Kinetics of chaperone activity of proteins Hsp70 and Hdj1 in human leukemia U-937 cells after preconditioning with thermal shock or compound U-133

Abstract

Kinetics of the chaperone activity of proteins Hsp70 and Hdj1 were analyzed in human U-937 promonocytes during their response to heat shock or to treatment with the echinochrome triacetyl glucoside derivative U-133. To measure the chaperone activity of both proteins, a special test was developed for their recognition and binding of a denatured protein. Using this test, the chaperone activity could be concurrently estimated in large numbers of cellular or tissue extracts. We also estimated the contents of both chaperones in cells by immunoblotting. The values for contents of Hsp70 and Hdj1 obtained by two independent test systems coincided, and this suggested that the substrate-binding activity could change proportionally to the chaperone content in the protein mixture. Therefore, the test developed by us can be employed for high throughput screening of drugs activating cellular chaperones. The analysis of quantity and activity of two cellular chaperones during the cell response to heat stress or to the drug-like substance U-133 showed that both factors caused the accumulation of chaperones with similar kinetics. We conclude that the efficiency of drug preconditioning could be close to the efficiency of hyperthermia and that the high activity of chaperones could be retained in human cells for no less than 1.5 days.

Hsp70 Induction and Anticancer Activity of U-133, the Acetylated Trisglucosydic Derivative of Echinochrome

“…It was established that trisglucoside U-133 significantly increased Hsp70 expression in human erythroleukemia K562 cells [12]. The analysis of quantity and activity of cellular chaperones during the human leukemia U-937 cell response to heat stress or to the U-133 application showed that both factors caused the accumulation of chaperones with similar kinetics [13].…”

“…Previously, we found that both heat shock and the U-133 substance were effective inducers of Hsp70, and the amount of the protein remained high during at least 24 h. The content of Hsp70 in the heattreated cells increased approximately 3 h earlier and the protein itself remained in the cells for a longer time than after the treatment with U-133 [13].…”

Chaperone Hsp70 is involved in the molecular mechanisms of slow wave sleep regulation

“…The increase in the SWS duration and the decrease in the wakefulness duration were observed by us [9] in rats after the transfection of the VLPO neurons with the lentivector pLKO.1 shRNA Hdj1, which led to a 80% reduction in the level of co chaperone Hdj1 (HSP40 family). It is known that Hdj1 closely interacts with Hsp70, regulating its bind ing to the target protein [13].…”

“…The increase in the SWS duration and the decrease in the wakefulness duration were observed by us [9] in rats after the transfection of the VLPO neurons with the lentivector pLKO.1 shRNA Hdj1, which led to a 80% reduction in the level of co chaperone Hdj1 (HSP40 family). It is known that Hdj1 closely interacts with Hsp70, regulating its bind ing to the target protein [13].Therefore, the increase in the SWS duration depends on the increase in the level of Hsp70 [8] and/or the decrease in the level of its co chaperone Hdj1 [9] in the sleep "center." These changes appar ently enhance the function of the inhibitory system in the VLPO on maintaining the wakefulness "centers" in the switched off state.…”

Механизмы Антирадикальной Активности 2,3,5,6,8-Пентагидрокси-7-Этил-1,4-Нафтохинона (Обзор)

“…È íàêîíåö, óñòàíîâëåíî, ÷òî ïîëèôåíîëàì ïðèñóùè è ðàçëè÷íûå ãåíîìíûå ýôôåêòû [11,16,29,71]. Èññëåäîâàíèÿ ïîñëåäíèõ ëåò ïîêàçàëè, ÷òî ìîäóëèðîâàòü ãåííóþ àêòèâíîñòü ñïîñîáåí è ýõèíîõðîì À [72,73,74,75].…”