Na+/Ca2+ exchange inhibition protects the rat heart from ischemia-reperfusion injury by blocking energy-wasting processes

2005 ◽  
Vol 288 (4) ◽  
pp. H1699-H1707 ◽  
Author(s):  
Hiroji Hagihara ◽  
Yoshiro Yoshikawa ◽  
Yoshimi Ohga ◽  
Chikako Takenaka ◽  
Ken-ya Murata ◽  
...  

We have recently reported that exposure of rat hearts to high Ca2+ produces a Ca2+ overload-induced contractile failure in rat hearts, which was associated with proteolysis of α-fodrin. We hypothesized that contractile failure after ischemia-reperfusion (I/R) is similar to that after high Ca2+ infusion. To test this hypothesis, we investigated left ventricular (LV) mechanical work and energetics in the cross-circulated rat hearts, which were subjected to 15 min global ischemia and 60 min reperfusion. Sixty minutes after I/R, mean systolic pressure-volume area (PVA; a total mechanical energy per beat) at midrange LV volume (mLVV) (PVAmLVV) was significantly decreased from 5.89 ± 1.55 to 3.83 ± 1.16 mmHg·ml·beat−1·g−1 ( n = 6). Mean myocardial oxygen consumption per beat (Vo2) intercept of (Vo2-PVA linear relation was significantly decreased from 0.21 ± 0.05 to 0.15 ± 0.03 μl O2·beat−1·g−1 without change in its slope. Initial 30-min reperfusion with a Na+/Ca2+ exchanger (NCX) inhibitor KB-R7943 (KBR; 10 μmol/l) significantly reduced the decrease in mean PVAmLVV and Vo2 intercept ( n = 6). Although Vo2 for the Ca2+ handling was finally decreased, it transiently but significantly increased from the control for 10–15 min after I/R. This increase in Vo2 for the Ca2+ handling was completely blocked by KBR, suggesting an inhibition of reverse-mode NCX by KBR. α-Fodrin proteolysis, which was significantly increased after I/R, was also significantly reduced by KBR. Our study shows that the contractile failure after I/R is similar to that after high Ca2+ infusion, although the contribution of reverse-mode NCX to the contractile failure is different. An inhibition of reverse-mode NCX during initial reperfusion protects the heart against reperfusion injury.

2010 ◽  
Vol 298 (2) ◽  
pp. H643-H651 ◽  
Author(s):  
Yoshiro Yoshikawa ◽  
Guo-Xing Zhang ◽  
Koji Obata ◽  
Yoshimi Ohga ◽  
Hiroko Matsuyoshi ◽  
...  

We have previously indicated that calpain inhibitor-1 prevents the heart from ischemia- reperfusion injury associated with the impairment of total Ca2+ handling by inhibiting the proteolysis of α-fodrin. However, this inhibitor is insoluble with water and inappropriate for clinical application. The aim of the present study was to investigate the protective effect of a newly developed calpain inhibitor, SNJ-1945 (SNJ), with good aqueous solubility on left ventricular (LV) mechanical work and energetics in the cross-circulated rat hearts. SNJ (150 μM) was added to KCl (30 meq) cardioplegia (CP). Mean end-systolic pressure at midrange LV volume (ESPmLVV) and systolic pressure-volume area (PVA) at mLVV (PVAmLVV; a total mechanical energy per beat) were hardly changed after CP plus SNJ arrest-reperfusion (post-CP + SNJ), whereas ESPmLVV and PVAmLVV in post-CP group were significantly ( P < 0.01) decreased. Mean myocardial oxygen consumption for the total Ca2+ handling in excitation-contraction coupling did not significantly decrease in post-CP + SNJ group, whereas it was significantly ( P < 0.01) decreased in post-CP group. The mean amounts of 145- and 150-kDa fragments of α-fodrin in the post-CP group were significantly larger than those in normal and post-CP + SNJ groups. In contrast, the mean amounts of L-type Ca2+ channel and sarcoplasmic reticulum Ca2+-ATPase were not significantly different among normal, post-CP, and post-CP + SNJ groups. Our results indicate that soluble SNJ attenuates cardiac dysfunction due to CP arrest-reperfusion injury associated with the impairment of the total Ca2+ handling in excitation-contraction coupling by inhibiting the proteolysis of α-fodrin.


