LOX-1 inhibition in myocardial ischemia-reperfusion injury: modulation of MMP-1 and inflammation

2002 ◽  
Vol 283 (5) ◽  
pp. H1795-H1801 ◽  
Author(s):  
Dayuan Li ◽  
Victor Williams ◽  
Ling Liu ◽  
Hongjiang Chen ◽  
Tatsuya Sawamura ◽  
...  

A recently identified lectin-like oxidized low-density lipoprotein receptor (LOX-1) mediates endothelial cell injury and facilitates inflammatory cell adhesion. We studied the role of LOX-1 in myocardial ischemia-reperfusion (I/R) injury. Anesthetized Sprague-Dawley rats were subjected to 60 min of left coronary artery (LCA) ligation, followed by 60 min of reperfusion. Rats were treated with saline, LOX-1 blocking antibody JXT21 (10 mg/kg), or nonspecific anti-goat IgG (10 mg/kg) before I/R. Ten other rats underwent surgery without LCA ligation and served as a sham control group. LOX-1 expression was markedly increased during I/R ( P < 0.01 vs. sham control group). Simultaneously, the expression of matrix metalloproteinase-1 (MMP-1) and adhesion molecules (P-selectin, VCAM-1, and ICAM-1) was also increased in the I/R area ( P < 0.01 vs. sham control group). There was intense leukocyte accumulation in the I/R area in the saline-treated group. Treatment of rats with the LOX-1 antibody prevented I/R-induced upregulation of LOX-1 and reduced MMP-1 and adhesion molecule expression as well as leukocyte recruitment. LOX-1 antibody, but not nonspecific IgG, also reduced myocardial infarct size ( P < 0.01 vs. saline-treated I/R group). To explore the link between LOX-1 and adhesion molecule expression, we measured expression of oxidative stress-sensitive p38 mitogen-activated protein kinase (p38 MAPK). The activity of p38 MAPK was increased during I/R ( P < 0.01 vs. sham control), and use of LOX-1 antibody inhibited p38 MAPK activation ( P < 0.01). These findings indicate that myocardial I/R upregulates LOX-1 expression, which through p38 MAPK activation increases the expression of MMP-1 and adhesion molecules. Inhibition of LOX-1 exerts an important protective effect against myocardial I/R injury.

1997 ◽  
Vol 272 (5) ◽  
pp. H2327-H2336 ◽  
Author(s):  
P. Liu ◽  
C. E. Hock ◽  
R. Nagele ◽  
P. Y. Wong

In the present study, the contribution of nitric oxide (NO), superoxide, and peroxynitrite to the inflammatory response induced by myocardial ischemia-reperfusion (MI/R) was investigated. Male Sprague-Dawley rats were anesthetized, and the left main coronary artery was ligated for 20 min and reperfused for 5 h. MI/R induced severe arrhythmias, indicated by a significantly elevated arrhythmia score in the MI/R group compared with that in the sham control group. Creatine kinase activity in the left ventricular free wall of the MI/R group was significantly reduced by 38%. In contrast, myeloperoxidase activity in the left ventricular free wall of the MI/R group was increased by 140%. Similarly, superoxide and tissue NO levels in the ischemic region of the heurt were increased by 140 and 90%, respectively. Superoxide and NO values in the nonischemic regions were similar to the sham control group. Total NO synthase (NOS) activity was elevated by 212%; moreover, inducible NOS (iNOS) activity increased 6.7-fold in the ischemic vs. nonischemic regions. MI/R also induced both systemic and remote organ (lung) inflammatory responses. Circulating neutrophils and plasma NO levels were increased by 163 and 138%, respectively, in MI/R rats compared with sham control animals. NO levels and superoxide generation were increased by 90 and 176%, respectively, in the lung tissues. The expression of iNOS and peroxynitrite generation were demonstrated by immunohistochemical staining with polyclonal anti-iNOS and monoclonal anti-nitrotyrosine antibodies, respectively. Sections of both the ischemic area of the ventricular wall and the lung tissue of MI/R animals exhibited a marked immunoreactivity with anti-iNOS and anti-nitrotyrosine antibodies, indicating the presence of iNOS and nitrotyrosine. Our data indicate that NO, superoxide, and peroxynitrite formation are elevated after reperfusion of the ischemic heart, suggesting that these inflammatory mediators may be involved in MI/R injury.


