Inhibition of TRPC6 degradation suppresses ischemic brain damage in rats.
Brain injury after focal cerebral ischemia, the most common cause of stroke, develops from a series of pathological processes, including excitotoxicity, inflammation, and apoptosis. While NMDA receptors have been implicated in excitotoxicity, attempts to prevent ischemic brain damage by blocking NMDA receptors have been disappointing. Disruption of neuroprotective pathways may be another avenue responsible for ischemic damage, and thus preservation of neuronal survival may be important for prevention of ischemic brain injury. Here, we report that suppression of proteolytic degradation of transient receptor potential canonical 6 (TRPC6) prevented ischemic neuronal cell death in a rat model of stroke. The TRPC6 protein level in neurons was greatly reduced in ischemia via NMDA receptor-dependent calpain proteolysis of the N-terminal domain of TRPC6 at Lys¹⁶. This downregulation was specific for TRPC6 and preceded neuronal death. In a rat model of ischemia, activating TRPC6 prevented neuronal death, while blocking TRPC6 increased sensitivity to ischemia. A fusion peptide derived from the calpain cleavage site in TRPC6 inhibited degradation of TRPC6, reduced infarct size, and improved behavioral performance measures via the cAMP response element-binding protein (CREB) signaling pathway. Thus, TRPC6 proteolysis contributed to ischemic neuronal cell death, and suppression of its degradation preserved neuronal survival and prevented ischemic brain damage.
Du
Wanlu
W
Laboratory of Neural Signal Transduction, Institute of Neuroscience, Shanghai Institutes for Biological Sciences, State Key Laboratory of Neuroscience, The Graduate School, Chinese Academy of Sciences, Shanghai, China.
Huang
Junbo
J
Yao
Hailan
H
Zhou
Kechun
K
Duan
Bo
B
Wang
Yizheng
Y
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002154:Calpain / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology; D008297:Male; D009474:Neurons / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D050052:TRPC Cation Channels / Q000037:antagonists & inhibitors* / Q000378:metabolism
D017362:Cyclic AMP Response Element-Binding Protein; D018696:Neuroprotective Agents; D016194:Receptors, N-Methyl-D-Aspartate; D050052:TRPC Cation Channels; C492145:Trpc6 protein, rat; D002154:Calpain
Nat Med. 2005 Dec;11(12):1322-9
16286924
Proc Natl Acad Sci U S A. 2002 May 28;99(11):7461-6
12032305
Trends Pharmacol Sci. 1998 Feb;19(2):59-66
9550943
Proc Natl Acad Sci U S A. 1984 Jun;81(11):3572-6
6328521
Biochem J. 1990 Oct 15;271(2):515-22
2173565
Nat Neurosci. 2007 May;10(5):559-67
17396124
Cell Calcium. 2003 May-Jun;33(5-6):451-61
12765690
Curr Neurovasc Res. 2007 May;4(2):143-51
17504212
Trends Neurosci. 1999 Sep;22(9):391-7
10441299
Curr Opin Neurobiol. 1996 Oct;6(5):667-72
8937832
Nature. 1999 Jan 21;397(6716):259-63
9930701
Cell Calcium. 2002 Jun;31(6):253-64
12098215
Stroke. 1998 May;29(5):1037-46; discussion 1047
9596255
Nat Neurosci. 2003 Aug;6(8):837-45
12858178
Trends Neurosci. 2000 Feb;23(2):48-53
10652539
Nat Cell Biol. 2009 May;11(5):624-30
19363486
Mol Cell Neurosci. 2000 Aug;16(2):87-96
10924253
Lancet. 1994 Sep 10;344(8924):721-4
7915779
Neuron. 2000 Jan;25(1):11-4
10707967
Adv Neurol. 1996;71:167-74; discussion 174-5
8790798
Neuron. 1988 Jun;1(4):279-87
2856162
Neurosci Biobehav Rev. 1997 Mar;21(2):193-206
9062943
Novartis Found Symp. 2004;258:140-9; discussion 149-59, 263-6
15104180
Stroke. 1989 Jan;20(1):84-91
2643202
J Neurotrauma. 1994 Apr;11(2):187-96
7932797
J Neurosci. 1986 Nov;6(11):3103-11
3021924
Eur J Pharmacol. 2008 Mar 31;583(1):135-47
18289524
Mol Cell Biol. 2006 Feb;26(3):1038-50
16428456
Cell. 2009 May 15;137(4):761-72
19450521
Nature. 2000 May 18;405(6784):360-4
10830966
J Biol Chem. 1997 Jun 20;272(25):16010-7
9188504
Cell. 2004 Sep 17;118(6):687-98
15369669
Circ Res. 2001 Feb 16;88(3):325-32
11179201
Antioxid Redox Signal. 2003 Oct;5(5):597-607
14580316
Nat Neurosci. 2009 Oct;12(10):1300-7
19734892
Proc Natl Acad Sci U S A. 2004 Sep 21;101(38):13861-6
15358862
FEBS J. 2007 Jul;274(13):3210-7
17565598
Brain Res Mol Brain Res. 1996 Dec 31;43(1-2):21-9
9037515
Mol Cell Biol. 1997 Jan;17(1):460-8
8972227
Nature. 2003 Dec 4;426(6966):517-24
14654832
Nat Rev Neurosci. 2003 May;4(5):399-415
12728267
Cell. 1996 May 31;85(5):661-71
8646775
Mol Cell Biol. 2005 Aug;25(16):6980-9
16055711
J Neurosci. 1993 Aug;13(8):3510-24
8101871
Neuropharmacology. 2008 Sep;55(3):363-89
18308347
J Cereb Blood Flow Metab. 1999 Feb;19(2):128-32
10027766
J Biol Chem. 2003 Nov 28;278(48):47842-52
12970363
Philos Trans R Soc Lond B Biol Sci. 1996 Mar 29;351(1338):365-73
8730773
Cell. 2003 Dec 26;115(7):863-77
14697204
Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9652-6
7568191
Annu Rev Biochem. 2007;76:387-417
17579562
Curr Mol Med. 2004 Mar;4(2):131-6
15032709
Trends Neurosci. 2000 Apr;23(4):159-66
10717675
Neurosci Lett. 1994 Feb 14;167(1-2):149-52
8177514
FEBS Lett. 1995 Oct 16;373(3):193-8
7589464
Restor Neurol Neurosci. 1998;13(1-2):3-10
12671283
Biochim Biophys Acta. 2004 Dec 6;1742(1-3):21-36
15590053
J Neurosci. 2001 Dec 1;21(23):9204-13
11717354
Nature. 2005 Apr 14;434(7035):894-8
15758952
Oncogene. 2007 Aug 2;26(35):5107-14
17310992
Cell. 2002 Mar 8;108(5):595-8
11893331
Physiol Rev. 1999 Oct;79(4):1431-568
10508238