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Xing H, Sabe SA, Shi G, Harris DD, Liu Y, Sellke FW, Feng J. Role of Protein Kinase C in Metabolic Regulation of Coronary Endothelial Small Conductance Calcium-Activated Potassium Channels. J Am Heart Assoc 2024; 13:e031028. [PMID: 38293916 PMCID: PMC11056132 DOI: 10.1161/jaha.123.031028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 11/02/2023] [Indexed: 02/01/2024]
Abstract
BACKGROUND Small conductance calcium-activated potassium (SK) channels are largely responsible for endothelium-dependent coronary arteriolar relaxation. Endothelial SK channels are downregulated by the reduced form of nicotinamide adenine dinucleotide (NADH), which is increased in the setting of diabetes, yet the mechanisms of these changes are unclear. PKC (protein kinase C) is an important mediator of diabetes-induced coronary endothelial dysfunction. Thus, we aimed to determine whether NADH signaling downregulates endothelial SK channel function via PKC. METHODS AND RESULTS SK channel currents of human coronary artery endothelial cells were measured by whole cell patch clamp method in the presence/absence of NADH, PKC activator phorbol 12-myristate 13-acetate, PKC inhibitors, or endothelial PKCα/PKCβ knockdown by using small interfering RNA. Human coronary arteriolar reactivity in response to the selective SK activator NS309 was measured by vessel myography in the presence of NADH and PKCβ inhibitor LY333531. NADH (30-300 μmol/L) or PKC activator phorbol 12-myristate 13-acetate (30-300 nmol/L) reduced endothelial SK current density, whereas the selective PKCᵦ inhibitor LY333531 significantly reversed the NADH-induced SK channel inhibition. PKCβ small interfering RNA, but not PKCα small interfering RNA, significantly prevented the NADH- and phorbol 12-myristate 13-acetate-induced SK inhibition. Incubation of human coronary artery endothelial cells with NADH significantly increased endothelial PKC activity and PKCβ expression and activation. Treating vessels with NADH decreased coronary arteriolar relaxation in response to the selective SK activator NS309, and this inhibitive effect was blocked by coadministration with PKCβ inhibitor LY333531. CONCLUSIONS NADH-induced inhibition of endothelial SK channel function is mediated via PKCβ. These findings may provide insight into novel therapeutic strategies to preserve coronary microvascular function in patients with metabolic syndrome and coronary disease.
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Affiliation(s)
- Hang Xing
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Sharif A. Sabe
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Guangbin Shi
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Dwight D. Harris
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Frank W. Sellke
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Rhode Island HospitalAlpert Medical School of Brown UniversityProvidenceRI
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Zhang Z, Li X, He J, Wang S, Wang J, Liu J, Wang Y. Molecular mechanisms of endothelial dysfunction in coronary microcirculation dysfunction. J Thromb Thrombolysis 2023; 56:388-397. [PMID: 37466848 DOI: 10.1007/s11239-023-02862-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/01/2023] [Indexed: 07/20/2023]
Abstract
Coronary microvascular endothelial cells (CMECs) react to changes in coronary blood flow and myocardial metabolites and regulate coronary blood flow by balancing vasoconstrictors-such as endothelin-1-and the vessel dilators prostaglandin, nitric oxide, and endothelium-dependent hyperpolarizing factor. Coronary microvascular endothelial cell dysfunction is caused by several cardiovascular risk factors and chronic rheumatic diseases that impact CMEC blood flow regulation, resulting in coronary microcirculation dysfunction (CMD). The mechanisms of CMEC dysfunction are not fully understood. However, the following could be important mechanisms: the overexpression and activation of nicotinamide adenine dinucleotide phosphate oxidase (Nox), and mineralocorticoid receptors; the involvement of reactive oxygen species (ROS) caused by a decreased expression of sirtuins (SIRT3/SIRT1); forkhead box O3; and a decreased SKCA/IKCA expression in the endothelium-dependent hyperpolarizing factor electrical signal pathway. In addition, p66Shc is an adapter protein that promotes oxidative stress; although there are no studies on its involvement with cardiac microvessels, it is possible it plays an important role in CMD.
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Affiliation(s)
- Zhiyu Zhang
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China
| | - Xiangjun Li
- Department of Experimental Pharmacology and Toxicology, College of Pharmacy, Jilin University, Changchun, 130000, China
| | - Jiahuan He
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China
| | - Shipeng Wang
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China
| | - Jingyue Wang
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China
| | - Junqian Liu
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China
| | - Yushi Wang
- Department of Cardiology, The First Hospital of Jilin University, No. 71 of Xinmin Street, Changchun, 13000, China.
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3
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Kant S, Xing H, Liu Y, Harrington EO, Sellke FW, Feng J. Acute protein kinase C beta inhibition preserves coronary endothelial function after cardioplegic hypoxia/reoxygenation. JTCVS OPEN 2023; 15:242-251. [PMID: 37808045 PMCID: PMC10556935 DOI: 10.1016/j.xjon.2023.06.014] [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: 03/12/2023] [Revised: 06/18/2023] [Accepted: 06/27/2023] [Indexed: 10/10/2023]
Abstract
Objective Protein kinase C (PKC) influences myocardial contractility and susceptibility to long-term cardiac dysfunction after ischemia-reperfusion injury. In diabetes, PKC inhibition has a protective effect in terms of microvascular dysfunction. SK-channel dysfunction also influences endothelial dysfunction in cardioplegic hypoxia-reoxygenation (CP-H/R). Here, we examine whether acute inhibition of PKC beta protects against CP-H/R-induced coronary endothelial and SK channel dysfunction. Methods Isolated mouse coronary arterioles, half pretreated with selective PKC inhibitor ruboxistaurin (RBX), were subjected to hyperkalemic, cardioplegic hypoxia (1 hour), and reoxygenation (1 hour) with Krebs buffer. Sham control vessels were continuously perfused with oxygenated Krebs buffer without CP-H/R. After 1 hour of reoxygenation, responses to the endothelium-dependent vasodilator adenosine-diphosphate (ADP) and the SK-channel activator NS309 were examined. Endothelial SK-specific potassium currents from mouse heart endothelial cells were examined using whole-cell path clamp configurations in response to NS309 and SK channel blockers apamin and TRAM34. Results CP-H/R significantly decreased coronary relaxation responses to ADP (P = .006) and NS309 (P = .0001) compared with the sham control group. Treatment with selective PKC beta inhibitor RBX significantly increased recovery of coronary relaxation responses to ADP (P = .031) and NS309 (P = .004) after CP-H/R. Treatment with RBX significantly increased NS309-mediated potassium currents following CP-H/R (P = .0415). Apamin and TRAM34 sensitive currents were significantly greater in CP-H/R + RBX versus CP-H/R mouse heart endothelial cells (P = .0027). Conclusions Acute inhibition of PKC beta significantly protected mouse coronary endothelial function after CP-H/R injury. This suggests that acute PKC beta inhibition may be a novel approach for preventing microvascular dysfunction during CP-H/R.