2006 ◽  
Vol 291 (2) ◽  
pp. H658-H667 ◽  
Author(s):  
Cherry Ballard-Croft ◽  
Adam C. Locklar ◽  
Gentian Kristo ◽  
Robert D. Lasley

Ischemia-reperfusion activates ERK and p38 MAPK in cardiac membranes, but the role of caveolae in MAPK signaling during this stress has not been studied. The purpose of this study was to determine the effect of in vivo myocardial ischemia-reperfusion on the level and distribution of caveolin-1 and -3 and cholesterol as well as MAPK activation in caveolin-enriched fractions. Adult male rats were subjected to in vivo regional myocardial ischemia induced by 25 min of coronary artery occlusion and 10 min ( n = 5) or 2 h ( n = 4) of reperfusion. Another group of rats served as appropriate nonischemic time controls ( n = 4). A discontinuous sucrose density gradient was used to isolate caveolae/lipid rafts from ischemic and nonischemic heart tissue. Caveolin-1 and -3, as well as cholesterol, were enriched in the light fractions. A redistribution of caveolin-3 and a reduction in caveolin-1 and cholesterol levels in the light fractions occurred after 10 min of reperfusion. The ERKs were activated in ischemic zone light and heavy fractions by 10 min of reperfusion. p44 ERK was activated after 2 h of reperfusion only in the light fractions, whereas p42 ERK phosphorylation was increased in the light and heavy fractions. Although no p38 MAPK activation occurred after 10 min of reperfusion, 2 h of reperfusion caused significant activation of p38 MAPK in nonischemic zone light and heavy fractions. These results show the importance of caveolar membrane/lipid rafts in MAPK signaling and suggest that subcellular compartmentation of p44/p42 ERKs and p38 MAPK may play distinct roles in the response to myocardial ischemia-reperfusion.


2005 ◽  
Vol 288 (3) ◽  
pp. H1359-H1366 ◽  
Author(s):  
Cherry Ballard-Croft ◽  
Gentian Kristo ◽  
Yukihiro Yoshimura ◽  
Easton Reid ◽  
Byron J. Keith ◽  
...  

Although acute adenosine preconditioning (PC) is well established, the signaling pathways mediating this cardioprotection remain unclear. Because adenosine receptor agonists activate p38 MAPK and this kinase has been implicated in ischemic and pharmacological PC, the purpose of this study was to determine the role of p38 MAPK in acute adenosine receptor PC. The role of p38 MAPK activation in discrete subcellular compartments during ischemia-reperfusion was also determined. The following groups were used in an in vivo rat ischemia-reperfusion model: 1) control (10% DMSO iv), 2) the A1/A2a adenosine receptor AMP-579 (50 μg/kg iv), 3) AMP-579 + the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 100 μg/kg iv), 4) AMP-579 + the p38 MAPK inhibitor SB-203580 (1 mg/kg iv), and 5) SB-203580 alone. p38 MAPK activation was measured by Western blot analysis in cytosolic, mitochondrial, membrane, and nuclear/myofilament fractions obtained from hearts at preischemic, ischemic, and reperfusion time points. A significant reduction in infarct size was observed with AMP-579 PC, an effect blocked by DPCPX or SB-203580 pretreatment. AMP-579 treatment was associated with a significant increase in p38 MAPK activation in the nuclear/myofilament fraction before ischemia, whereas no activation of this kinase occurred during ischemia or reperfusion. In contrast, p38 MAPK was activated in the mitochondrial fraction by ischemia and in the cytosolic, mitochondrial, and membrane fractions by reperfusion in the control group. SB-203580 blocked the AMP-579-induced increase in phosphorylation of the downstream p38 substrate activating transcription factor-2. These results suggest a role for p38 MAPK activation in discrete subcellular compartments in acute adenosine A1 receptor PC.


2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Fadhil G. Al-Amran ◽  
Najah R. Hadi ◽  
Haider S. H. Al-Qassam

Background. Global myocardial ischemia reperfusion injury after heart transplantation is believed to impair graft function and aggravate both acute and chronic rejection episodes. Objectives. To assess the possible protective potential of MK-886 and 3,5-diiodothyropropionic acid DITPA against global myocardial ischemia reperfusion injury after heart transplantation. Materials and Methods. Adult albino rats were randomized into 6 groups as follows: group I sham group; group II, control group; groups III and IV, control vehicles (1,2); group V, MK-886 treated group. Donor rats received MK-886 30 min before transplantation, and the same dose was repeated for recipients upon reperfusion; in group VI, DITPA treated group, donors and recipients rats were pretreated with DITPA for 7 days before transplantation. Results. Both MK-886 and DITPA significantly counteract the increase in the levels of cardiac TNF-α, IL-1β, and ICAM-1 and plasma level of cTnI (). Morphologic analysis showed that both MK-886 and DITPA markedly improved () the severity of cardiac injury in the heterotopically transplanted rats. Conclusions. The results of our study reveal that both MK-886 and DITPA may ameliorate global myocardial ischemia reperfusion injury after heart transplantation via interfering with inflammatory pathway.


