2005 Fiscal Year Final Research Report Summary
The study on the glutamate-induced glial cell death mechanism for modulation of apoptosis to necrosis by arachidonic acid-mediated lipid peroxidation
| Project/Area Number |
15590268
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pathological medical chemistry
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| Research Institution | Kanazawa University Graduate School of Medical Science |
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Principal Investigator |
HIGUCHI Yoshihiro Kanazawa Univ., Grad.Sch.Med.Sci., Res Assoc, 医学系研究科, 助手 (10019630)
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| Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Takashi Kanazawa Univ., Grad.Sch.Med.Sci., Assoc Prof., 医学系研究科, 助教授 (40210009)
TANII Hideji Kanazawa Univ., Grad.Sch.Med.Sci., Assoc Prof., 医学系研究科, 助教授 (90110618)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Glutamate / Glia / Apoptosis / Necrosis / Glutathione / Ultraviolet / Giant DNA fragmentation / Lipid peroxidation |
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| Research Abstract |
Glutamate induced glutathione (GSH) depletion leading to cell death in C6 rat glioma cells through accumulation of reactive oxygen species (ROS) or hydroperoxides. A significant increase of 12-lipoxygenase activities was observed in the presence of arachidonic acid (AA) under the GSH depletion. AA promoted the glutamate-induced cell death reducing caspase-3 activity and diminishing internucleosomal DNA fragmentation observed in apoptosis. Furthermore, AA diminished intracellular NAD, ATP and membrane potential revealing a dysfunction of mitochondrial membrane. Ac-DEVD, a caspase inhibitor, did not suppresse the glutamate-induced cytolysis. These results suggest that AA promotes cell death by inducing to necrosis from caspase-3 independent apoptosis through lipid peroxidation initiated by ROS or lipid hydroperoxides generated during the GSH depletion in C6 cells.
Next, we studied the effect of AA on UV-induced cell death. At lethal dose, UV-C (254 nm) radiation induces cell dysfunction leading to apoptosis or necrosis. During the cell death of T-24 human bladder carcinoma cells, 1-2 Mbp giant DNA fragmentation was observed and consequently the DNA fragmentation was proceeded into high molecular weight 100-800 kbp DNA fragmentation followed by ladder-like inter-nucleosomal DNA fragmentation. Reactive lipid peroxides or oxygen species were not produced. In contrast, increase of caspase-3 and reduction of intracellular NAD and poly (ADP-ribose) polymerase were observed. UV-C radiation induces giant DNA fragmentation leading to apoptosis associated without producing DCFH detectable reactive oxygen species and with activation of caspase-3 and internucleosomal DNA fragmentation in T-24 carcinoma cells.
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Research Products
(19 results)
