1
|
Das A, Reis F. mTOR Signaling: New Insights into Cancer, Cardiovascular Diseases, Diabetes and Aging. Int J Mol Sci 2023; 24:13628. [PMID: 37686434 PMCID: PMC10487471 DOI: 10.3390/ijms241713628] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
The mechanistic/mammalian target of rapamycin (mTOR), a member of the phosphoinositide 3-kinase (PI3K) related kinase family, integrates intracellular and environmental cues that coordinate a diverse set of cellular/tissue functions, such as cell growth, proliferation, metabolism, autophagy, apoptosis, longevity, protein/lipid/nucleotide synthesis, and tissue regeneration and repair [...].
Collapse
Affiliation(s)
- Anindita Das
- Division of Cardiology, Pauley Heart Center, Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Flávio Reis
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-504 Coimbra, Portugal
- Institute of Pharmacology & Experimental Therapeutics & Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Pandey S, Madreiter-Sokolowski CT, Mangmool S, Parichatikanond W. High Glucose-Induced Cardiomyocyte Damage Involves Interplay between Endothelin ET-1/ET A/ET B Receptor and mTOR Pathway. Int J Mol Sci 2022; 23:13816. [PMID: 36430296 PMCID: PMC9699386 DOI: 10.3390/ijms232213816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
Patients with type two diabetes mellitus (T2DM) are at increased risk for cardiovascular diseases. Impairments of endothelin-1 (ET-1) signaling and mTOR pathway have been implicated in diabetic cardiomyopathies. However, the molecular interplay between the ET-1 and mTOR pathway under high glucose (HG) conditions in H9c2 cardiomyoblasts has not been investigated. We employed MTT assay, qPCR, western blotting, fluorescence assays, and confocal microscopy to assess the oxidative stress and mitochondrial damage under hyperglycemic conditions in H9c2 cells. Our results showed that HG-induced cellular stress leads to a significant decline in cell survival and an impairment in the activation of ETA-R/ETB-R and the mTOR main components, Raptor and Rictor. These changes induced by HG were accompanied by a reactive oxygen species (ROS) level increase and mitochondrial membrane potential (MMP) loss. In addition, the fragmentation of mitochondria and a decrease in mitochondrial size were observed. However, the inhibition of either ETA-R alone by ambrisentan or ETA-R/ETB-R by bosentan or the partial blockage of the mTOR function by silencing Raptor or Rictor counteracted those adverse effects on the cellular function. Altogether, our findings prove that ET-1 signaling under HG conditions leads to a significant mitochondrial dysfunction involving contributions from the mTOR pathway.
Collapse
Affiliation(s)
- Sudhir Pandey
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
| | | | - Supachoke Mangmool
- Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Warisara Parichatikanond
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
- Centre of Biopharmaceutical Science for Healthy Ageing (BSHA), Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Endothelin and the Cardiovascular System: The Long Journey and Where We Are Going. BIOLOGY 2022; 11:biology11050759. [PMID: 35625487 PMCID: PMC9138590 DOI: 10.3390/biology11050759] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 12/12/2022]
Abstract
Simple Summary In this review, we describe the basic functions of endothelin and related molecules, including their receptors and enzymes. Furthermore, we discuss the important role of endothelin in several cardiovascular diseases, the relevant clinical evidence for targeting the endothelin pathway, and the scope of endothelin-targeting treatments in the future. We highlight the present uses of endothelin receptor antagonists and the advancements in the development of future treatment options, thereby providing an overview of endothelin research over the years and its future scope. Abstract Endothelin was first discovered more than 30 years ago as a potent vasoconstrictor. In subsequent years, three isoforms, two canonical receptors, and two converting enzymes were identified, and their basic functions were elucidated by numerous preclinical and clinical studies. Over the years, the endothelin system has been found to be critical in the pathogenesis of several cardiovascular diseases, including hypertension, pulmonary arterial hypertension, heart failure, and coronary artery disease. In this review, we summarize the current knowledge on endothelin and its role in cardiovascular diseases. Furthermore, we discuss how endothelin-targeting therapies, such as endothelin receptor antagonists, have been employed to treat cardiovascular diseases with varying degrees of success. Lastly, we provide a glimpse of what could be in store for endothelin-targeting treatment options for cardiovascular diseases in the future.
Collapse
|
6
|
Sellke N, Kuczmarski A, Lawandy I, Cole VL, Ehsan A, Singh AK, Liu Y, Sellke FW, Feng J. Enhanced coronary arteriolar contraction to vasopressin in patients with diabetes after cardiac surgery. J Thorac Cardiovasc Surg 2018; 156:2098-2107. [PMID: 30057184 PMCID: PMC6242764 DOI: 10.1016/j.jtcvs.2018.05.090] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/10/2018] [Accepted: 05/13/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Cardioplegic arrest (CP) and cardiopulmonary bypass (CPB) are associated with vasomotor dysfunction of coronary arterioles in patients with diabetes (DM) undergoing cardiac surgery. We hypothesized that DM may up-regulate vasopressin receptor expression and alter the contractile response of coronary arterioles to vasopressin in the setting of CP/CPB. METHODS Right atrial tissue samples of patients with DM and without (ND) (n = 8 in each group) undergoing cardiac surgery were harvested before and after CP/CPB. The isolated coronary arterioles (80-150 μm) dissected from the harvested right atrial tissue samples were cannulated and pressurized (40 mm Hg) in a no-flow state. The changes in diameter were measured with video microscopy. The protein expression/localization of vasopressin 1A receptors (V1A) and vasopressin 1B receptors (V1B) in the atrial tissue were measured by immune-blotting and immunohistochemistry. RESULTS The pre-CP/CPB contractile responses of the coronary arterioles to vasopressin were significantly increased post-CP/CPB in both the ND and DM groups. This effect was more pronounced in the vessels from patients in the DM group than that of vessels from patients in the ND group (P < .05). Vasopressin-induced contractile response of the coronary arterioles was inhibited in the presence of the specific V1A antagonist SR 49059 (10-7 M) in both ND and DM vessels (P < .05). The post-CP/CPB protein levels of V1A were significantly increased compared with pre-CP/CPB values in both the ND and DM groups (P < .05), whereas this increase was greater in DM than that of ND (P < .05). Immunohistochemistry staining further indicates that V1B were mainly expressed in the myocardium but not in vascular smooth muscle. CONCLUSIONS CP/CPB and DM are both associated with up-regulation in V1 receptor expression/localization in human myocardium. Vasopressin may induce coronary arteriolar constriction via V1A. This alteration may lead to increased coronary arteriolar spasm in patients with DM undergoing CP/CPB and cardiac surgery.
