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Liu MX, Yang J, Qin Y, Li ZD, Jin J, Zhang YB, Yang XJ. ESMOLOL PROTECTS AGAINST LPS-INDUCED CARDIAC INJURY VIA THE AMPK/mTOR/ULK1 PATHWAY IN RAT. Shock 2023; 59:469-476. [PMID: 36579896 DOI: 10.1097/shk.0000000000002071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
ABSTRACT Aim: The purpose of this study was to investigate the effect of esmolol (ES) on LPS-induced cardiac injury and the possible mechanism. Methods: Sepsis was induced by i.p. injection of LPS (10 mg/kg) in male Sprague-Dawley rats pretreated with ES, 3-methyladenine or rapamycin. The severity of myocardial damage was analyzed by hematoxylin-eosin staining, and myocardial damage scores were calculated. The concentration of cardiac troponin was measured by enzyme-linked immunosorbent assay. The expression of autophagy-related proteins (beclin-1, LC3-II, p-AMPK, p-ULK1, p-mTOR) in myocardial tissue was detected by Western blotting. Autophagosome formation and the ultrastructural damage of mitochondria were assessed using transmission electron microscopy. Results: LPS induced an increase in myocardial damage score in a time-dependent manner, accompanied with an increase in autophagy at 3 h and decrease in autophagy at 6, 12, and 24 h. Pretreatment of LPS-treated rats with ES or rapamycin reduced myocardial injury (release of cardiac troponin, myocardial damage score) and increased autophagy (LC3-II, beclin-1, p-AMPK, and p-ULK1 levels and autophagosome numbers) at 12 and 24 h. In contrast, 3-methyladenine showed no effect. Conclusion: Esmolol alleviates LPS-induced myocardial damage through activating the AMPK/mTOR/ULK1 signal pathway-regulated autophagy.
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Affiliation(s)
- Mao-Xia Liu
- Department of Intensive Care Unit, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jia Yang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan, Shanxi China
| | - Yan Qin
- Department of Emergency Medicine, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zheng-da Li
- Department of Intensive Care Unit, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Jun Jin
- Department of Intensive Care Unit, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yan-Bing Zhang
- Department of Anesthesiology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Xin-Jing Yang
- Department of Intensive Care Unit, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
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Lakin R, Debi R, Yang S, Polidovitch N, Goodman JM, Backx PH. Differential negative effects of acute exhaustive swim exercise on the right ventricle are associated with disproportionate hemodynamic loading. Am J Physiol Heart Circ Physiol 2021; 320:H1261-H1275. [PMID: 33416456 DOI: 10.1152/ajpheart.00603.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute exhaustive endurance exercise can differentially impact the right ventricle (RV) versus the left ventricle (LV). However, the hemodynamic basis for these differences and its impact on postexercise recovery remain unclear. Therefore, we assessed cardiac structure and function along with hemodynamic properties of mice subjected to single bouts (216 ± 8 min) of exhaustive swimming (ES). One-hour after ES, LVs displayed mild diastolic impairment compared with that in sedentary (SED) mice. Following dobutamine administration to assess functional reserve, diastolic and systolic function were slightly impaired. Twenty-four hours after ES, LV function was largely indistinguishable from that in SED. By contrast, 1-h post swim, RVs showed pronounced impairment of diastolic and systolic function with and without dobutamine, which persisted 24 h later. The degree of RV impairment correlated with the time-to-exhaustion. To identify hemodynamic factors mediating chamber-specific responses to ES, LV pressure was recorded during swimming. Swimming initiated immediate increases in heart rates (HRs), systolic pressure, dP/dtmax and -dP/dtmin, which remained stable for ∼45 min. LV end-diastolic pressures (LVEDP) increased to ≥45 mmHg during the first 10 min and subsequently declined. After 45 min, HR and -dP/dtmin declined, which correlated with gradual elevations in LVEDP (to ∼45 mmHg) as mice approached exhaustion. All parameters rapidly normalized postexercise. Consistent with human studies, our findings demonstrate a disproportionate negative impact of acute exhaustive exercise on RVs that persisted for at least 24 h. We speculate that the differential effects of exhaustive exercise on the ventricles arise from a ∼2-fold greater hemodynamic load in the RV than in LV originating from profound elevations in LVEDPs as mice approach exhaustion.NEW & NOTEWORTHY Acute exhaustive exercise differentially impacts the right ventricle (RV) versus left ventricle (LV), yet the underlying hemodynamic basis remains unclear. Using pressure-volume analyses and pressure-telemetry implantation in mice, we confirmed a marked disproportionate and persistent negative impact of exhaustive exercise on the RV. These differences in responses of the ventricles to exhaustive exercise are of clinical relevance, reflecting ∼2-fold greater hemodynamic RV loads versus LVs arising from massive (∼45 mmHg) increases in LV end-diastolic pressures at exhaustion.
