[DOXORUBICIN-INDUCED ALTERATIONS IN PRO-AND ANTIOXIDANT BALANCE AND THEIR CORRECTION BY CURCUMIN IN THE NEONATAL RAT CARDIOMYOCYTES CULTURE].

It was studied the effect of doxorubicin on the HIF system and the pro-antioxidant balance of neonatal cardiomyocytes as well as the possibility of the oxidative stress correcting using curcumin. It has been revealed that the expression of mRNA HIF-1α using doxorubicin at a dose of 0.5 µM was 2.9 ± 0.8 cu, so it decreased by 20% compared to control--3.6 ± 0.7 cu (P < 0.05). The level of expression of the HIF target gene PDK-1 also significantly decreased (4 times). During the incubation with doxorubicin, the number of live cells decreased by 50.4% relative to control. And after using doxorubicin and curcumin together, the percentage of dead cells decreased by 7,7 compared to doxorubicin only. Doxorubicin intoxication led to a significant increase in the secondary products of lipid peroxidation (TBARS) in cardiomyocytes by 3.6 times and hydrogen peroxide by 64%. Prolonged incubation with doxorubicin reduced the enzymatic activity of Mn-SOD by 32%, while catalase activity increased by 72% compared to control. Adding of curcumin to the cardiomyocyte cell culture contributed to increasing of the Mn-SOD activity by 14%, catalase--by 23%. The level of TBARS increased by 1,4 times compared with the control, and the level of H2O2 increased by 20%. The joint use of doxorubicin and curcumin resulted in a significant reduction of free radical oxidation unlike effect of doxorubicin per se. Specifically, there was lessening of TBARS and H2O2 (at 56.7 and 18.4% respectively), while decreasing of the catalase hyperactivation (19%) and rising of the Mn-SOD activity (35%).

Silencing of TERT decreases levels of miR-1, miR-21, miR-29a and miR-208a in cardiomyocytes.

To test the hypothesis that telomerase reverse transcriptase (TERT) as an RNA-dependent RNA polymerase could be involved in the amplification of microRNA (miRNA), we have determined the levels of immature and mature miRNA in cultured neonatal rat cardiomyocytes, during the silencing of TERT by siRNA. The silencing of the TERT gene led to the reduction of both telomerase activity and the TERT mRNA expression when compared with scrambled RNA. TERT gene silencing resulted in the decrement of three studied mature miRNAs levels: miRNA-21, miRNA-29a and miRNA-208a when compared with scrambled RNA; but miRNA-1, it was not changed significantly. At the same time, levels of immature miRNA-1 and miRNA-208a were not changed, although the levels of immature miRNA-29a and pri-miRNA-1 were decreased. The data obtained allow us to permit that TERT is a genome-independent source of mature miRNA, and the changes in telomerase activity can significantly influence the level of miRNA in cardiomyocytes.

Genetic predisposition to essential hypertension in children: analysis of 17 single nucleotide polymorphisms.

Study of 17 single nucleotide polymorphisms has been performed to determine the factors of genetic predisposition to essential hypertension. Polymerase chain reaction (PCR) with subsequent analysis of restriction fragment length, allele specific PCR or real-time PCR was used for genotyping of 17 single nucleotide polymorphisms in 14 genes in 145 children with essential hypertension and 144 healthy persons with following complex multivariate statistical analysis. Two single nucleotide polymorphisms--MMP9 (C(-1562) --> T) and NOS3 (Glu298 --> Asp)--rs3918242 and rs1799983--were shown to represent the main independent effects with the highest predictive potential (77.1% as indicated by binary logistic regression and 74.6% testing accuracy shown by Multifactorial Dimensionality Reduction). MMP9 (C(-1562 --> T) and NOS3 (Glu298 --> Asp) potentially may be used to create predictive algorithm for determination of predisposition to arterial hypertension in children.