Molecular Mechanisms of Apoptosis in HL-60 Cells Induced by a Nitric Oxide-Releasing Compound |
| |
Authors: | Munehisa Yabuki A Shwji Yoko Inni Keisuke Hamazaki Tamotsu Yoshioka Tatsuji Yasuda Alan A Horton Kozo Utsumi |
| |
Institution: |
a Depul-iwrent of Cell Chemistry, Institute of Molecular and Cell Biology, Okayama University Medical School, Okuyama, Japan
b Institute of Medical Science, Center for Adult Diseases, Kurashiki, 250, Bukuro-cho, Kurashiki, Japan
c School of Biochemistry, University of Birmingham, Edgbaston, Birmingham, UK |
| |
Abstract: | Nitric oxide (NO) generated from 1-hydroxy-2-0×0-3, 3-bis(2-aminoethyl)-l-triazene (NOC 18), an NO-releasing compound, induced monocytic differentiation of human promyelocytic leukemia HL-60 cells as assessed by expression of nonspecific esterases and morphologic maturation. Simultaneously, DNA fragmentation and morphological alterations typical of apoptosis were also induced. To investigate the mechanisms of apoptosis during differentiation of HL-60 cells induced by NO, the endogenous levels of Bcl-2 and Bax were assessed by immunoblotting. Treatment of cells with NOC 18 slightly reduced the level of Bcl-2 followed by Bax. These changes might be involved in the induction of apoptosis. The involvement of the activation of the interleukin-lβ converting enzyme (ICE) family of proteases (caspases), such as ICE and CPP32, in the pathways was also investigated. CPP32, but not ICE, was strongly activated in response to NOC 18 stimulation, thereby implicating CPP32-like activity in the induction of apoptosis. Moreover, the possible involvement of tyrosine phosphorylation in apoptosis was investigated. Pretreatment of cells with herbimycin A, an inhibitor of tyrosine kinases, suppressed DNA fragmentation and CPP32-like activity, whereas pretreatment with vanadate, an inhibitor of tyrosine phosphatases, enhanced both parameters, suggesting that tyrosine phosphorylation might be involved in the pathways of apoptosis in HL-60 cells induced by NO. |
| |
Keywords: | Nitric oxide HL-60 cells cell differentiation apoptosis DNA fragmentation Bcl-2 Bax caspase ICE CPP32 tyrosine phosphorylation |
本文献已被 InformaWorld 等数据库收录! |
|