Reduction of lipoxidative load by secretory phospholipase A2 inhibition protects against neurovascular injury following experimental stroke in rat.
BACKGROUND
In animal models, ischemia reperfusion (IR) injury triggers membrane lipid degradation and accumulation of lipoxidative exacerbations in neurovascular unit, leading to blood brain barrier (BBB) damage and neurologic deficits. In this study, we investigated whether impeding membrane lipid breakdown by inhibiting secretory phospholipase A2 (sPLA2) activity reduces BBB leakage, leading to neuroprotection and functional recovery.


METHODS
Focal cerebral IR injury was induced by middle cerebral artery occlusion (MCAO) in adult male rats. A sPLA2 inhibitor, 7,7-dimethyleicosadienoic acid (DEDA), was administered following IR injury. DEDA-treated animals were compared with vehicle-treated in terms of BBB leakage, edema, infarct volume, and neurological deficit. Membrane lipid degradation and the expression/activity of sPLA2 were also assessed. The role of one of the sPLA2 products, arachidonic acid (AA), on the morphology of the differentiated neuronal cell PC12 was examined by light microscopy.


RESULTS
Treatment with DEDA after IR injury not only reduced BBB leakage but also decreased infarct volume and improved neurologic function. The treatment attenuated both the activity of sPLA2 and the levels of sPLA2-derived oxidized products. The metabolites of lipid oxidation/peroxidation, including the protein carbonyl, were reduced as well. The treatment also restored the levels of glutathione, indicating attenuation of oxidative stress. In vitro treatment of PC12 cells with DEDA did not restore the AA-mediated inhibition of neurite formation and the levels of glutathione, indicating that effect of DEDA is up stream to AA release.


CONCLUSIONS
sPLA2-derived oxidative products contribute to significant neurovascular damage, and treatment with sPLA2 inhibitor DEDA ameliorates secondary injury by reducing exacerbations from lipoxidative stress.
Hoda
Md Nasrul
MN
Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, USA. hoda@musc.edu
Singh
Inderjit
I
Singh
Avtar K
AK
Khan
Mushfiquddin
M
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D001929:Brain Edema / Q000188:drug therapy / Q000503:physiopathology / Q000517:prevention & control; D020520:Brain Infarction / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology / Q000627:therapeutic use; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy / Q000201:enzymology / Q000503:physiopathology; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D016716:PC12 Cells; D054497:Phospholipases A2, Secretory / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D020521:Stroke / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D016896:Treatment Outcome
D004791:Enzyme Inhibitors; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; C059778:7,7-dimethyl-5,8-eicosadienoic acid; D054497:Phospholipases A2, Secretory
Arterioscler Thromb Vasc Biol. 2006 Mar;26(3):514-9
16357311
Biochem Biophys Res Commun. 1999 Nov;265(1):116-22
10548500
Neurosci Lett. 1995 Jun 30;193(2):85-8
7478165
Front Biosci. 2008 Jan 01;13:1917-25
17981679
Crit Rev Neurobiol. 2003;15(1):61-90
14513863
Prostaglandins Other Lipid Mediat. 2002 Aug;68-69:3-58
12432908
J Neurooncol. 1988 Dec;6(4):339-42
2464672
Anal Biochem. 2002 Mar 15;302(2):191-8
11878797
J Cereb Blood Flow Metab. 2008 Oct;28(10):1686-96
18545259
J Biol Chem. 2006 Mar 10;281(10):6718-25
16380371
J Neurosci Res. 2003 Aug 1;73(3):308-15
12868064
Brain Res. 1996 Aug 19;730(1-2):150-64
8883899
J Neurochem. 1997 Sep;69(3):889-901
9282910
Ann N Y Acad Sci. 1993 May 28;679:110-20
8512179
J Lipid Res. 2006 Jul;47(7):1478-92
16645197
Neurochem Res. 1999 Oct;24(10):1225-32
10492517
Brain Res Rev. 2007 Apr;54(1):34-66
17222914
J Neurochem. 1999 Aug;73(2):684-92
10428065
Brain Res. 2007 Feb 23;1134(1):199-205
17204250
Pharmacol Rev. 2006 Sep;58(3):591-620
16968951
J Pharmacol Exp Ther. 1992 Sep;262(3):1161-7
1382129
Mol Pharmacol. 2002 Jan;61(1):114-26
11752212
Stroke. 1989 Jan;20(1):84-91
2643202
Methods Enzymol. 1990;186:464-78
1978225
Cancer Metastasis Rev. 1994 Dec;13(3-4):303-8
7712592
J Cereb Blood Flow Metab. 2005 Feb;25(2):177-92
15647746
Am J Physiol. 1988 Mar;254(3 Pt 2):H578-83
3348434
J Neurotrauma. 2000 Oct;17(10):871-90
11063054
Stroke. 2001 Oct;32(10):2376-81
11588329
Prostaglandins Leukot Essent Fatty Acids. 2004 Sep;71(3):161-9
15253885
J Endotoxin Res. 2000;6(1):41-50
11061031
Neurosurgery. 1989 Sep;25(3):369-72
2505159
Curr Med Chem. 2005;12(25):3011-26
16378502
J Biol Chem. 2001 Apr 13;276(15):12035-40
11134037
J Neurosci Res. 2004 Jul 1;77(1):63-81
15197739
Free Radic Biol Med. 2006 Feb 1;40(3):376-87
16443152
J Neuroinflammation. 2006 May 11;3:12
16689995
Biochem Biophys Res Commun. 1996 Dec 13;229(2):643-7
8954951
J Pharmacol Exp Ther. 1994 Dec;271(3):1624-9
7996477
Brain Res. 2002 Sep 27;951(1):96-106
12231462
J Biol Chem. 1996 Dec 27;271(52):33157-60
8969167
Science. 1994 Sep 23;265(5180):1883-5
7522345
J Lipid Res. 2004 Feb;45(2):205-13
14657205
Agents Actions. 1993;39 Spec No:C39-42
8273580
J Cereb Blood Flow Metab. 2001 Jan;21(1):2-14
11149664
J Pineal Res. 2008 Nov;45(4):459-67
18624955
J Neurochem. 2004 Aug;90(3):637-45
15255941
J Exp Biol. 2004 Aug;207(Pt 18):3221-31
15299043
Annu Rev Biochem. 2008;77:495-520
18405237
FEBS Lett. 2002 Oct 30;531(1):7-11
12401194
J Neurochem. 1990 Jul;55(1):1-15
2113081
Acta Neuropathol. 1987;73(3):209-19
2441558
Prostaglandins. 1984 Apr;27(4):553-62
6427852
Science. 1978 Jul 28;201(4353):358-60
663662
Neurotoxicology. 2007 Nov;28(6):1220-9
17854901
J Neurosci Res. 2004 May 15;76(4):519-27
15114624
J Neurochem. 2007 Jul;102(2):365-77
17437550
Exp Eye Res. 2000 Apr;70(4):503-17
10865999
Neurochem Res. 1997 Mar;22(3):273-80
9051661
J Neurochem. 2008 Aug;106(4):1766-79
18540993
Neuroscience. 2008 Apr 22;153(1):175-81
18367342
Free Radic Biol Med. 2003 Sep 15;35(6):636-47
12957656
Stroke. 1996 Sep;27(9):1616-22; discussion 1623
8784138