EPIGENETIC MODIFICATION UNDER THE INFLUENCE OF PEPTIDE BIOREGULATORS ON THE "OLD" CHROMATIN.

In the present study, on the one hand, the epigenetic modification of condensed "old" chromatin was determined, and on the other hand, the influence of peptide bioregulators (Ala-Glu-Asp-Gly-Epitalon; Lys-Glu-Asp-Ala-Livagen; Ala-Glu-Asp-Pro - Cortagen and Lys-Glu - Vilon) on condensed chromatin in lymphocytes from old individuals. Were used molecular-cytogenetic methods: differential scanning calorimetry; activity of ribosomal genes of acrocentric chromosome satellite stalks-NORs; polymorphism of structural pericentromeric C-heterochromatin; variability of the facultative heterochromatin (sister chromatid exchanges - SCE) in the culture of lymphocytes from 75-88-year-old individuals. The analysis of results shows the chromosome progressive heterochromatinization (condensation of eu - and heterochromatin regions) occur in aging. Epigenetics process - heterochromatinization can deactivate many previously functioning active genes. It blocks certain stages of normal metabolic processes in the cell, which inhibits many specific enzymes and leads to aging pathologies. We show that peptide bioregulators induced unrolling deheterochromatinization (decondensation) of total heterochromatin, deheterochromatinization of satellite stalks of acrocentric chromosome, activating synthetic processes of ribosomal genes, does not cause deheterochromatinized of pericentromeric structural heterochromatin. This data also indicates that each of the studied peptide bioregulators (Ala-Glu-Asp-Gly; Lys-Glu-Asp-Ala; Ala-Glu-Asp-Pro and Lys-Glu) has a selective effect on definite regions of chromosomes. Thus, short peptide bioregulators induce selective heterochromatinization and deheterochromatinization of chromosome regions (remodeling of facultative heterochromatin) in individuals 75-88 years old that opens up new opportunities in the treatment of aging diseases.

EPIGENETIC MODIFICATION UNDER THE INFLUENCE OF PEPTIDE BIOREGULATORS ON "AGED" HETEROCHROMATIN.

Following the completion of the Human Genome Project, the strategic direction of modern genetics has moved toward functional genomics, to explore the functions of non-coding regions of DNA. These non-coding regions are localized in heterochromatin. The functions of heterochromatin largely remain unclear. Facultative heterochromatin occurs in aging. The effect of synthetic peptide bioregulators (tetrapeptides: Ala-Glu-Asp-Gly; Lys-Glu-Asp-Ala; Ala-Glu-Asp-Pro and dipeptide - Lys-Glu) on total heterochromatin, constitutive (structural) and facultative heterochromatin in cultured lymphocytes of individuals aged 75-88 and 20 - 40 years have been studied. We used a molecular-cytogenetic methods: differential scanning calorimetry; activity of ribosomal genes of acrocentric chromosome satellite stalks - NORs; C-heterochromatin; sister chromatid exchanges (SCE). The results showed that peptide bioregulators: 1. induce unrolling - deheterochromatinization of total heterochromatin, constitutive (pericentromeric, telomeric, and nucleolar organizer regions (NOR)) and facultative heterochromatin; 2. induce higher level of SCEs (deheterochromatinization), were registered in telomeric heterochromatin and decreased (heterochromatinization) SCEs level in the medial regions of chromosome arms; 3. each peptide bioregulator selectively deheterochromatinizes a specific region of chromosomes releasing inactive (once active) genes, which, apparently, can contribute to the targeted treatment of aging diseases. The proposed genetic mechanism responsible for the remodeling of constitutive and facultative heterochromatin emphasizes the importance of external and internal factors in the development of diseases and may lead to the development of a strategy for the therapeutic treatment of senile pathology.

COMPARATIVE ANALYSIS OF WHOLE CARTILAGE TISSUE THERMOSTABILITY IN DISEASED PATIENTS VERSUS INJURED PATIENTS.