2005 ◽  
Vol 288 (4) ◽  
pp. H1690-H1698 ◽  
Author(s):  
Yoshiro Yoshikawa ◽  
Hiroji Hagihara ◽  
Yoshimi Ohga ◽  
Chikako Nakajima-Takenaka ◽  
Ken-ya Murata ◽  
...  

We hypothesized that calpain inhibitor-1 protected left ventricular (LV) function from ischemia-reperfusion injury by inhibiting the proteolysis of α-fodrin. To test this hypothesis, we investigated the effect of calpain inhibitor-1 on LV mechanical work and energetics in the cross-circulated rat hearts that underwent 15-min global ischemia and 60-min reperfusion ( n = 9). After ischemia-reperfusion with calpain inhibitor-1, mean end-systolic pressure at midrange LV volume and systolic pressure-volume area (PVA) at midrange LV volume (total mechanical energy per beat) were hardly changed, although they were significantly ( P < 0.01) decreased after ischemia-reperfusion without calpain inhibitor-1. Mean myocardial oxygen consumption per beat (Vo2) intercepts (PVA-independent Vo2; Vo2 for the total Ca2+ handling in excitation-contraction coupling and basal metabolism) of Vo2-PVA linear relations were also unchanged after ischemia-reperfusion with calpain inhibitor-1, although they were significantly ( P < 0.01) decreased after ischemia-reperfusion without calpain inhibitor-1. There were no significant differences in O2 costs of LV PVA and contractility among the hearts in control (or normal) postischemia-reperfusion and postischemia-reperfusion with calpain inhibitor-1. Western blot analysis of α-fodrin and the immunostaining of 150-kDa products of α-fodrin confirmed that calpain inhibitor-1 almost completely protected the proteolysis of α-fodrin. Our results indicate that calpain inhibitor-1 prevents the heart from ischemia-reperfusion injury associated with the impairment of total Ca2+ handling by directly inhibiting the proteolysis of α-fodrin.


2021 ◽  
Vol 12 ◽  
Author(s):  
Zhenyu Fan ◽  
Liangliang Cai ◽  
Shengnan Wang ◽  
Jing Wang ◽  
Bohua Chen

Baicalin is a natural flavonoid glycoside that confers protection against myocardial ischemia/reperfusion (I/R) injury. However, its mechanism has not been fully understood. This study focused on elucidating the role of ferroptosis in baicalin-generated protective effects on myocardial ischemia/reperfusion (I/R) injury by using the myocardial I/R rat model and oxygen–glucose deprivation/reoxygenation (OGD/R) H9c2 cells. Our results show that baicalin improved myocardial I/R challenge–induced ST segment elevation, coronary flow (CF), left ventricular systolic pressure , infarct area, and pathological changes and prevented OGD/R-triggered cell viability loss. In addition, enhanced lipid peroxidation and significant iron accumulation along with activated transferrin receptor protein 1 (TfR1) signal and nuclear receptor coactivator 4 (NCOA4)-medicated ferritinophagy were observed in in vivo and in vitro models, which were reversed by baicalin treatment. Furthermore, acyl-CoA synthetase long-chain family member 4 (ACSL4) overexpression compromised baicalin-generated protective effect in H9c2 cells. Taken together, our findings suggest that baicalin prevents against myocardial ischemia/reperfusion injury via suppressing ACSL4-controlled ferroptosis. This study provides a novel target for the prevention of myocardial ischemia/reperfusion injury.


2009 ◽  
Vol 297 (5) ◽  
pp. H1736-H1743 ◽  
Author(s):  
Chikako Nakajima-Takenaka ◽  
Guo-Xing Zhang ◽  
Koji Obata ◽  
Kiyoe Tohne ◽  
Hiroko Matsuyoshi ◽  
...  

