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Wang J, Papanicolaou K, Tryon R, Sangalang J, Salazar B, Suarez-Pierre A, Dong J, Lee A, Larson E, Holmes S, O’Rourke B, Nichols C, Lawton J. Kir1.1 and SUR1 are not implicated as subunits of an adenosine triphosphate-sensitive potassium channel involved in diazoxide cardioprotection. JTCVS OPEN 2023; 15:231-241. [PMID: 37808059 PMCID: PMC10556815 DOI: 10.1016/j.xjon.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/29/2023] [Accepted: 06/06/2023] [Indexed: 10/10/2023]
Abstract
Objective The adenosine triphosphate-sensitive potassium channel opener diazoxide mimics ischemic preconditioning and is cardioprotective. Clarification of diazoxide's site and mechanism of action could lead to targeted pharmacologic therapies for patients undergoing cardiac surgery. Several mitochondrial candidate proteins have been investigated as potential adenosine triphosphate-sensitive potassium channel components. Renal outer medullary potassium (Kir1.1) and sulfonylurea sensitive regulatory subunit 1 have been suggested as subunits of a mitochondrial adenosine triphosphate-sensitive potassium channel. We hypothesized that pharmacologic blockade or genetic deletion (knockout) of renal outer medullary potassium and sensitive regulatory subunit 1 would result in loss of diazoxide cardioprotection in models of global ischemia with cardioplegia. Methods Myocyte volume and contractility were compared after Tyrode's physiologic solution (20 minutes), stress (hyperkalemic cardioplegia ± diazoxide, ± VU591 (Kir1.1 inhibitor), N = 9 to 23 each, 20 min), and Tyrode's (20 minutes). Isolated mouse (wild-type, sensitive regulatory subunit 1 [-/-], and cardiac knockout renal outer medullary potassium) hearts were given cardioplegia ± diazoxide (N = 9-16 each) before global ischemia (90 minutes) and 30 minutes reperfusion. Left ventricular pressures were compared before and after ischemia. Results Stress (cardioplegia) was associated with reduced myocyte contractility that was prevented by diazoxide. Isolated myocytes were not responsive to diazoxide in the presence of VU591. In isolated hearts, diazoxide improved left ventricular function after prolonged ischemia compared with cardioplegia alone in wild-type and knockout (sensitive regulatory subunit 1 [-/-] and cardiac knockout renal outer medullary potassium) mice. Conclusions Isolated myocyte and heart models may measure independent and separate actions of diazoxide. By definitive genetic deletion, these data indicate that sensitive regulatory subunit 1 and renal outer medullary potassium are not implicated in cardioprotection by diazoxide.
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Affiliation(s)
- Jie Wang
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Kyriakos Papanicolaou
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Md
| | - Robert Tryon
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Mo
| | - Janelle Sangalang
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Ben Salazar
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Md
| | | | - Jie Dong
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Anson Lee
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Emily Larson
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Sari Holmes
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Brian O’Rourke
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Md
| | - Colin Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Mo
| | - Jennifer Lawton
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
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Velez AK, Etchill E, Giuliano K, Kearney S, Jones M, Wang J, Cho B, Brady MB, Dodd‐o J, Meyer JM, Lawton JS. ATP-Sensitive Potassium Channel Opener Diazoxide Reduces Myocardial Stunning in a Porcine Regional With Subsequent Global Ischemia Model. J Am Heart Assoc 2022; 11:e026304. [PMID: 36444837 PMCID: PMC9851454 DOI: 10.1161/jaha.122.026304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background ATP-sensitive potassium channels are inhibited by ATP and open during metabolic stress, providing endogenous myocardial protection. Pharmacologic opening of ATP potassium channels with diazoxide preserves myocardial function following prolonged global ischemia, making it an ideal candidate for use during cardiac surgery. We hypothesized that diazoxide would reduce myocardial stunning after regional ischemia with subsequent prolonged global ischemia, similar to the clinical situation of myocardial ischemia at the time of revascularization. Methods and Results Swine underwent left anterior descending occlusion (30 minutes), followed by 120 minutes global ischemia protected with hyperkalemic cardioplegia±diazoxide (N=6 each), every 20 minutes cardioplegia, then 60 minutes reperfusion. Cardiac output, time to wean from cardiopulmonary bypass, left ventricular (LV) function, caspase-3, and infarct size were compared. Six animals in the diazoxide group separated from bypass by 30 minutes, whereas only 4 animals in the cardioplegia group separated. Diazoxide was associated with shorter but not significant time to wean from bypass (17.5 versus 27.0 minutes; P=0.13), higher, but not significant, cardiac output during reperfusion (2.9 versus 1.5 L/min at 30 minutes; P=0.05), and significantly higher left ventricular ejection fraction at 30 minutes (42.5 versus 15.8%; P<0.01). Linear mixed regression modeling demonstrated greater left ventricular developed pressure (P<0.01) and maximum change in ventricular pressure during isovolumetric contraction (P<0.01) in the diazoxide group at 30 minutes of reperfusion. Conclusions Diazoxide reduces myocardial stunning and facilitates separation from cardiopulmonary bypass in a model that mimics the clinical setting of ongoing myocardial ischemia before revascularization. Diazoxide has the potential to reduce myocardial stunning in the clinical setting.
