EFFECT OF INTRACELLULAR REDOX STATUS ON IMMUNOLOGICALLY COMPETENT CELLS : APPLICATION OF THE INDICATOR FOR EVALUATION OF OXIDATIVE STRESS

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15590118
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental pharmacy
• Research Institution: SETSUNAN UNIVERSITY
• Principal Investigator: UENO Hitoshi SETSUNAN UNIVERSITY, FACULTY OF PHARMACEUTICAL SCIENCES, ASSOCIATE PROFESSOR, 薬学部, 助教授 (20176621)
• Co-Investigator(Kenkyū-buntansha): OKUNO Tomofumi SETSUNAN UNIVERSITY, FACULTY OF PHARMACEUTICAL SCIENCES, TEACHING ASSOCIATE, 薬学部, 助手 (30288972)
• Project Period (FY): 2003 – 2004
• Keywords: reactive oxidant intermediates / redox / immune disruption / apoptosis / ROI / carboxy-DCFH-DA / hydrogen peroxide / flowcytometry

Research Abstract

This study was conducted to investigate about relationship between signal transduction in immunologically competent cells and the intracellular redox status that is in a balance on the formation of reactive oxidant intermediates (ROI) and the defense ability against oxidative stress and also to develop an evaluation system for immune disruption by exogenous oxidative stress. When both human cell lines, T-cell leukemia (Jurkat) and promyelocytic leukemia (HL-60) were exposed to hydrogen peroxide (H_2O_2) at the concentration of less than 50 μmol/L that causes mild oxidative stress, ROI was detected by carboxy-DCFH-DA flow cytometry only in the latter cells. This result indicated that there was a difference in redox status between both cell lines even though the same extent of oxidative stress was suffered. In HL-60 cells, viability was decreased by H_2O_2 exposure and this was caused by apoptosis. Production of TNF-α was observed when the cells were exposed to the concentration levels of H_2O_2 that caused apoptosis. Treatment of TNF-α at the detection levels also resulted in the induction of apoptosis. These results suggest that carboxy-DCFH-DA flow cytometry is capable to detect the formation of intracellular ROI which is concomitant with apoptosis induction and TNF-α formation.