We investigated left ventricular (LV) mechanical work and energetics in the cross-circulated (blood-perfused) isoproterenol [Iso 1.2 mg·kg−1·day−1 for 3 days (Iso3) or 7 days (Iso7)]-induced hypertrophied rat heart preparation under isovolumic contraction-relaxation. We evaluated pressure-time curves per beat, end-systolic pressure-volume and end-diastolic pressure-volume relations, and myocardial O2 consumption per beat (V̇o2)-systolic pressure-volume area (PVA; a total mechanical energy per beat) linear relations at 240 beats/min, because Iso-induced hypertrophied hearts failed to completely relax at 300 beats/min. The LV relaxation rate at 240 beats/min in Iso-induced hypertrophied hearts was significantly slower than that in control hearts [saline 24 μl/day for 3 and 7 days (Sa)] with unchanged contraction rate. The V̇o2-intercepts (composed of basal metabolism and Ca2+ cycling energy consumption in excitation-contraction coupling) of V̇o2-PVA linear relations were unchanged associated with their unchanged slopes in Sa, Iso3, and Iso7 groups. The oxygen costs of LV contractility were also unchanged in all three groups. The amounts of expression of sarcoplasmic reticulum Ca2+-ATPase, phospholamban (PLB), phosphorylated-Ser16 PLB, phospholemman, and Na+-K+-ATPase are significantly decreased in Iso3 and Iso7 groups, although the amount of expression of NCX1 is unchanged in all three groups. Furthermore, the marked collagen production (types I and III) was observed in Iso3 and Iso7 groups. These results suggested the possibility that lowering the heart rate was beneficial to improve mechanical work and energetics in isoproterenol-induced hypertrophied rat hearts, although LV relaxation rate was slower than in normal hearts.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xinhua Yao ◽  
Yalan Li ◽  
Mingzhe Tao ◽  
Shuang Wang ◽  
Liangqing Zhang ◽  
...  

The anesthetic propofol confers cardioprotection against myocardial ischemia-reperfusion injury (IRI) by reducing reactive oxygen species (ROS). However, its cardioprotection on patients is inconsistent. Similarly, the beneficial effect of tight glycemic control during cardiac surgery in patients has recently been questioned. We postulated that low glucose (LG) may promote ROS formation through enhancing fatty acid (FA) oxidation and unmask propofol cardioprotection during IRI. Rat hearts were isolated and randomly assigned to be perfused with Krebs-Henseleit solution with glucose at 5.5 mM (LG) or 8 mM (G) in the absence or presence of propofol (5 μg/mL) or propofol plus trimetazidine (TMZ). Hearts were subjected to 35 minutes of ischemia followed by 60 minutes of reperfusion. Myocardial infarct size (IS) and cardiac CK-MB were significantly higher in LG than in G group (P < 0.05), associated with reduced left ventricular developed pressure and increases in postischemic cardiac contracture. Cardiac 15-F2t-isoprostane was higher, accompanied with higher cardiac lipid transporter CD36 protein expression in LG. Propofol reduced IS, improved cardiac function, and reduced CD36 in G but not in LG. TMZ facilitated propofol cardioprotection in LG. Therefore, isolated heart with low glucose lost sensitivity to propofol treatment through enhancing FA oxidation and TMZ supplementation restored the sensitivity to propofol.


2014 ◽  
Vol 17 (5) ◽  
pp. 263 ◽  
Author(s):  
C. Murat Songur ◽  
Merve Ozenen Songur ◽  
Sinan Sabit Kocabeyoglu ◽  
Bilgen Basgut

<p><b>Background:</b> We sought to investigate the effects of the angiotension II receptor blocker candesartan on ischemia-reperfusion injury using a cardioplegia arrested isolated rat heart model.</p><p><b>Methods:</b> Ischemia-reperfusion injury was induced in isolated rat hearts with 40 minutes of global ischemia followed by a 30-minute reperfusion protocol. Throughout the experiment, constant pressure perfusion was achieved using a Langendorff apparatus. Cardioplegic solution alone, and in combination with candesartan, was administered before ischemia and 20 minutes after ischemia. Post-ischemic recovery of contractile function, left ventricular developed pressure, left ventricular end-diastolic pressure and contraction and relaxation rates were evaluated.</p><p><b>Results:</b> In the control group, left ventricular developed pressure, rate pressure product, contraction and relaxation rates and coronary flow significantly decreased but coronary resistance increased following reperfusion. With the administration of candesartan alone, parameters did not differ compared to controls. Contractile parameters improved in the group that received candesartan in combination with the cardioplegia compared to the group that received cardioplegia alone; however, the difference between these two groups was insignificant.</p><p><b>Conclusion:</b> In this study, the addition of candesartan to a cardioplegic arrest protocol routinely performed during cardiac surgery did not provide a significant advantage in protection against ischemia-reperfusion injury compared with the administration of cardioplegic solution alone.</p>


2006 ◽  
Vol 104 (3) ◽  
pp. 495-502 ◽  
Author(s):  
Yasuo M. Tsutsumi ◽  
Hemal H. Patel ◽  
N Chin Lai ◽  
Toshiyuki Takahashi ◽  
Brian P. Head ◽  
...  

