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Almela P, Victoria Milanés M, Luisa Laorden M. Tyrosine hydroxylase phosphorylation after naloxone-induced morphine withdrawal in the left ventricle. Basic Res Cardiol 2008; 104:366-76. [DOI: 10.1007/s00395-008-0768-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 11/19/2008] [Indexed: 12/27/2022]
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Garlid KD, Costa ADT, Quinlan CL, Pierre SV, Dos Santos P. Cardioprotective signaling to mitochondria. J Mol Cell Cardiol 2008; 46:858-66. [PMID: 19118560 DOI: 10.1016/j.yjmcc.2008.11.019] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 11/07/2008] [Accepted: 11/26/2008] [Indexed: 01/05/2023]
Abstract
Mitochondria are central players in the pathophysiology of ischemia-reperfusion. Activation of plasma membrane G-coupled receptors or the Na,K-ATPase triggers cytosolic signaling pathways that result in cardioprotection. Our working hypothesis is that the occupied receptors migrate to caveolae, where signaling enzymes are scaffolded into signalosomes that bud off the plasma membrane and migrate to mitochondria. The signalosome-mitochondria interaction then initiates intramitochondrial signaling by opening the mitochondrial ATP-sensitive K(+) channel (mitoK(ATP)). MitoK(ATP) opening causes an increase in ROS production, which activates mitochondrial protein kinase C epsilon (PKCvarepsilon), which inhibits the mitochondrial permeability transition (MPT), thus decreasing cell death. We review the experimental findings that bear on these hypotheses and other modes of protection involving mitochondria.
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Affiliation(s)
- Keith D Garlid
- Department of Biology, Portland State University, Portland, OR 97201-0751, USA.
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Abstract
This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd.,Flushing, NY 11367, United States.
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Zhai P, Sadoshima J. Overcoming an energy crisis?: an adaptive role of glycogen synthase kinase-3 inhibition in ischemia/reperfusion. Circ Res 2008; 103:910-3. [PMID: 18948628 DOI: 10.1161/01.res.0000338259.37472.b6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cardioprotective effects of propofol in isolated ischemia-reperfused guinea pig hearts: role of KATP channels and GSK-3beta. Can J Anaesth 2008; 55:595-605. [PMID: 18840589 DOI: 10.1007/bf03021433] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE Propofol exerts cardioprotective effects, but the involved mechanisms remain obscure. The present study examines the cardioprotective effects of propofol and its role in cardiac function, including its effect on K(ATP) channel opening and the inhibition of GSK-3beta activity in ischemia-reperfused hearts. METHODS Ischemia-reperfusion (I/R) was produced in isolated guinea pig hearts by stopping coronary perfusion for 25 min, followed by reperfusion. The hearts were incubated for ten minutes, with or without propofol (25 or 50 microM), or for five minutes with 500 microM 5-hydroxydecanoate (a mitochondrial K(ATP) channel blocker) or 30 microM HMR1098 (sarcolemmal K(ATP) channel blocker), followed by five minutes with 50 microM propofol before ischemia. Action potentials on the anterior epicardial surface of the ventricle were monitored using a high-resolution charge-coupled device camera system, and at five minutes after reperfusion, GSK-3beta phosphorylation at the serine residue, Ser9, was examined. RESULTS After 35 min of reperfusion, propofol (25 and 50 microM) blunted the adverse effects of I/R and reduced infarct size (P < 0.05). In addition, prior incubation with 5-hydroxydecanoate or HMR1098 had no effect on functional recovery improved by 50 microM propofol. At five minutes after reperfusion, propofol (25 and 50 microM) shortened the duration of the action potential and increased the levels of phospho-GSK-3beta (P < 0.05). CONCLUSIONS Propofol enhanced mechanical cardiac recovery and reduced infarct size. The data further suggest that GSK-3beta play an important role in propofol cardioprotective actions during coronary reperfusion, but mitochondrial K(ATP) channels do not.
