[The role of heat shock proteins 27 and 70 in redox-dependent regulation of apoptosis in Jurkat tumor cells]. / Uchastie belkov teplovogo shoka 27 i 70 v redoks-zavisimoi reguliatsii apoptoza opukholevykh kletok linii Jurkat.

Heat shock proteins Hsp) act as molecular chaperones, protecting enzymes and other proteins against reactive oxygen species. The objective of the study was to investigate the role of Hsp27 in maintaining the balance of the glutathione system and Hsp70 concentrations as well as in implementing Jurkat tumor cell apoptosis. Addition of the Hsp27 inhibitor KRIBB3 (5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxazol) to Jurkat cells resulted in glutathione redox imbalance (increased GSSG and increased glutathione reductase activity), a decrease in Hsp70 concentrations, and also increased cell apoptosis as compared with to the intact cell culture. The proposed selective regulation of chaperone activity is a promising direction in regulating apoptosis at the cellular level.

[The role of oxidative protein modification and the gluthatione system in modulation of the redox status of breast epithelial cells].

The effects of the SH-group blocker N-ethylmaleimide (NEM) and thiol group protector 1,4-dithioerythritol (DTE) on the redox status of cells HBL-100 cells, oxidative modification of their proteins and the state of glutathione and thioredoxin systems have been investigated. Breast epithelial cells cultivated in the presence of NEM were characterized by decreased redox status, increased glutathione reductase activity, and increased concentrations of products of irreversible oxidative modification of protein and amino acids. Cultivation of HBL-100 cells in the presence of DTE resulted in a shift of the redox status towards reduction processes and increased reversible protein modification by glutathionylation. The proposed model of intracellular redox modulation may be used in the development of new therapeutic approaches to treat diseases accompanied by impaired redox homeostasis (e.g. oncologic, inflammatory, cardiovascular and neurodegenerative disease).