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Affiliation(s)
- Shawn Kant
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Hang Xing
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Elizabeth O. Harrington
- Vascular Research Laboratory, Department of Medicine, Providence VA Medical Center, Alpert Medical School of Brown University, Providence, RI
| | - Frank W. Sellke
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
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4
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Abstract
Potassium homeostasis affects cardiac rhythm and contractility, along with vascular reactivity and vascular smooth muscle proliferation. This chapter will focus on potassium dynamics during and after cardiac surgery involving cardioplegic arrest and cardiopulmonary bypass (CPB). Hyperkalemic, hypothermic solutions are frequently used to induce cardioplegic arrest and protect the heart during cardiac surgery involving CPB. Common consequences of hyperkalemic cardioplegic arrest and reperfusion include microvascular dysfunction involving several organ systems and myocardial dysfunction. Immediately after CPB, blood potassium levels often drop precipitously due to a variety of factors, including CPB -induced electrolyte depletion and frequent, long-term administration of insulin during and after surgery. Meanwhile, some patients with pre-existing kidney dysfunction may experience postoperative hyperkalemia following cardioplegia. Any degree of postoperative hyper/hypokalemia significantly elevates the risk of cardiac arrythmias and subsequent myocardial failure. Therefore, proper management of blood potassium levels during and after cardioplegia/CPB is crucial for optimizing patient outcomes following cardiac surgery.
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Xu C, Sellke FW, Abid MR. Assessments of microvascular function in organ systems. Am J Physiol Heart Circ Physiol 2022; 322:H891-H905. [PMID: 35333121 PMCID: PMC9037705 DOI: 10.1152/ajpheart.00589.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 01/23/2023]
Abstract
Microvascular disease plays critical roles in the dysfunction of all organ systems, and there are many methods available to assess the microvasculature. These methods can either assess the target organ directly or assess an easily accessible organ such as the skin or retina so that inferences can be extrapolated to the other systems and/or related diseases. Despite the abundance of exploratory research on some of these modalities and their possible applications, there is a general lack of clinical use. This deficiency is likely due to two main reasons: the need for standardization of protocols to establish a role in clinical practice or the lack of therapies targeted toward microvascular dysfunction. Also, there remain some questions to be answered about the coronary microvasculature, as it is complex, heterogeneous, and difficult to visualize in vivo even with advanced imaging technology. This review will discuss novel approaches that are being used to assess microvasculature health in several key organ systems, and evaluate their clinical utility and scope for further development.
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Affiliation(s)
- Cynthia Xu
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
| | - Frank W Sellke
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
| | - M Ruhul Abid
- Cardiovascular Research Center, Rhode Island Hospital, Providence, Rhode Island
- Division of Cardiothoracic Surgery, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
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6
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Metabolic regulation and dysregulation of endothelial small conductance calcium activated potassium channels. Eur J Cell Biol 2022; 101:151208. [DOI: 10.1016/j.ejcb.2022.151208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
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Mirman B, Ikeda I, Zhang Z, Liu Y, Yu L, Ehsan A, Feng J, Sellke F. Effects of neuropeptide Y on the microvasculature of human skeletal muscle. Surgery 2020; 168:155-159. [PMID: 32493616 DOI: 10.1016/j.surg.2020.04.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/07/2020] [Accepted: 04/12/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Neuropeptide Y acts directly on the vasculature as a cotransmitter with norepinephrine for an augmented contraction. Little, however, is known about the effects of neuropeptide Y on the microvasculature of human skeletal muscle. Neuropeptide Y signaling has not been studied in the setting of cardiac surgery and cardiopulmonary bypass. We investigated the role of neuropeptide Y signaling on vasomotor tone in the microvessels of human skeletal muscle, as well as the effect of cardiopulmonary bypass on neuropeptide Y-induced responsiveness. METHODS Specimens taken from intercostal muscles were collected from patients, pre- and post-cardiopulmonary bypass, undergoing coronary artery bypass grafting or cardiac valve surgery (n = 8/group). Microvessels (157 ± 47 microns) were isolated in vitro in a no-flow state. Arterial microvascular responses to a neuropeptide Y agonist, a Y1 receptor antagonist, phenylephrine, and the coadministration of neuropeptide Y and phenylephrine were examined. The abundance and localization of the Y1 receptor were measured using Western blot and immunofluorescence, respectively. RESULTS Arterial microvessels showed responsiveness to the neuropeptide Y agonist (10-9 to 4 × 10-7 mol/L) both before and after cardiopulmonary bypass, reaching a 12.5% vasoconstriction from the baseline luminal diameter. With administration of the Y1 receptor antagonist after neuropeptide Y, the contractile response was eliminated (n = 3/group, P = .04). No difference in vasoconstriction was observed between pre- and post-cardiopulmonary bypass groups (P = .73). The coadministration of neuropeptide Y and phenylephrine (10-9 to 10-4 mol/L) elicited no difference in vasoconstriction (n = 7/group, P = .06 both pre- and post-cardiopulmonary bypass) when compared with phenylephrine alone (10-9 to 10-4 mol/L). No change in the protein expression or localization of the Y1 receptor was detected by Western blotting (n = 6/group, P = .44) or immunofluorescence (n = 6/group, P = .13). CONCLUSION Neuropeptide Y induced vasoconstriction, suggesting that neuropeptide Y may play an important role in the regulation of the peripheral microvasculature. There was no change in microvascular responsiveness to neuropeptide Y after cardiopulmonary bypass nor were there any synergistic effects of neuropeptide Y on phenylephrine-induced vasoconstriction in the skeletal muscle microvasculature.
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Affiliation(s)
- Benjamin Mirman
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Ian Ikeda
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Zhiqi Zhang
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Lucy Yu
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Afshin Ehsan
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Frank Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI.
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Ziegler O, Anderson K, Liu Y, Ehsan A, Fingleton J, Sodha N, Feng J, Sellke FW. Skeletal muscle microvasculature response to β-adrenergic stimuli is diminished with cardiac surgery. Surgery 2019; 167:493-498. [PMID: 31493902 DOI: 10.1016/j.surg.2019.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 07/08/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Cardiac surgery and cardiopulmonary bypass are associated with alterations in blood pressure in the perioperative period, which, if uncontrolled, can result in end organ damage or dysfunction. Microvessels, significant contributors to blood pressure, both in the myocardium and peripheral skeletal muscle, have diminished responsiveness to major mediators of vascular tone, including thromboxane and serotonin after cardiopulmonary bypass. Responsiveness of these vessels to β-adrenergic stimulation, a major mediator of vascular tone, has not yet been studied. In this report, we investigated the role of β-adrenergic receptors in vascular tone regulation in human skeletal muscle microvessels before and after β-adrenergic stimulation. METHODS Skeletal muscle microvessels were isolated from patients undergoing cardiac surgery before and after cardiopulmonary bypass. Vessels were exposed in an ex vivo model to the β-adrenergic agonist isoproterenol, or the direct adenylyl cyclase activator, forskolin, and the selective β-receptor antagonist ICI18.551 hydrochloride plus isoproterenol. Immunofluorescence of β receptors and Western blotting were also performed. RESULTS Microvessels showed diminished responsiveness to isoproterenol (10-6 to 10-4M) after cardiopulmonary bypass (n = 8/group, P = .01). Pretreatment with the selective β-2 blocker ICI18.551 (10-6M) prevented isoproterenol-induced microvascular relaxation (P = .001). Forskolin-induced relaxation response was also significantly diminished after cardiopulmonary bypass (n = 4/group, P < .05 versus before cardiopulmonary bypass). No significant changes in the total protein expression of β-1, β-2, and β-3 receptors were detected by western blotting or immunofluorescence. CONCLUSION Microvessels isolated from human skeletal muscle show diminished responsiveness to isoproterenol and its downstream activator forskolin after cardiopulmonary bypass, suggesting there is an alteration in β-adrenergic receptor responsive in adenylate cyclase. The relaxation response to isoproterenol was via activation β-2 receptors without changes in β-adrenergic receptor abundance.