Collapse
Affiliation(s)
- Nicholas 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
| | - Alex Kuczmarski
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Isabella Lawandy
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI
| | - Victoria L Cole
- 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
| | - Arun K Singh
- 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
| | - 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
| | - 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.
| |
Collapse
|
7
|
Ribeiro RVP, Badiwala MV, Ramzy D, Tumiati LC, Rao V. Recipient hypertonic saline infusion prevents cardiac allograft dysfunction. J Thorac Cardiovasc Surg 2018; 157:615-625.e1. [PMID: 30121134 DOI: 10.1016/j.jtcvs.2018.07.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation. METHODS Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured. RESULTS Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001). CONCLUSIONS Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction.
Collapse
Affiliation(s)
- Roberto V P Ribeiro
- Heart Transplant Program, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Division of Cardiovascular Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Mitesh V Badiwala
- Heart Transplant Program, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Division of Cardiovascular Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Danny Ramzy
- Division of Cardiothoracic Surgery, Cedars-Sinai Heart Institute, Los Angeles, Calif
| | - Laura C Tumiati
- Heart Transplant Program, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Division of Cardiovascular Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Vivek Rao
- Heart Transplant Program, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Division of Cardiovascular Surgery, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
8
|
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.
Collapse
|
9
|
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.
Collapse
|
10
|
Le Guillou V, Tamion F, Jouet I, Richard V, Mulder P, Bessou JP, Doguet F. Mesenteric endothelial dysfunction in a cardiopulmonary bypass rat model: the effect of diabetes. Diab Vasc Dis Res 2012; 9:270-9. [PMID: 22278737 DOI: 10.1177/1479164111434432] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Diabetes is a risk factor for perioperative complications after cardiac surgery. We studied its effects on mesenteric endothelial function in a cardiopulmonary bypass (CPB) model. METHODS Forty Wistar rats were divided into four groups: sham (D-CPB-), cardiopulmonary bypass (D-CPB+), diabetic (D+CPB-) and diabetic that have undergone CPB (D+CPB+). Two samples of mesenteric artery were used for nitric oxide synthase (NOS) Western blot analysis, and two others for assessing contractile response and endothelium relaxations. Nitrite products and tumour necrosis factor-alpha (TNF-α) were assessed as markers of inflammatory response. RESULTS We observed an enhanced contractile response to the α-adrenergic agonist associated with impairment of mesenteric vasorelaxation in D+CPB+ rats. Western immunoblot analysis of D+CPB+ highlighted an additive effect of hyper-expression of inducible NOS. A significantly increased inflammatory response was observed after CPB in diabetic animals. CONCLUSIONS This work confirms the potential deleterious impact of diabetes on the mesenteric endothelium during CPB in cardiac surgery.
Collapse
Affiliation(s)
- Vincent Le Guillou
- Department of Thoracic and Cardiovascular Surgery, Rouen University Hospital, France
| | | | | | | | | | | | | |
Collapse
|
11
|
Impact of Endothelial Activation on Infective and Inflammatory Complications after Cardiac Surgery in type II Diabetes Mellitus. Int J Artif Organs 2011; 34:469-80. [DOI: 10.5301/ijao.2011.8329] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2011] [Indexed: 11/20/2022]
Abstract
Purpose Altered endothelial response has been described in diabetics after cardiac surgery. Infections and inflammatory organ damage often complicate the postoperative course. We evaluated endothelial/cytokine response (ECR) after cardiac surgery and its role on infective/inflammatory complications of type II diabetic patients. Methods Perioperative ECR of 60 diabetic patients (Group A) undergoing cardiopulmonary bypass was compared to that of 60 non-diabetics (Group B). Hemodynamics, endothelial markers [vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1)], pro-inflammatory (IL-2, IL-6, IL-8) and anti-inflammatory cytokines (IL-10) were analyzed preoperatively (T0), at time of aortic declamping (T1), at ITU admission (T2), at 12 h (T3) and 24 h (T4) postoperatively. Postoperative infective/inflammatory complications were registered, and the related ECR was analyzed. Results Hemodynamics were comparable. No differences were found in perioperative IL-6 (p=0.776) and IL-8 (p=0.660) between the 2 groups. However, the diabetics showed significantly higher endothelial activation (VEGF p=0.0001, p=0.0001 since T1 to T3; MCP-1 p=0.0001, p<0.007 at T1, T3 and T4) with lower IL-10 (p=0.0001, p<0.05 at T2, T3, T4) and lower IL-2 secretion (p=0.0001, p<0.0001 at T1, T2). Infections developed in 23.3% of the diabetics; inflammatory complications in 13.3%. Those developing infections showed significantly lower IL-2 (p=0.042; p ≤. 021 at T1 and T2) than patients without infections, whereas those with complicated inflammatory lung or renal injury had higher MCP-1 leakage (p=0.006) with lower IL-10 (p=0.005). Conclusions The diabetics showed higher endothelial activation and lower antiinflammatory response to CPB compared to non-diabetics. Infections in diabetic patients correlated with depressed IL-2, while inflammatory complications correlated to higher endothelial activation and lower anti-inflammatory cytokine secretion.
