title: Fluorescence imaging of ATP in neutrophils from patients with sepsis using organelle-localizable fluorescent chemosensors.
abstract: BACKGROUND
  The activation of polymorphonuclear neutrophils (PMNs) plays an important role in sepsis. Previously, we showed that ATP release and feedback via ATP receptors are essential for PMN activation; however, the dynamics remain poorly understood. Two new fluorescent chemosensors, PMAP-1 and MitoAP-1, were developed to detect ATP in the plasma membrane and mitochondria of living cells, respectively. In this study, we aimed to evaluate ATP localization using these chemosensors in PMNs of sepsis patients.
  
  
  METHODS
  Live PMNs isolated from 16 sepsis patients and healthy controls (HCs) were stained with these chemosensors and observed by confocal microscopy, and their mean fluorescence intensities (MFIs) were evaluated using flow cytometry. CD11b expression in PMNs was also evaluated.
  
  
  RESULTS
  The MFIs of PMAP-1 and MitoAP-1 and CD11b expression in PMNs from sepsis patients on days 0-1 were significantly higher than those of HCs. The MFI of PMAP-1 and CD11b expression on days 3-4 decreased significantly compared to those observed at days 0-1, whereas MitoAP-1 MFI was maintained at a high level. The PMAP-1 MFI was significantly positively correlated with CD11b expression, white blood cell counts, neutrophil counts, and C-reactive protein levels in patients.
  
  
  CONCLUSIONS
  The higher MFIs of PMAP-1 and MitoAP-1 in sepsis patients suggest a pivotal role of ATP for PMN activation. The temporal difference in ATP levels suggests that ATP plays different roles in the mitochondria and on the cell surface. These data should contribute to the understanding of the dynamics of ATP in PMNs and help to develop a novel therapy for sepsis.
authors.affiliation: Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan. ksueyoshi@juntendo-urayasu.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Sueyoshi
authors.affiliation: Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sumi
authors.affiliation: Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kuroda
authors.affiliation: Lipid Biology Laboratory, Riken Advanced Science Institute, Wako, Saitama, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Institute for Environmental and Gender Specific Medicine, Juntendo University, Urayasu, Chiba, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Institute for Environmental and Gender Specific Medicine, Juntendo University, Urayasu, Chiba, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Iwabuchi
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kurishita
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Shigemitsu
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Hamachi
authors.affiliation: Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
keywords: Flow cytometry; MitoAP-1; Mitochondria; PMAP-1; Plasma membrane; Polymorphonuclear neutrophils (PMNs)