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Affiliation(s)
- Olivia Ziegler
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Kelsey Anderson
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Afshin Ehsan
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - James Fingleton
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Neel Sodha
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI.
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Sabe SA, Feng J, Liu Y, Scrimgeour LA, Ehsan A, Sellke FW. Decreased contractile response of peripheral arterioles to serotonin after CPB in patients with diabetes. Surgery 2018; 164:288-293. [PMID: 29759300 DOI: 10.1016/j.surg.2018.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/02/2018] [Accepted: 03/02/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Regulation of coronary vasomotor tone by serotonin is significantly changed after cardioplegic arrest and reperfusion. The current study investigates whether cardiopulmonary bypass may also affect peripheral arteriolar response to serotonin in patients with or without diabetes. METHODS Human peripheral microvessels (90-180 µm diameter) were dissected from harvested skeletal muscle tissues from diabetic and non-diabetic patients before and after cardiopulmonary bypass and cardiac surgery (n = 8/group). In vitro contractile response to serotonin was assessed by videomicroscopy in the presence or absence of serotonin alone (10-9-10-5M) or combined with the selective serotonin 1B receptor (5-HT1B) antagonist, SB224289 (10-6M). 5-HT1A/1B protein expression in the skeletal muscle was measured by Western-blot and immunohistochemistry. RESULTS There were no significant differences in contractile response of peripheral arterioles to serotonin (10-5M) pre-cardiopulmonary bypass between diabetic and non-diabetic patients. After cardiopulmonary bypass, contractile response to serotonin was significantly impaired in both diabetic and non-diabetic patients compared to their pre-cardiopulmonary bypass counterparts (P < .05). This effect was more pronounced in diabetic patients than non-diabetic patients (P < .05 versus non-diabetic). The contractile response to serotonin was significantly inhibited by the 5-HT1B antagonist in both diabetic and non-diabetic vessels (P < .05 versus serotonin alone). There were no significant differences in the expression/distribution of 5-HT1A/1B between non-diabetic and diabetic groups or between pre- versus post- cardiopulmonary bypass vessels. CONCLUSIONS Cardiopulmonary bypass is associated with decreased contractile response of peripheral arterioles to serotonin and this effect was exaggerated in the presence of diabetes. Serotonin-induced contractile response of the peripheral arterioles was via 5-HT1B in both diabetic and non-diabetic patients.
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Affiliation(s)
- Sharif A Sabe
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI
| | - Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI
| | - Laura A Scrimgeour
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI
| | - Afshin Ehsan
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, RI .
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Microvascular dysfunction in patients with diabetes after cardioplegic arrest and cardiopulmonary bypass. Curr Opin Cardiol 2018; 31:618-624. [PMID: 27652811 DOI: 10.1097/hco.0000000000000340] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE OF REVIEW The purpose of the current review is to describe the changes of microvascular function in patients with diabetes after cardioplegic arrest and cardiopulmonary bypass (CPB) and cardiac surgery. RECENT FINDINGS Cardiac surgery, especially that involving cardioplegia and CPB, is associated with significant changes in vascular reactivity of coronary/peripheral microcirculation, vascular permeability, gene/protein expression, and programmed cell death, as well as with increased morbidity and mortality after surgical procedures. In particular, these changes are more profound in patients with poorly controlled diabetes. SUMMARY Because alterations in vasomotor regulation are critical aspects of mortality and morbidity of cardioplegia/CPB, a better understanding of diabetic regulation of microvascular function may lead to improved postoperative outcomes of patients with diabetes after cardioplegia/CPB and cardiac surgery.
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Yu X, Stallone JN, Heaps CL, Han G. The activation of G protein-coupled estrogen receptor induces relaxation via cAMP as well as potentiates contraction via EGFR transactivation in porcine coronary arteries. PLoS One 2018; 13:e0191418. [PMID: 29360846 PMCID: PMC5779678 DOI: 10.1371/journal.pone.0191418] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 01/04/2018] [Indexed: 01/09/2023] Open
Abstract
Estrogen exerts protective effects against cardiovascular diseases in premenopausal women, but is associated with an increased risk of both coronary heart disease and stroke in older postmenopausal women. Studies have shown that activation of the G-protein-coupled estrogen receptor 1 (GPER) can cause either relaxation or contraction of arteries. It is highly likely that these dual actions of GPER may contribute to the seemingly paradoxical effects of estrogen in regulating coronary artery function. The objective of this study was to test the hypothesis that activation of GPER enhances agonist-stimulated porcine coronary artery contraction via epidermal growth factor receptor (EGFR) transactivation and its downstream extracellular signal-regulated kinases (ERK1/2) pathway. Isometric tension studies and western blot were performed to determine the effect of GPER activation on coronary artery contraction. Our findings demonstrated that G-1 caused concentration-dependent relaxation of ET-1-induced contraction, while pretreatment of arterial rings with G-1 significantly enhanced ET-1-induced contraction. GPER antagonist, G-36, significantly inhibited both the G-1-induced relaxation effect and G-1-enhanced ET-1 contraction. Gallein, a Gβγ inhibitor, significantly increased G-1-induced relaxation, yet inhibited G-1-enhanced ET-1-mediated contraction. Similarly, inhibition of EGFR with AG1478 or inhibition of Src with phosphatase 2 further increased G-1-induced relaxation responses in coronary arteries, but decreased G-1-enhanced ET-1-induced contraction. Western blot experiments in porcine coronary artery smooth muscle cells (PCASMC) showed that G-1 increased tyrosine phosphorylation of EGFR, which was inhibited by AG-1478. Furthermore, enzyme-linked immunosorbent assays showed that the level of heparin-binding EGF (HB-EGF) released by ET-1 treatment increased two-fold; whereas pre-incubation with G-1 further increased ET-1-induced HB-EGF release to four-fold over control conditions. Lastly, the role of ERK1/2 was determined by applying the MEK inhibitor, PD98059, in isometric tension studies and detecting phospho-ERK1/2 in immunoblotting. PD98059 potentiated G-1-induced relaxation response, but blocked G-1-enhanced ET-1-induced contraction. By western blot, G-1 treatment decreased phospho-ERK1/2, however, in the presence of the adenylyl cyclase inhibitor, SQ22536, G-1 significantly increased ERK1/2 phosphorylation in PCASMC. These data demonstrate that activation of GPER induces relaxation via cAMP as well as contraction via a mechanism involving transactivation of EGFR and the phosphorylation of ERK1/2 in porcine coronary arteries.