Collapse
|
12
|
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.
Collapse
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
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Feng J, Chu LM, Robich MP, Clements RT, Khabbaz KR, Hagberg R, Liu Y, Osipov RM, Sellke FW. Effects of cardiopulmonary bypass on endothelin-1-induced contraction and signaling in human skeletal muscle microcirculation. Circulation 2010; 122:S150-5. [PMID: 20837906 DOI: 10.1161/circulationaha.109.928226] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND We investigated the effects of cardiopulmonary bypass (CPB) on the contractile response of human peripheral microvasculature to endothelin-1 (ET-1), examined the role of specific ET receptors and protein kinase C-alpha (PKC-α), and analyzed ET-1-related gene/protein expression in this response. METHODS AND RESULTS Human skeletal muscle arterioles (90 to 180 μm in diameter) were dissected from tissue harvested before and after CPB from 30 patients undergoing cardiac surgery. In vitro contractile response to ET-1 was assessed by videomicroscopy, with and without an endothelin-A (ET-A) receptor antagonist, an endothelin-B (ET-B) antagonist, or a PKC-α inhibitor. The post-CPB contractile response of peripheral arterioles to ET-1 was significantly decreased compared with pre-CPB response. The response to ET-1 was significantly inhibited in the presence of the ET-A antagonist BQ123 but unchanged in the presence of the ET-B receptor antagonist BQ788. Pretreatment with the PKC-α inhibitor safingol reversed ET-1-induced response from contraction to relaxation. The total protein levels of ET-A and ET-B receptors were not altered after CPB. Microarray analysis showed no significant changes in the gene expression of ET receptors, ET-1-related proteins, and protein kinases after CPB. CONCLUSIONS CPB decreases myogenic contractile function of human peripheral arterioles in response to ET-1. The contractile response to ET-1 is through activation of ET-A receptors and PKC-α. CPB has no effects on ET-1-related gene/protein expression. These results provide novel mechanisms of ET-1-induced contraction in the setting of vasomotor dysfunction after cardiac surgery.
Collapse
Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI 02903, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
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.
Collapse
Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Feng J, Liu Y, Khabbaz KR, Hagberg R, Sodha NR, Osipov RM, Sellke FW. Endothelin-1-induced contractile responses of human coronary arterioles via endothelin-A receptors and PKC-alpha signaling pathways. Surgery 2010; 147:798-804. [PMID: 20079914 DOI: 10.1016/j.surg.2009.11.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 11/24/2009] [Indexed: 10/19/2022]
Abstract
BACKGROUND We investigated the contractile function in responses to endothelin-1 (ET-1) in the human coronary microvasculature as well as the roles of endothelin receptors and protein kinase C-alpha (PKC-alpha) in these responses. METHODS Human atrial tissue was harvested from patients who underwent cardiac surgery pre- and post-cardioplegia (CP)/cardiopulmanory bypass (CPB). Microvascular constriction was assessed in pre- and post-CP/CPB samples in responses to ET-1, in the presence and absence of an endothelin-A (ET-A) receptor antagonist, an endothelin-B (ET-B) receptor antagonist, or a PKC-alpha inhibitor, respectively. The expression and localization of the ET-A and ET-B receptors were also examined using immunoblot and immunofluorescence photomicroscopy. RESULTS The post-CP/CPB contractile response of coronary arterioles to ET-1 was significantly decreased compared with the pre-CP/CPB responses. The response to ET-1 was significantly inhibited in the presence of the ET-A antagonist BQ123 (10(-7)mol/L), but these values remained unchanged with the ET-B receptor antagonist BQ788 (10(-7)mol/L). Pretreatment with the PKC-alpha inhibitor safingol (2.5 x 10(-5) mol/L) reversed the ET-1 responses from contraction into relaxation. The total polypeptide levels of ET-A and ET-B receptors were not altered post-CP/CPB. Immunoblot and immunofluorescent staining displayed strong signals for ET-A receptors and relatively weak signals for ET-B receptors localized on coronary microvasculature. CONCLUSION CP/CPB decreases the contractile function of human coronary microvessels in responses to ET-1. ET-A receptors are predominantly localized in the human coronary microcirculation, whereas ET-B receptors seem to be less abundant. The contractile response to ET-1 is in part through the activation of ET-A receptors and PKC-alpha. These results suggest a role of ET-1-induced contraction in the vasomotor dysfunction after cardiac surgery.
Collapse
Affiliation(s)
- Jun Feng
- Division of Cardiothoracic Surgery, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Liu HM, Liu KX, Cheng MH, Liu Y, Lei S, Irwin MG, Xia Z. Bosentan affects 15-F2t-isoprostane adverse effects on postischemic rat hearts. J Surg Res 2009; 168:18-26. [PMID: 20006348 DOI: 10.1016/j.jss.2009.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 06/25/2009] [Accepted: 07/11/2009] [Indexed: 11/28/2022]
Abstract
BACKGROUND 15-F(2t)-isoprostane (IsoP), a marker of reactive oxygen species-induced oxidative stress, is increased after myocardial ischemia and reperfusion. It exerts deleterious effects on postischemic myocardium accompanied with increased release of endothelin-1 (ET-1), a potent vasoconstrictor. We hypothesized that IsoP exacerbates myocardial ischemia-reperfusion injury by stimulating ET-1 production, and that ET-1 blockade can attenuate or prevent these deleterious effects of IsoP. METHODS Adult rat hearts were perfused by the Langendorff technique with Krebs-Henseleit solution (KH) at a constant flow rate of 10 mL/min. Global myocardial ischemia was induced by stopping KH perfusion for 40 min followed by 60 min of reperfusion. Hearts were randomized to one of the five groups (n = 8 each): untreated control, treated with IsoP (100 nM), or the ET-1 receptor A/B antagonist bosentan (1 μM) alone or in combination 10 min prior to, during 40 min global ischemia and 15 min of reperfusion, or treated with IsoP as above plus delayed administration of bosentan after 15 min of reperfusion. RESULTS Coronary effluent ET-1 concentrations in the IsoP group were higher than those in the control group during ischemia and reperfusion (P < 0.05), which was associated with increased release of cardiac-specific creatine kinase, reduced cardiac contractility during reperfusion, and increased myocardial infarct size (all P < 0.05 versus control). Bosentan administration during early reperfusion exacerbated the IsoP deleterious effects, while delayed administration attenuated it. CONCLUSION 15-F(2t)-isoprostane-induced ET-1 production during later reperfusion is detrimental to functional recovery of damaged myocardium, while ET-1 increase during early reperfusion seems to improve it.
