Biochemical Properties of Human Oral Polymorphonuclear Leukocytes |
| |
Authors: | Hiroko Nakahara Eisuke F. Sato Rumi Ishisaka Tomoko Kanno Tamotsu Yoshioka Tatsuji Yasuda Masayasu Inoue Kozo Utsumih |
| |
Affiliation: | a Department of Cell Chemistry, Institute of Molecular and Cell Biology, Okayama University Medical School, Okayama, Japanb Institute of Medical Science, Kurashiki Medical Center, Kurashiki, Japanc Department of Biochemistry, Osaka City University Medical School, Osaka, Japan |
| |
Abstract: | Polymorphonuclear leukocytes (PMN) isolated from the oral cavity of healthy human volunteers, spontaneously generated superoxide, nitric oxide (NO) and other reactive oxygen species (ROS) which exhibited strong luminol chemiluminescence (LCL). To understand the physiological roles of oral PMN (OPMN), biochemical properties of the cells were analyzed. Biochemical analysis revealed that OPMN were already primed under physiological conditions. Western blot analysis revealed that they strongly expressed the inducible type of NO synthase (NOS II) and exhibited the activity to catalyze tyrosine phosphoryla-tion of various proteins including a 115 kDa protein (cbl product). OPMN also generated H2O2 and OH by some superoxide dismutase (SOD)-sensitive mechanism and released myeloperoxidase (MPO). Kinetic analysis using specific inhibitors revealed that OCI generated by OPMN was predominantly responsible for the enhanced LCL. During the incubation under standard culture conditions, OPMN underwent apoptosis which proceeded more rapidly than that of the circulating PMN (CPMN). Immunochemical analysis revealed that expression of apoptosis-related gene products, such as Bcl-2, Bcl-xL and Bax, was below detectable levels with both cell types. However, caspase-3 but not caspase-1 was markedly activated in OPMN. These results indicate that the primed OPMN spontaneously generate ROS and play an important role in the defense mechanism in the oral cavity and that the generated ROS activate caspase-3 thereby inducing apoptosis of the cells. |
| |
Keywords: | Apoptosis Bcl-2 caspase-3 NOS II oral polymorphonuclear leukocyte reactive oxygen species tyrosine phosphorylation |
本文献已被 InformaWorld 等数据库收录! |
|