We conducted comparative thermodynamic analysis of femoral cartilages tissue of injured (healthy) patients and patients with congenital hip dislocation. It is shown, that temperature which corresponds to maximum of heat absorption peak of femoral cartilages tissue of diseased patient is on 6.4oC lower than heat absorption peak of femoral cartilages tissue of healthy patient. Heat absorbed during denaturation process in all these cases are close to each other with experimental error accuracy and corresponds to 52±2.6, 51±2.6 and 50±2.5 J/g of dried biomass accordingly. Analysis of the published data makes it possible to assert that the dominant heat absorption stage on DSC curves of tested fresh tissues samples is associated with melting of collagen fibers, hence the thermal stability of the collagen fibers in the patient's tissue is reduced relative to norm.

[GENOMIC VARIABILITY IN PATIENTS WITH DUCTAL FORM OF BREAST CANCER AND THE POSSIBILITY OF CORRECTION THE PEPTIDE BIOREGULATOR AND METAL IONS].

Level of genome stability (structural aberrations, aneuploidy and fragile sites) was studied in cells of the lymphocyte culture of ductal breast cancer patients (DBC). Was studied the correctional influence of separate and combinative action of peptide bioregulator (Ala-Glu-Asp-Gly) and heavy metal - nickel. It is shown that DBC patients are characterized by high level of genome instability, which is the result of the chromatin changing state. The used tests makes it possible to conclude that in the case of this form of cancer subordinates to specific epigenetic variation as a hetero- also euchromatic regions of genome. The agents - peptide bioregulator (Ala-Glu-Asp-Gly) and nickel ions, used in cell culture of ductal breast cancer patients, revealed the protective effect what indicates the prospects to further study for their involving purpose in combined therapy of this form of cancer.

Influence of tetrapeptide on chromatin thermostability.

It is known that short peptides are capable to interact with DNA, as a result of changes in particular gene expression. In the given work, influence of Ala-Asp-Glu-Leu peptide on thermostability of white rat liver chromatin, in which H1 histone and non-histone proteins are depleted, have been studied. It was shown that in 10 nm chromatin filaments, in which nucleosomas do not interact, the tetrapeptide unfolds the nucleosomal nucleus (core) and this causes release of about 15% of core DNA that melts in the melting temperature range of internucleosomal linker DNA. Thus, the studied tetrapeptide can increase accessibility of DNA for transcription.

Effect of the peptide bronchogen (Ala-Asp-Glu-Leu) on DNA thermostability.

Thermodynamic parameters of DNA melting in the presence of a peptide bronchogen in various concentrations were estimated on a differential scanning microcalorimeter. Bronchogen was shown to serve as a DNA-stabilizing agent. Bronchogen increased the melting temperature of DNA from calf thymus and mouse liver by 3.1°C in a narrow range of r (molar ratio of bronchogen/DNA b.p., 0.01-0.055). A further increase in r was not accompanied by changes in the melting temperature. The complex melting enthalpy (ΔH(melt)) remained unchanged in this range of r (0.01-1.0). ΔH(melt) for DNA from the thymus and mouse liver was 11.4 and 12.7 cal/g, respectively. Our results indicate that bronchogen is not an adenine-thymine-specific or guanine-cytosine-specific ligand. The type of binding is considered as strong and occasional. The binding occurs with both strands of DNA (mainly with nitrogen bases).

Influence of anticarcinogenic metalloporphyrin Cu(II)TOEPyP(4) on DNA thermostability in vitro.

The influence of a new anticarcinogenic compound Cu(II)TOEPyP(4) (Cu(II)-Meso-tetra(4-N-oxyethylpyridyl) porphyrin) (the analogue of TMPy4[tetra(N-mrthyl-4-pyridyl)-porphyrin chloride] - an inhibitor of telomerase activity - on the thermostability of calf thymus DNA in vitro has been studied. It has been shown that Cu(II)TOEPyP(4) is a stronger stabilizing DNA agent, which is expressed with an increase of its thermostability by 20 degrees C. It was determined that complex formation does not disturb the DNA double-helix, and the melting enthalpy (DeltaHm) remains unchanged and it is equal to 11.6+/-1.0 cal/gDNA in the range 0.002

Microcalorimetric study of human blood lymphocytes culture at presence of copper, cadmium and prostamax.