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Affiliation(s)
- Xuan Yu
- Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
| | - John N. Stallone
- Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
- Women's Health Division, Michael E. DeBakey Institute Texas A&M University, College Station, TX, United States of America
| | - Cristine L. Heaps
- Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
- Women's Health Division, Michael E. DeBakey Institute Texas A&M University, College Station, TX, United States of America
| | - Guichun Han
- Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
- Women's Health Division, Michael E. DeBakey Institute Texas A&M University, College Station, TX, United States of America
- * E-mail:
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Decreased coronary arteriolar response to K Ca channel opener after cardioplegic arrest in diabetic patients. Mol Cell Biochem 2018; 445:187-194. [PMID: 29305679 PMCID: PMC6033646 DOI: 10.1007/s11010-017-3264-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/23/2017] [Indexed: 01/16/2023]
Abstract
We have recently found that diabetes is associated with the inactivation of the calcium-activated potassium channels (KCa) in endothelial cells, which may contribute to endothelial dysfunction in diabetic patients at baseline. In the current study, we further investigated the effects of diabetes on coronary arteriolar responses to the small (SK) and intermediate (IK) KCa opener NS309 in diabetic and non-diabetic patients and correlated that data with the changes in the SK/IK protein expression/distribution in the setting of cardioplegic ischemia and reperfusion (CP) and cardiopulmonary bypass (CPB). Coronary arterioles from the harvested right atrial tissue samples from diabetic and non-diabetic patients (n = 8/group) undergoing cardiac surgery were dissected pre- and post-CP/CPB. The in vitro relaxation response of pre-contracted arterioles was examined in the presence of the selective SK/IK opener NS309 (10−9–10−5 M). The protein expression/localization of KCa channels in the harvested atrial tissue samples, coronary microvessels, and primary cultured human coronary endothelial cells were assayed by Western blotting and immunohistochemistry. The relaxation response to NS309 post-CP/CPB was significantly decreased in diabetic and non-diabetic groups compared to their pre-CP/CPB responses, respectively (P < 0.05). Furthermore, this decrease was greater in the diabetic group than that of the non-diabetic group (P < 0.05). There were no significant differences in the total protein expression/distribution of SK/IK in the human myocardium, coronary microvessels or coronary endothelial cells between diabetic and non-diabetic groups or between pre- and post-CP/CPB (P > 0.05). Our results suggest that diabetes further inactivates SK/IK channels of coronary microvasculature early after CP/CPB and cardiac surgery. The lack of diabetic changes in SK/IK protein abundances in the setting of CP/CPB suggests that the effect is post-translational. This alteration may contribute to post-operative endothelial dysfunction in the diabetic patients early after CP/CPB and cardiac surgery.
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Feng J, Anderson K, Singh AK, Ehsan A, Mitchell H, Liu Y, Sellke FW. Diabetes Upregulation of Cyclooxygenase 2 Contributes to Altered Coronary Reactivity After Cardiac Surgery. Ann Thorac Surg 2017; 104:568-576. [PMID: 28223053 PMCID: PMC5891657 DOI: 10.1016/j.athoracsur.2016.11.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 09/26/2016] [Accepted: 11/07/2016] [Indexed: 11/17/2022]
Abstract
BACKGROUND We hypothesized that upregulation of inducible cyclooxygenase 2 (COX-2) contributes to altered coronary arteriolar reactivity early after cardioplegic arrest and cardiopulmonary bypass (CP/CPB) in patients with diabetes mellitus who are undergoing cardiac surgery. METHODS The right atrial tissue samples of nondiabetes (ND), controlled diabetes (CDM), and uncontrolled diabetes (UDM) patients undergoing cardiac surgery were harvested before and after CP/CPB. Coronary arterioles (80 to 150 μm) were dissected from the harvested atrial tissue samples, cannulated, and pressurized. The changes in diameter were measured with video microscopy. The protein expression and localization of COX-1 and COX-2 were assayed by Western blot and immunohistochemistry. RESULTS In the diabetes arterioles, bradykinin-induced relaxation response was inhibited by the selective COX-2 inhibitor NS398 at baseline (p < 0.05). This effect was more pronounced in UDM arterioles than CDM (p < 0.05). After CP/CPB, bradykinin-induced responses in all groups were inhibited by NS398, but this effect was more pronounced in the UDM patients (p < 0.05). The intensities of COX-2 staining of coronary arterioles and COX-2 protein levels in myocardium were higher in diabetes than nondiabetes at baseline (p < 0.05). The post-CP/CPB protein levels of the inducible COX-2 were significantly increased compared with pre-CP/CPB values in all groups (p < 0.05), whereas this increase was higher with diabetes than with ND (p < 0.05). Furthermore, these effects were more profound in UDM than CDM (p < 0.05). CONCLUSIONS Diabetes and CP/CPB are associated with upregulation in COX-2 expression in human coronary vasculature. Upregulation of COX-2 expression may contribute to bradykinin-induced coronary arteriolar relaxation in diabetic patients undergoing cardiac surgery.
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Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Kelsey Anderson
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Arun K Singh
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Afshin Ehsan
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Hunter Mitchell
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Yuhong Liu
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island.
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Potz BA, Scrimgeour LA, Feng J, Sellke FW. Diabetes and Cardioplegia. JOURNAL OF NATURE AND SCIENCE 2017; 3:e394. [PMID: 28758150 PMCID: PMC5533287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cardiac surgery with cardiopulmonary bypass and cardioplegic arrest is associated with injury to the vasculature and microcirculation leading to coronary microvascular dysfunction, permeability changes and cardiac dysfunction. In the setting of cardiopulmonary bypass with cardioplegia, poorly-controlled diabetes is associated with significant changes in endothelium-dependent and independent vascular dysfunction, vascular reactivity, vascular permeability, protein expression, cell death, coronary/peripheral microcirculation and reduced vasomotor tone leading to hypotension and impaired endothelial function. The gene expression profiles after cardiopulmonary bypass with cardioplegic arrest is quantitatively and qualitatively different in patients with diabetes. Gene expression profiling capitalizing on the differences between patients with and without diabetes is a good place to identify potential medical targets.
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Affiliation(s)
- Brittany A. Potz
- Alpert Warren Medical School of Brown University, 2 Dudley Street, MOC 360, Providence, RI 02905, USA
| | - Laura A. Scrimgeour
- Alpert Warren Medical School of Brown University, 2 Dudley Street, MOC 360, Providence, RI 02905, USA
| | - Jun Feng
- Alpert Warren Medical School of Brown University, 2 Dudley Street, MOC 360, Providence, RI 02905, USA
| | - Frank W. Sellke
- Alpert Warren Medical School of Brown University, 2 Dudley Street, MOC 360, Providence, RI 02905, USA
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15
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Prostanoids in the pathophysiology of human coronary artery. Prostaglandins Other Lipid Mediat 2017; 133:20-28. [PMID: 28347710 DOI: 10.1016/j.prostaglandins.2017.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 02/16/2017] [Accepted: 03/23/2017] [Indexed: 01/16/2023]
Abstract
Coronary artery disease is one of the leading causes of death in wordwide. There is growing evidence that prostanoids are involved in the physiology and pathophysiology of the human coronary artery by controlling vascular tone, remodelling of the vascular wall or angiogenesis. In this review, the production of prostanoids and the expression of prostanoid receptors in human coronary artery in health or disease are described. In addition, the interactions between sex hormones and prostanoids, their participations in the development of coronary artery diseases have been addressed. Globally, most of the studies performed in human coronary artery preparations have shown that prostacyclin (PGI2) has beneficial effects by inducing vasodilatation and promoting angiogenesis while reverse effects are confirmed by thromboxane A2 (TxA2). More studies are needed to determine the roles of the other prostanoids (PGE2, PGD2 and PGF2α) in vascular functions of the human coronary artery. Finally, in addition to the in vitro data about the human coronary artery, myocardial infarction induced by cyclooxygenase-2 (COX-2) inhibitor and the protective effects of aspirin after coronary artery bypass surgery suggest that prostanoids are key mediators in coronary homeostasis.