Collapse
Affiliation(s)
- Hui-min Liu
- Department of Anesthesiology, Anesthesiology Research Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | | | | | | | | | | | | |
Collapse
|
17
|
Kim BO, Verma S, Weisel RD, Fazel S, Jia ZQ, Mizuno T, Li RK. Preservation of heart function in diabetic rats by the combined effects of muscle cell implantation and insulin therapy. Eur J Heart Fail 2007; 10:14-21. [PMID: 18160341 DOI: 10.1016/j.ejheart.2007.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 10/12/2007] [Accepted: 11/06/2007] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Diabetic cardiomyopathy is a common cause of heart failure in diabetic patients, but current treatments do not directly improve ventricular function. Cell transplantation can prevent cardiac dilatation after injury, and may also prevent congestive heart failure in diabetic cardiomyopathy. AIM This study evaluated the functional effects of smooth muscle cells (SMCs) implanted into the myocardium of insulin- and non insulin-treated diabetic rats. METHODS Four weeks after streptozotocin infusion, adult Wistar rats were implanted with BrdU-labelled SMCs or culture media (N=12/group). Six rats in each group were also treated with insulin. Echocardiograms were performed at 0, 4 and 8 weeks after streptozotocin injection, and histology and heart function were evaluated at 4 weeks after implantation. RESULTS Blood glucose levels decreased after insulin treatment. Among cell-injected rats, histology indicated that those that did not receive insulin retained fewer surviving BrdU+ SMCs, and a smaller volume of myocardial tissue positive for alpha-smooth muscle actin. Cardiac function was preserved in the insulin-treated groups relative to those that did not receive insulin. Among insulin-treated rats, the cell-injected group functioned better than the media-injected group. CONCLUSIONS Diabetic cardiomyopathy is partially treatable with insulin; however, a combination of SMC transplantation and insulin treatment produced the best functional result. Cell transplantation may prevent the progression of diabetic cardiomyopathy in patients whose glucose levels are controlled with insulin.
Collapse
Affiliation(s)
- Byung-Ok Kim
- Toronto General Research Institute, Division of Cardiovascular Surgery, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
18
|
Deschamps AM, Zavadzkas J, Murphy RL, Koval CN, McLean JE, Jeffords L, Saunders SM, Sheats NJ, Stroud RE, Spinale FG. Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion. Am J Physiol Heart Circ Physiol 2007; 294:H875-83. [PMID: 18065523 DOI: 10.1152/ajpheart.00918.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The matrix metalloproteinases (MMPs), in particular, membrane type 1 MMP (MT1-MMP), are increased in the context of myocardial ischemia and reperfusion (I/R) and likely contribute to myocardial dysfunction. One potential upstream induction mechanism for MT1-MMP is endothelin (ET) release and subsequent protein kinase C (PKC) activation. Modulation of ET and PKC signaling with respect to MT1-MMP activity with I/R has yet to be explored. Accordingly, this study examined in vivo MT1-MMP activation during I/R following modification of ET signaling and PKC activation. With the use of a novel fluorogenic microdialysis system, myocardial interstitial MT1-MMP activity was measured in pigs (30 kg; n = 9) during I/R (90 min I/120 min R). Local ET(A) receptor antagonism (BQ-123, 1 microM) and PKC inhibition (chelerythrine, 1 microM) were performed in parallel microdialysis probes. MT1-MMP activity was increased during I/R by 122 +/- 10% (P < 0.05) and was unchanged from baseline with ET antagonism and/or PKC inhibition. Selective PKC isoform induction occurred such that PKC-betaII increased by 198 +/- 31% (P < 0.05). MT1-MMP phosphothreonine, a putative PKC phosphorylation site, was increased by 121 +/- 8% (P < 0.05) in the I/R region. These studies demonstrate for the first time that increased interstitial MT1-MMP activity during I/R is a result of the ET/PKC pathway and may be due to enhanced phosphorylation of MT1-MMP. These findings identify multiple potential targets for modulating a local proteolytic pathway operative during I/R.
