Changes in elemental concentrations are associated with early stages of apoptosis in human monocyte-macrophages exposed to oxidized low-density lipoprotein: an X-ray microanalytical study.
This study examines ion homeostasis in monocyte-macrophages committed to death by apoptosis. X-ray microanalysis has been used to demonstrate that intracellular concentrations of potassium decreased whilst those of sodium increased following 3 h of exposure to 100 microg/ml of oxidized low-density lipoprotein (LDL) in vitro. In contrast, the maximal incidence of cell death, as determined by the inability to exclude trypan blue, was not seen until 24 h of exposure. At 12 h, less than 1 per cent of cells were stained using terminal transferase-mediated DNA nick-end labelling, which is generally accepted as a marker of late stages in the apoptotic pathway. This is the first demonstration of early perturbations of ion homeostasis in monocyte-macrophages exposed to concentrations of oxidized LDL known to cause apoptosis.
Multi-Imaging Centre, University of Cambridge, Department of Anatomy, Tennis Court Road, Cambridge CB2 3DY, U.K.
J N
JN
Skepper
I
I
Karydis
M R
MR
Garnett
L
L
Hegyi
S J
SJ
Hardwick
A
A
Warley
M J
MJ
Mitchinson
N R
NR
Cary
D017209:Apoptosis; D002712:Chlorides / Q000378:metabolism; D004577:Electron Probe Microanalysis; D006706:Homeostasis; D006801:Humans; D020287:In Situ Nick-End Labeling; D007501:Iron / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D008274:Magnesium / Q000378:metabolism; D017348:Microscopy, Electron, Scanning Transmission; D010758:Phosphorus / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013997:Time Factors
D002712:Chlorides; D008077:Lipoproteins, LDL; D010758:Phosphorus; D012964:Sodium; D007501:Iron; D008274:Magnesium; D011188:Potassium