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Affiliation(s)
- Ana K. Velez
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Eric Etchill
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Katherine Giuliano
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Sean Kearney
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Melissa Jones
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Jie Wang
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
| | - Brian Cho
- Division of Cardiac Anesthesiology, Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Mary Beth Brady
- Division of Cardiac Anesthesiology, Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Jeffrey Dodd‐o
- Division of Cardiac Anesthesiology, Department of Anesthesiology and Critical Care MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Joseph M. Meyer
- Division of Cardiology, Department of MedicineJohns Hopkins University School of MedicineBaltimoreMD
| | - Jennifer S. Lawton
- Division of Cardiac Surgery, Department of SurgeryJohns Hopkins University School of MedicineBaltimoreMD
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Ahmad T, Wang J, Velez AK, Suarez-Pierre A, Clement KC, Dong J, Sebestyen K, Canner JK, Murphy MP, Lawton JS. Cardioprotective mechanisms of mitochondria-targeted S-nitrosating agent and adenosine triphosphate-sensitive potassium channel opener are mutually exclusive. JTCVS OPEN 2021; 8:338-354. [PMID: 36004142 PMCID: PMC9390287 DOI: 10.1016/j.xjon.2021.07.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 07/30/2021] [Indexed: 11/22/2022]
Abstract
Background Myocytes exposed to stress exhibit significant swelling and reduced contractility. These consequences are ameliorated by adenosine triphosphate-sensitive potassium (KATP) channel opener diazoxide (DZX) via an unknown mechanism. KATP channel openers also provide cardioprotection in multiple animal models. Nitric oxide donors are similarly cardioprotective, and their combination with KATP activation may provide synergistic benefit. We hypothesized that mitochondria-targeted S-nitrosating agent (MitoSNO) would provide synergistic cardioprotection with DZX. Methods Myocyte volume and contractility were compared following Tyrode's physiologic solution (20 minutes) and stress (hyperkalemic cardioplegia [CPG] ± DZX; n = 5-20 each; 20 minutes) with or without MitoSNO (n = 5-11 each) at the end of stress, followed by Tyrode's solution (20 minutes). Isolated mouse hearts received CPG ± DZX (n = 8-10 each) before global ischemia (90 minutes) with or without MitoSNO (n = 8 each) at the end of ischemia, followed by reperfusion (30 minutes). Left ventricular (LV) pressures were compared using a linear mixed model to assess the impact of treatment on the outcome, adjusting for baseline and balloon volume. Results Stress (CPG) was associated with reduced myocyte contractility that was prevented by DZX and MitoSNO individually; however, their combination was associated with loss of cardioprotection. Similarly, DZX and MitoSNO improved LV function after prolonged ischemia compared with CPG alone, and cardioprotection was lost with their combination. Conclusions MitoSNO and DZX provide cardioprotection that is lost with their combination, suggesting mutually exclusive mechanisms of action. The lack of a synergistic beneficial effect informs the current knowledge of the cardioprotective mechanisms of DZX and will aid planning of future clinical trials.