Collapse
Affiliation(s)
- Anne M Deschamps
- Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC 29403, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Lekli I, Szabo G, Juhasz B, Das S, Das M, Varga E, Szendrei L, Gesztelyi R, Varadi J, Bak I, Das DK, Tosaki A. Protective mechanisms of resveratrol against ischemia-reperfusion-induced damage in hearts obtained from Zucker obese rats: the role of GLUT-4 and endothelin. Am J Physiol Heart Circ Physiol 2007; 294:H859-66. [PMID: 18065527 DOI: 10.1152/ajpheart.01048.2007] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The resveratrol-induced cardiac protection was studied in Zucker obese rats. Rats were divided into five groups: group 1, lean control; group 2, obese control (OC); group 3, obese rats treated orally with 5 mg kg(-1) day(-1) of resveratrol (OR) for 2 wk; group 4, obese rats received 10% glucose solution ad libitum for 3 wk (OG); and group 5, obese rats received 10% glucose for 3 wk and resveratrol (OGR) during the 2nd and 3rd wk. Body weight, serum glucose, and insulin were measured, and then hearts were isolated and subjected to 30 min of ischemia followed by 120 min of reperfusion. Heart rate, coronary flow, aortic flow, developed pressure, the incidence of reperfusion-induced ventricular fibrillation, and infarct size were measured. Resveratrol reduced body weight and serum glucose in the OR compared with the OC values (414 +/- 10 g and 7.08 +/- 0.41 mmol/l, respectively, to 378 +/- 12 g and 6.11 +/- 0.44 mmol/l), but insulin levels were unchanged. The same results were obtained for the OG vs. OGR group. Resveratrol improved postischemic cardiac function in the presence or absence of glucose intake compared with the resveratrol-free group. The incidence of ventricular fibrillation and infarct size was reduced by 83 and 20% in the OR group, and 67 and 16% in the OGR group, compared with the OC and OG groups, respectively. Resveratrol increased GLUT-4 expression and reduced endothelin expression and cardiac apoptosis in ischemic-reperfused hearts in the presence or absence of glucose intake. Thus the protective effect of resveratrol could be related to its direct effects on the heart.
Collapse
Affiliation(s)
- Istvan Lekli
- Department of Pharmacology, Faculty of Pharmacy, Health Science Center, University of Debrecen, Debrecen, Hungary
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Lazar HL. Alterations in myocardial metabolism in the diabetic myocardium. Semin Thorac Cardiovasc Surg 2007; 18:289-92. [PMID: 17395024 DOI: 10.1053/j.semtcvs.2006.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2006] [Indexed: 12/17/2022]
Abstract
Free fatty acids are the preferred substrate for the myocardium. However, under conditions of ischemia, glucose becomes the primary myocardial energy source. Its metabolism avoids the toxic end-products of free fatty acids, which include oxygen free radicals. Patients with diabetes mellitus have impaired uptake of glucose. As a consequence the diabetic myocardium relies heavily on free fatty acid metabolism as its energy source. The results of these alterations in myocardial metabolism ultimately contribute to changes in endothelial function, inflammation, and oxidative stress. This review describes the defects in diabetic myocardial metabolism and how they contribute to cardiovascular dysfunction. The mechanisms by which intravenous insulin infusions can be used to modulate these changes in myocardial metabolism to improve clinical outcomes are discussed.
Collapse
Affiliation(s)
- Harold L Lazar
- Boston University School of Medicine, Department of Cardiothoracic Surgery, Boston Medical Center, Boston, MA 02118, USA.
| |
Collapse
|
21
|
Apple KA, McLean JE, Squires CE, Schaeffer B, Sample JA, Murphy RL, Deschamps AM, Leonardi AH, Allen CM, Hendrick JW, Stroud RE, Mukherjee R, Spinale FG. Differential effects of protein kinase C isoform activation in endothelin-mediated myocyte contractile dysfunction with cardioplegic arrest and reperfusion. Ann Thorac Surg 2006; 82:664-71. [PMID: 16863782 DOI: 10.1016/j.athoracsur.2006.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 03/06/2006] [Accepted: 03/07/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Increased myocardial interstitial levels of endothelin (ET) occur during cardioplegic arrest (CA) and may contribute to contractile dysfunction. Endothelin receptor transduction involves the protein kinase-C (PKC) family comprised of multiple isoforms with diverse functions. Which PKC isoforms may be involved in ET-induced contractile dysfunction after CA remains unknown. METHODS Shortening velocity was measured in isolated left ventricular porcine myocytes and randomized (minimum of 30 per group): normothermia (cell culture media for 2 hours at 37 degrees C); CA (2 hours in CA solution [4 degrees C, 24 mEq K+] followed by reperfusion in cell media); ET/CA (100 pM ET incubated during CA and reperfusion). These studies were carried out in the presence and absence of PKC inhibitors (500 nM) and directed against members of the classical PKC subfamily (beta I, beta II, gamma) and the novel subfamily (epsilon, eta). RESULTS Cardiac arrest reduced shortening velocity by approximately 50%, which was further reduced in the presence of ET. Inhibition of either the beta II or gamma PKC isoform significantly increased shortening velocity from ET/CA as well as CA only values. In separate studies (n = 3), total beta II and phosphorylated beta II increased by over 150% with ET/CA (p < 0.05). Taken together, these results suggest that a predominant intracellular effector for the negative contractile effects mediated by ET in the context of CA is the PKC isoform beta II. CONCLUSIONS Targeted inhibition of specific PKC isoforms relieves the negative inotropic effects of ET after simulated CA. These findings provide important mechanistic support for the development of targeted inhibitory strategies with respect to ET signaling and myocyte contractile dysfunction in the context of CA and reperfusion.