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Affiliation(s)
- Robert Lakin
- Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada.,Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Ryan Debi
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Sibao Yang
- Department of Biology, York University, Toronto, Ontario, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Nazari Polidovitch
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Jack M Goodman
- Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, Ontario, Canada.,Division of Cardiology, University Health Network, Toronto, Ontario, Canada
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Exercise Preconditioning Plays a Protective Role in Exhaustive Rats by Activating the PI3K-Akt Signaling Pathway. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:3598932. [PMID: 32063981 PMCID: PMC6998755 DOI: 10.1155/2020/3598932] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/12/2019] [Accepted: 12/20/2019] [Indexed: 12/24/2022]
Abstract
Objective To investigate whether exercise preconditioning (EP) protects the rat heart from exhaustive exercise- (EE-) induced injury by inducing the PI3K-Akt signaling pathway. Methods 84 male Sprague-Dawley rats were randomly divided into 6 groups (n = 14 rats per group): control group (Con), exhaustive exercise group (EE), exercise preconditioning group (EP), exercise preconditioning + exhaustive exercise group (EP + EE), LY294002 (PI3K inhibitor) + exercise preconditioning + exhaustive exercise group (LY + EP + EE), and LY294002 group (LY). The Con and LY did not exercise. The remaining groups were subjected to treadmill running. The structure of myocardial tissue and serum biomarkers of myocardial injury were observed. Hemodynamic parameters were recorded with a pressure-volume catheter. TUNEL assay was used to detect the apoptosis of cardiac myocytes, and the level of mitochondrial membrane permeability transforming pore (mPTP) in myocardium was evaluated using ELISA. Pathway and apoptosis-related proteins in myocardium were assessed using western blotting. Results Compared to the Con group, the EE group showed remarkable myocardial injury, such as cardiac dysfunction and myocardial apoptosis. Compared to the EE group, the injuries in the EP + EE group were improved. EP increased the PI3K-Akt signaling pathway and regulated Bcl-2 family to decrease the mPTP openness level. However, the cardioprotective effects of EP were attenuated when pretreated with the LY294002. Conclusions EP protected the heart from EE-induced injury, and it may improve the cardiac function and reduce the cardiomyocyte apoptosis by activating the PI3K-Akt signaling pathway.
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Yuan JQ, Yuan Y, Pan SS, Cai K. Altered expression levels of autophagy-associated proteins during exercise preconditioning indicate the involvement of autophagy in cardioprotection against exercise-induced myocardial injury. J Physiol Sci 2020; 70:10. [PMID: 32066368 PMCID: PMC7026234 DOI: 10.1186/s12576-020-00738-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/04/2020] [Indexed: 01/24/2023]
Abstract
Exercise has been reported to induce autophagy. We hypothesized that exercise preconditioning (EP)-related autophagy in cardiomyocytes could be attributed to intermittent ischemia-hypoxia, allowing the heart to be protected for subsequent high-intensity exercise (HE). We applied approaches, chromotrope-2R brilliant green (C-2R BG) staining and plasma cTnI levels measuring, to characterize two periods of cardioprotection after EP: early EP (EEP) and late EP (LEP). Further addressing the relationship between ischemia-hypoxia and autophagy, key proteins, Beclin1, LC3, Cathepsin D, and p62, were determined by immunohistochemical staining, western blotting, and by their adjacent slices with C-2R BG. Results indicated that exercise-induced ischemia-hypoxia is a key factor in Beclin1-dependent autophagy. High-intensity exercise was associated with the impairment of autophagy due to high levels of LC3II and unchanged levels of p62, intermittent ischemia-hypoxia by EP itself plays a key role in autophagy, which resulted in more favorable cellular effects during EEP-cardioprotection compared to LEP.