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Das S, Wong R, Rajapakse N, Murphy E, Steenbergen C. Glycogen synthase kinase 3 inhibition slows mitochondrial adenine nucleotide transport and regulates voltage-dependent anion channel phosphorylation. Circ Res 2008; 103:983-91. [PMID: 18802025 DOI: 10.1161/circresaha.108.178970] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Inhibition of glycogen synthase kinase (GSK)-3 reduces ischemia/reperfusion injury by mechanisms that involve the mitochondria. The goal of this study was to explore possible molecular targets and mechanistic basis of this cardioprotective effect. In perfused rat hearts, treatment with GSK inhibitors before ischemia significantly improved recovery of function. To assess the effect of GSK inhibitors on mitochondrial function under ischemic conditions, mitochondria were isolated from rat hearts perfused with GSK inhibitors and were treated with uncoupler or cyanide or were made anoxic. GSK inhibition slowed ATP consumption under these conditions, which could be attributable to inhibition of ATP entry into the mitochondria through the voltage-dependent anion channel (VDAC) and/or adenine nucleotide transporter (ANT) or to inhibition of the F(1)F(0)-ATPase. To determine the site of the inhibitory effect on ATP consumption, we measured the conversion of ADP to AMP by adenylate kinase located in the intermembrane space. This assay requires adenine nucleotide transport across the outer but not the inner mitochondrial membrane, and we found that GSK inhibitors slow AMP production similar to their effect on ATP consumption. This suggests that GSK inhibitors are acting on outer mitochondrial membrane transport. In sonicated mitochondria, GSK inhibition had no effect on ATP consumption or AMP production. In intact mitochondria, cyclosporin A had no effect, indicating that ATP consumption is not caused by opening of the mitochondrial permeability transition pore. Because GSK is a kinase, we assessed whether protein phosphorylation might be involved. Therefore, we performed Western blot and 1D/2D gel phosphorylation site analysis using phos-tag staining to indicate proteins that had decreased phosphorylation in hearts treated with GSK inhibitors. Liquid chromatographic-mass spectrometric analysis revealed 1 of these proteins to be VDAC2. Taken together, we found that GSK-mediated signaling modulates transport through the outer membrane of the mitochondria. Both proteomics and adenine nucleotide transport data suggest that GSK regulates VDAC and that VDAC may be an important regulatory site in ischemia/reperfusion injury.
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Affiliation(s)
- Samarjit Das
- Department of Pathology, Johns Hopkins University, Baltimore, MD 21205, USA
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Pagel PS, Krolikowski JG, Pratt PF, Shim YH, Amour J, Warltier DC, Weihrauch D. Inhibition of glycogen synthase kinase or the apoptotic protein p53 lowers the threshold of helium cardioprotection in vivo: the role of mitochondrial permeability transition. Anesth Analg 2008; 107:769-75. [PMID: 18713881 DOI: 10.1213/ane.0b013e3181815b84] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Prosurvival signaling kinases inhibit glycogen synthase kinase-3beta (GSK-3beta) activity and stimulate apoptotic protein p53 degradation. Helium produces cardioprotection by activating prosurvival kinases, but whether GSK and p53 inhibition mediate this process is unknown. We tested the hypothesis that inhibition of GSK or p53 lowers the threshold of helium cardioprotection via a mitochondrial permeability transition pore (mPTP)-dependent mechanism. METHODS Rabbits (n = 85) instrumented for hemodynamic measurement and subjected to a 30 min left anterior descending coronary artery (LAD) occlusion and 3 h reperfusion received 0.9% saline (control), or 1, 3, or 5 cycles of 70% helium-30% oxygen administered for 5 min interspersed with 5 min of an air-oxygen mixture (fraction of inspired oxygen concentration = 0.30) before LAD occlusion. Other rabbits received the GSK inhibitor SB 216763 (SB21; 0.2 or 0.6 mg/kg), the p53 inhibitor pifithrin-alpha (PIF; 1.5 or 3.0 mg/kg), or SB21 (0.2 mg/kg) or PIF (1.5 mg/kg) plus helium (1 cycle) before LAD occlusion in the presence or absence of the mPTP opener atractyloside (5 mg/kg). RESULTS Helium reduced (P < 0.05) myocardial infarct size (35 +/- 6 [n = 7], 25 +/- 4 [n = 7], and 20 +/- 3% [n = 6] of area at risk, 1, 3, and 5 cycles, respectively) compared with control (44 +/- 6% [n = 7]). SB21 (0.6 [n = 7] but not 0.2 mg/kg [n = 6]) and PIF (3.0 [n = 6] but not 1.5 mg/kg [n = 7]) also reduced necrosis. SB21 (0.2 mg/kg) or 1.5 mg/kg PIF (1.5 mg/kg) plus helium (1 cycle; n = 6 per group) decreased infarct size to an equivalent degree as three cycles of helium alone, and this cardioprotection was blocked by atractyloside (n = 7 per group). CONCLUSIONS Inhibition of GSK or p53 lowers the threshold of helium-induced preconditioning via a mPTP-dependent mechanism in vivo.