Collapse
Affiliation(s)
- Kimberly A Apple
- Division of Cardiothoracic Surgery, Medical University of South Carolina, and The Ralph H. Johnson Veteran's Affairs Medical Center, Charleston, South Carolina 29425, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Lango R, Smoleński RT, Rogowski J, Siebert J, Wujtewicz M, Słomińska EM, Lysiak-Szydłowska W, Yacoub MH. Propionyl-L-carnitine improves hemodynamics and metabolic markers of cardiac perfusion during coronary surgery in diabetic patients. Cardiovasc Drugs Ther 2006; 19:267-75. [PMID: 16187006 DOI: 10.1007/s10557-005-3349-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
UNLABELLED Diabetic hearts are particularly vulnerable to ischemia-reperfusion injury during cardiac surgery. Application of carnitine derivatives could be beneficial not only because of metabolic effects but also by protecting vasculature. This study aimed to evaluate hemodynamic changes associated with propionyl-L-carnitine and L-carnitine administration and its correlation with biochemical markers of cardiac vascular function. METHODS Sixty-eight diabetic patients undergoing cardiopulmonary bypass coronary operation were given intravenously 20 mg/kg b.w. L-carnitine (LC), 24 mg/kg b.w. propionyl-L-carnitine (PC), or placebo (Cont). Endothelin and nucleotide metabolites were determined intraoperatively in arterial and coronary sinus blood and heart biopsies. RESULTS Cardiac index at 6 and 12 h after cardiopulmonary bypass was significantly higher in PC (3.30 +/- 0.12 and 3.47 +/- 0.15 L/min/m2) as compared to Cont (2.92 +/- 0.13 and 2.91 +/- 0.16 L/min/m2; P = 0.04 and P = 0.01, respectively). Mean pulmonary artery pressure was lower in PC at 6 (20.8 +/- 0.91 mmHg) and 12 h (20.7 +/- 0.81 mmHg) in comparison to Cont (23.5 +/- 0.75 and 23.4 +/- 0.75 mmHg; P = 0.03 and P = 0.02, respectively). Trans-cardiac endothelin difference on reperfusion was higher in Cont (0.33 +/- 0.26 pmol/L) than in LC (-0.61 +/- 0.24 pmol/L, P = 0.012) and tended to be higher than in PC (-0.29 +/- 0.17 pmol/L, P = 0.056). Trans-cardiac hypoxanthine difference after 10 min reperfusion was significantly higher in Cont (6.22 +/- 1.08 micromol/L) in comparison to LC (3.17 +/- 0.66 micromol/L, P = 0.025) and PC (2.36 +/- 0.73 micromol/L, P = 0.006). Myocardial hypoxanthine concentration was lowest in PC. CONCLUSIONS Significant improvement of hemodynamics following propionyl-L-carnitine administration in diabetic patients undergoing on-bypass coronary surgery was accompanied by reduced trans-cardiac endothelin difference and rapid hypoxanthine washout during reperfusion suggesting improvement of metabolism or vascular function.
Collapse
Affiliation(s)
- Romuald Lango
- Department of Anesthesiology and Intensive Care, Medical University of Gdańsk, Debinki, 7 80-211, Poland.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Xia Z, Kuo KH, Godin DV, Walker MJ, Tao MCY, Ansley DM. 15-F2t-isoprostane exacerbates myocardial ischemia-reperfusion injury of isolated rat hearts. Am J Physiol Heart Circ Physiol 2005; 289:H1366-72. [PMID: 15937102 DOI: 10.1152/ajpheart.00042.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species induce formation of 15-F2t-isoprostane (15-F2t-IsoP), a specific marker of in vivo lipid peroxidation, which is increased after myocardial ischemia and during the subsequent reperfusion. 15-F2t-IsoP possesses potent bioactivity under pathophysiological conditions. However, it remains unknown whether 15-F2t-IsoP, by itself, can influence myocardial ischemia-reperfusion injury (IRI). Adult rat hearts were perfused by the Langendorff technique with Krebs-Henseleit (KH) solution at a constant flow rate of 10 ml/min. 15-F2t-IsoP (100 nM), SQ-29548 (1 μM, SQ), a thromboxane receptor antagonist that can abolish the vasoconstrictor effect of 15-F2t-IsoP, 15-F2t-IsoP + SQ in KH, or KH alone (vehicle control) was applied for 10 min before induction of 40 min of global ischemia followed by 60 min of reperfusion. During ischemia, saline (control), 15-F2t-IsoP, 15-F2t-IsoP + SQ, or SQ in saline was perfused through the aorta at 60 μl/min. 15-F2t-IsoP, 15-F2t-IsoP + SQ, or SQ in KH was infused during the first 15 min of reperfusion. Coronary effluent endothelin-1 concentrations were significantly higher in the group treated with 15-F2t-IsoP than in the control group during ischemia and also in the later phase of reperfusion ( P < 0.05). Infusion of 15-F2t-IsoP increased release of cardiac-specific creatine kinase, reduced cardiac contractility during reperfusion, and increased myocardial infarct size relative to the control group. SQ abolished the deleterious effects of 15-F2t-IsoP. 15-F2t-IsoP exacerbates myocardial IRI and may, therefore, act as a mediator of IRI. 15-F2t-IsoP-induced endothelin-1 production during cardiac reperfusion may represent a mechanism underlying the deleterious actions of 15-F2t-IsoP.
Collapse
Affiliation(s)
- Zhengyuan Xia
- University of British Columbia, Department of Anesthesiology, Vancouver, BC, Canada V5Z 4E3
| | | | | | | | | | | |
Collapse
|
24
|
Kelsall CJ, Chester AH, Amrani M, Singer DRJ. C-Type Natriuretic Peptide Relaxes Human Coronary Artery Bypass Grafts Preconstricted by Endothelin-1. Ann Thorac Surg 2005; 80:1347-51. [PMID: 16181867 DOI: 10.1016/j.athoracsur.2005.01.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Revised: 01/19/2005] [Accepted: 01/28/2005] [Indexed: 11/13/2022]
Abstract
BACKGROUND Endothelin is implicated in graft spasm after coronary artery bypass grafting. We assessed reversal by the endothelium-derived vasodilator C-type natriuretic peptide of prior contraction of radial artery and other vessels commonly used for coronary artery bypass surgery. METHODS Segments of human radial artery, saphenous vein, and internal mammary artery were mounted in organ baths after removal from patients undergoing cardiac surgery (n = 34; 64 +/- 2 years). Effects of increasing concentrations of C-type natriuretic peptide (with or without aprotinin, 1,000 U/mL) on endothelin-induced contraction were compared with acetylcholine, sodium nitroprusside, and papaverine. RESULTS C-type natriuretic peptide relaxed endothelin precontraction in all vessels (F = 17.8, 36.3, and 48.4, respectively; p < 0.001), with maximum relaxations of 44%, 54%, and 66% in saphenous vein, internal mammary artery, and radial artery, respectively. Aprotinin did not affect relaxation to C-type natriuretic peptide. Acetylcholine relaxed the saphenous vein weakly, with maximal relaxation of 9% at 10(-6) M. However, the radial artery and internal mammary artery relaxed strongly to acetylcholine. The highest concentration of papaverine completely relaxed all vessels, but responses were less sensitive than to sodium nitroprusside or acetylcholine. CONCLUSIONS C-type natriuretic peptide reverses endothelin-induced constriction in arterial and venous conduits used for coronary artery bypass, particularly the radial artery. Proteolytic breakdown of C-type natriuretic peptide by local vascular enzymes appears of little importance in vitro. This signals the therapeutic potential of using C-type natriuretic peptide as an antagonist of graft vasospasm after coronary artery bypass surgery.