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Affiliation(s)
- Jian-Qi Yuan
- School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai, 200438, China
| | - Yang Yuan
- School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai, 200438, China
| | - Shan-Shan Pan
- School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai, 200438, China.
| | - Ke Cai
- School of Kinesiology, Shanghai University of Sport, 399 Changhai Road, Shanghai, 200438, China
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Late Exercise Preconditioning Promotes Autophagy against Exhaustive Exercise-Induced Myocardial Injury through the Activation of the AMPK-mTOR-ULK1 Pathway. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5697380. [PMID: 32656262 PMCID: PMC7322587 DOI: 10.1155/2019/5697380] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/10/2019] [Indexed: 02/02/2023]
Abstract
Accumulating evidence shows that the AMPK-mTOR pathway modulates autophagy via coordinated phosphorylation of ULK1. The aim of the present study was to investigate the relationship between AMPK, mTOR, and ULK1 during late exercise preconditioning (LEP), and to explore whether LEP-induced myocardial protection is related to the autophagy. The exercise preconditioning (EP) protocol was as follows: rats were instructed to for run four repeated in duration of 10 minutes (including 10 minutes rest between each period) on a treadmill. Exhaustive exercise (EE) after LEP pretreatment and administration of wortmannin (an autophagy inhibitor that suppresses Class III PI3K-kinase (PI3KC3) activity) were added to test the protective effect. Cardiac troponin I (cTnI), and transmission electron microscopy (TEM), along with hematoxylin-basic fuchsin-picric acid (HBFP) staining, were used to evaluate the myocardial ischemic-hypoxic injury and protection. Western blot was used to analyze the relationship of autophagy-associated proteins. Exhaustive exercise caused severe myocardial ischemic-hypoxic injury, which led to an increase in cTnI levels, changes of ischemia–hypoxia, and cells ultrastructure. Compared with the EE group, LEP significantly suppressed exhaustive exercise-induced myocardial injury. However, wortmannin attenuated LEP-induced myocardial protection by inhibiting autophagy. Compared with the C group, AMPK was increased in the LEP, EE, and LEP+EE groups, but phosphorylation of AMPK at Thr172 was not significantly changed. Exercise did not have any effect on mTOR expression. Compared with the C group, ULK1 was increased and the ULK1ser757/ULK1 ratio was decreased in the LEP and LEP+EE groups. ULK1 was not significantly affected in the EE group, however, phosphorylation of ULK1 at Ser757 was remarkably decreased. To sum up, our results suggested that LEP promoted autophagy through the activation of AMPK-mTOR-ULK1 pathway, and that activated autophagy was partially involved in myocardial protection against EE-induced myocardial ischemic-hypoxic injury.
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H 2O 2 Signaling-Triggered PI3K Mediates Mitochondrial Protection to Participate in Early Cardioprotection by Exercise Preconditioning. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1916841. [PMID: 30147831 PMCID: PMC6083504 DOI: 10.1155/2018/1916841] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/05/2018] [Accepted: 06/19/2018] [Indexed: 12/15/2022]
Abstract
Previous studies have shown that early exercise preconditioning (EEP) imparts a protective effect on acute cardiovascular stress. However, how mitophagy participates in exercise preconditioning- (EP-) induced cardioprotection remains unclear. EEP may involve mitochondrial protection, which presumably crosstalks with predominant H2O2 oxidative stress. Our EEP protocol involves four periods of 10 min running with 10 min recovery intervals. We added a period of exhaustive running and a pretreatment using phosphoinositide 3-kinase (PI3K)/autophagy inhibitor wortmannin to test this protective effect. By using transmission electron microscopy (TEM), laser scanning confocal microscopy, and other molecular biotechnology methods, we detected related markers and specifically analyzed the relationship between mitophagic proteins and mitochondrial translocation. We determined that exhaustive exercise associated with various elevated injuries targeted the myocardium, oxidative stress, hypoxia-ischemia, and mitochondrial ultrastructure. However, exhaustion induced limited mitochondrial protection through a H2O2-independent manner to inhibit voltage-dependent anion channel isoform 1 (VDAC1) instead of mitophagy. EEP was apparently safe to the heart. In EEP-induced cardioprotection, EEP provided suppression to exhaustive exercise (EE) injuries by translocating Bnip3 to the mitochondria by recruiting the autophagosome protein LC3 to induce mitophagy, which is potentially triggered by H2O2 and influenced by Beclin1-dependent autophagy. Pretreatment with the wortmannin further attenuated these effects induced by EEP and resulted in the expression of proapoptotic phenotypes such as oxidative injury, elevated Beclin1/Bcl-2 ratio, cytochrome c leakage, mitochondrial dynamin-1-like protein (Drp-1) expression, and VDAC1 dephosphorylation. These observations suggest that H2O2 generation regulates mitochondrial protection in EEP-induced cardioprotection.
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Parkin Mediates Mitophagy to Participate in Cardioprotection Induced by Late Exercise Preconditioning but Bnip3 Does Not. J Cardiovasc Pharmacol 2018. [DOI: 10.1097/fjc.0000000000000572] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Spahn DR. Artificial oxygen carriers: a new future? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2018; 22:46. [PMID: 29471841 PMCID: PMC5824566 DOI: 10.1186/s13054-018-1949-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/09/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Donat R Spahn
- Institute of Anesthesiology, Anesthesiology - Intensive Care Medicine - OR-Management, University of Zurich and University Hospital Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland.