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Affiliation(s)
- Paul S Pagel
- Clement J. Zablocki Veterans Affairs Medical Center, Anesthesia Service, 5000 W. National Ave., Milwaukee, WI 53295, USA.
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Cohen MV, Yang XM, Downey JM. Acidosis, oxygen, and interference with mitochondrial permeability transition pore formation in the early minutes of reperfusion are critical to postconditioning's success. Basic Res Cardiol 2008; 103:464-71. [PMID: 18626679 DOI: 10.1007/s00395-008-0737-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 06/19/2008] [Indexed: 11/24/2022]
Abstract
Repetitive cycles of reflow/reocclusion in the initial 2 min following release of a prolonged coronary occlusion, i.e., ischemic postconditioning (IPoC), salvages ischemic myocardium. We have proposed that the intermittent ischemia prevents formation of mitochondrial permeability transition pores (MPTP) by maintaining an acidic myocardial pH for several minutes until survival kinases can be activated. To determine other requisites of IPoC, isolated rabbit hearts were subjected to 30 min of regional myocardial ischemia and 120 min of reperfusion. Infarct size was determined by staining with triphenyltetrazolium chloride. During the first 2 min of reperfusion the perfusate was either at pH 7.4 following equilibration with 95% O(2)/5% CO(2), pH 6.9 following equilibration with 80% N(2)/20% CO(2), or pH 7.8 following equilibration with 100% O(2). Whereas acidic, oxygenated perfusate for the first 2 min of reperfusion was cardioprotective, protection was lost when acidic perfusate was hypoxic. However, the acidic, hypoxic hearts could be rescued by addition of phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, to the perfusate. Therefore, both low pH and restoration of oxygenation are necessary for protection, and the signaling step requiring combined oxygen and H(+) must be upstream of PKC. To gain further insight into the mechanism of IPoC, the latter was effected with 6 cycles of 10-s reperfusion/10-s reocclusion. Its protective effect was abrogated by either making the oxygenated perfusate alkaline during the reperfusion phases or making the reperfusion buffer hypoxic. Presumably the repeated coronary occlusions during IPoC keep myocardial pH low while the resupply of oxygen during the intermittent reperfusion provides fuel for the redox signaling that acts to prevent MPTP formation even after restoration of normal myocardial pH. Hearts treated simultaneously with IPoC and alkaline perfusate could not be rescued by addition to the perfusate of either PMA or SB216763 which inhibits GSK-3beta, the putative last cytoplasmic signaling step in the signal transduction cascade leading to MPTP inhibition. Yet cyclosporin A which also inhibits MPTP formation does rescue hearts made alkaline during IPoC. In view of prior studies in which the ROS scavenger N-2-mercaptopropionyl glycine aborts IPoC's protection, our data reveal that IPoC's reperfusion periods are needed to support redox signaling rather than improve metabolism. The low pH, on the other hand, is equally necessary and seems to suppress MPTP directly rather than through upstream signaling.
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Affiliation(s)
- Michael V Cohen
- Dept. of Physiology, University of South Alabama, College of Medicine, Mobile, AL 36688, USA.
