Bax ablation protects against myocardial ischemia-reperfusion injury in transgenic mice

2003 ◽  
Vol 284 (6) ◽  
pp. H2351-H2359 ◽  
Author(s):  
Edith Hochhauser ◽  
Shaye Kivity ◽  
Daniel Offen ◽  
Nilanjana Maulik ◽  
Hajime Otani ◽  
...  

The role of the proapototic Bax gene in ischemia-reperfusion (I/R) injury was studied in three groups of mice: homozygotic knockout mice lacking the Bax gene (Bax−/−), heterozygotic mice (Bax+/−), and wild-type mice (Bax+/+). Isolated hearts were subjected to ischemia (30 min, 37°C) and then to 120 min of reperfusion. The left ventricular developed force of Bax-deficient vs. Bax+/+ hearts at stabilization and at 120 min of reperfusion was 1,411 ± 177 vs. 1,161 ± 137 mg and 485 ± 69 vs. 306 ± 68 mg, respectively. Superior cardiac function of Bax−/− hearts after I/R was accompanied by a decrease in creatine kinase release, caspase 3 activity, irreversible ischemic injury, and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cardiomyocytes. Electron microscopic evaluation revealed reduced damage to mitochondria and the nuclear chromatin structure in Bax-deficient mice. In the Bax+/− hearts, the damage markers were moderate. The superior tolerance of Bax knockout hearts to I/R injury recommends this gene as a potential target for therapeutic intervention in patients with severe and intractable myocardial ischemia.

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<0.01) and more severe cardiac dysfunction (left ventricular ejection fraction [LVEF] 12.77%±6.07% vs. 27.44%±4.47%, P<0.01; left ventricular end-diastolic volume [LVEDV] 147.18±25.82 vs. 101.31±33.20, P<0.05; left ventricular end-systolic volume [LVESV] 129.11±30.17 vs. 74.29±28.54, P<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<0.05), interleukin (IL)-1β (0.87±0.053 vs. 0.79±0.083, P<0.05), IL-18 (0.52±0.063 vs. 0.49±0.098, P<0.05) and tissue necrosis factor (TNF)-α (1.47±0.17 vs. 1.03±0.11, P<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


2016 ◽  
Vol 38 (4) ◽  
pp. 1365-1375 ◽  
Author(s):  
Jie Jian ◽  
Feifei Xuan ◽  
Feizhang Qin ◽  
Renbin Huang

Background/Aims: Previous studies have demonstrated that Bauhinia championii flavone (BCF) exhibits anti-oxidative, anti-hypoxic and anti-stress properties. This study was designed to investigate whether BCF has a cardioprotective effect against myocardial ischemia/reperfusion (I/R) injuries in rats and to shed light on its possible mechanism. Methods: The model of I/R was established by ligating the left anterior descending coronary artery for 30 min, then reperfusing for 180 min. Hemodynamic changes were continuously monitored. The content of malondialdehyde (MDA) as well as the lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were assessed. The release of interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of cardiomyocytes was determined by caspase-3 activity and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression of TLR4, NF-κBp65, Bcl-2 and Bax were detected by western blotting. Results: Pretreatment with BCF significantly reduced the serum levels of LDH, MDA and IL-6, but increased the activities of SOD and GSH-Px. It also attenuated myocardial infarct size, reduced the apoptosis rate and preserved cardiac function. Furthermore, BCF inhibited caspase-3 activity and the expression of TLR4, phosphorylated NF-κBp65 and Bax, but enhanced the expression of Bcl-2. Conclusion: These results provide substantial evidence that BCF exerts a protective effect on myocardial I/R injury, which may be attributed to attenuating lipid peroxidation, the inflammatory response and apoptosis.


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.


2000 ◽  
Vol 279 (1) ◽  
pp. H329-H338 ◽  
Author(s):  
Feng Gao ◽  
Theodore A. Christopher ◽  
Bernard L. Lopez ◽  
Eitan Friedman ◽  
Guoping Cai ◽  
...  

