title: Role of nuclear lamins in nuclear segmentation of human neutrophils.
abstract: Nuclear breakdown leading to the formation of apoptotic bodies has been postulated to involve degradation of nuclear structural proteins, such as lamins A/C and B. Although nuclear segmentation occurs during the maturation of polymorphonuclear leukocytes (neutrophils), its mechanism is not known. We found that human neutrophils have lamin B but lack lamins A/C while mononuclear cells possess all three types of lamin as assessed by immunoblotting. Differentiation of human promyelocytic HL-60 cells into neutrophil-like cells was also accompanied by the down-regulation of lamins A/C but not of lamin B. Moreover, when compared with normal cells, neutrophils with the Pelger-Huët anomaly of nuclear hyposegmentation exhibited significantly lower activity of caspase-6, a lamin A/C-cleaving enzyme. Differentiated HL-60 cells showed higher activity of caspase-6 than that of untreated cells. These observations allow us to speculate that remodeling of nuclear lamins might underlie the mechanism for nuclear segmentation of neutrophils.
authors.affiliation: Institute of Medical Science, Kurashiki Medical Center, Okayama, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yabuki
authors.forename: T
authors.initials: T
authors.lastname: Miyake
authors.forename: Y
authors.initials: Y
authors.lastname: Doi
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
authors.forename: K
authors.initials: K
authors.lastname: Hamazaki
authors.forename: T
authors.initials: T
authors.lastname: Yoshioka
authors.forename: A A
authors.initials: AA
authors.lastname: Horton
authors.forename: K
authors.initials: K
authors.lastname: Utsumi
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D053178:Caspase 6; D020169:Caspases / Q000378:metabolism; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000502:physiology* / Q000648:ultrastructure*; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D034904:Lamin Type A; D034921:Lamin Type B; D034882:Lamins; D009504:Neutrophils / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000378:metabolism*; D010381:Pelger-Huet Anomaly / Q000097:blood; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D034904:Lamin Type A; D034921:Lamin Type B; D034882:Lamins; D009687:Nuclear Proteins; D014212:Tretinoin; D006861:Hydrogen Peroxide; C505514:CASP6 protein, human; D053178:Caspase 6; D020169:Caspases