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Peart JN, Headrick JP. Sustained cardioprotection: exploring unconventional modalities. Vascul Pharmacol 2008; 49:63-70. [PMID: 18675381 DOI: 10.1016/j.vph.2008.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 06/27/2008] [Accepted: 07/08/2008] [Indexed: 01/18/2023]
Abstract
Since Murry et al. [Murry, C.E., Jennings, R.B., Reimer, K.A., 1986. Preconditioning with ischemia: a delay of lethal cell injury in ischemic myocardium. Circulation. 74, 1124-36.] initially reported on the powerful protective effects of ischemic preconditioning (PC), a plethora of experimental investigations have identified varied preconditioning protocols or mimetics to achieve cardioprotection. These stimuli predominantly act via archetypal mediators identified in associated signalling studies (including PI3-K, Akt, PKC, mitochondrial K(ATP) channels). Despite an intense research effort over the last 20 years, there remains a paucity of evidence that this protective paradigm is clinically exploitable. This may arise due to a number of drawbacks to conventional protection, including effects of age, disease, and interactions with other pharmacological agents. This encourages investigation of alternate strategies that trigger protection via unconventional signalling (distinct from conventional PC) and/or mediate sustained shifts in ischemic tolerance in hearts of varying age and disease status. This review considers briefly drawbacks to conventional PC, and focuses on alternate strategies for generating prolonged states of cardiac protection.
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Affiliation(s)
- Jason N Peart
- Heart Foundation Research Centre, Griffith University, Australia.
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ROS-independent preconditioning in neurons via activation of mitoK(ATP) channels by BMS-191095. J Cereb Blood Flow Metab 2008; 28:1090-103. [PMID: 18212794 DOI: 10.1038/sj.jcbfm.9600611] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Previously, we have shown that the selective mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel opener BMS-191095 (BMS) induces neuronal preconditioning (PC); however, the exact mechanism of BMS-induced neuroprotection remains unclear. In this study, we have identified key components of the cascade resulting in delayed neuronal PC with BMS using isolated rat brain mitochondria and primary cultures of rat cortical neurons. BMS depolarized isolated mitochondria without an increase in reactive oxygen species (ROS) generation and induced rapid phosphorylation of Akt and glycogen synthase kinase-3beta. Long-term (3 days) treatment of neurons with BMS resulted in sustained mitochondrial depolarization, decreased basal ROS generation, and elevated ATP levels. This treatment also elicited almost complete protection against glutamate excitotoxicity, which could be abolished using the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin, but not with the superoxide dismutase (SOD) mimetic M40401. Long-term BMS treatment induced a PI3K-dependent increase in the expression and activity of catalase without affecting manganese SOD and copper/zinc-dependent SOD. Finally, the catalase inhibitor 3-aminotriazole dose-dependently antagonized the neuroprotective effect of BMS-induced PC. In summary, BMS depolarizes mitochondria without ROS generation, activates the PI3K-Akt pathway, improves ATP content, and increases catalase expression. These mechanisms appear to play important roles in the neuroprotective effect of BMS.
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Pagel PS. Postconditioning by volatile anesthetics: salvaging ischemic myocardium at reperfusion by activation of prosurvival signaling. J Cardiothorac Vasc Anesth 2008; 22:753-65. [PMID: 18922439 DOI: 10.1053/j.jvca.2008.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Indexed: 12/26/2022]
Affiliation(s)
- Paul S Pagel
- Anesthesia Service, Clement J Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA.