The purpose of this study was to determine whether the protective effects of adenosine on myocardial ischemia-reperfusion injury are altered with age, and if so, to clarify the mechanisms that underlie this change related to nitric oxide (NO) derived from the vascular endothelium. Isolated perfused rat hearts were exposed to 30 min of ischemia and 60 min of reperfusion. In the adult hearts, administration of adenosine (5 μmol/l) stimulated NO release (1.06 ± 0.19 nmol · min−1 · g−1, P < 0.01 vs. vehicle), increased coronary flow, improved cardiac functional recovery (left ventricular developed pressure 79 ± 3.8 vs. 57 ± 3.1 mmHg in vehicle, P < 0.001; maximal rate of left ventricular pressure development 2,385 ± 103 vs. 1,780 ± 96 in vehicle, P < 0.001), and reduced myocardial creatine kinase loss (95 ± 3.9 vs. 159 ± 4.6 U/100 mg protein, P < 0.01). In aged hearts, adenosine-stimulated NO release was markedly reduced (+0.42 ± 0.12 nmol · min−1 · g−1 vs. vehicle), and the cardioprotective effects of adenosine were also attenuated. Inhibition of NO production in the adult hearts significantly decreased the cardioprotective effects of adenosine, whereas supplementation of NO in the aged hearts significantly enhanced the cardioprotective effects of adenosine. The results show that the protective effects of adenosine on myocardial ischemia-reperfusion injury are markedly diminished in aged animals, and that the loss in NO release in response to adenosine may be at least partially responsible for this age-related alteration.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Ralf Erkens ◽  
Tatsiana Suvorava ◽  
Thomas R. Sutton ◽  
Bernadette O. Fernandez ◽  
Monika Mikus-Lelinska ◽  
...  

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a key master switch that controls the expression of antioxidant and cytoprotective enzymes, including enzymes catalyzing glutathione de novo synthesis. In this study, we aimed to analyze whether Nrf2 deficiency influences antioxidative capacity, redox state, NO metabolites, and outcome of myocardial ischemia reperfusion (I/R) injury. In Nrf2 knockout (Nrf2 KO) mice, we found elevated eNOS expression and preserved NO metabolite concentrations in the aorta and heart as compared to wild types (WT). Unexpectedly, Nrf2 KO mice have a smaller infarct size following myocardial ischemia/reperfusion injury than WT mice and show fully preserved left ventricular systolic function. Inhibition of NO synthesis at onset of ischemia and during early reperfusion increased myocardial damage and systolic dysfunction in Nrf2 KO mice, but not in WT mice. Consistent with this, infarct size and diastolic function were unaffected in eNOS knockout (eNOS KO) mice after ischemia/reperfusion. Taken together, these data suggest that eNOS upregulation under conditions of decreased antioxidant capacity might play an important role in cardioprotection against I/R. Due to the redundancy in cytoprotective mechanisms, this fundamental antioxidant property of eNOS is not evident upon acute NOS inhibition in WT mice or in eNOS KO mice until Nrf2-related signaling is abrogated.


2002 ◽  
Vol 282 (4) ◽  
pp. H1421-H1426 ◽  
Author(s):  
Yasuhiko Ikeda ◽  
Lindon H. Young ◽  
Allan M. Lefer

Calpains are ubiquitous neutral cysteine proteases. Although their physiological role has yet to be clarified, calpains seem to be involved in the expression of cell adhesion molecules. Therefore, we hypothesized that a selective calpain inhibitor could attenuate polymorphonuclear (PMN) leukocyte-induced myocardial ischemia-reperfusion (I/R) injury. We examined the effects of the calpain inhibitor Z-Leu-Leu-CHO in isolated ischemic (20 min) and reperfused (45 min) rat hearts perfused with PMNs. Z-Leu-Leu-CHO (10 and 20 μM, respectively) significantly improved left ventricular developed pressure (LVDP) ( P< 0.01) and the maximal rate of development of LVDP ( P< 0.01) compared with I/R hearts perfused without Z-Leu-Leu-CHO. In addition, Z-Leu-Leu-CHO significantly reduced PMN adherence to the vascular endothelium and subsequent infiltration into the postischemic myocardium ( P < 0.01). Moreover, Z-Leu-Leu-CHO significantly inhibited expression of P-selectin on the rat coronary microvascular endothelium ( P < 0.01). These results provide evidence that Z-Leu-Leu-CHO significantly attenuates PMN-mediated I/R injury in the isolated perfused rat heart to a significant extent via downregulation of P-selectin expression.


2001 ◽  
Vol 281 (3) ◽  
pp. H1223-H1232 ◽  
Author(s):  
Peiyong Zhai ◽  
Thomas E. Eurell ◽  
Robert P. Cotthaus ◽  
Elizabeth H. Jeffery ◽  
Janice M. Bahr ◽  
...  

