoarthritis is a widespread age-related disease, that has no effective targeted therapy. In this regard, bioengineering methods are being actively developed that can stimulate the restoration of cartilage tissue. These methods include chondrogenic differentiation of stem cells, which is stimulated by various biomolecules, including short peptides and polypeptide complexes. It was studied the effect of the cartilage polypeptide complex (CPC) and AED peptide on gene expression and protein synthesis of chondrogenic differentiation - SOX9, aggrecan, type II collagen and COMP - in human mesenchymal stem cell (MSC) during replicative aging. AED peptide at the concentration of 200 ng/ml activates gene expression and protein synthesis during aging of MSCs. CPC has the same effect in the concentration 2000 ng/ml. These data indicate the stimulating effect of studied peptides on regulation of chondrogenesis and open up prospects for further investigation of their effectiveness in osteoarthritis models.

[Peptides prevent the forming of secretory phenotype of chondrocytes associated with the aging.]

Secretory phenotype associated with the aging (SASP) of chondrocytes forms the conditions for the musculoskeletal system diseases development, in particular, osteoarthritis (OA). The search for effective methods for OA treating is an urgent task of molecular gerontology. The purpose of this work is to characterize the SASP of chondrocytes and to conduct a comparative assessment of the effect of AED peptide and the cartilage polypeptide complex (CPC). It was found that chondrocyte's SASP is characterized by an increase of the synthesis of p16, p21, p53 pro-apoptotic proteins, TNF-α, IL-1α pro-inflammatory cytokines and a decrease of Sirt1synthesis. Peptides AED and CPC normalize the synthesis of molecules that form SASP of chondrocytes. This effect may explain their geroprotective effect and effectiveness in studies of various pathologies of the musculoskeletal system, including OA.

[Secretory phenotype of the human endothelial cells associated with replicative and induced aging.]

The aging-associated secretory phenotype (SASP) is a heterogeneous phenotype of cells secreting pro-inflammatory cytokines, growth factors, apoptosis' regulatory molecules, and proteases. SASP is one of the three main hallmarks of senescent cells. Dysregulation of the synthesis of SASP-forming molecules leads to the development of age-associated diseases, including cardiovascular pathology. The aim of this study is to characterize the SASP of human endotheliocytes during replicative and induced aging. Isolated human umbilical vein endothelial cells HUVEC were used to model replicative and inflammation-induced aging. It has been established that the molecules that form SASP during replicative and inflammation-induced aging of HUVEC are molecules that control apoptosis (p16, p21, p53), adhesion (E-selectin, VCAM-1) and some cytokines (IL-1ß, IL-6). With replicative aging of endotheliocytes, the synthesis of apoptosis' regulatory molecules increases to a greater extent. Inflammation-induced aging of HUVEC is characterized by a multiple increase in the synthesis of adhesion molecules and pro-inflammatory cytokines.

[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.

[Morphological compound and indicators of the blood clotting system in severe COVID-19 patients of middle aged and elderly during treatment of Tocilizumab and Thymalin.]

The aim of the work was a comparative study of Tocilizumab and Thymalin effects on the morphological composition and indicators of the blood clotting system in COVID-19 of middle aged and elderly patients. Severe COVID-19 patients were divided into 3 groups: 1st - control (basic therapy), 2nd - basic therapy +Tocilizumab, 3rd - basic therapy +Thymalin. Hospital mortality in COVID-19 patients after standard therapy, Tocilizumab and Thymalin application was 40,9; 28,4 and 20,6% accordingly. The number of platelets increased by 1,5 times, the concentration of fibrinogen in blood decreased by 78% and activated partial thromboplastin time decreased by 9,3% in patients taking Tocilizumab. Under the influence of Tocilizumab, the platelet/white blood cell and platelet/lymphocyte ratios increased by 1,6 and 1,4 times, which may be a predictor of an unfavorable outcome of COVID-19. Thymalin increased the number of lymphocytes and monocytes by 2 times, the number of leukocytes - by 1,3 times, the number of platelets in the blood - by 1,5 times. Thymain decreased the platelet/lymphocyte and neutrophil/lymphocyte ratios by 1,4 times and 2 times. The use of Thymalin decreased the level of fibrinogen, lactate dehydrogenase and D-dimer in the blood by 1,2; 1,8 and 1,7 times, respectively. Thymalin, compared with Tocilizumab, meets the principles of pathogenic therapy for severe COVID-19 of middle aged and elderly patients to a greater extent, having a normalizing effect on the morphological composition and indicators of the blood clotting system.