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Key Words
- CPG, cardioplegia
- DZX, diazoxide
- EDP, end-diastolic pressure
- KATP, adenosine triphosphate–sensitive potassium
- KHB, Krebs–Henseleit buffer
- LV, left ventricular
- LVDP, left ventricular developed pressure
- MitoSNO, mitochondrial-selective S–nitrosating agent
- NO, nitric oxide
- ROS, reactive oxygen species
- SDH, succinate dehydrogenase
- SUR, sulfonylurea
- basic science
- ion channels
- ischemia
- preconditioning
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Affiliation(s)
- Thaniyyah Ahmad
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Jie Wang
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Ana Karen Velez
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | | | - Kathleen C. Clement
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Jie Dong
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
| | - Krisztian Sebestyen
- Johns Hopkins Center for Outcomes Research, Johns Hopkins University, Baltimore, Md
| | - Joseph K. Canner
- Johns Hopkins Center for Outcomes Research, Johns Hopkins University, Baltimore, Md
| | - Michael P. Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Jennifer S. Lawton
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University, Baltimore, Md
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Makepeace CM, Suarez-Pierre A, Kanter EM, Schuessler RB, Nichols CG, Lawton JS. Superior diastolic function with K ATP channel opener diazoxide in a novel mouse Langendorff model. J Surg Res 2018; 227:186-193. [PMID: 29804852 DOI: 10.1016/j.jss.2018.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/11/2018] [Accepted: 02/14/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND Adenosine triphosphate-sensitive potassium (KATP) channel openers have been found to be cardioprotective in multiple animal models via an unknown mechanism. Mouse models allow genetic manipulation of KATP channel components for the investigation of this mechanism. Mouse Langendorff models using 30 min of global ischemia are known to induce measurable myocardial infarction and injury. Prolongation of global ischemia in a mouse Langendorff model could allow the determination of the mechanisms involved in KATP channel opener cardioprotection. METHODS Mouse hearts (C57BL/6) underwent baseline perfusion with Krebs-Henseleit buffer (30 min), assessment of function using a left ventricular balloon, delivery of test solution, and prolonged global ischemia (90 min). Hearts underwent reperfusion (30 min) and functional assessment. Coronary flow was measured using an inline probe. Test solutions included were as follows: hyperkalemic cardioplegia alone (CPG, n = 11) or with diazoxide (CPG + DZX, n = 12). RESULTS Although the CPG + DZX group had greater percent recovery of developed pressure and coronary flow, this was not statistically significant. Following a mean of 74 min (CPG) and 77 min (CPG + DZX), an additional increase in end-diastolic pressure was noted (plateau), which was significantly higher in the CPG group. Similarly, the end-diastolic pressure (at reperfusion and at the end of experiment) was significantly higher in the CPG group. CONCLUSIONS Prolongation of global ischemia demonstrated added benefit when DZX was added to traditional hyperkalemic CPG. This model will allow the investigation of DZX mechanism of cardioprotection following manipulation of targeted KATP channel components. This model will also allow translation to prolonged ischemic episodes associated with cardiac surgery.
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Affiliation(s)
- Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Alejandro Suarez-Pierre
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Evelyn M Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri; Center for the Investigation of Membrane Excitability Diseases (CIMED), Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer S Lawton
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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Henn MC, Janjua MB, Zhang H, Kanter EM, Makepeace CM, Schuessler RB, Nichols CG, Lawton JS. Increased tolerance to stress in cardiac expressed gain-of-function of adenosine triphosphate-sensitive potassium channel subunit Kir6.1. J Surg Res 2016; 206:460-465. [PMID: 27884343 DOI: 10.1016/j.jss.2016.08.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/22/2016] [Accepted: 08/05/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND The adenosine triphosphate-sensitive potassium (KATP) channel opener diazoxide (DZX) prevents myocyte volume derangement and reduced contractility secondary to stress. KATP channels are composed of pore-forming (Kir6.1 or Kir6.2) and regulatory (sulfonylurea receptor, SUR1 or SUR2) subunits. Gain of function (GOF) of Kir6.1 subunits has been implicated in cardiac pathology in Cantu syndrome in humans (cardiomegaly, lymphedema, and pericardial effusions). We hypothesized that GOF of Kir6.1 subunits would result in altered myocyte response to stress. MATERIALS AND METHODS Isolated cardiac myocytes from wild type (WT) and transgenic Kir6.1GOF mice were exposed to Tyrode's physiologic solution for 20 min, test solution (Tyrode's or stress [hyperkalemic cardioplegia {CPG, known myocyte stress}] +/- KATP channel opener DZX), followed by Tyrode's for 20 min. Myocyte volume and contractility were measured and compared. RESULTS WT myocytes demonstrated significant swelling in response to stress, but significantly less swelling was seen in Kir6.1GOF myocytes. DZX prevented swelling secondary to CPG in WT but resulted in a nonsignificant reduction in swelling in Kir6.1GOF myocytes. Both WT and Kir6.1GOF myocytes demonstrated a reduction in contractility during stress, although this was only significant in Kir6.1GOF myocytes. DZX was not associated with an improvement in contractility in Kir6.1GOF myocytes following stress. CONCLUSIONS Similar to previous results in Kir6.1(-/-) myocytes, Kir6.1GOF myocytes demonstrate resistance (less volume derangement) to stress of cardioplegia. Understanding the role of Kir6.1 in myocyte response to stress may aid in the treatment of patients with Cantu syndrome and warrants further investigation.
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Affiliation(s)
- Matthew C Henn
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - M Burhan Janjua
- Department of Neurological Surgery, Weill Cornell Medical College, New York, New York
| | - Haixia Zhang
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Evelyn M Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Jennifer S Lawton
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri.