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Signal transducer and activator of transcription 3 is involved in the cardioprotective signalling pathway activated by insulin therapy at reperfusion. Basic Res Cardiol 2008; 103:444-53. [PMID: 18500485 DOI: 10.1007/s00395-008-0728-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 04/23/2008] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To evaluate the significance of the JAK-STAT pathway in insulin-induced cardioprotection from reperfusion injury. METHODS In isolated perfused rat hearts subjected to insulin therapy (0.3 mU/ml) +/- AG490 (5 microM, JAK-STAT inhibitor), the phosphorylation state of STAT3 and Akt was determined after 15 min of reperfusion. Infarct size was measured after 120 min of reperfusion. Isolated cardiac myocytes from wild type (WT) and cardiac specific STAT3 deficient mice were treated with insulin at reoxygenation following simulated ischemia (SI, 26 h). Cell viability was measured after 120 min of reoxygenation following SI, whereas phosphorylation state of Akt was measured after 15 min of reoxygenation following SI. RESULTS Insulin given at reperfusion led to phosphorylation of STAT3 and Akt both of which were inhibited by AG490. AG490 also blocked the insulin-dependent decrease in infarct size, supporting a role for JAK-STAT in cardioprotection. In addition, insulin protection from SI was blocked in myocytes from the STAT3 deficient mice, or in WT mice treated with AG490. Furthermore, insulin failed to phosphorylate Akt in the STAT3 deficient cardiomyocytes. CONCLUSION Insulin-induced cardioprotection at reperfusion occurs through activation of STAT3. Inhibiting STAT3 by AG490, or STAT3 depletion in cardiac myocytes affects activation of Akt, suggesting close interaction between STAT3 and Akt in the cardioprotective signalling pathway activated by insulin treatment at reperfusion.
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Peart JN, Gross ER, Reichelt ME, Hsu A, Headrick JP, Gross GJ. Activation of kappa-opioid receptors at reperfusion affords cardioprotection in both rat and mouse hearts. Basic Res Cardiol 2008; 103:454-63. [DOI: 10.1007/s00395-008-0726-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Accepted: 04/30/2008] [Indexed: 12/27/2022]
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Gross ER, Hsu AK, Gross GJ. Delayed cardioprotection afforded by the glycogen synthase kinase 3 inhibitor SB-216763 occurs via a KATP- and MPTP-dependent mechanism at reperfusion. Am J Physiol Heart Circ Physiol 2008; 294:H1497-500. [PMID: 18223186 DOI: 10.1152/ajpheart.01381.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies in our laboratory suggest that an acute inhibition of glycogen synthase kinase 3 (GSK3) by SB-216763 (SB21) is cardioprotective when administered just before reperfusion. However, it is unknown whether the GSK inhibitor SB21 administered 24 h before ischemia is cardioprotective and whether the mechanism involves ATP-sensitive potassium (K(ATP)) channels and the mitochondrial permeability transition pore (MPTP). Male Sprague-Dawley rats were administered the GSK inhibitor SB21 (0.6 mg/kg) or vehicle 24 h before ischemia. Subsequently, the rats were acutely anesthetized with Inactin and underwent 30 min of ischemia and 2 h of reperfusion followed by infarct size determination. Subsets of rats received either the sarcolemmal K(ATP) channel blocker HMR-1098 (6 mg/kg), the mitochondrial K(ATP) channel blocker 5-hydroxydecanoic acid (5-HD; 10 mg/kg), or the MPTP opener atractyloside (5 mg/kg) either 5 min before SB21 administration or 5 min before reperfusion 24 h later. The infarct size was reduced in SB21 compared with vehicle (44 +/- 2% vs. 61 +/- 2%, respectively; P < 0.01). 5-HD administered either before SB21 treatment or 5 min before reperfusion the following day abrogated SB21-induced protection (54 +/- 4% and 61 +/- 2%, respectively). HMR-1098 did not affect the SB21-induced infarct size reduction when administered before the SB21 treatment (43 +/- 1%); however, HMR-1098 partially abrogated the SB21-induced infarct size reduction when administered just before reperfusion 24 h later (52 +/- 1%). The MPTP opening either before SB21 administration or 5 min before reperfusion abrogated the infarct size reduction produced by SB21 (61 +/- 2% and 62 +/- 2%, respectively). Hence, GSK inhibition reduces infarct size when given 24 h before the administration via the opening K(ATP) channels and MPTP closure.
