Abstract
Parstatin, the N-terminal 41-amino-acid peptide cleaved by thrombin from the protease-activated receptor 1, protects against rat myocardial ischemia and reperfusion injury. In this study, we determined that the parstatin fragment 1-26, the putative signal peptide of protease-activated receptor 1, contains the functional domain of parstatin. We assessed a synthesized parstatin(1-26) peptide in an in vivo rat model of myocardial regional ischemia-reperfusion injury (n = 6/group). Infarct size in control rat hearts was 58 ± 1% area at risk. Parstatin(1-26) was able to reduce infarct size to 13 ± 1% (P < 0.001) and 22 ± 1% area at risk (P < 0.01) when given before or after reperfusion. The infarct-sparing effects of parstatin(1-26) were abolished by inhibition of Gi proteins (pertussis toxin), phosphoinositide 3-kinase/Akt (wortmannin), nitric-oxide synthase (NOS; NG-monomethyl-l-arginine), soluble guanylyl cyclase [1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ)], and sarcolemmal and mitochondrial KATP channels [glibenclamide, 5-hydroxydecanoic acid, and sodium (5-(2-(5-chloro-2-methoxybenzamido)ethyl)-2-methoxyphenylsulfonyl) (methylcarbamothioyl)amide (HMR 1098)]. Parstatin(1-26) cardioprotection was also abolished by atractyloside, a mitochondrial permeability transition pore (mPTP) opener. The inhibitors and opener alone had no effect on infarct size. Furthermore, preischemic treatment with parstatin(1-26) increased Akt and endothelial NOS phosphorylation at the time of reperfusion. After a 120-min reperfusion, parstatin(1-26) increased nitric oxide levels (12 ± 0.4 to 17 ± 0.9 mmol/g tissue) and cyclic GMP levels (87 ± 21 to 395 ± 36 pmol/g tissue). Parstatin(1-26) treatment either before or after ischemia results in an extremely efficacious protection against ischemia-reperfusion injury that depends on a Gi protein-mediated pathway involving mPTP, the end effector of the preconditioning pathway. This suggests that parstatin(1-26) has a potential therapeutic role in the treatment of ischemia and reperfusion injury.
Footnotes
This work was supported by the Medical College of Wisconsin Department of Medicine [Grant 9910176] (to J.L.S.); and the Cardiovascular Research Center [Grant 3303496] (to J.L.S.).
N.E.T and J.L.S. declare competing financial interest because of submission of patent applications covering parstatin and parstatin(1-26): Tsopanoglou NE, Maragoudakis ME, Vinores S, Gartaganis S, and Strande JL (2009). Parstatin peptides and uses thereof. Patent application 12/572,018. 2009 Oct 1; and Tsopanoglou NE, Maragoudakis ME, Liatsikos E, and Strande JL (2009). Parstatin peptides and uses in renal ischemia reperfusion injury. Patent application 61/247,611. 2009 Oct. 1.
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
doi:10.1124/jpet.109.162602.
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ABBREVIATIONS:
- PAR1
- protease-activated receptor 1
- PTX
- pertussis toxin
- NOS
- nitric-oxide synthase
- NO
- nitric oxide
- NOx
- nitrite and nitrate
- sGC
- soluble guanylyl cyclase
- sarc
- sarcolemmal
- mito
- mitochondrial
- mPTP
- mitochondrial permeability transition pore
- eNOS
- endothelial NOS
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- Par
- parstatin
- l-NMA
- NG-monomethyl-l-arginine
- 5-HD
- 5-hydroxydecanoic acid
- PI3K
- phosphoinositide 3-kinase
- HMR 1098
- sodium (5-(2-(5-chloro-2-methoxybenzamido)ethyl)-2-methoxyphenylsulfonyl)(methylcarbamothioyl)amide
- ODQ
- 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one
- DMSO
- dimethyl sulfoxide
- AAR
- area at risk.
- Received October 9, 2009.
- Accepted December 14, 2009.
- Copyright © 2010 by The American Society for Pharmacology and Experimental Therapeutics
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