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Gonca E, Rapposelli S, Darıcı F, Digiacomo M, Yılmaz Z. Antiarrhythmic activity of a new spiro-cyclic benzopyran activator of the cardiac mitochondrial ATP dependent potassium channels. Arch Pharm Res 2016; 39:1212-22. [PMID: 27357534 DOI: 10.1007/s12272-016-0779-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/18/2016] [Indexed: 11/24/2022]
Abstract
'Compound A' (4(ı)-(N-(4-acetamidobenzyl))-2,2-dimethyl-2,3-dihydro-5(ı)H-spiro[chromene-4,2(ı)-[1,4]oxazinan]-5(ı)-one) is a new spiro-cyclic benzopyran activator of the mitochondrial ATP-dependent potassium channels (mitoKATP). We researched the effect of compound A on ischemia/reperfusion (I/R)-induced ventricular arrhythmias. We also tested the hypothesis that the application of the activation of mitoKATP in combination with the inhibition of sarcolemmal ATP-dependent potassium channels (sarcKATP) may produce a stronger antiarrhythmic effect. In anesthetized rats, myocardial ischemia was performed by ligating the left main coronary artery followed by reperfusion. At a dose of 10 mg/kg, compound A significantly decreased arrhythmia scores and the total length of arrhythmias, whereas this was found to be ineffective at a dose of 3 mg/kg. Pre-treatment with 5-HD, a selective mitoKATP blocker, abolished the antiarrhythmic effect of compound A. Both diazoxide, a selective mitoKATP opener and HMR 1098, a selective sarcKATP blocker, significantly decreased the total length of arrhythmias. However, the combination of neither diazoxide nor compound A with HMR 1098 showed no additional therapeutic benefit. These results reveal that compound A may have a dose-dependent antiarrythmic effect, which is more pronounced than the antiarrhythmic effect of diazoxide. The antiarrhythmic effect of compound A may possibly depend on mitoKATP activation.
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Affiliation(s)
- Ersöz Gonca
- Department of Biology, Faculty of Art and Sciences, Bülent Ecevit University, Zonguldak, Turkey.
| | - Simona Rapposelli
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126, Pisa, Italy
| | - Faruk Darıcı
- Department of Biology, Faculty of Art and Sciences, Bülent Ecevit University, Zonguldak, Turkey
| | - Maria Digiacomo
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126, Pisa, Italy
| | - Zehra Yılmaz
- Department of Pharmacology, Faculty of Medicine, Harran University, Şanliurfa, Turkey
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Henn MC, Janjua MB, Kanter EM, Makepeace CM, Schuessler RB, Nichols CG, Lawton JS. Adenosine Triphosphate-Sensitive Potassium Channel Kir Subunits Implicated in Cardioprotection by Diazoxide. J Am Heart Assoc 2015; 4:e002016. [PMID: 26304939 PMCID: PMC4599460 DOI: 10.1161/jaha.115.002016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background ATP-sensitive potassium (KATP) channel openers provide cardioprotection in multiple models. Ion flux at an unidentified mitochondrial KATP channel has been proposed as the mechanism. The renal outer medullary kidney potassium channel subunit, potassium inward rectifying (Kir)1.1, has been implicated as a mitochondrial channel pore-forming subunit. We hypothesized that subunit Kir1.1 is involved in cardioprotection (maintenance of volume homeostasis and contractility) of the KATP channel opener diazoxide (DZX) during stress (exposure to hyperkalemic cardioplegia [CPG]) at the myocyte and mitochondrial levels. Methods and Results Kir subunit inhibitor Tertiapin Q (TPN-Q) was utilized to evaluate response to stress. Mouse ventricular mitochondrial volume was measured in the following groups: isolation buffer; 200 μmol/L of ATP; 100 μmol/L of DZX+200 μmol/L of ATP; or 100 μmol/L of DZX+200 μmol/L of ATP+TPN-Q (500 or 100 nmol/L). Myocytes were exposed to Tyrode’s solution (5 minutes), test solution (Tyrode’s, cardioplegia [CPG], CPG+DZX, CPG+DZX+TPN-Q, Tyrode’s+TPN-Q, or CPG+TPN-Q), N=12 for all (10 minutes); followed by Tyrode’s (5 minutes). Volumes were compared. TPN-Q, with or without DZX, did not alter mitochondrial or myocyte volume. Stress (CPG) resulted in myocyte swelling and reduced contractility that was prevented by DZX. TPN-Q prevented the cardioprotection afforded by DZX (volume homeostasis and maintenance of contractility). Conclusions TPN-Q inhibited myocyte cardioprotection provided by DZX during stress; however, it did not alter mitochondrial volume. Because TPN-Q inhibits Kir1.1, Kir3.1, and Kir3.4, these data support that any of these Kir subunits could be involved in the cardioprotection afforded by diazoxide. However, these data suggest that mitochondrial swelling by diazoxide does not involve Kir1.1, 3.1, or 3.4.
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Affiliation(s)
- Matthew C Henn
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
| | - M Burhan Janjua
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
| | - Evelyn M Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
| | - Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO (C.G.N.)
| | - Jennifer S Lawton
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (M.C.H., B.J., E.M.K., C.M.M., R.B.S., J.S.L.)
