TY - JOUR
T1 - Creating conditions similar to those that occur during exposure of cells to microgravity induces apoptosis in human lymphocytes by 5-lipoxygenase-mediated mitochondrial uncoupling and cytochrome c release
AU - Maccarrone, Mauro
AU - Battista, Natalia
AU - Meloni, Mariantonia
AU - Bari, Monica
AU - Galleri, Grazia
AU - Pippia, Proto
AU - Cogoli, Augusto
AU - Finazzi-Agrò, Alessandro
PY - 2003/4
Y1 - 2003/4
N2 - Creating conditions similar to those that occur during exposure of cells to microgravity induced a sixfold increase of apoptotic bodies and DNA fragments in human lymphocytes, paralleled by an early (within 2 h) fourfold increase in 5-lipoxygenase (5-LOX) activity and a fivefold decrease in mitochondrial membrane potential and increase in cytochrome c release (within 4 and 8 h, respectively). Similar membrane potential and cytochrome c release were observed in isolated mitochondria treated with physiological amounts of 5-LOX and were enhanced by creating conditions similar to those that occur during exposure of cells to microgravity. 5-LOX inhibitors, 5,8,11,14-eicosatetraynoic acid and caffeic acid, completely prevented apoptosis, whereas the phospholipase A2 inhibitor methyl-arachidonoyl fluorophosphonate and the 5-LOX activating protein inhibitor MK886 reduced it to 65-70%. The intracellular calcium chelator EGTA-acetoxymethylester reduced 5-LOX activity and apoptosis to 30-40% of controls, whereas the p38 mitogen-activated protein kinase inhibitor SB203580 was ineffective. The caspase-3 and caspase-9 inhibitors Z-Asp(OCH 3)-Glu(OCH3)-Val-Asp(OCH3)-fluoromethylketone (FMK) and Z-Leu-Glu(OCH3)-His-Asp(OCH3)-FMK reduced apoptotic bodies to 25-30% of the control cells. Finally, creating conditions similar to those that occur during exposure of cells to microgravity did not induce apoptosis in human lymphoma U937 cells, which did not express an active 5-LOX.
AB - Creating conditions similar to those that occur during exposure of cells to microgravity induced a sixfold increase of apoptotic bodies and DNA fragments in human lymphocytes, paralleled by an early (within 2 h) fourfold increase in 5-lipoxygenase (5-LOX) activity and a fivefold decrease in mitochondrial membrane potential and increase in cytochrome c release (within 4 and 8 h, respectively). Similar membrane potential and cytochrome c release were observed in isolated mitochondria treated with physiological amounts of 5-LOX and were enhanced by creating conditions similar to those that occur during exposure of cells to microgravity. 5-LOX inhibitors, 5,8,11,14-eicosatetraynoic acid and caffeic acid, completely prevented apoptosis, whereas the phospholipase A2 inhibitor methyl-arachidonoyl fluorophosphonate and the 5-LOX activating protein inhibitor MK886 reduced it to 65-70%. The intracellular calcium chelator EGTA-acetoxymethylester reduced 5-LOX activity and apoptosis to 30-40% of controls, whereas the p38 mitogen-activated protein kinase inhibitor SB203580 was ineffective. The caspase-3 and caspase-9 inhibitors Z-Asp(OCH 3)-Glu(OCH3)-Val-Asp(OCH3)-fluoromethylketone (FMK) and Z-Leu-Glu(OCH3)-His-Asp(OCH3)-FMK reduced apoptotic bodies to 25-30% of the control cells. Finally, creating conditions similar to those that occur during exposure of cells to microgravity did not induce apoptosis in human lymphoma U937 cells, which did not express an active 5-LOX.
KW - Arachidonate cascade
KW - Calcium
KW - Caspase
KW - Cyclooxygenase
KW - Mitochondrial membrane potential
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U2 - 10.1189/jlb.0602295
DO - 10.1189/jlb.0602295
M3 - Article
C2 - 12660222
AN - SCOPUS:0037645143
VL - 73
SP - 472
EP - 481
JO - Journal of Leukocyte Biology
JF - Journal of Leukocyte Biology
SN - 0741-5400
IS - 4
ER -