Collapse
Affiliation(s)
- Christopher J Kelsall
- Department of Cardiothoracic Surgery, Heart Science Centre and Harefield Hospital, Harefield, Middlesex, United Kingdom.
| | | | | | | |
Collapse
|
25
|
Voisine P, Ruel M, Khan TA, Bianchi C, Xu SH, Kohane I, Libermann TA, Otu H, Saltiel AR, Sellke FW. Differences in gene expression profiles of diabetic and nondiabetic patients undergoing cardiopulmonary bypass and cardioplegic arrest. Circulation 2005; 110:II280-6. [PMID: 15364876 DOI: 10.1161/01.cir.0000138974.18839.02] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Diabetes mellitus is an independent risk factor for early postoperative mortality and complications after coronary artery bypass grafting (CABG). We sought to compare the cardiac gene expression responses to cardiopulmonary bypass (CPB) and cardioplegic arrest (C) in patients with and without diabetes. METHODS AND RESULTS Twenty atrial myocardium samples were harvested from 5 type II insulin-dependent diabetic and 5 matched nondiabetic patients undergoing CABG, before and after CPB/C. Oligonucleotide microarray analyses of 12625 genes were performed on the 10 sample pairs using matched pre-CPB tissues as controls. Array results were validated with Northern blotting and immunoblotting. Compared with pre-CPB/C, post-CPB/C myocardial tissues revealed 851 upregulated and 480 downregulated genes with a threshold P< or =0.025 (signal-to-noise ratio, 4.04) in the diabetic group, compared with 480 upregulated and 626 downregulated genes (signal-to-noise ratio, 3.04) in the nondiabetic group (P<0.001). There were 18 genes that were upregulated >4-fold in diabetic and nondiabetic patients (including inflammatory/transcription activators FOS, CYR 61, and IL-6, apoptotic gene NR4A1, stress gene DUSP1, and glucose-transporter gene SLC2A3). However, 28 genes showed such marked upregulation in the diabetic group exclusively (including inflammatory/transcription activators MYC, IL8, IL-1beta, growth factor vascular endothelial growth factor, amphiregulin, and glucose metabolism-involved gene insulin receptor substrate 1), and 27 genes in the nondiabetic group only, including glycogen-binding subunit PPP1R3C. CONCLUSIONS Gene expression profile after CPB/C is quantitatively and qualitatively different in patients with diabetes. These results have important implications for the design of tailored myocardial protection and operative strategies for diabetic patients undergoing CPB/C.
Collapse
Affiliation(s)
- Pierre Voisine
- Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass 02215, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Multani MM, Ikonomidis JS, Kim PY, Miller EA, Payne KJ, Mukherjee R, Dorman BH, Spinale FG. Dynamic and differential changes in myocardial and plasma endothelin in patients undergoing cardiopulmonary bypass. J Thorac Cardiovasc Surg 2005; 129:584-90. [PMID: 15746742 DOI: 10.1016/j.jtcvs.2004.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The bioactive peptide endothelin modulates left ventricular function by changing afterload, coronary vascular tone, and myocardial contractility. However, whether increased plasma endothelin levels observed in patients during and after coronary revascularization and cardiopulmonary bypass reflect actual myocardial interstitial levels are unknown. METHODS A microdialysis probe (outer diameter: 0.77 mm; length: 4 mm) was placed in the left ventricular apical midmyocardium in 20 patients and myocardial interstitial fluid was collected (2.5 microL/min) at baseline and up to 30 minutes after cardiopulmonary bypass. Myocardial interstitial and systemic arterial endothelin were measured by radioimmunoassay. RESULTS Baseline myocardial interstitial endothelin was over 6-fold higher than plasma (20.11 +/- 2.07 vs 3.19 +/- 0.25 fmol/mL, P < .05). Plasma endothelin increased by 23% +/- 12% at 60 minutes of cardiopulmonary bypass whereas myocardial interstitial endothelin increased by 105% +/- 24%, P < .05), and this change was higher than in the plasma ( P < .05). Although no further change in plasma endothelin occurred during cardiopulmonary bypass, myocardial interstitial levels increased further after crossclamp removal (400% +/- 75%) and remained significantly higher than plasma at separation from cardiopulmonary bypass. CONCLUSION The unique findings of this study were 2-fold: First, significant compartmentalization of endothelin exists within the human myocardium. Second, a significantly higher and temporally disparate change in myocardial interstitial endothelin occurs during and after cardiopulmonary bypass when compared with systemic levels. These dynamic changes in myocardial endothelin likely influence coronary vascular tone and contractility.