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Henn MC, Janjua MB, Zhang H, Kanter EM, Makepeace CM, Schuessler RB, Nichols CG, Lawton JS. Diazoxide Cardioprotection Is Independent of Adenosine Triphosphate-Sensitive Potassium Channel Kir6.1 Subunit in Response to Stress. J Am Coll Surg 2015; 221:319-25. [PMID: 25872691 DOI: 10.1016/j.jamcollsurg.2015.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/10/2015] [Indexed: 10/24/2022]
Abstract
BACKGROUND The sarcolemmal adenosine triphosphate-sensitive potassium channel (sK(ATP)), composed primarily of potassium inward rectifier (Kir) 6.2 and sulfonylurea receptor 2A subunits, has been implicated in cardiac myocyte volume regulation during stress; however, it is not involved in cardioprotection by the adenosine triphosphate-sensitive potassium channel (K(ATP)) channel opener diazoxide (7-chloro-3-methyl-1,2,4-benzothiadiazine-1,1-dioxide [DZX]). Paradoxically, the sK(ATP) channel subunit Kir6.2 is necessary for detrimental myocyte swelling secondary to stress. The Kir6.1 subunit can also contribute to K(ATP) channels in the heart, and we hypothesized that this subunit might play a role in myocyte volume regulation in response to stress. STUDY DESIGN Isolated cardiac myocytes from either wild-type mice or mice lacking the Kir6.1 subunit (Kir6.1[-/-]) were exposed to control Tyrode's solution (TYR) for 20 minutes, test solution (TYR, hypothermic hyperkalemic cardioplegia [CPG], or CPG + K(ATP) channel opener DZX [CPG + DZX]) for 20 minutes, followed by TYR for 20 minutes. Myocyte volume and contractility were measured and analyzed. RESULTS Both wild-type and Kir6.1(-/-) myocytes demonstrated substantial swelling during exposure to stress (CPG), which was prevented by DZX. Wild-type myocytes also demonstrated reduced contractility during stress of CPG that was prevented by DZX. However, Kir6.1(-/-) myocytes did not show reduced contractility during stress. CONCLUSIONS These data indicate that K(ATP) channel subunit Kir6.1 is not necessary for DZX's maintenance of cell volume during the stress of CPG. The absence of Kir6.1 does not affect the contractile properties of myocytes during stress, suggesting the absence of Kir6.1 improves myocyte tolerance to stress via an unknown mechanism.
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Affiliation(s)
- Matthew C Henn
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | | | - Haixia Zhang
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO
| | - Evelyn M Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO
| | - Jennifer S Lawton
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO.
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Janjua MB, Makepeace CM, Anastacio MM, Schuessler RB, Nichols CG, Lawton JS. Cardioprotective benefits of adenosine triphosphate-sensitive potassium channel opener diazoxide are lost with administration after the onset of stress in mouse and human myocytes. J Am Coll Surg 2014; 219:803-13. [PMID: 25158912 DOI: 10.1016/j.jamcollsurg.2014.05.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/28/2014] [Accepted: 05/06/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Adenosine triphosphate-sensitive (KATP) potassium channel opener diazoxide (DZX) maintains myocyte volume and contractility during stress via an unknown mechanism when administered at the onset of stress. This study was performed to investigate the cardioprotective potential of DZX when added after the onset of the stresses of hyperkalemic cardioplegia, metabolic inhibition, and hypo-osmotic stress. STUDY DESIGN Isolated mouse ventricular and human atrial myocytes were exposed to control Tyrode's solution (TYR) for 10 to 20 minutes, test solution for 30 minutes (hypothermic hyperkalemic cardioplegia [CPG], CPG + 100uM diazoxide [CPG+DZX], metabolic inhibition [MI], MI+DZX, mild hypo-osmotic stress [0.9T], or 0.9T + DZX), with DZX added after 10 or 20 minutes of stress, followed by 20 minutes of re-exposure to TYR (±DZX). Myocyte volume (human + mouse) and contractility (mouse) were compared. RESULTS Mouse and human myocytes demonstrated significant swelling during exposure to CPG, MI, and hypo-osmotic stress that was not prevented by DZX when administered either at 10 or 20 minutes after the onset of stress. Contractility after the stress of CPG in mouse myocytes significantly declined when DZX was administered 20 minutes after the onset of stress (p < 0.05 vs TYR). Contractility after hypo-osmotic stress in mouse myocytes was not altered by the addition of DZX. CONCLUSIONS To maintain myocyte volume homeostasis and contractility during stress (hyperkalemic cardioplegia, metabolic inhibition, and hypo-osmotic stress), KATP channel opener diazoxide requires administration at the onset of stress in this isolated myocyte model. These data have potential implications for any future clinical application of diazoxide.
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Affiliation(s)
- M Burhan Janjua
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Carol M Makepeace
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Melissa M Anastacio
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO
| | - Jennifer S Lawton
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, MO.