Background Isoflurane reduces myocardial ischemia-reperfusion injury within hours to days of reperfusion. Whether isoflurane produces sustained cardiac protection has never been examined. The authors studied isoflurane-induced cardiac protection in the intact mouse after 2 h and 2 weeks of reperfusion and determined the dependence of this protection on adenosine triphosphate-dependent potassium channels and the relevance of this protection to myocardial function and apoptosis. Methods Mice were randomly assigned to receive oxygen or isoflurane for 30 min with 15 min of washout. Some mice received mitochondrial (5-hydroxydecanoic acid) or sarcolemmal (HMR-1098) adenosine triphosphate-dependent potassium channel blockers with or without isoflurane. Mice were then subjected to a 30-min coronary artery occlusion followed by 2 h or 2 weeks of reperfusion. Infarct size was determined at 2 h and 2 weeks of reperfusion. Cardiac function and apoptosis were determined 2 weeks after reperfusion. Results Isoflurane did not change hemodynamics. Isoflurane reduced infarct size after reperfusion when compared with the control groups (27.7 +/- 6.3 vs. 41.7 +/- 6.4% at 2 h and 19.6 +/- 5.9 vs. 28.8 +/- 9.0% at 2 weeks). Previous administration of 5-hydroxydecanoic acid, but not HMR-1098, abolished isoflurane-induced cardiac protection. At 2 weeks, left ventricular end-diastolic diameter was decreased significantly and end-systolic pressure and maximum and minimum dP/dt were improved by isoflurane. Isoflurane-treated mice subjected to ischemia and 2 weeks of reperfusion showed less expression of proapoptotic genes, significantly decreased expression of cleaved caspase-3, and significantly decreased deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling-positive nuclei compared with the control group. Conclusions Cardiac protection induced by isoflurane against necrotic and apoptotic cell death is associated with an acute memory period that is sustained and functionally relevant 2 weeks after ischemia-reperfusion injury in mice in vivo.


2001 ◽  
Vol 280 (2) ◽  
pp. H802-H811 ◽  
Author(s):  
Brian P. Lipton ◽  
Abraham P. Bautista ◽  
Joseph B. Delcarpio ◽  
Kathleen H. McDonough

With the use of a syngeneic model, we demonstrate that rat polymorphonuclear neutrophils (PMNs) exacerbate ischemia-reperfusion injury in the isolated rat heart. However, PMNs (19 × 106cells) from lipopolysaccharide (LPS)-treated rats (LPS-PMNs; 100 mg/kg administered 7 h before exsanguination) induce less reperfusion injury in the isolated heart. Average recovery of left ventricular developed pressure after 20 min of ischemia and 60 min of reperfusion was 51 ± 4% in hearts receiving PMNs from saline-treated control rats (saline-PMNs) versus 78 ± 2% in hearts receiving LPS-PMNs. Ischemic hearts reperfused with LPS-PMNs recovered to the same extent as did hearts reperfused with Krebs buffer only. LPS-PMNs and saline-PMNs showed no difference in basal or phorbol ester-induced superoxide production. Whereas twice the number of LPS-PMNs was positive for nitroblue tetrazolium, the percent positive for L-selectin, a receptor integral in PMN-adhesion to endothelium, was 50% less in LPS-PMNs than in controls. After reperfusion, three-fourths of the saline-PMNs remained within the hearts, whereas only one-fourth of LPS-PMNs were trapped. These data suggest that PMNs from LPS-treated rats do not exacerbate ischemia-reperfusion injury as do control PMNs, possibly, due to impaired PMN adhesion to endothelium as a result of decreased L-selectin receptors.


2021 ◽  
Vol 10 (13) ◽  
pp. 2968
Author(s):  
Alessandro Bellis ◽  
Giuseppe Di Gioia ◽  
Ciro Mauro ◽  
Costantino Mancusi ◽  
Emanuele Barbato ◽  
...  