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Affiliation(s)
- Eric R Gross
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Lee YC, Jang YH, Kim JM, Kim AR, Kim CJ, Kim YN. Effect of A Kappa-opioid Receptor Agonist U50488H Given at Early Reperfusion Phase in Isolated Rat Hearts. Korean J Anesthesiol 2008. [DOI: 10.4097/kjae.2008.54.3.s29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Yong Cheol Lee
- Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea
| | - Young Ho Jang
- Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea
| | - Jin Mo Kim
- Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea
| | - Ae Ra Kim
- Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea
| | - Chan Jin Kim
- Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea
| | - Yoon Nyun Kim
- Department of Internal Medicine, School of Medicine, Keimyung University, Daegu, Korea
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Liu Y, Yang XM, Iliodromitis EK, Kremastinos DT, Dost T, Cohen MV, Downey JM. Redox signaling at reperfusion is required for protection from ischemic preconditioning but not from a direct PKC activator. Basic Res Cardiol 2008; 103:54-9. [PMID: 17999029 PMCID: PMC2660167 DOI: 10.1007/s00395-007-0683-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 10/01/2007] [Indexed: 10/22/2022]
Abstract
Redox signaling prior to a lethal ischemic insult is an important step in triggering the protected state in ischemic preconditioning. When the preconditioned heart is reperfused a second sequence of signal transduction events, the mediator pathway, occurs which is believed to inhibit mitochondrial permeability transition pore formation that normally destroys mitochondria in much of the reperfused tissue. Prominent among the mediator pathway's events is activation of phosphatidylinositol 3-kinase and extracellular signal-regulated kinase. Recently it was found that both activation of PKC and generation of reactive oxygen species (ROS) at the time of reperfusion are required for protection in preconditioned hearts. To establish their relative order we tested whether ROS formation at reperfusion is required in hearts protected by direct activation of PKC at reperfusion. Isolated rabbit hearts were exposed to 30 min of regional ischemia and 2 h of reperfusion. Preconditioned hearts received 5 min of global ischemia and 10 min of reperfusion prior to the index ischemia. Another group of preconditioned hearts was exposed to 300 microM of the ROS scavenger N-(2-mercaptopropionyl) glycine (MPG) for 20 min starting 5 min prior to reperfusion. Infarct size was measured by triphenyltetrazolium staining. Preconditioning reduced infarct size from 36% +/- 2% of the ischemic zone in control hearts to only 18 +/- 2%. MPG during early reperfusion completely blocked preconditioning's protection (33 +/- 3% infarction). MPG given in the same dose and schedule to non-preconditioned hearts had no effect on infarct size. In the last group phorbol 12-myristate 13-acetate (PMA) (0.05 nM) was given to non-preconditioned hearts from 1 min before to 5 min after reperfusion in addition to MPG administered as in the other groups. MPG did not block protection from an infusion of PMA as infarct size was only 9 +/- 2% of the risk zone. We conclude that while redox signaling during the first few minutes of reperfusion is an essential component of preconditioning's protective mechanism, this step occurs upstream of PKC activation.
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Affiliation(s)
- Yanping Liu
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Xi-Ming Yang
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Efstathios K. Iliodromitis
- Second University Department of Cardiology, Attikon General Hospital, Medical School, University of Athens, Athens, Greece
| | - Dimitrios Th. Kremastinos
- Second University Department of Cardiology, Attikon General Hospital, Medical School, University of Athens, Athens, Greece
| | - Turhan Dost
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Michael V. Cohen
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Department of Medicine, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - James M. Downey
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama, USA
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Abstract
Advanced age is a strong independent predictor for death, disability, and morbidity in patients with structural heart disease. With the projected increase in the elderly population and the prevalence of age-related cardiovascular disabilities worldwide, the need to understand the biology of the aging heart, the mechanisms for age-mediated cardiac vulnerability, and the development of strategies to limit myocardial dysfunction in the elderly have never been more urgent. Experimental evidence in animal models indicate attenuation in cardioprotective pathways with aging, yet limited information is available regarding age-related changes in the human heart. Human cardiac aging generates a complex phenotype, only partially replicated in animal models. Here, we summarize current understanding of the aging heart stemming from clinical and experimental studies, and we highlight targets for protection of the vulnerable senescent myocardium. Further progress mandates assessment of human tissue to dissect specific aging-associated genomic and proteomic dynamics, and their functional consequences leading to increased susceptibility of the heart to injury, a critical step toward designing novel therapeutic interventions to limit age-related myocardial dysfunction and promote healthy aging.
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Affiliation(s)
- Arshad Jahangir
- Marriott Heart Disease Research Program, Division of Cardiovascular Diseases, and Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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