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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Anastacio MM, Kanter EM, Makepeace CM, Keith AD, Zhang H, Schuessler RB, Nichols CG, Lawton JS. Relationship between mitochondrial matrix volume and cellular volume in response to stress and the role of ATP-sensitive potassium channel. Circulation 2013; 128:S130-5. [PMID: 24030396 DOI: 10.1161/circulationaha.112.000128] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cardiac myocytes demonstrate significant swelling and associated reduced contractility in response to stress that is prevented by the ATP-sensitive potassium channel opener, diazoxide (DZX) via an unknown mechanism. One proposed mechanism of cardioprotection is mitochondrial matrix swelling. To establish the relationship between mitochondrial and cellular volume during stress, this study examined the effect of DZX on mitochondrial volume. METHODS AND RESULTS Isolated mouse mitochondria were exposed to the following solutions: Tyrode, isolation buffer, cardioplegia (CPG)±DZX±ATP-sensitive potassium channel inhibitor, 5-hydroxydecanoate, and metabolic inhibition (MI) ± DZX ± 5-hydroxydecanoate. Mitochondrial volume was measured. DZX resulted in significant mitochondrial swelling (P<0.0001 versus Tyrode). MI and CPG resulted in significant mitochondrial swelling compared with baseline volume. The addition of DZX did not alter the response of mitochondrial volume to CPG (P=0.912) but increased swelling in response to MI (P=0.036). The addition of 5-hydroxydecanoate to MI + DZX or CPG+DZX significantly reduced mitochondrial swelling (P<0.003 MI+DZX versus MI + DZX + 5HD; P<0.001 CPG+DZX versus CPG + DZX + 5HD). CONCLUSIONS Both cellular and mitochondrial volume increased during exposure to MI and CPG. DZX did not alter mitochondrial volume during CPG; however, it was associated with an increase in mitochondrial volume during MI. 5-Hydroxydecanoate reduced mitochondrial volume during exposure to both stresses with DZX, supporting a role for a mitochondrial ATP-sensitive potassium channel in the mechanism of cardioprotection by DZX.
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Affiliation(s)
- Melissa M Anastacio
- Division of Cardiothoracic Surgery, Department of Surgery (M.M.A., E.M.K., C.M.M., A.D.K., R.B.S., J.S.L.) and Departments of Cell Biology and Physiology (H.Z., C.G.N.), Washington University School of Medicine, St. Louis, MO
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12
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Cardioprotective mechanism of diazoxide involves the inhibition of succinate dehydrogenase. Ann Thorac Surg 2013; 95:2042-50. [PMID: 23642436 DOI: 10.1016/j.athoracsur.2013.03.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/16/2013] [Accepted: 03/04/2013] [Indexed: 01/09/2023]
Abstract
BACKGROUND The adenosine triphosphate-sensitive potassium (KATP) channel opener, diazoxide, preserves myocyte volume homeostasis and contractility during stress via an unknown mechanism. Pharmacologic overlap has been suggested between succinate dehydrogenase (SDH) activity and KATP channel modulators. Diazoxide may be cardioprotective due to the inhibition of SDH which may form a portion of the mitochondrial KATP channel. To determine the role of inhibition of SDH in diazoxide's cardioprotection, this study utilized glutathione to prevent the inhibition of SDH. METHODS SDH activity was measured in isolated mitochondria exposed to succinate (control), malonate (inhibitor of succinate dehydrogenase), diazoxide, and varying concentrations of glutathione alone or in combination with diazoxide. Enzyme activity was measured by spectrophotometric analysis. To evaluate myocyte volume and contractility, cardiac myocytes were superfused with Tyrode's physiologic solution (Tyrode's) (20 minutes), followed by test solution (20 minutes), including Tyrode's, hyperkalemic cardioplegia (stress), cardioplegia + diazoxide, cardioplegia + diazoxide + glutathione, or glutathione alone; followed by Tyrode's (20 minutes). Myocyte volume and contractility were recorded using image grabbing software. RESULTS Both malonate and diazoxide inhibited succinate dehydrogenase. Glutathione prevented the inhibition of succinate dehydrogenase by diazoxide in a dose-dependent manner. The addition of diazoxide prevented the detrimental myocyte swelling due to cardioplegia alone and this benefit was lost with the addition of glutathione. However, glutathione elicited an independent cardioprotective effect on myocyte contractility. CONCLUSIONS The ability of diazoxide to provide beneficial myocyte homeostasis during stress involves the inhibition of succinate dehydrogenase, which may also involve the opening of a purported mitochondrial adenosine triphosphate sensitive potassium channel.