[Senescence-associated secretory phenotype and inflammaging: the role in cardiovascular diseases.]

Senescent cells take part into development the age-related diseases by formation the SASP: senescence-associated secretory phenotype. SASP is characterized by synthesis of signal molecules include proinflammatory cytokines. SASP promotes the inflammaging - chronic, low-grade, subclinical inflammatory process, that is the one of cardio-vascular diseases risk factor in older age-groups. In the review we describe the key SASP molecules of cardiomyocytes, endotheliocytes and vascular smooth muscle cells and its role in the pathogenesis of age-associated cardiovascular diseases.

[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.

[The influence of AEDG and KE peptides on mitochondries stain and L7A ribosomes protein expression during human pineal gland and thymus cell senescence in vitro.]

It was verified new molecular targets of geroprotective activity of AEDG (epitalon) and KE (vilon) peptides by the method of confocal laser scanning microscopy. It was shown that the MitoTracker Red mitochondries staining decreased and L7A ribosomal protein synthesis compensatory increased during pineal and thymic cell senescence in vitro. AEDG peptide increases in 1,5 times the square of MitoTracker Red mitochondries staining and decreases on 22% the expression of ribosomal protein L7A in cultures of human pineal gland cells during its senescence. KE peptide increases in 1,5 times the square of MitoTracker Red mitochondries staining and decreases on 15% the expression of ribosomal protein L7A in cultures of human thymic cells during its senescence. The square of MitoTracker Red mitochondries staining decreases and the expression of L7A ribosomal protein compensatory increases during pineal gland and thymic cells senescence. We can suppose that AEDG and KE peptides have a tissue-specific effect that normalizes the functions of mitochondria and ribosomes of pinealocytes and thymocytes.

[AEDG peptide regulates human circadian rhythms genes expression during pineal gland accelerated aging.]

Night work provides biorhythms desynchronization, disorder of melatonin-producing function and accelerated pineal gland aging. One of the promising geroprotectors restoring the pineal melatonin synthesis is the AEDG (Ala-Glu-Asp-Gly) peptide. AEDG peptide increases in 1,7 times the 6-sulfatoxymelatonin (6-SOMT) excretion in the urine of middle-aged people. Moreover, AEDG peptide normalized circadian Clock and Csnk1e genes hyper expression in leukocytes in 1,9-2,1 times and increases the Cry2 gene hypo expression in peripheral blood lymphocytes in 2 times in people with reduced melatonin-producing epiphysis function. The geroprotective effect of the AEDG peptide is based on its ability to restore the epiphysis melatonin-producing function by means regulation of human circadian genes expression.

Thymalin: Activation of Differentiation of Human Hematopoietic Stem Cells.

Thymalin is a polypeptide complex isolated from the thymus and regulating the functions of the immune system. Thymalin is effective in therapy of acute respiratory syndrome, chronic obstructive bronchitis, and other immunopathology. Thymalin increases functional activity of T lymphocytes, but the targeted molecular mechanism of its biological activity requires further study. We studied the influence of thymalin on differentiation of human hematopoietic stem cells (HSC) and expression of CD28 molecule involved in the implementation of antiviral immunity in COVID-19 infection. It was found that thymalin reduced the expression of CD44 (stem cell marker) and CD117 (molecule of the intermediate stage of HSC differentiation) by 2-3 times and increased the expression of CD28 (marker of mature T lymphocytes) by 6.8 times. This indirectly indicates that thymalin stimulated differentiation of CD117+ cells into mature CD28+T lymphocytes. It is known that in patients with severe COVID-19, the number of CD28+, CD4+, CD8+T lymphocytes in the blood decreased, which attested to a pronounced suppression of immunity. It is possible that the antiviral effect of thymalin consists in compensatory stimulation of HSC differentiation into CD28+T lymphocytes at the stage of immunity suppression in unfavorable course of viral infection. Thymalin can be considered as an immunoprotective peptide drug for the prevention of COVID-19.

Comparison of the Effects of KE and AED Peptides on Functional Activity of Human Skin Fibroblasts during Their Replicative Aging.