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Sorop O, van den Heuvel M, van Ditzhuijzen NS, de Beer VJ, Heinonen I, van Duin RWB, Zhou Z, Koopmans SJ, Merkus D, van der Giessen WJ, Danser AHJ, Duncker DJ. Coronary microvascular dysfunction after long-term diabetes and hypercholesterolemia. Am J Physiol Heart Circ Physiol 2016; 311:H1339-H1351. [PMID: 27591223 DOI: 10.1152/ajpheart.00458.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/01/2016] [Indexed: 02/07/2023]
Abstract
Coronary microvascular dysfunction (CMD) has been proposed as an important component of diabetes mellitus (DM)- and hypercholesterolemia-associated coronary artery disease (CAD). Previously we observed that 2.5 mo of DM and high-fat diet (HFD) in swine blunted bradykinin (BK)-induced vasodilation and attenuated endothelin (ET)-1-mediated vasoconstriction. Here we studied the progression of CMD after 15 mo in the same animal model of CAD. Ten male swine were fed a HFD in the absence (HFD, n = 5) or presence of streptozotocin-induced DM (DM + HFD, n = 5). Responses of small (∼300-μm-diameter) coronary arteries to BK, ET-1, and the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine were examined in vitro and compared with those of healthy (Normal) swine (n = 12). Blood glucose was elevated in DM + HFD (17.6 ± 4.5 mmol/l) compared with HFD (5.1 ± 0.4 mmol/l) and Normal (5.8 ± 0.6 mmol/l) swine, while cholesterol was markedly elevated in DM + HFD (16.8 ± 1.7 mmol/l) and HFD (18.1 ± 2.6 mmol/l) compared with Normal (2.1 ± 0.2 mmol/l) swine (all P < 0.05). Small coronary arteries showed early atherosclerotic plaques in HFD and DM + HFD swine. Surprisingly, DM + HFD and HFD swine maintained BK responsiveness compared with Normal swine due to an increase in NO availability relative to endothelium-derived hyperpolarizing factors. However, ET-1 responsiveness was greater in HFD and DM + HFD than Normal swine (both P < 0.05), resulting mainly from ETB receptor-mediated vasoconstriction. Moreover, the calculated vascular stiffness coefficient was higher in DM + HFD and HFD than Normal swine (both P < 0.05). In conclusion, 15 mo of DM + HFD, as well as HFD alone, resulted in CMD. Although the overall vasodilation to BK was unperturbed, the relative contributions of NO and endothelium-derived hyperpolarizing factor pathways were altered. Moreover, the vasoconstrictor response to ET-1 was enhanced, involving the ETB receptors. In conjunction with our previous study, these findings highlight the time dependence of the phenotype of CMD.
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Affiliation(s)
- Oana Sorop
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands; and
| | - Mieke van den Heuvel
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Department of Internal Medicine, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nienke S van Ditzhuijzen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Vincent J de Beer
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ilkka Heinonen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Richard W B van Duin
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Zhichao Zhou
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Sietse J Koopmans
- Livestock Research, Wageningen University and Research Center, Wageningen, The Netherlands
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wim J van der Giessen
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands; and
| | - A H Jan Danser
- Department of Internal Medicine, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Dirk Jan Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands;
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Tabeling C, Noe E, Naujoks J, Doehn JM, Hippenstiel S, Opitz B, Suttorp N, Klopfleisch R, Witzenrath M. PKCα Deficiency in Mice Is Associated with Pulmonary Vascular Hyperresponsiveness to Thromboxane A2 and Increased Thromboxane Receptor Expression. J Vasc Res 2016; 52:279-88. [PMID: 26890419 DOI: 10.1159/000443402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 12/14/2015] [Indexed: 11/19/2022] Open
Abstract
Pulmonary vascular hyperresponsiveness is a main characteristic of pulmonary arterial hypertension (PAH). In PAH patients, elevated levels of the vasoconstrictors thromboxane A2 (TXA2), endothelin (ET)-1 and serotonin further contribute to pulmonary hypertension. Protein kinase C (PKC) isozyme alpha (PKCα) is a known modulator of smooth muscle cell contraction. However, the effects of PKCα deficiency on pulmonary vasoconstriction have not yet been investigated. Thus, the role of PKCα in pulmonary vascular responsiveness to the TXA2 analog U46619, ET-1, serotonin and acute hypoxia was investigated in isolated lungs of PKCα-/- mice and corresponding wild-type mice, with or without prior administration of the PKC inhibitor bisindolylmaleimide I or Gö6976. mRNA was quantified from microdissected intrapulmonary arteries. We found that broad-spectrum PKC inhibition reduced pulmonary vascular responsiveness to ET-1 and acute hypoxia and, by trend, to U46619. Analogously, selective inhibition of conventional PKC isozymes or PKCα deficiency reduced ET-1-evoked pulmonary vasoconstriction. The pulmonary vasopressor response to serotonin was unaffected by either broad PKC inhibition or PKCα deficiency. Surprisingly, PKCα-/- mice showed pulmonary vascular hyperresponsiveness to U46619 and increased TXA2 receptor (TP receptor) expression in the intrapulmonary arteries. To conclude, PKCα regulates ET-1-induced pulmonary vasoconstriction. However, PKCα deficiency leads to pulmonary vascular hyperresponsiveness to TXA2, possibly via increased pulmonary arterial TP receptor expression.
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Affiliation(s)
- Christoph Tabeling
- Department of Infectious Diseases and Pulmonary Medicine, Charitx00E9; - Universitx00E4;tsmedizin Berlin, Berlin, Germany
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Rottlerin-induced BKCa channel activation impairs specific contractile responses and promotes vasodilation. Ann Thorac Surg 2014; 99:626-34. [PMID: 25527424 DOI: 10.1016/j.athoracsur.2014.07.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 07/16/2014] [Accepted: 07/21/2014] [Indexed: 12/27/2022]
Abstract
BACKGROUND Activation of large conductance calcium-activated potassium (BKCa) channels is cardioprotective for ischemic injury and can enhance vasorelaxation. Rottlerin has recently been identified as a potent BKCa activator. We demonstrated that rottlerin improves cardiac function and increases coronary flow when used as a cardioplegia additive in rat and mouse models of cardioplegic arrest and reperfusion. In this study we examined the effectiveness and specificity of the putative BKCa activator rottlerin on vascular reactivity in response to specific contractile and dilatory agonists. METHODS Aortic rings from wild-type (wt) and BKCa knock-out (KO) mice were mounted in a tissue bath with force transducers. The vasodilatory effect of rottlerin was evaluated after pre-constriction with U46619. Dose responses to the contractile agonists U46619 and phenylephrine (PE), and vasodilation responses to rottlerin, hydrogen sulfide (H2S), and sodium nitroprusside (SNP) were performed after pretreatment with rottlerin. Similar studies were performed in pig coronary vessels. RESULTS The BKCa KO mouse aortic rings exhibited spontaneous contraction and had greater contractile responses to U46619 and reduced vasodilation to SNP compared with wt mice. The wt and KO responses to phenylephrine were similar. Rottlerin dose dependently dilated wild-type vessels, but not in BKCa KO animals. Pretreatment with rottlerin caused depressed U46619 responses, but had no effect on PE, SNP, or H2S-mediated responses. However, pig coronary vessels pretreated with rottlerin exhibited reduced contractile responses and enhanced nitric oxide-dependent dilation. CONCLUSIONS Rottlerin directly causes vasodilation through BKCa channel dependent mechanisms. The BKCa channel activator pretreatment enhances vasodilatory responses and impairs specific vasoconstrictive agonists.