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Che L, Li D. The Effects of Exercise on Cardiovascular Biomarkers: New Insights, Recent Data, and Applications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 999:43-53. [PMID: 29022256 DOI: 10.1007/978-981-10-4307-9_3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The benefit of regular exercise or physical activity with appropriate intensity on improving cardiopulmonary function and endurance has long been accepted with less controversy. The challenge remains, however, quantitatively evaluate the effect of exercise on cardiovascular health due in part to the amount and intensity of exercise varies widely plus lack of effective, robust and efficient biomarker evaluation systems. Better evaluating the overall function of biomarker and validate biomarkers utility in cardiovascular health should improve the evidence regarding the benefit or the effect of exercise or physical activity on cardiovascular health, in turn increasing the efficiency of the biomarker on individuals with mild to moderate cardiovascular risk. In this review, beyond traditional cytokines, chemokines and inflammatory factors, we systemic reviewed the latest novel biomarkers in metabolomics, genomics, proteomics, and molecular imaging mainly focus on heart health, as well as cardiovascular diseases such as atherosclerosis and ischemic heart disease. Furthermore, we highlight the state-of-the-art biomarker developing techniques and its application in the field of heart health. Finally, we discuss the clinical relevance of physical activity and exercise on key biomarkers in molecular basis and practical considerations.
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Affiliation(s)
- Lin Che
- Department of Cardiology, Shanghai Tingyi Hospital, Tingyi University School of Medicine, Shanghai, 200065, China.
| | - Dong Li
- Department of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Los Angeles, CA, 90502, USA
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High-Dose Polymerized Hemoglobin Fails to Alleviate Cardiac Ischemia/Reperfusion Injury due to Induction of Oxidative Damage in Coronary Artery. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:125106. [PMID: 26161234 PMCID: PMC4487275 DOI: 10.1155/2015/125106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 12/19/2014] [Accepted: 12/22/2014] [Indexed: 02/05/2023]
Abstract
Objective. Ischemia/reperfusion (I/R) injury is an unavoidable event for patients in cardiac surgery under cardiopulmonary bypass (CPB). This study was designed to investigate whether glutaraldehyde-polymerized human placenta hemoglobin (PolyPHb), a hemoglobin-based oxygen carrier (HBOC), can protect heart against CPB-induced I/R injury or not and to elucidate the underlying mechanism. Methods and Results. A standard dog CPB model with 2-hour cardiac arrest and 2-hour reperfusion was established. The results demonstrated that a low-dose PolyPHb (0.1%, w/v) provided a significant protection on the I/R heart, whereas the high-dose PolyPHb (3%, w/v) did not exhibit cardioprotective effect, as evidenced by the impaired cardiac function, decreased myocardial oxygen utilization, and elevated enzymes release and pathological changes. Further study indicated that exposure of isolated coronary arteries or human umbilical vein endothelial cells (HUVECs) to a high-dose PolyPHb caused impaired endothelium-dependent relaxation, which was companied with increased reactive oxygen species (ROS) production, reduced superoxide dismutase (SOD) activity, and elevated malonaldehyde (MDA) formation. Consistent with the increased oxidative stress, the NAD(P)H oxidase activity and subunits expression, including gp91phox, p47phox, p67phox, and Nox1, were greatly upregulated. Conclusion. The high-dose PolyPHb fails to protect heart from CPB-induced I/R injury, which was due to overproduction of NAD(P)H oxidase-induced ROS and resultant endothelial dysfunction.
