Induction of cardioprotection by small netrin-1-derived peptides

Abstract

Li Q, Cai H. Induction of cardioprotection by small netrin-1-derived peptides. Am J Physiol Cell Physiol 309: C100 -C106, 2015. First published April 29, 2015; doi:10.1152/ajpcell.00332.2014.-We have shown that netrin-1 induces potent cardioprotection via extracellular signal-regulated kinases 1 and 2 (ERK1/2)-dependent endothelial nitric oxide synthase (eNOS)/NO activation. The present study investigated cardioprotective effects of small netrin-1-derived peptides. We synthesized three laminin (Lam) V peptides and found those time dependently increased phosphorylation of ERK1/2 and eNOSs1179 in endothelial cells at the same molar concentration used for netrin-1. Preperfusion with Lam V peptides induced a substantial reduction in infarct size (control 39.3 Ϯ 0.2% vs. 14.6 Ϯ 2.3%, 23.0 Ϯ 2.8%, and 18.8 Ϯ 0.8% for V1, V2, and V3, respectively). Furthermore, reperfusion with all three also induced potent cardioprotection (control 37.6 Ϯ 1.3% vs. 17.6 Ϯ 3.2%, 20.6 Ϯ 1.7%, and 15.8 Ϯ 2.0% for V1, V2, and V3, respectively), implicating that these peptides are consistently beneficial whenever they are delivered to the heart. Based on the sequence alignment, we found a region of high sequence homology and synthesized smaller peptides [V1-9 amino acid (aa), V2-10aa, and V3-11aa]. These smaller peptides markedly reduced infarct size during reperfusion (V1-9aa 16.8 Ϯ 2.2%, V2-10aa 18.6 Ϯ 1.7%, and V3-11aa 16.7 Ϯ 3.0% vs. control 37.6 Ϯ 1.3%). A negative control V3-16aa with no sequence homology failed to protect the heart. Of note, the core area has the characteristic sequence of: Cx(1-2)Cx(3-4)Tx(0 -1)G. Furthermore, all three smaller peptides induced NO production in endothelial cells that could in turn diffuse to cardiomyocytes to promote survival. Combined applications of V1-9aa and V2-10aa synergistically induced more NO production. Taken together, these data strongly suggest that small netrin-1-derived peptides are highly effective in protecting the heart against myocardial ischemia-reperfusion injury and has the potential to be developed into peptide drugs directly applicable to the treatment of myocardial infarction.netrin-1-derived small peptides; cardioprotection; ischemia-reperfusion injury; I/R; ERK1/2; endothelial nitric oxide synthase; eNOS MYOCARDIAL INFARCTION (MI) occurs when blood cannot flow to part of the heart because of occlusion of coronary arteries, and the heart muscle is injured as a result, which leads to impaired cardiac function (13). The conventional therapy for MI is to restore blood perfusion as soon as possible to salvage some of the myocardium (8). However, reperfusion itself can paradoxically cause myocardial injury, at least in part mediated by increased oxidative stress (3, 9). Until now, no pharmacological agents have been proven clinically effective in reducing reperfusion injury. We have previously shown that a novel protein, netrin-1, can function as a potent cardioprotective agent (5,20,21,26). It induces cardioprotection against ischemia-reperfusion (I/R) injury both ex vivo and in...

Netrin-1 promotes diabetic corneal wound healing through molecular mechanisms mediated via the adenosine 2B receptor

“…According to previous descriptions, netrin-1, mediated through different receptors, may regulate different signaling pathways and play distinct roles in physiological and pathophysiological conditions 13 . Other than the function of axon guidance, netrin-1 can also protect the kidney against ischemia-reperfusion injury, regulate angiogenesis, and even promote tumor growth 14 – 17 . In addition, netrin-1 was found recently to possess an anti-inflammatory capacity in lung injury and inflammatory peritonitis 18 , 19 .…”

Potential therapeutics for myocardial ischemia-reperfusion injury. Focus on “Induction of cardioprotection by small netrin-1-derived peptides”

“…Therefore, it is important to identify the minimal functional peptide that could preserve netrin-1 function in activating the receptor DCC and stimulating downstream signaling events. In this issue of the American Journal of Physiology-Cell Physiology, Cai's group extend their previous finding and identify a 9-amino acid (aa) core sequence in the laminin V region of netrin-1 to be highly effective in cardioprotection (5).…”

“…Significantly, in preclinical studies, these synthetic peptides V1, V2, and V3 were observed to induce similar cardioprotection against I/R injury when compared with netrin-1 when either preperfused or simultaneously perfused to the heart. The data demonstrate that these peptides are consistently beneficial whenever they are delivered to the heart and have the potential to be developed as therapies for myocardial infarction (5).…”

Neuronal guidance proteins in cardiovascular inflammation

“…Nitric oxide (NO)—a key molecule preserving endothelial function—was identified as a major mediator of the cardioprotective effects of Ntn1. Ntn1 induces NO production through the DCC receptor followed by Erk and eNOS activation, and Ntn1 administration leads to a substantial NO-dependent reduction in myocardial infarct sizes ex vivo [ 42 , 98 ]. The concept of post-infarct tissue conservation by Ntn1 was further shown in diabetic mice [ 33 ].…”

“…The concept of post-infarct tissue conservation by Ntn1 was further shown in diabetic mice [ 33 ]. As the administration of small synthesized peptides containing Ntn1 domains successfully induced NO production in an animal model, pharmacological approaches have been developed to mimic the cardioprotective effects of Ntn1 [ 42 ]. The Ntn1–DCC–NO axis further attenuates mitochondrial superoxide production and preserves mitochondrial integrity in cardiomyocytes post-conditioned with Ntn1 after IR injury [ 8 , 9 , 76 ].…”