We studied the effect of KE and AED peptides on the expression of sirtuin-1, sirtuin-6, collagen I, cytokines (IL-1, TGF-ß), and transcription factor NF-κB in human skin fibroblasts during their replicative aging. Immunocytochemical analysis and confocal microscopy showed that KE peptide reduces the synthesis of factors of the inflammatory response IL-1, NF-κB, and TGF-ß and stimulates the synthesis of sirtuin-6. KE peptide normalizes the immunological function of human skin fibroblasts during their aging. AED peptide activates the synthesis of sirtuin-1, sirtuin-6, and collagen I in human skin fibroblasts during their replicative aging, which attests to its geroprotective effect.

Sirtuins as Possible Predictors of Aging and Alzheimer's Disease Development: Verification in the Hippocampus and Saliva.

Verification of signaling molecules in the saliva is a non-invasive method of diagnosis and evaluation of treatment effectiveness in different pathologies. Sirtuins (SIRT), proteins from NAD-dependent histone deacetylases, are supposed to be involved in the pathogenesis of Alzheimerэs disease. Age-related decrease in sirtuins expression induces many pathophysiological processes that could lead to neurodegeneration. We studied the expression of SIRT1, SIRT3, SIRT5, and SIRT6 in the hippocampus and saliva of humans without neurological pathologies and in patients with Alzheimer's disease of elderly and senile age. In elderly and senile patients, the expression of SIRT1, SIRT3, and SIRT6 in the hippocampus and saliva was 1.5-4.9-fold reduced in comparison with healthy individuals of the corresponding age. In healthy senile persons, the expression of SIRT6 in the hippocampus and saliva was 2.5-4.5-fold lower than in healthy elderly individuals. Measurement of SIRT1, SIRT3, and SIRT6 concentration in the saliva can be used as an additional method for intravital non-invasive diagnosis of Alzheimer's disease in patients of advanced age. SIRT6 concentration in the saliva can be recommended as a marker for assessment of the rate of aging.

[Neuroprotective effects of peptides.]

Neurodegenerative diseases are a heterogeneous group of nervous system pathologies. They are found mainly in people of an older age group. The incidence of neurodegenerative diseases is continuously growing due to an increase in the average life expectancy of the population. At the moment, there are no effective and safe treatments for neurodegenerative diseases, which are most often diagnosed at the stage of decompensation, when therapy is ineffective and does not bring positive outcomes. Most of the currently used drugs act only symptomatically. The review provides analyzed data and information about the prospects of using peptide bioregulators as neuroprotectors with high physiological activity and low immunogenicity.

[Short peptides: regulation of skin function during aging.]

Short peptides are applied for supporting skin function during ageing, because they can permeate the intact stratum corneum of the epidermis and affect the cells of the dermis. Short peptides are part of natural metabolism of cells and many of them have geroprotective properties. In the review we are considering the base sorts of peptides that are used for normalized skin fibroblasts function: matrikines, carnosine, collagen peptides, cytokine and growth factor analogs, defensins, immunoprotective peptides and polyfunctional peptides. Polyfunctional peptides (AcSDKP, KED, AEDG, AED) have geroprotective properties, slow apoptosis and stimulate skin cell proliferation, also increase functional activity of skin fibroblasts, normalize intracellular matrix hemostasis. Polyfunctional peptides are the antioxidants and immunoprotectors and can activate microcirculation in dermis. Peptide regulation of skin function during ageing are the fast-developing and prospective area in molecular gerontology.

Peptide KE in Human Proteome.

Peptide KE exhibits immunoprotective, geroprotective, and oncostatic activities and stimulates functional activity of fibroblasts. The KE motif is present in amino acid sequences of some cytokines and peptide hormones functionally similar to KE peptide. However, the relationship between the presence of KE motif and protein functions on the scale of known human proteome has not yet received sufficient attention. The incidence of bioregulatory peptide KE in proteins of various functional groups constituting human proteome is studied. The study is carried out with the use of the available data on the human proteome (UniProt portal) comprising 20,417 proteins. The levels of KE motifs were maximum in cytoplasmic and nuclear proteins, while the presence of KE in the membrane and all other proteins was the minimum. KE peptide molecules released from nuclear proteins during limited proteolysis can bind to DNA and regulate gene expression.