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Feng J, Liu Y, Dobrilovic N, Singh AK, Sabe AA, Guan Y, Bianchi C, Sellke FW. Altered expression and activation of mitogen-activated protein kinases in diabetic heart during cardioplegic arrest and cardiopulmonary bypass. Surgery 2013; 154:436-43. [PMID: 23972649 DOI: 10.1016/j.surg.2013.05.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 05/10/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND We investigated whether mitogen-activated protein kinases (MAPKs) are changed in the hearts of patients with diabetes after cardioplegia and cardiopulmonary bypass (CP/CPB) operations. METHODS Biopsies from the right atrial appendage were harvested pre- and post-CP/CPB from nondiabetic (ND) patients (n = 8, hemoglobin A1c (HbA1c) = 5.4 ± 0.12); patients with controlled diabetes (CDM) (n = 8, HbA1c = 6.5 ± 0.15); and patients with uncontrolled diabetes (UDM) (n = 8, HbA1c = 9.6 ± 0.3) undergoing coronary artery bypass grafting. The expression and/or activation of the p38-MAPK, ERK1/2, JNK, and MKP-1 in the right-atrial tissues were analyzed by Western blotting. The vasomotor function of coronary arterioles was measured by videomicroscopy. RESULTS The post-CP/CPB levels of total p38-MAPK were decreased in the 3 groups as compared with their pre-CP/CPB levels (P < .05). There were increases in phospho-p38-MAPK, phospho-ERK1/2, and MKP-1 in UDM patients as compared with ND and CDM patients at baseline (P < .05). Compared to pre-CP/CPB, the post-CP/CPB levels of phospho-p38-MAPK decreased in the UDM group but were unaltered in the ND and CDM groups; however, the post-CP/CPB levels of phospho-p38-MAPK still remained greater than the post-CP/CPB levels of the other 2 groups. Post-CP/CPB levels of phospho-ERK1/2 were increased in the ND and CDM groups but were decreased in the UDM group compared to their pre-CP/CPB levels, respectively (P < .05). There were no significant differences in phospho-JNK in 3 groups at baseline. Post-CP/CPB levels of phospho-JNK, however, were increased in the 3 groups and were more pronounced in the myocardium of the UDM group (P < .05). After CP/CPB, the protein levels of MKP-1 were unchanged in the 3 groups when compared with their pre-CP/CPB levels. Post-CP/CPB levels of MKP-1, however, remained greater in the UDM group than in the ND and CDM groups. The post-CP/CPB contractile responses to the thromboxane A2 analog U46619 were significantly impaired in all 3 groups compared with pre-CP/CPB contractile responses. These impairments were more pronounced in the UDM group. CONCLUSION Uncontrolled diabetes is associated with changes in expression of and activation of MAPKs and vasomotor dysfunction in the setting of CP/CPB.
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Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI 02905, USA
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Dobson GP, Faggian G, Onorati F, Vinten-Johansen J. Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era? Front Physiol 2013; 4:228. [PMID: 24009586 PMCID: PMC3755226 DOI: 10.3389/fphys.2013.00228] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/05/2013] [Indexed: 12/16/2022] Open
Abstract
Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.
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Affiliation(s)
- Geoffrey P. Dobson
- Department of Physiology and Pharmacology, Heart and Trauma Research Laboratory, James Cook UniversityTownsville, QLD, Australia
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Francesco Onorati
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Jakob Vinten-Johansen
- Cardiothoracic Research Laboratory of Emory University Hospital Midtown, Carlyle Fraser Heart CenterAtlanta, GA, USA
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Feng J, Chu LM, Dobrilovic N, Liu Y, Singh AK, Sellke FW. Decreased coronary microvascular reactivity after cardioplegic arrest in patients with uncontrolled diabetes mellitus. Surgery 2012; 152:262-9. [PMID: 22828147 DOI: 10.1016/j.surg.2012.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Accepted: 04/30/2012] [Indexed: 12/18/2022]
Abstract
BACKGROUND We investigated the effects of cardioplegic arrest and reperfusion on coronary arteriolar responses to endothelium-dependent and -independent vasodilators and associated signaling pathways in uncontrolled diabetic, well controlled diabetic, and case-matched nondiabetic patients undergoing coronary artery bypass graft surgery. METHODS Coronary arterioles from harvested right atrial tissues were dissected pre- and post-cardioplegic arrest and reperfusion from uncontrolled diabetic (n = 10; hemoglobin A1c = 9.3 ± 0.3), well controlled diabetic (n = 10; hemoglobin A1c = 6.2 ± 0.2), and nondiabetic patients (n = 10; hemoglobin A1c = 5.1 ± 0.1) undergoing coronary artery bypass graft surgery. RESULTS The baseline microvascular response to adenosine 5'-diphosphate, substance P, and sodium nitroprusside of arterioles from uncontrolled diabetic patients were decreased compared to the respective response from nondiabetic or well controlled diabetic patients (P < .05). The vasodilatory responses to adenosine 5'-diphosphate and substance P after cardioplegic arrest and reperfusion were significantly decreased in all 3 groups compared to pre-cardioplegic arrest and reperfusion responses (P < .05). However, these decreases were more pronounced in the uncontrolled diabetic group (P < .05). The expression of protein kinase C-α, protein kinase C-β, and protein oxidation in atrial tissues was significantly increased in the uncontrolled diabetic group compared to the nondiabetic or controlled diabetes groups. CONCLUSION Uncontrolled diabetes is associated with endothelium-dependent and -independent vascular dysfunction of coronary arterioles. In addition, uncontrolled diabetes worsens the recovery of coronary arteriolar function after cardioplegic arrest and reperfusion. These alterations are associated with an increased expression/activation of protein kinase C-α and protein kinase C-β and enhanced oxidative stress.