Research goal was study of separate and joint influence of bioregulator prostamax and Cu(II) and Cd(II) ions on the chromatin structure in situ. The thermal characteristics of the denaturation process of blood lymphocytes culture of aging people in the presence of some microg quantities of Cu(II) and Cd(II) ions have been determined. It has been shown that Cu(II) and Cd(II) ions at these low concentrations don't influence on the temperature stability of membrane, nuclear and cytoplasm proteins. It has been shown that Cu(II) ions cause an additional condensation of the heterochromatin, and Cd(II) ions cause decondensation of heterochromatin and its partial denaturation.

The microcalorimetric investigation of cellular suspensions of blood lymphocytes from healthily and suffering from atherosclerosis individuals.

The denaturation thermodynamic parameters--enthalpy (DeltaH) and temperature of hetero-and active chromatin of lymphocytes and metabolic heat of these cells were determined for healthy and suffering from atherosclerosis individuals. It is supposed that atherosclerosis disease leads to chromatin rebuilding in the interphase state and decrease of cell survival. The chromatin rebuilding may be imagined as partially unfolding of 30 nm chromatin fiber into 10 nm one due to loss of some part of H1 histone.

Thermodynamic properties of blood plasma of patient suffering from atherosclerosis.

The goal of the work is to find out the changes in the heat parameters of blood plasma denaturation of a son and a granddaughter, in comparison with the same parameters of a 91 years old grandfather with atherosclerosis. The significant changes in heat (Q(d)) and denaturation temperature (T(d)) of albumin, globulins and fibrinogen of 91-year-old patient suffering from atherosclerosis relative to the norm (88-year-old man) are found out. In particular, Q(d) increase by 60% of albumin fat fraction and fibrinogen of F domain and the increase of their T(d) by 2.4 degrees C and 2.8 degrees C relative to the norm; Q(d) decrease by 1.8 times and T(d) increase by 2.9 degrees C of gamma globulin relative to the norm; Q(d) decrease by 6 time of D domain fibrinogen and and globulins by 1.4 and 2.9 times relative to the norm. Total denaturation heat of donor blood plasma is equal to 25.5+/-3 J/g and patient suffering from atherosclerosis is equal to 22.0 J/g. The most significant changes of heat parameters are observed between grandfather and granddaughter: an increase of D domain T(d) by 4 degrees C and Q(d) by 6 times; T(d) increase of albumin fat fraction by 4.3 degrees C and its Q(d) decrease by 10% of granddaughter in comparison with her grandfather. As value Qd of proteins is directly proportional to protein concentration in solutions, we conclude that the significant changes of concentration main proteins in blood plasma and changes of their thermodynamic stability occur at atherosclerosis, relative to the norm.

Microcalorimetric investigation of DNA, poly(dA)poly(dT) and poly[d(A-C)]poly[d(G-T)] melting in the presence of water soluble (meso tetra (4 N oxyethylpyridyl) porphyrin) and its Zn complex.

