[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.

[Prevalence of Markers of Chronic Kidney Disease in Patients With Arterial Hypertension: Results of Epidemiological Study CHRONOGRAF].

In an noninterventional observational open multicenter program CHRONOGRAF the prevalence of markers of chronic kidney disease (CKD) was studied in 1600 patients with arterial hypertension with and without type 2 diabetes mellitus. Glomerular filtration rate (GFR) was calculated (CKD­EPI formula) and albuminuria (AU) was determined as albumin/creatinine (A/Cr) ratio in the morning portion of urine. In 49.4% of patients decreased GFR 30 mg/g was detected. Decrease of GFR 30 mg/g - in 32.6%, combination of reduced GFR and high/very high AU - in 18%. High or very high level of combined risk of progression to CKD and cardiovascular complications had 28.5% of patients.

Nephroprotective Effect of EDL Peptide at Acute Injury of Kidneys of Different Genesis.

EDL peptide produced a nephroprotective effect on experimental models gentamycin-induced nephropathy and ischemia/reperfusion kidney injury in rats. The nephroprotective effect of EDL peptide manifested in prevention of oliguria and retention azotemia, a decrease in proteinuria and sodium excretion, prevention of critical decrease in activities of antioxidant enzymes, suppression of LPO, and normalization of energy supply to kidneys cells. Our findings confirm the prospects of further studies of the nephroprotective properties of peptide EDL in various pathologies of the kidneys.

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.

Peptides Restore Functional State of the Kidneys During Cisplatin-Induced Acute Renal Failure.

The effects of polypeptide complex from the kidney and short peptides AED, EDL, and AEDG on renal functions were studied in rats with cisplatin-induced acute renal failure. AED peptide decreased protein excretion and electrolyte concentration in the urine. Polypeptide complex from the kidney and peptides EDL and AEDG normalized diuresis, creatinine concentration in the urine and its excretion, glomerular filtration rate, and absolute resorption of sodium ions and reduced protein concentration in the urine and its excretion, the concentrations of sodium and potassium ions in the urine, and other parameters. EDL peptide produced was potent nephroprotective effect. It is known that the polypeptide complex of the kidney and short peptides restore the expression of signal molecules (marker of functional state of the kidneys), so these peptide substances can have nephroprotective effect during various renal pathologies.

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.

Peptides regulate expression of signaling molecules in kidney cell cultures during in vitro aging.

We studied the effect of polypeptide complex isolated from calf kidney and short peptides T-31 (AED) and T-35 (EDL) on the expression of signaling molecules, markers of cell renewal (Ki-67, p53), remodeling of the extracellular matrix (MMP-14), and immune response (IL-8) in primary kidney cell cultures during aging. The complex of renal polypeptides and T-31 peptide activate cell renewal processes during aging of the renal epithelium, while gelatinase MMP-14 is the target of T-35 peptide.

[Tripeptides slow down aging process in renal cell culture].

The mechanism of geroprotective effect of peptides AED and EDL was studied in ageing renal cell culture. Peptide AED and EDL increase cell proliferation, decreasing expression of marker of aging p16, p21, p53 and increasing expression of SIRT-6 in young and aged renal cell culture. The reduction of SIRT-6 synthesis in cell is one of the causes of cell senescence. On the basis of experimental data models of interaction of peptides with various sites of DNA were constructed. Both peptides form most energetically favorable complexes with d(ATATATATAT)2 sequences in minor groove of DNA. It is shown that interaction of peptides AED and EDL with DNA is the cause of gene expression, encoded marker of ageing in renal cells.

[Molecular aspects of renal desease].

The review considers molecular mechanisms of chronic renal failure and cancer kidney disease. The most important molecules inducing inflammation are cytokines (MCP-1, TNFalpha, IFN-gamma, IL-1,6,8,18), matrix metalloproteinases MMP-2,3,9,14, tissue inhibitors of metalloproteinases (TIMPs) and grow factors (VEGF PDGE FGF). This signal molecules regulate the activity of immune cells and remodeling extracellular matrix (ECM) components taken place in inflammatory reactions, proliferation, apoptosis and also in the differentiation of kidney cells. On the basis of these data nowadays developed new highly selective approaches to diagnosis, prediction, estimation of efficiency of treatment of renal disease and creating of target drugs.