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Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, USA
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22
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Potts LB, Ren Y, Lu G, Kuo E, Ngo E, Kuo L, Hein TW. Constriction of retinal arterioles to endothelin-1: requisite role of rho kinase independent of protein kinase C and L-type calcium channels. Invest Ophthalmol Vis Sci 2012; 53:2904-12. [PMID: 22427601 DOI: 10.1167/iovs.12-9542] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Although endothelin-1 (ET-1) is a potent vasoconstrictor peptide implicated in several retinal pathologies, the underlying mechanism of vasoconstriction is understood incompletely. We addressed this issue by assessing the contributions of extracellular calcium (Ca²⁺), L-type voltage-operated calcium channels (L-VOCCs), Rho kinase (ROCK), and protein kinase C (PKC) to ET-1-induced constriction of porcine retinal arterioles, all of which have been implicated commonly in vascular smooth muscle contraction. METHODS Porcine retinal arterioles (~50-100 μm) were isolated for vasomotor study and molecular assessment of ROCK isoforms. RESULTS Isolated arterioles developed stable basal tone at 55 cmH₂O luminal pressure and constricted to ET-1 (0.1 nM) with a 40 ± 6% reduction in resting diameter in 20 minutes. In the absence of extraluminal Ca²⁺, arterioles lost basal tone and failed to constrict to ET-1. Although L-VOCC inhibitor nifedipine reduced basal tone and blocked vasoconstriction to PKC activator PDBu, vasoconstriction to ET-1 was unaffected. The broad-spectrum PKC inhibitor Gö-6983 abolished vasoconstriction to PDBu, but did not alter ET-1-induced vasoconstriction or basal tone. Incubation of arterioles with ROCK inhibitor H-1152 abolished basal tone and vasoconstrictions to ET-1 and PDBu. Both ROCK1 and ROCK2 isoforms were expressed in the retinal arteriolar wall. CONCLUSIONS Extracellular Ca²⁺ entry via L-VOCCs and basal ROCK activity play important roles in the maintenance of basal tones of porcine retinal arterioles. ET-1-induced constriction is mediated by extracellular Ca²⁺ entry independent of L-VOCCs and by ROCK activation without the involvement of PKC. However, direct PKC activation can cause vasoconstriction via L-VOCC and ROCK signaling.
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Affiliation(s)
- Luke B Potts
- Department of Systems Biology and Translational Medicine, College of Medicine, Texas A&M Health Science Center, Temple, Texas, USA
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Mazzuca MQ, Khalil RA. Vascular endothelin receptor type B: structure, function and dysregulation in vascular disease. Biochem Pharmacol 2012; 84:147-62. [PMID: 22484314 DOI: 10.1016/j.bcp.2012.03.020] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 03/22/2012] [Indexed: 12/21/2022]
Abstract
Endothelin-1 (ET-1) is a major regulator of vascular function, acting via both endothelin receptor type A (ET(A)R) and type B (ET(B)R). Although the role of ET(A)R in vascular smooth muscle (VSM) contraction has been studied, little is known about ET(B)R. ET(B)R is a G-protein coupled receptor with a molecular mass of ~50 kDa and 442 amino acids arranged in seven transmembrane domains. Alternative splice variants of ET(B)R and heterodimerization and cross-talk with ET(A)R may affect the receptor function. ET(B)R has been identified in numerous blood vessels with substantial effects in the systemic, renal, pulmonary, coronary and cerebral circulation. ET(B)R in the endothelium mediates the release of relaxing factors such as nitric oxide, prostacyclin and endothelium-derived hyperpolarizing factor, and could also play a role in ET-1 clearance. ET(B)R in VSM mediates increases in [Ca(2+)](i), protein kinase C, mitogen-activated protein kinase and other pathways of VSM contraction and cell growth. ET-1/ET(A)R signaling has been associated with salt-sensitive hypertension (HTN) and pulmonary arterial hypertension (PAH), and ET(A)R antagonists have shown some benefits in these conditions. In search for other pathogenetic factors and more effective approaches, the role of alterations in endothelial ET(B)R and VSM ET(B)R in vascular dysfunction, and the potential benefits of modulators of ET(B)R in treatment of HTN and PAH are being examined. Combined ET(A)R/ET(B)R antagonists could be more efficacious in the management of conditions involving upregulation of ET(A)R and ET(B)R in VSM. Combined ET(A)R antagonist with ET(B)R agonist may need to be evaluated in conditions associated with decreased endothelial ET(B)R expression/activity.
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Affiliation(s)
- Marc Q Mazzuca
- Vascular Surgery Research Laboratory, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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Feng J, Liu Y, Chu LM, Clements RT, Khabbaz KR, Robich MP, Bianchi C, Sellke FW. Thromboxane-induced contractile response of human coronary arterioles is diminished after cardioplegic arrest. Ann Thorac Surg 2011; 92:829-36. [PMID: 21871266 DOI: 10.1016/j.athoracsur.2011.04.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/05/2011] [Accepted: 04/07/2011] [Indexed: 10/17/2022]
Abstract
BACKGROUND We investigated the contractile response of human coronary microvasculature to thromboxane A-2 (TXA-2), with and without the blockade of TXA-2 receptors or the inhibition of phospholipase-C (PLC) or of protein kinase C-α (PKC-α) in the human coronary microvasculature before and after cardioplegia, followed by reperfusion (CP/Rep). Protein/gene expression and localization of TXA-2 receptors, TXA-2 synthase, PLC, and other TXA-2-related proteins was also examined. METHODS Right atrial tissue was harvested before and after cold blood cardioplegia, followed by about 10 minutes of reperfusion, from 28 patients undergoing cardiac operations. Coronary arterioles (90 to 170 μm in diameter) were dissected from the harvested tissue. RESULTS The post-CP/Rep contractile response of coronary arterioles to TXA-2 analog U-46619 was significantly impaired vs pre-CP/Rep (p<0.05). The TXA-2 receptor antagonist SQ-29548 (10(-6) M) prevented the contractile response to U-46619 (p<0.05). Pretreatment with the PLC inhibitor U73122 (10(-6) M) significantly inhibited the U-46619-induced contractile response (p<0.05). Administration of the PKC-α inhibitor safingol failed to affect U-46619-induced contraction. Total protein levels and gene expression of TXA-2 receptors, TXA-2 synthase, PLC-β3, phospho-PLC-β3, PLC-γ1, and phospho-PLC-γ1 were not altered after CP/Rep. Confocal microscopy showed no significant differences in the expression of TXA-2 receptors or PLC-β3 in the microcirculation. TXA-2 receptors and PLC-β3 were both present in smooth muscle and endothelium. CONCLUSIONS Cardioplegia/Rep decreases the contractile response of human coronary arterioles to TXA-2 soon after cardiac operations. The contractile response to the TXA-2 analog U-46619 is through activation of TXA-2 receptors and PLC.
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Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA
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van den Heuvel M, Sorop O, Koopmans SJ, Dekker R, de Vries R, van Beusekom HMM, Eringa EC, Duncker DJ, Danser AHJ, van der Giessen WJ. Coronary microvascular dysfunction in a porcine model of early atherosclerosis and diabetes. Am J Physiol Heart Circ Physiol 2011; 302:H85-94. [PMID: 21984550 DOI: 10.1152/ajpheart.00311.2011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Detailed evaluation of coronary function early in diabetes mellitus (DM)-associated coronary artery disease (CAD) development is difficult in patients. Therefore, we investigated coronary conduit and small artery function in a preatherosclerotic DM porcine model with type 2 characteristics. Streptozotocin-induced DM pigs on a saturated fat/cholesterol (SFC) diet (SFC + DM) were compared with control pigs on SFC and standard (control) diets. SFC + DM pigs showed DM-associated metabolic alterations and early atherosclerosis development in the aorta. Endothelium-dependent vasodilation to bradykinin (BK), with or without blockade of nitric oxide (NO) synthase, endothelium-independent vasodilation to an exogenous NO-donor (S-nitroso-N-acetylpenicillamine), and vasoconstriction to endothelin (ET)-1 with blockade of receptor subtypes, were assessed in vitro. Small coronary arteries, but not conduit vessels, showed functional alterations including impaired BK-induced vasodilatation due to loss of NO (P < 0.01 vs. SFC and control) and reduced vasoconstriction to ET-1 (P < 0.01 vs. SFC and control), due to a decreased ET(A) receptor dominance. Other vasomotor responses were unaltered. In conclusion, this model demonstrates specific coronary microvascular alterations with regard to NO and ET-1 systems in the process of early atherosclerosis in DM. In particular, the altered ET-1 system correlated with hyperglycemia in atherogenic conditions, emphasizing the importance of this system in DM-associated CAD development.