Thermodynamic parameters of melting process (DeltaHm, Tm, DeltaTm) of calf thymus DNA, poly(dA)poly(dT) and poly(d(A-C)).poly(d(G-T)) were determined in the presence of various concentrations of TOEPyP(4) and its Zn complex. The investigated porphyrins caused serious stabilization of calf thymus DNA and poly poly(dA)poly(dT), but not poly(d(A-C))poly(d(G-T)). It was shown that TOEpyp(4) revealed GC specificity, it increased Tm of satellite fraction by 24 degrees C, but ZnTOEpyp(4), on the contrary, predominantly bound with AT-rich sites and increased DNA main stage Tm by 18 degrees C, and Tm of poly(dA)poly(dT) increased by 40 degrees C, in comparison with the same polymers without porphyrin. ZnTOEpyp(4) binds with DNA and poly(dA)poly(dT) in two modes--strong and weak ones. In the range of r from 0.005 to 0.08 both modes were fulfilled, and in the range of r from 0.165 to 0.25 only one mode--strong binding--took place. The weak binding is characterized with shifting of Tm by some grades, and for the strong binding Tm shifts by approximately 30-40 degrees C. Invariability of DeltaHm of DNA and poly(dA)poly(dT), and sharp increase of Tm in the range of r from 0.08 to 0.25 for thymus DNA and 0.01-0.2 for poly(dA)poly(dT) we interpret as entropic character of these complexes melting. It was suggested that this entropic character of melting is connected with forcing out of H2O molecules from AT sites by ZnTOEpyp(4) and with formation of outside stacking at the sites of binding. Four-fold decrease of calf thymus DNA melting range width DeltaTm caused by increase of added ZnTOEpyp(4) concentration is explained by rapprochement of AT and GC pairs thermal stability, and it is in agreement with a well-known dependence, according to which DeltaT approximately TGC-TAT for DNA obtained from higher organisms (L. V. Berestetskaya, M. D. Frank-Kamenetskii, and Yu. S. Lazurkin. Biopolymers 13, 193-205 (1974)). Poly (d(A-C))poly(d(G-T)) in the presence of ZnTOEpyp(4) gives only one mode of weak binding. The conclusion is that binding of ZnTOEpyp(4) with DNA depends on its nucleotide sequence.

Anti-aging peptide bioregulators induce reactivation of chromatin.

The effect of synthetic peptide bioregulators (Epitalon, Livagen and Vilon) on structural and facultative heterochromatin of cultivated lymphocytes have been studied among old (75-88yr.) people. The data obtained indicate that epitalon, livagen and vilon: 1) activate synthetic processes, caused by reactivation of ribosomal genes as a result of deheterochromatinization (decondensation) of nucleolus organizer regions; 2) induce unrolling (deheterochromatinization) of total heterochromatin; 3) release genes repressed by heterochromatinization (condensation) of euchromatic regions forming facultative heterochromatin; 4) epitalon and livagen induce deheterochromatinization (decondensation) of pericentromeric structural heterochromatin of the chromosomes1 and 9. However, vilon does not induce deheterochromatinization of pericentromeric structural heterochromatin. These results indicate that peptide bioregulators Epitalon, Livagen and Vilon cause activation (deheterochromatinization) of chromatin in lymphocytes of old individuals.

Thermal characteristics of Spirulina platensis cells under nongrowing conditions at various values of pH medium.

The total value of heat (-Q) evolved by green-blue microalgae Spirulina platensis cells in a dark and stationary regime in the range of pH values 8.0-11.6 was determined. It was established that (-Q) reaches its maximum value at 360 +/- 40 J/g of dry biomass in the pH range 9.3-10.3 and then sharply dropped relative to these values and reached zero at pH 7.5 +/- 0.2 and 11.8 +/- 0.2. It is affirmed that an optimum regime for preservation of Spirulina platensis cell viability in a dark and stationary regime is pH range 9.3-10.3. It was also shown that the peak of heat evolution with maximum about 45 degrees C, reflecting mainly the respiration of cells (oxygen absorption rate), did not displace along the temperature scale at a change of pH from 9.3 to 10.4 and slightly displaced lower and higher of these values of pH. It is supposed that the thermostability of biomacromolecules and their complexes responsible for cell respiration does not depend on pH medium in pH range 9.3-10.3.

Effects of Livagen peptide on chromatin activation in lymphocytes from old people.

We studied the effects of the synthetic peptide Livagen on activity of ribosomal genes, denaturation parameters of heterochromatin, polymorphism of structural C-heterochromatin, and variability of facultative heterochromatin in lymphocytes from old people. Livagen induced activation of ribosomal genes, decondensation of pericentromeric structural heterochromatin, and release of genes repressed due to age-related condensation of euchromatic regions in chromosomes. Our results indicate that Livagen causes de-heterochromatinization (activation) of chromatin, which is realized via modification of heterochromatin and heterochromatinized regions in chromosomes from old people.