[Investigation of signal molecules in saliva: prospects of application for diagnostics of myocardial infarction and the aging rate of different age people.]

Among the diseases of the cardiovascular system in elderly people, ischemic heart disease and myocardial infarction (MI) occupy the first place in the structure of mortality. One of the main causes of disability and death from MI is late diagnosis. In this regard, the search for new, highly informative and non-invasive methods for diagnosing MI is an important task of molecular gerontology. An enzyme immunoassay showed that the concentration of TNF-α, IL-8 cytokines and p16 aging marker in saliva in elderly people without cardiovascular pathologies (CP) increases in 2,1-4,8 times as compared with middle-aged people. At the same time, in elderly people without CP the concentration in the saliva of the hormone irisin (FNDC5) decreases by 1,8 times as compared with middle-aged people. In middle-aged patients with MI the concentration of IL-8, TNF-α, MMP8, MMP9 in saliva increases 4,3-15,3 times, and FNDC5 decreases 1,8 times compared with those parameters without CP in this age group. In elderly people with MI the concentration of IL-8, TNF-α, MMP8 and MMP9 in saliva increases 4,3-7,1 times as compared with elderly people without CP. Thus, the study of the concentration of signaling molecules IL-8, TNF-α, MMP8, MMP9 in saliva can be used as a non-invasive method for diagnosing MI in people of middle and elderly age. To assess the rate of aging of the organism in middle-aged and elderly people without CP, a study of the concentration of p16 and FNDC5 molecules in saliva is recommended.

[Aging of skin fibroblasts: genetic and epigenetic factors.]

Gerontocosmetology is the rapid developing knowledge area that has a very large applied meaning. Herewith a lot of information about skin aging and geroprotectors for skin rejuvenation hasn't a scientific background. Thus, understanding the fundamental mechanisms of skin aging becomes the actual task of molecular gerontology. Skin fibroblasts are the polyfunctional cell population that synthesize a number of biologically active substances and participate in maintaining of extracellular matrix homeostasis, skin hydratation and endocrine and immune function. In the review genetic (accumulation of nuclear and mitochondrial DNA mistakes) and epigenetic factors of skin fibroblasts aging are described. Role of AP-1, NF-κB, c-jun, CCN1, TGF-ß, TNF-α, MMP-1, MMP-3, MMP-8, MMP-9 and glycation in skin fibroblasts aging are discussed. There are some data about decreasing of skin fibroblasts ability to migration and synthesis of paxillins and aquaporin-3 (AQP3) during aging. Role of hormonal regulation in skin fibroblasts aging are described. Geroprotective action of melatonin to skin fibroblasts are showed. Reviewed molecular-cellular aspects of skin fibroblasts aging can be take into consideration for scientific background of using of cosmetic products for retarding of skin aging rate.

[The influence of peptides on the morphofunctional state of old rats kidneys.]

More than a quarter of the elderly and senile age population suffers from kidney pathology. For this reason, a prophylaxis of kidney diseases with the safe and effective nephroprotectors is a priority of gerontology. An influence of polypeptide kidney complex (PKC), peptides AED, EDL, AEDG on the functional state of old rats kidneys was studied in research. Administration of PKC, peptides AED and EDL increased diuresis by 1,2-1,4 times. PKC and peptide AED reduced urine protein level and protein excretion by 1,5-2,8 times. PKC, peptides AED and EDL increased distal sodium transport by 1,2-1,3 times. Peptides AED and EDL increased sodium excretion by 1,3 and 1,6 times, respectively. Renal effects of peptide AEDG resulted in a reduction of glomerular filtration rate by 21%, decrease in urine protein level by 3,1 times and protein excretion - by 2,5 times. Peptide AEDG reduced absolute sodium reabsorption by 1,3 times and increased distal sodium transport by 1,4 times. Realization of glomerular-tubular and tubular-tubular balances is verified by correlation between glomerular filtration rate (GFR) and absolute sodium reabsorption, proximal and distal sodium reabsorption. In kidney tissue a stimulation of the antioxidant enzymes activity on the background of inhibition of the peroxidation processes intensity was observed, which in complex with morphological data evidences the absence of nephrotoxic effects. PKC, peptides AED, EDL and AEDG may be considered as nephroprotective agents in kidney aging.