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Affiliation(s)
- Mieke van den Heuvel
- Department of Cardiology, Division of Pharmacology, Vascular and Metabolic Diseases, Cardiovascular Research School COEUR, Erasmus University Medical Center, Rotterdam, The Netherlands
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von Brandenstein M, Depping R, Schäfer E, Dienes HP, Fries JW. Protein kinase C α regulates nuclear pri-microRNA 15a release as part of endothelin signaling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1793-802. [DOI: 10.1016/j.bbamcr.2011.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 05/12/2011] [Accepted: 06/09/2011] [Indexed: 01/07/2023]
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Affiliation(s)
- Jun Feng
- Department of Surgery, Alpert Medical School of Brown University, Providence, RI, USA.
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Impaired contractile response of human peripheral arterioles to thromboxane A-2 after cardiopulmonary bypass. Surgery 2011; 150:263-71. [PMID: 21801963 DOI: 10.1016/j.surg.2011.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 06/13/2011] [Indexed: 10/17/2022]
Abstract
BACKGROUND We studied the contractile response of human peripheral microvasculature to thromboxane A-2 (TXA-2) before and after cardiopulmonary bypass (CPB), with and without the blockade of TXA-2 receptors, or the inhibition of phospholipase C (PLC), phospholipase A-2 (PLA-2) or protein kinase C (PKC)-α. We also examined the protein/gene expression and localization of TXA-2 receptors, TXA-2 synthase, PLC, and other TXA-2-related proteins. METHODS Skeletal muscle arterioles (90-180 μm in diameter) were harvested pre- and post-CPB from patients (n = 28) undergoing cardiac surgery. RESULTS The post-CPB contractile response of skeletal muscle arterioles to TXA-2 analog U-46619 was impaired compared with pre-CPB (P < .05). The presence of TXA-2 receptor antagonist SQ-29548 (10(-6)mol/L) prevented the contractile response to U-46619 (P < .05). Pretreatment with the PLC inhibitor U-73122 (10(-6)mol/L) significantly inhibited the U-46619-induced contractile response (P < .01). Administration of the PLA-2 inhibitor quinacrine (10(-6)mol/L) or PKC-α inhibitor safingol (2 × 10(-5)mol/L), however, failed to affect U-46619-induced contraction. Total protein levels and gene expression of TXA-2 receptors, and TXA-2 synthase of skeletal muscle, were not altered post-CPB. Confocal microscopy showed no differences in the expression of PLCβ-3 in the microcirculation. PLCβ-3 was localized to both smooth muscle and endothelium. CONCLUSION CPB decreases the contractile response of human peripheral arterioles to TXA-2 soon after cardiac surgery. This response may be in part responsible for the decrease in vascular tone, and accompanying hypotension sometimes observed after cardiac operations utilizing CPB.
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Robich MP, Osipov RM, Chu LM, Feng J, Burgess TA, Oyamada S, Clements RT, Laham RJ, Sellke FW. Temporal and spatial changes in collateral formation and function during chronic myocardial ischemia. J Am Coll Surg 2010; 211:470-80. [PMID: 20729101 DOI: 10.1016/j.jamcollsurg.2010.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 06/01/2010] [Indexed: 11/17/2022]
Abstract
BACKGROUND We investigated time dependence and spatial progression of cardiac function and angiogenesis signaling in a porcine model of chronic myocardial ischemia. STUDY DESIGN Yorkshire mini-swine (n = 7/group) were subjected to chronic myocardial ischemia by placing an ameroid constrictor on the left circumflex coronary artery under general anesthesia. Swine were sacrificed after either 4 or 7 weeks of ischemia. Myocardial function, angiographic evidence of angiogenesis, microvessel function, molecular signaling, and levels of apoptosis and oxidative stress were assessed. RESULTS Flow reserve was significantly increased at 7 versus 4 weeks. Myocardial function (+dP/dt) improved 1.5-fold by 7 weeks. In the ischemic territory, microvessels at 4 weeks displayed abnormal contraction responses to serotonin, which diminished at 7 weeks. Delta-like ligand 4 protein expression decreased at 7 weeks; expression of vascular endothelial growth factor (VEGF) and phospho-endothelial nitric acid synthase (eNOS) increased. The number of apoptotic cells was decreased at 7 weeks, and antiapoptotic markers heat shock protein (HSP) 27 and HSP 90 were upregulated at 7 weeks. There was an increase in proliferating endothelial cells at 7 weeks as compared with 4 weeks. In the adjacent normal ventricle, microvessels demonstrated smaller contraction responses to endothelin-1 and serotonin at 7 weeks. There was an increase in protein peroxidation in the ischemic territory at 7 weeks. CONCLUSIONS Over time, myocardial perfusion, function, and angiogenic signaling improved in the ischemic myocardium and adjacent normal territory compared with what is observed shortly after coronary occlusion.
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Affiliation(s)
- Michael P Robich
- Department of Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI, USA
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Feng J, Liu Y, Khabbaz KR, Hagberg R, Robich MP, Clements RT, Bianchi C, Sellke FW. Decreased contractile response to endothelin-1 of peripheral microvasculature from diabetic patients. Surgery 2010; 149:247-52. [PMID: 20727565 DOI: 10.1016/j.surg.2010.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 07/01/2010] [Indexed: 11/18/2022]
Abstract
BACKGROUND We compared the contractile responses to endothelin-1 (ET-1) with and without the inhibition of ET-A receptors and protein kinase C-alpha (PKC-α) in the human peripheral microvasculature of diabetic and case-matched, nondiabetic patients. METHODS Chest wall skeletal muscle was harvested from patients with and without diabetics undergoing cardiac surgery. Peripheral arterioles (90-180 μm in diameter) were dissected from the harvested tissue. Microvascular constriction was assessed by videomicroscopy in response to ET-1 with and without an endothelin-A (ET-A) receptor antagonist, an endothelin B (ET-B) antagonist, or a PKC-α inhibitor. RESULTS ET-1 induced a dose-dependent contractile response of skeletal muscle arterioles from diabetic and nondiabetic patients. The contractile response of diabetic arterioles from both prebypass and postbypass to ET-1 (10(-9) mol/L) was decreased compared with those of nondiabetic patients (P < .05). The contractile responses of microvessels of both diabetics and nondiabetics to ET-1 were inhibited in the presence of either ET-A receptor antagonist BQ123 (10(-7) mol/L) or the PKC-α inhibitor safingol (2 × 10(-5) mol/L, P < .05, respectively). In contrast, the ET-1-induced vasoconstriction was not affected by the administration of the ET-B receptor antagonist BQ788 (10(-7) mol/L). There were no differences in skeletal muscle levels of the ET-A and ET-B receptors between diabetic and nondiabetic groups. CONCLUSION Diabetic patients demonstrated a decreased contractile response to ET-1 in human peripheral microvasculature. The contractile response of diabetic vessels to ET-1 occurs via activation of ET-A receptors and PKC-α. These results provide novel mechanisms of ET-1-induced contraction in vasomotor dysfunction in patients with diabetes.
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Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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