We investigated the effects of phytoestrogen on global myocardial ischemia-reperfusion injury in five groups of female rats. A high-phytoestrogen group (HPE) was ovariectomized (Ovx) and fed a diet containing soybean protein and a high-isoflavone soy extract. Another Ovx group of rats was fed the same diet as the HPE group but treated with the estrogen receptor blocker ICI-182,780 (HPE + ICI). A third group of Ovx rats was fed a diet containing soybean protein alone (low-phytoestrogen content; LPE). A fourth Ovx group was fed a diet free of phytoestrogen (Ovx). The fifth group of rats was sham ovariectomized (sham). Hearts from all rats were subjected to 30 min of global, hypothermic (4°C), cardioplegic ischemia and 120 min of normothermic (37°C) reperfusion with oxygenated Krebs-Henseleit buffer. Compared with either the sham or the HPE group, the Ovx and HPE + ICI groups had significantly decreased first derivative of left ventricular pressure (dP/d t), coronary flow rate (CFR), nitrite production and mitochondrial respiratory function and significantly increased Ca2+ accumulation and myocardial histological and ultrastructural injury. The CFR of the LPE group was significantly different from that of either Ovx or HPE + ICI group but the dP/d t, nitrite production, Ca2+ accumulation, and mitochondrial function were not. Our results indicate that diets containing phytoestrogen extract play a cardioprotective role in global myocardial ischemia-reperfusion in female rats.


2019 ◽  
Vol 317 (3) ◽  
pp. C525-C533 ◽  
Author(s):  
Yu Tina Zhao ◽  
Jianfeng Du ◽  
Naohiro Yano ◽  
Hao Wang ◽  
Jianguo Wang ◽  
...  

p38-Regulated/activated protein kinase (PRAK) plays a critical role in modulating cellular survival and biological function. However, the function of PRAK in the regulation of myocardial ischemic injury remains unknown. This study is aimed at determining the function of PRAK in modulating myocardial ischemia-reperfusion injury and myocardial remodeling following myocardial infarction. Hearts were isolated from adult male homozygous PRAK−/− and wild-type mice and subjected to global ischemia-reperfusion injury in Langendorff isolated heart perfusion. PRAK−/− mice mitigated postischemic ventricular functional recovery and decreased coronary effluent. Moreover, the infarct size in the perfused heart was significantly increased by deletion of PRAK. Western blot showed that deletion of PRAK decreased the phosphorylation of ERK1/2. Furthermore, the effect of deletion of PRAK on myocardial function and remodeling was also examined on infarcted mice in which the left anterior descending artery was ligated. Echocardiography indicated that PRAK−/− mice had accelerated left ventricular systolic dysfunction, which was associated with increased hypertrophy in the infarcted area. Deletion of PRAK augmented interstitial fibrosis and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive myocytes. Furthermore, immunostaining analysis shows that CD31-postive vascular density and α-smooth muscle actin capillary staining decreased significantly in PRAK−/− mice. These results indicate that deletion of PRAK enhances susceptibility to myocardial ischemia-reperfusion injury, attenuates cardiac performance and angiogenesis, and increases interstitial fibrosis and apoptosis in the infarcted hearts.


2020 ◽  
Vol 10 (6) ◽  
pp. 895-900 ◽  
Author(s):  
Lili Xu ◽  
Zhe Wang ◽  
Lixiang Deng

Myocardial ischemia-reperfusion injury (MIRI) can cause myocardial damage. Vaspin can protect against myocardial damage. However, the effect of vaspin on MIRI rats and the expression of NLRP3 remains unclear. Sprague-Dawley rats were separated into sham group; MIRI group and Vaspin group, in which 100 ng/ml vaspin was administrated before model preparation followed by analysis of cardiac function by M-mode ultrasound, level of NLRP3, of type I collagen, IL-6 and TNF-α by ELISA, SOD activity and ROS by spectrophotometry and Bcl-2 and PI3K/AKT signaling protein expression by Western Blot. In MIRI group, left ventricular end-systolic diameter (LVESD), left ventricular mass index (LVMI), left ventricular end-diastolic diameter (LVEDD), NLRP3 expression, contents of type I collagen, IL-6, TNF-α as well as ROS were significantly increased and SOD activity was significantly decreased with decreased Bcl-2 expression and upregulated pAKT and pPI3K (P < 0.05). In Vaspin group, LVESD, LVMI and LVEDD and NLRP3 expression as well as type I collagen, IL-6, TNF-α and ROS was decreased, SOD activity and Bcl-2 expression was significantly increased with downregulated pAKT and pPI3K (P < 0.05). Vaspin can regulate PI3K/AKT signaling pathway, inhibit NLRP3 expression, regulate oxidative stress, inhibit inflammation, reduce apoptosis, improve and improve cardiac function of myocardial ischemia-reperfusion injury in rats.


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