Alterations in membrane cholesterol cause mobilization of lipid rafts from specific granules and prime human neutrophils for enhanced adherence-dependent oxidant production
Alterations in membrane cholesterol cause mobilization of lipid rafts from specific granules and prime human neutrophils for enhanced adherence-dependent oxidant production
复制标题
DOI：
10.1097/shk.0b013e318047b893
复制
发表时间：
2007-09-01
期刊：
影响因子：
3.1
通讯作者：
Lentsch, Alex B.
中科院分区：
文献类型：
--
作者：
Solomkin, Joseph S.;Robinson, Chad T.;Lentsch, Alex B.
The present study sought to examine the function of membrane lipid rafts in adherence-dependent oxidant production in human neutrophils. Rafts are membrane domains that are rich in glycosphingolipids and cholesterol and are thought to be the foci for formation of signaling complexes in a variety of cells. Disruption of lipid rafts by depletion of membrane cholesterol with the chelating agent methyl-beta-cyclodextrin (M beta CD) has been widely used to examine the function of lipid rafts. Here, we report that treatment of human neutrophils with M beta CD unexpectedly caused priming of these cells, manifested as enhanced adherence-dependent oxidant production. Treatment of neutrophils with M beta CD dose-dependently increased oxidant production after adhesion to fibronectin-coated plates. This priming effect was associated with recruitment of CD11b- and CD66b-rich raft domains from the specific granules, as determined by immunoblot and flow cytometry. Confocal microscopy showed that M beta CD caused otherwise untreated neutrophils to rapidly adhere and spread on fibronectin-coated plates. Furthermore, three-dimensional reconstruction microscopy studies showed that M beta CD caused expansion and coalescence of raft domains that covered most of the cell surface. These large raft domains expressed CD11b primarily in the core of these regions. Our studies demonstrate that cholesterol depletion with M beta CD results in neutrophil priming manifested as enhanced adherence-dependent oxidant production. These studies caution against assumption that any observed M beta CD effects are a function of reduced raft formation.