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Oláh A, Németh BT, Mátyás C, Horváth EM, Hidi L, Birtalan E, Kellermayer D, Ruppert M, Merkely G, Szabó G, Merkely B, Radovits T. Cardiac effects of acute exhaustive exercise in a rat model. Int J Cardiol 2015; 182:258-66. [DOI: 10.1016/j.ijcard.2014.12.045] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 10/31/2014] [Accepted: 12/20/2014] [Indexed: 12/21/2022]
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Li T, Zhou R, Yao Y, Yang Q, Zhou C, Wu W, Li Q, You Z, Zhao X, Yang L, Li C, Zhu D, Qiu Y, Luo M, Tan Z, Li H, Chen Y, Gong G, Feng Y, Dian K, Liu J. Angiotensin-converting enzyme inhibitor captopril reverses the adverse cardiovascular effects of polymerized hemoglobin. Antioxid Redox Signal 2014; 21:2095-108. [PMID: 24483164 PMCID: PMC4215427 DOI: 10.1089/ars.2013.5606] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
AIM Cell-free hemoglobin-based oxygen carriers (HBOCs) may increase the risk of myocardial infarction and death. We studied the effect of an angiotensin-converting enzyme (ACE) inhibitor on HBOC-induced adverse cardiovascular outcomes and elucidated the underlying mechanisms. RESULTS With a dog cardiopulmonary bypass model, we demonstrated that a high-dose HBOC (3%, w/v) did not reduce-but aggravated-cardiac ischemia/reperfusion injury. Animals administered a high-dose HBOC experienced coronary artery constriction and depression of cardiac function. Exposure of isolated coronary arteries or human umbilical vein endothelial cells to high-dose HBOC caused impaired endothelium-dependent relaxation, increased endothelial cell necrosis/apoptosis, and elevated NAD(P)H oxidase expression (gp91(phox), p47(phox), p67(phox), and Nox1) and reactive oxygen species (ROS) production. All observed adverse outcomes could be suppressed by the ACE inhibitor captopril (100 μM). Co-incubation with free radical scavenger tempol or NAD(P)H oxidase inhibitor apocynin had no effect on captopril action, suggesting that the positive effects of captopril are ROS- and NAD(P)H oxidase dependent. ACE inhibition by captopril also contributed to these effects. In addition, bioavailable nitrite oxide (NO) reduced by high-dose HBOC was preserved by captopril. Furthermore, HBOC, at concentrations greater than 0.5%, inhibited large conductance Ca(2+)-activated K(+) channel currents in vascular smooth muscle cells in a dose-dependent manner, although captopril failed to improve current activity, providing additional evidence that captopril's effects are mediated by the endothelium, but not by the smooth muscle. INNOVATION AND CONCLUSION Captopril alleviates high-dose HBOC-induced endothelial dysfunction and myocardial toxicity, which is mediated by synergistic depression of NAD(P)H oxidase subunit overproduction and increases in vascular NO bioavailability.
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Affiliation(s)
- Tao Li
- 1 Laboratory of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University , Chengdu, China
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Ogbi M, Obi I, Johnson JA. An inhibitor of the δPKC interaction with the d subunit of F1Fo ATP synthase reduces cardiac troponin I release from ischemic rat hearts: utility of a novel ammonium sulfate precipitation technique. PLoS One 2013; 8:e70580. [PMID: 23936451 PMCID: PMC3731279 DOI: 10.1371/journal.pone.0070580] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 06/20/2013] [Indexed: 11/19/2022] Open
Abstract
We have previously reported protection against hypoxic injury by a cell-permeable, mitochondrially-targeted δPKC-d subunit of F1Fo ATPase (dF1Fo) interaction inhibitor [NH2-YGRKKRRQRRRMLA TRALSLIGKRAISTSVCAGRKLALKTIDWVSFDYKDDDDK-COOH] in neonatal cardiac myo-cytes. In the present work we demonstrate the partitioning of this peptide to the inner membrane and matrix of mitochondria when it is perfused into isolated rat hearts. We also used ammonium sulfate ((NH4)2SO4) and chloroform/methanol precipitation of heart effluents to demonstrate reduced card-iac troponin I (cTnI) release from ischemic rat hearts perfused with this inhibitor. 50% (NH4)2SO4 saturation of perfusates collected from Langendorff rat heart preparations optimally precipitated cTnI, allowing its detection in Western blots. In hearts receiving 20 min of ischemia followed by 30, or 60 min of reperfusion, the Mean±S.E. (n=5) percentage of maximal cTnI release was 30 ± 7 and 60 ± 17, respectively, with additional cTnI release occurring after 150 min of reperfusion. Perfusion of hearts with the δPKC-dF1Fo interaction inhibitor, prior to 20 min of ischemia and 60-150 min of reperfusion, reduced cTnI release by 80%. Additionally, we found that when soybean trypsin inhibitor (SBTI), was added to rat heart effluents, it could also be precipitated using (NH4)2SO4 and detected in western blots. This provided a convenient method for normalizing protein recoveries between groups. Our results support the further development of the δPKC-dF1Fo inhibitor as a potential therapeutic for combating cardiac ischemic injury. In addition, we have developed an improved method for the detection of cTnI release from perfused rat hearts.
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Affiliation(s)
- Mourad Ogbi
- Department of Pharmacology & Toxicology and Program in Regenerative Medicine, Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, Georgia, United States of America
| | - Ijeoma Obi
- Department of Pharmacology & Toxicology and Program in Regenerative Medicine, Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, Georgia, United States of America
| | - John A. Johnson
- Department of Pharmacology & Toxicology and Program in Regenerative Medicine, Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, Georgia, United States of America
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