TY - JOUR
T1 - Differential behavior of sPLA2-V and sPLA2-X in human neutrophils
AU - Solodkin-Szaingurten, I.
AU - Levy, R.
AU - Hadad, N.
N1 - Funding Information:
This work was supported by a grant from the Ministry of Health, Israel No. 5772. We thank Dr. M Gelb of the University of Washington (Seattle) for supplying recombinant sPLA 2 proteins and anti sPLA 2 antibodies and Dr. M. Nakamura for providing anti gp91 phox antibodies.
PY - 2007/2/1
Y1 - 2007/2/1
N2 - Neutrophils and differentiated PLB-985 cells contain various types of PLA2s including the 85 kDa cytosolic PLA2 (cPLA2), Ca2+-independent PLA2 (iPLA2) and secreted PLA2s (sPLA2s). The present study focuses on the behavior of sPLA2s in neutrophils and PLB cells and their relationship to cPLA2α. The results of the present research show that the two types of sPLA2 present in neutrophils, sPLA2-V and sPLA2-X, which are located in the azurophil granules, are differentially affected by physiological stimuli. While sPLA2-V is secreted to the extacellular milieu, sPLA2-X is detected on the plasma membranes after stimulation. Stimulation of neutrophils with formyl-Met-Leu-Phe (fMLP), opsonized zymosan (OZ) or A23187 resulted in a different kinetics of sPLA2 secretion as detected by its activity in the neutrophil supernatants. Neutrophil priming by inflammatory cytokines or LPS enhanced sPLA2 activity detected in the supernatant after stimulation by fMLP. This increased activity was due to increased secretion of sPLA2-V to the supernatant and not to release of sPLA2-X. sPLA2 in granulocyte-like PLB cells exhibit identical characteristics to neutrophil sPLA2, with similar activity and optimal pH of 7.5. Granulocyte-like cPLA2α-deficient PLB cells serve as a good model to study whether sPLA2 activity is regulated by cPLA2α. Secretion and activity of sPLA2 were found to be similar in granulocyte-like PLB cells expressing or lacking cPLA2α, indicating that they are not under cPLA2α regulation.
AB - Neutrophils and differentiated PLB-985 cells contain various types of PLA2s including the 85 kDa cytosolic PLA2 (cPLA2), Ca2+-independent PLA2 (iPLA2) and secreted PLA2s (sPLA2s). The present study focuses on the behavior of sPLA2s in neutrophils and PLB cells and their relationship to cPLA2α. The results of the present research show that the two types of sPLA2 present in neutrophils, sPLA2-V and sPLA2-X, which are located in the azurophil granules, are differentially affected by physiological stimuli. While sPLA2-V is secreted to the extacellular milieu, sPLA2-X is detected on the plasma membranes after stimulation. Stimulation of neutrophils with formyl-Met-Leu-Phe (fMLP), opsonized zymosan (OZ) or A23187 resulted in a different kinetics of sPLA2 secretion as detected by its activity in the neutrophil supernatants. Neutrophil priming by inflammatory cytokines or LPS enhanced sPLA2 activity detected in the supernatant after stimulation by fMLP. This increased activity was due to increased secretion of sPLA2-V to the supernatant and not to release of sPLA2-X. sPLA2 in granulocyte-like PLB cells exhibit identical characteristics to neutrophil sPLA2, with similar activity and optimal pH of 7.5. Granulocyte-like cPLA2α-deficient PLB cells serve as a good model to study whether sPLA2 activity is regulated by cPLA2α. Secretion and activity of sPLA2 were found to be similar in granulocyte-like PLB cells expressing or lacking cPLA2α, indicating that they are not under cPLA2α regulation.
KW - Granulocyte-like PLB cell
KW - Neutrophils
KW - PLB-985 cells
KW - Secreted PLA
UR - http://www.scopus.com/inward/record.url?scp=33846833931&partnerID=8YFLogxK
U2 - 10.1016/j.bbalip.2006.11.013
DO - 10.1016/j.bbalip.2006.11.013
M3 - Article
C2 - 17275398
AN - SCOPUS:33846833931
SN - 1388-1981
VL - 1771
SP - 155
EP - 163
JO - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
JF - Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
IS - 2
ER -