In vitro effect of recombinant human granulocyte colony-stimulating factor on canine neutrophil apoptosis.
Apoptosis is essential in eliminating neutrophils (polymorphonuclear leukocytes: PMNs) in animals. The suppression of PMN apoptosis is believed to be beneficial in eradicating pathogens and is implicated in the pathogenesis of human inflammatory diseases. In the present study, canine PMNs were stimulated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) to investigate the in vitro effect on the apoptosis of canine PMNs. Apoptotic cell rates were assessed by flow cytometry in relation to the ability of PMNs to produce reactive oxygen species (ROS). Canine PMN apoptosis was markedly suppressed by rhG-CSF treatment, in association with the retention of the PMN ability to produce ROS. The addition of cycloheximide abolished this suppression by rhG-CSF. Moreover, canine PMNs, which were stimulated by rhG-CSF, expressed high levels of anti-apoptotic mcl-1 gene mRNA, as quantified by real-time polymerase chain reaction method. The results suggest that PMNs, stimulated by G-CSF, could work effectively over a longer period to eliminate pathogens, and that the prolongation of the PMN life-span might occasionally aggravate tissue injuries in dogs. In addition, the suppression of PMN apoptosis seems to be mediated by the induction of anti-apoptotic mcl-1 gene expression.
Oguma
Keisuke
K
Department of Pathobiology, Nihon University School of Veterinary Medicine, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan.
Sano
Junichi
J
Kano
Rui
R
Watari
Toshihiro
T
Moritomo
Tadaaki
T
Hasegawa
Atsuhiko
A
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D003513:Cycloheximide / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein; D016179:Granulocyte Colony-Stimulating Factor; D003513:Cycloheximide