Defective (e.g.infected or mechanically damaged) cells are destroyed by apoptosis - regulated cell death. Due to it the cells are constantly updated. Up to 70 billion cells are destroyed by apoptosis in a healthy human body every day. If the process changes (speeds up or slows down), it leads to oncological, autoimmune, neurodegenerative, and other disorders.
There are several enzymes called apoptotic endonucleases that participate in the programmed cell death. RUDN biochemists demonstrated that one of them named EndoG can stop the cell death process if it goes out of control. It turned out that increased EndoG secretion reduces the volumes of another endonuclease called DNase I and slows down the process of apoptosis on its early stage. Previously the two enzymes were supposed to work together, i.e. to mutually affect the DNA of a defective cell to destroy it. RUDN biochemists were the first to demonstrate that EndoG and DNase I were in fact more competitors than comrades.
“The EndoG enzyme acts as a protective mechanism against DNase I and DNA destruction. In this case the mechanism of cell death turns out to be very interesting: EndoG, the enzyme that destroys DNA, is able to stop apoptosis if it goes too far or too fast”, said Dmitry Zhdanov, a co-author of the work, a Candidate of Biology, and an Assistant Professor of Berezov Department of Biochemistry at RUDN.
To carry out the experimental research, RUDN biochemists used the blood of 50 people from 18 to 25 years of age without any diagnosed diseases. The scientists induced the increase of EndoG synthesis in T-lymphocytes of the donors. Then using a DNA-destroying substance called bleomycin the scientists initiated the process of apoptosis in the cells and measured the levels of EndoG and DNAse I. It turned out that the excess of EndoG reduced the level of DNAse I and therefore slowed down the whole process of apoptosis.
“We were the first to demonstrate the negative correlation between EndoG and DNAse I. This discovery may help fine-tune the response of a cell to any damage, and the activation of EndoG may become a protective mechanism against uncontrolled cell death”, added Zhdanov.
The participants of the study also represented Orekhovich Science and Training Institute for Biomedical Chemistry and Blokhin National Medical Research Center of Oncology.
RUDN soil scientists have revealed a direct correlation between the rate of soil formation of carbon dioxide, called CO2 emissions, and the content of microbial biomass in it. It is known that CO2 emission from soil is mainly conditioned by respiration of soil microorganisms and plant roots. The more CO2 soil emits, the more microbial biomass it usually contains. It was shown that CO2 emission by chernozem of different ecosystems (or different types of land use) correlates with the content of microbial biomass, and most closely with the rate of its microbial respiration. And the soil with good microbial properties has the “best quality”, is more fertile, provides the highest yield of crops and other plant biomass.
A RUDN chemist has synthesized a catalyst for the production of gamma-valerolactone — an energy-intensive “green” biofuel. The catalyst based on zirconium dioxide and zeolite has shown high efficiency in converting the waste of wood plant materials — methyl levulinate — to gamma-valerolactone.
Biochemists from RUDN University determined which substances in peach leaves provide the antioxidant effect their extract has. They investigated the composition of the powders obtained from leaves of several varieties of peach and found that high polyphenol content correlates with antioxidant properties. The results will help start production of antioxidants from natural sources.