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Anastacio MM, Kanter EM, Keith AD, Schuessler RB, Nichols CG, Lawton JS. Inhibition of Succinate Dehydrogenase by Diazoxide Is Independent of the ATP-Sensitive Potassium Channel Subunit Sulfonylurea Type 1 Receptor. J Am Coll Surg 2013; 216:1144-9. [PMID: 23535164 DOI: 10.1016/j.jamcollsurg.2013.01.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/03/2013] [Accepted: 01/23/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Diazoxide maintains myocyte volume and contractility during stress via an unknown mechanism. The mechanism of action may involve an undefined (genotype unknown) mitochondrial ATP-sensitive potassium channel and is dependent on the ATP-sensitive potassium channel subunit sulfonylurea type 1 receptor (SUR1). The ATP-sensitive potassium channel openers have been shown to inhibit succinate dehydrogenase (SDH) and a gene for a portion of SDH has been found in the SUR intron. Diazoxide may be cardioprotective via inhibition of SDH, which can form part of an ATP-sensitive potassium channel or share its genetic material. This study investigated the role of inhibition of SDH by diazoxide and its relationship to the SUR1 subunit. STUDY DESIGN Mitochondria were isolated from wild-type and SUR1 knockout mice. Succinate dehydrogenase activity was measured by spectrophotometric analysis of 2,6-dichloroindophenol reduction for 20 minutes as the relative change in absorbance over time. Mitochondria were treated with succinate (20 mM), succinate + 1% dimethylsulfoxide, succinate + malonate (8 mM) (competitive inhibitor of SDH), or succinate + diazoxide (100 μM). RESULTS Both malonate and diazoxide inhibit SDH activity in mitochondria of wild-type mice and in mice lacking the SUR1 subunit (p < 0.05 vs control). CONCLUSIONS The ability of DZX to inhibit SDH persists even after deletion of the SUR1 gene. Therefore, the enzyme complex SDH is not dependent on the SUR1 gene. The inhibition of SDH by DZX can play a role in the cardioprotection afforded by DZX; however, this role is independent of the ATP-sensitive potassium channel subunit SUR1.
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Affiliation(s)
- Melissa M Anastacio
- Department of Surgery, Division of Cardiothoracic Surgery, Washington University School of Medicine, St Louis, MO 63110, USA
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Maffit SK, Sellitto AD, Al-Dadah AS, Schuessler RB, Damiano RJ, Lawton JS. Diazoxide maintains human myocyte volume homeostasis during stress. J Am Heart Assoc 2012; 1:jah312. [PMID: 23130119 PMCID: PMC3487366 DOI: 10.1161/jaha.112.000778] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 02/14/2012] [Indexed: 11/30/2022]
Abstract
Background Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition results in significant animal myocyte swelling (6% to10%) and subsequent reduced contractility (10% to 20%). Both are eliminated by the adenosine triphosphate-sensitive potassium channel opener diazoxide (DZX). The relationship between swelling and reduced contractility suggests that the structural change may represent one mechanism of postoperative myocardial stunning. This study evaluated human myocyte volume during stress to investigate if similar phenomena exist in human myocytes. Methods and Results Human atrial myocytes isolated from tissue obtained during cardiac surgery were perfused with Tyrode's physiological solution (20 minutes, 37°C), test solution (20 minutes), and Tyrode's (37°C, 20 minutes). Test solutions (n=6 to 12 myocytes each) included Tyrode's (37°C or 9°C), Tyrode's+DZX (9°C), hyperkalemic cardioplegia (9°C)±DZX, cardioplegia+DZX+HMR 1098 (sarcolemmal adenosine triphosphate-sensitive potassium channel inhibitor, 9°C), cardioplegia+DZX+5-hydroxydeconoate (mitochondrial adenosine triphosphate-sensitive potassium channel inhibitor, 9°C), mild hyposmotic solution±DZX, metabolic inhibition±DZX, and metabolic inhibition+DZX+5-hydroxydeconoate. Myocyte volume was recorded every 5 minutes. Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition resulted in significant human myocyte swelling (8%, 7%, and 6%, respectively; all P<0.05 vs control). In all groups, the swelling was eliminated or lessened by DZX. The addition of channel inhibitors did not significantly alter results. Conclusions DZX maintains human myocyte volume homeostasis during stress via an unknown mechanism. DZX may prove to be clinically useful following the elucidation of its specific mechanism of action. (J Am Heart Assoc. 2012;1:jah3-e000778 doi: 10.1161/JAHA.112.000778.)