2011 ◽  
pp. 271-279 ◽  
Author(s):  
Y.-N. WU ◽  
H. YU ◽  
X.-H. ZHU ◽  
H.-J. YUAN ◽  
Y. KANG ◽  
...  

We previously demonstrated in rats that noninvasive delayed limb ischemic preconditioning (LIPC) induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb per day for three days confers the same cardioprotective effect as local ischemic preconditioning of the heart, but the mechanism has not been studied in depth. The aim of this project was to test the hypothesis that delayed LIPC enhances myocardial antioxidative ability during ischemia-reperfusion by a mitochondrial KATP channel (mito KATP)-dependent mechanism. Rats were randomized to five groups: ischemia-reperfusion (IR)-control group, myocardial ischemic preconditioning (MIPC) group, LIPC group, IR-5HD group and LIPC-5HD group. The MIPC group underwent local ischemic preconditioning induced by three cycles of 5-min occlusion and 5-min reperfusion of the left anterior descending coronary arteries. The LIPC and LIPC-5HD groups underwent LIPC induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb using a modified blood pressure aerocyst per day for three days. All rats were subjected to myocardial ischemia-reperfusion injury. The IR-5HD and LIPC-5HD groups received the mito KATP channel blocker 5-hydroxydecanoate Na (5-HD) before and during the myocardial ischemia-reperfusion injury. Compared with the IR-control group, both the LIPC and MIPC groups showed an amelioration of ventricular arrhythmia, reduced myocardial infarct size, increased activities of total superoxide dismutase, manganese-superoxide dismutase (Mn-SOD) and glutathione peroxidase, increased expression of Mn-SOD mRNA and decreased xanthine oxidase activity and malondialdehyde concentration. These beneficial effects of LIPC were prevented by 5-HD. In conclusion, delayed LIPC offers similar cardioprotection as local IPC. These results support the hypothesis that the activation of mito KATP channels enhances myocardial antioxidative ability during ischemia-reperfusion, thereby contributing, at least in part, to the anti-arrhythmic and anti-infarct effects of delayed LIPC.


2007 ◽  
Vol 292 (4) ◽  
pp. H1828-H1835 ◽  
Author(s):  
Giuseppina Milano ◽  
Sandrine Morel ◽  
Christophe Bonny ◽  
Michele Samaja ◽  
Ludwig K. von Segesser ◽  
...  

The c-Jun NH2-terminal kinase (JNK) pathway of the mitogen-activated protein kinase (MAPK) signaling cascade regulates cell function and survival after stress stimulation. Equally robust studies reported dichotomous results suggesting both protective and detrimental effects of JNK during myocardial ischemia-reperfusion (I/R). The lack of a highly specific JNK inhibitor contributed to this controversy. We recently developed a cell-penetrating, protease-resistant peptide inhibitor of JNK, d-JNKI-1. Here we report on the effects of d-JNKI-1 in myocardial I/R. d-JNKI-1 was tested in isolated-perfused adult rat hearts. Increased activation of JNK, p38-MAPK, and extracellular signal-regulated kinase-1/2 (ERK1/2), as assessed by kinase assays and Western blotting, occurred during I/R. d-JNKI-1 delivered before onset of ischemia prevented the increase in JNK activity while not affecting ERK1/2 and p38-MAPK activation. JNK inhibition reduced ischemic injury, as manifested by increased time to contracture ( P < 0.05) and decreased left ventricular end-diastolic pressure during ischemia ( P < 0.01), and enhanced posthypoxic recovery of systolic and diastolic function ( P < 0.01). d-JNKI-1 reduced mitochondrial cytochrome- c release, caspase-3 activation, and the number of apoptotic cells determined by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling ( P < 0.05), indicating suppression of the mitochondrial machinery of apoptosis. d-JNKI-1 delivered at the time of reperfusion did not improve functional recovery but still prevented apoptosis. In vivo, d-JNKI-1 reduced infarct size after coronary artery occlusion and reperfusion by ∼50% ( P < 0.01). In conclusion, d-JNKI-1 is an important compound that can be used in preclinical models to investigate the role of JNK signaling in vivo. Inhibition of JNK during I/R is cardioprotective in anesthetized rats in vivo.


Sign in / Sign up

Export Citation Format

Share Document