The significant reduction in ‘ischemic time’ through capillary diffusion of primary percutaneous intervention (pPCI) has rendered myocardial-ischemia reperfusion injury (MIRI) prevention a major issue in order to improve the prognosis of ST elevation myocardial infarction (STEMI) patients. In fact, while the ischemic damage increases with the severity and the duration of blood flow reduction, reperfusion injury reaches its maximum with a moderate amount of ischemic injury. MIRI leads to the development of post-STEMI left ventricular remodeling (post-STEMI LVR), thereby increasing the risk of arrhythmias and heart failure. Single pharmacological and mechanical interventions have shown some benefits, but have not satisfactorily reduced mortality. Therefore, a multitarget therapeutic strategy is needed, but no univocal indications have come from the clinical trials performed so far. On the basis of the results of the consistent clinical studies analyzed in this review, we try to design a randomized clinical trial aimed at evaluating the effects of a reasoned multitarget therapeutic strategy on the prevention of post-STEMI LVR. In fact, we believe that the correct timing of pharmacological and mechanical intervention application, according to their specific ability to interfere with survival pathways, may significantly reduce the incidence of post-STEMI LVR and thus improve patient prognosis.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W Zuo ◽  
R Tian ◽  
Q Chen ◽  
L Wang ◽  
Q Gu ◽  
...  

Abstract Background Myocardial ischemia-reperfusion injury (MIRI) is one of the leading causes of human death. Nod-like receptor protein-3 (NLRP3) inflammasome signaling pathway involved in the pathogenesis of MIRI. However, the upstream regulating mechanisms of NLRP3 at molecular level remains unknown. Purpose This study investigated the role of microRNA330-5p (miR-330-5p) in NLRP3 inflammasome-mediated MIRI and the associated mechanism. Methods Mice underwent 45 min occlusion of the left anterior descending coronary artery followed by different times of reperfusion. Myocardial miR-330-5p expression was examined by quantitative polymerase chain reaction (PCR), and miR-330-5p antagomir and agomir were used to regulate miR-330-5p expression. To evaluate the role of miR-330-5p in MIRI, Evans Blue (EB)/2, 3, 5-triphenyltetrazolium chloride (TTC) staining, echocardiography, and immunoblotting were used to assess infarct volume, cardiac function, and NLRP3 inflammasome activation, respectively. Further, in vitro myocardial ischemia-reperfusion model was established in cardiomyocytes (H9C2 cell line). A luciferase binding assay was used to examine whether miR-330-5p directly bound to T-cell immunoglobulin domain and mucin domain-containing molecule-3 (TIM3). Finally, the role of miR-330-5p/TIM3 axis in regulating apoptosis and NLRP3 inflammasome formation were evaluated using flow cytometry assay and immunofluorescence staining. Results Compared to the model group, inhibiting miR-330-5p significantly aggravated MIRI resulting in increased infarct volume (58.09±6.39% vs. 37.82±8.86%, P&lt;0.01) and more severe cardiac dysfunction (left ventricular ejection fraction [LVEF] 12.77%±6.07% vs. 27.44%±4.47%, P&lt;0.01; left ventricular end-diastolic volume [LVEDV] 147.18±25.82 vs. 101.31±33.20, P&lt;0.05; left ventricular end-systolic volume [LVESV] 129.11±30.17 vs. 74.29±28.54, P&lt;0.05). Moreover, inhibiting miR-330-5p significantly increased the levels of NLRP3 inflammasome related proteins including caspase-1 (0.80±0.083 vs. 0.60±0.062, P&lt;0.05), interleukin (IL)-1β (0.87±0.053 vs. 0.79±0.083, P&lt;0.05), IL-18 (0.52±0.063 vs. 0.49±0.098, P&lt;0.05) and tissue necrosis factor (TNF)-α (1.47±0.17 vs. 1.03±0.11, P&lt;0.05). Furthermore, TIM3 was confirmed as a potential target of miR-330-5p. As predicted, suppression of TIM3 by small interfering RNA (siRNA) ameliorated the anti-miR-330-5p-mediated apoptosis of cardiomyocytes and activation of NLRP3 inflammasome signaling pathway (Figure 1). Conclusion Overall, our study indicated that miR-330-5p/TIM3 axis involved in the regulating mechanism of NLRP3 inflammasome-mediated myocardial ischemia-reperfusion injury. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China Grants


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