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Affiliation(s)
- Sara K Maffit
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO
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Sellitto AD, Al-Dadah AS, Schuessler RB, Nichols CG, Lawton JS. An open sarcolemmal adenosine triphosphate-sensitive potassium channel is necessary for detrimental myocyte swelling secondary to stress. Circulation 2011; 124:S70-4. [PMID: 21911821 DOI: 10.1161/circulationaha.110.012039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Stress (exposure to hyperkalemic cardioplegia, metabolic inhibition, or osmotic) results in significant myocyte swelling and reduced contractility. In contrast to wild-type mice, these detrimental consequences are not observed in mice lacking the Kir6.2 subunit of the sarcolemmal ATP-sensitive potassium (sK(ATP)) channel after exposure to hyperkalemic cardioplegia. The hypothesis for this study was that an open sK(ATP) channel (Kir6.2 and SUR2A subunits) is necessary for detrimental myocyte swelling to occur in response to stress. METHODS AND RESULTS To investigate the role of the sK(ATP) channel in stress-induced myocyte swelling, high-dose pharmacological sK(ATP) channel blockade and genetic deletion (knockout of Kir6.2 subunit) were used. Myocytes were exposed sequentially to Tyrode control (20 minutes), test (stress) solution (20 minutes), and Tyrode control (20 minutes). To evaluate pharmacological channel blockade, myocytes were exposed to hyperkalemic cardioplegia (stress) with and without a K(ATP) channel blocker. To evaluate the effects of genetic deletion, wild-type and sK(ATP) knockout [Kir6.2(-/-)] myocytes were exposed to metabolic inhibition (stress). Myocyte volume was recorded using image-grabbing software. Detrimental myocyte swelling was prevented by high-dose sK(ATP) channel blockade (glibenclamide or HMR 1098) but not mitochondrial K(ATP) channel blockade (5-hydroxydecanoate) during exposure to hyperkalemic cardioplegia. Genetic deletion of the sK(ATP) channel prevented significant myocyte swelling in response to metabolic inhibition. CONCLUSIONS K(ATP) channel openers prevent detrimental myocyte swelling and reduce contractility in response to stress through an unknown mechanism. Paradoxically, the present data support a role for sK(ATP) channel activation in myocyte volume derangement in response to stress.
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Affiliation(s)
- Angela D Sellitto
- Division of Cardiothoracic Surgery, Washington University School of Medicine, St Louis, MO 63110, USA
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KIM JH, OH AY, CHOI YM, KU SY, KIM YY, LEE NJ, SEPAC A, BOSNJAK ZJ. Isoflurane decreases death of human embryonic stem cell-derived, transcriptional marker Nkx2.5(+) cardiac progenitor cells. Acta Anaesthesiol Scand 2011; 55:1124-31. [PMID: 22092211 DOI: 10.1111/j.1399-6576.2011.02509.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cardiac progenitor cells (CPCs) derived from human embryonic stem cells (hESCs) can multiply and generate cardiomyocytes, offering their tremendous potential for cardiac regenerative therapy. However, poor survival under stressful conditions is a major hurdle in the regeneration. We investigated whether isoflurane-induced preconditioning can increase hESC-derived CPC survival under oxidative stress. METHODS Undifferentiated hESCs were cultured in suspension with 20% FBS (fetal bovine serum) and 20 ng/ml of BMP-4 (bone morphogenetic protein-4) to form embryoid bodies and grown onto Matrigel-coated plates for 2-3 weeks. To characterise the differentiated CPCs, immunostaining for Nkx2.5 (nonspecific transcriptional marker) and Isl-1 was performed. hESC-derived CPCs were exposed to oxidative stress induced by H(2) O(2) and FeSO(4) . For anaesthetic preconditioning, CPCs were exposed to isoflurane (0.25, 0.5, 1.0 mM). CPC survival was determined by trypan blue exclusion. A mitoK(ATP) channels inhibitor, 5-hydroxydecanoic acid (200 μM) and an opener, diazoxide (100 μM), were used to investigate the involvement of mitoK(ATP) channels. RESULTS hESC-derived CPCs stained with Nkx2.5 were 95 ± 3% of total cell number. Isoflurane (0.5 and 1.0 mM)-preconditioned CPCs showed a significantly lower death rate compared with control (0.5 mM: 30.6 ± 10.7% and 1.0 mM: 28.5 ± 6.2% vs. control: 43.2 ± 9.9%). Inhibition of mitoK(ATP) channels with 5-HD completely abolished the protective effects of isoflurane. Diazoxide significantly decreased CPC death (29.5 ± 12.4%). However, when diazoxide was applied to CPC preconditioned with isoflurane, CPC death did not decrease further (28.7 ± 10.9%). CONCLUSION Isoflurane increased hESC-derived Nkx2.5(+) CPC survival under oxidative stress, and mitoK(ATP) channels may be involved in the protective effect.
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Affiliation(s)
| | | | | | | | | | - N. J. LEE
- Department of Anesthesiology and Pain Medicine; Seoul National University Bundang Hospital; Seonggnam-si; Korea
| | - A. SEPAC
- Department of Anesthesiology; Medical College of Wisconsin; Milwaukee; WI
| | - Z. J. BOSNJAK
- Department of Anesthesiology; Medical College of Wisconsin; Milwaukee; WI
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Shalaby A, Mennander A, Rinne T, Oksala N, Aanismaa R, Narkilahti S, Paavonen T, Laurikka J, Tarkka M. Aquaporin-7 expression during coronary artery bypass grafting with Diazoxide. SCAND CARDIOVASC J 2011; 45:354-9. [DOI: 10.3109/14017431.2011.583357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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