Collapse
|
27
|
Onorati F, Renzulli A, De Feo M, Galdieri N, Santè P, Mastroroberto P, Bilotta M, Cotrufo M. Perioperative enoximone infusion improves cardiac enzyme release after CABG. J Cardiothorac Vasc Anesth 2004; 18:409-14. [PMID: 15365919 DOI: 10.1053/j.jvca.2004.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To assess whether routine postoperative enoximone infusion compared with dobutamine improved clinical and biochemical results after coronary artery bypass grafting with cardiopulmonary bypass. DESIGN Prospective nonrandomized study. Data collection was blinded to the choice of inotrope. SETTING Double-institutional clinical investigation. PARTICIPANTS Two hundred sixteen consecutive patients undergoing myocardial revascularization between May 2000 and December 2002. INTERVENTIONS Seventy-two patients underwent myocardial revascularization and were treated with enoximone, 5 microg/kg/min (group A). They were compared in a ratio of 1:2 to 144 patients treated with dobutamine at the same dose (group B) after aortic cross-clamp removal. The groups proved to be homogenous in preoperative and intraoperative characteristics. MEASUREMENTS AND MAIN RESULTS Hospital outcome, electrocardiogram, echocardiography, further inotropic support, and biochemical markers of ischemia were compared. Subsets of patients with comorbidities and total arterial revascularization were analyzed. Perioperative myocardial infarction, postoperative low-output syndrome, intra-aortic balloon pump, atrial fibrillation, ST-segment changes, postoperative echocardiographic findings, and intensive care and hospital durations were similar between groups. In the postoperative course, more patients belonging to group A maintained low-dose inotropic support, whereas more patients belonging to group B required higher doses. Troponin I and creatine kinase-MB values were higher in patients of group B, especially when subgroups with diabetes, left ventricular hypertrophy, or total arterial revascularization were included. CONCLUSION Postoperative enoximone reduced troponin I release and need for inotropic support in patients undergoing on-pump myocardial revascularization. Subgroup data were confirmed in diabetes, left ventricular hypertrophy, and total arterial revascularization.
Collapse
Affiliation(s)
- Francesco Onorati
- Department of Cardiothoracic and Respiratory Sciences, Second University of Naples, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Spallarossa P, Barsotti A, Cordera R, Ghigliotti G, Maggi D, Brunelli C. Reduction of cardiovascular morbidity and mortality in type 2 diabetes. A rational approach to hypoglycemic therapy. J Endocrinol Invest 2004; 27:485-95. [PMID: 15279085 DOI: 10.1007/bf03345297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Type 2 diabetes mellitus is the single most important risk factor for the development of coronary artery disease. Unfortunately, the traditional therapeutic strategies for the treatment of hyperglycemia have proven to be ineffective in preventing cardiovascular complications. In recent years the number of available hypoglycemic agents has increased and considerable progress has been made regarding the comprehension of the pathophysiology of diabetes and its vascular complications. In the present article we firstly present benefits and risks of intensive vs standard hypoglycemic intervention, and the pros and cons of therapy targeted to postprandial hyperglycemia. Secondly, we discuss the cardiovascular effects of sulfonylurea agents and insulin, focusing on the role of intensive insulin treatment in the context of acute coronary syndromes. Thirdly, we review the epidemiological, clinical and experimental evidence linking insulin resistance and cardiovascular disease. Finally, we present the rationale and the role of metformin and thiazolidinedionetherapy in the prevention of cardiovascular complications. We conclude that the optimal use of the full spectrum of hypoglycemic agents has the potential to play a key role in the prevention of diabetes-related macrovascular complications.
Collapse
Affiliation(s)
- P Spallarossa
- Division of Cardiology, Department of Internal Medicine, University of Genoa, Italy.
| | | | | | | | | | | |
Collapse
|
29
|
|
30
|
Spinale FG. The bioactive peptide endothelin causes multiple biologic responses relevant to myocardial and vascular performance after cardiac surgery. J Thorac Cardiovasc Surg 2002; 123:1031-4. [PMID: 12063447 DOI: 10.1067/mtc.2002.124668] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
31
|
Verma S, Maitland A, Weisel RD, Li SH, Fedak PWM, Pomroy NC, Mickle DAG, Li RK, Ko L, Rao V. Hyperglycemia exaggerates ischemia-reperfusion-induced cardiomyocyte injury: reversal with endothelin antagonism. J Thorac Cardiovasc Surg 2002; 123:1120-4. [PMID: 12063458 DOI: 10.1067/mtc.2002.121973] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES We have previously demonstrated an importance of endothelin-1 in diabetic patients undergoing bypass surgery. Recent evidence suggests that cardiomyocytes might also produce endothelin-1, which might directly impair myocyte contractility by increasing intracellular calcium levels. Because hyperglycemia is a potent stimulus of endothelin-1 production, we hypothesized that increased production, action, or both of endothelin-1 might be a mediator of direct cardiomyocyte injury in diabetes. Therefore we studied the effects of endothelin receptor blockers (BQ-123 and bosentan) on hyperglycemia-induced endothelin-1 production and cellular injury after ischemia-reperfusion. METHODS Using a human ventricular heart cell model of simulated ischemia-reperfusion, we studied the effects of normoglycemia (5 mmol/L, 48 hours) and hyperglycemia (25 mmol/L, 48 hours) on cellular injury and endothelin-1 production. Furthermore, the effects of selective endothelin-A and mixed endothelin-A/B receptor antagonism (with BQ-123 and bosentan, respectively) were evaluated. RESULTS Cellular injury, as assessed by means of trypan blue uptake, was higher in human ventricular heart cells subjected to hyperglycemia and simulated ischemia-reperfusion injury (P =.01); this effect was prevented with both BQ-123 and bosentan (P =.01). In addition, heart cells from the hyperglycemic group elaborated more endothelin-1 after ischemia-reperfusion (P =.02). CONCLUSIONS Endothelin-1 production and cellular injury were greater in human ventricular heart cells subjected to hyperglycemic conditions and simulated ischemia-reperfusion. These effects are mediated by endothelin-A receptors because both BQ-123 and bosentan exerted similar degrees of protection. Endothelin receptor blockade is a novel strategy to improve the resistance of the diabetic heart to cardioplegic arrest and reperfusion.
Collapse
Affiliation(s)
- Subodh Verma
- Division of Cardiac Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|