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Aktay I, Billur D, Tuncay E, Turan B. An Overexpression of SLC30A6 Gene Contributes to Cardiomyocyte Dysfunction via Affecting Mitochondria and Inducing Activations in K-Acetylation and Epigenetic Proteins. Biochem Genet 2024; 62:3198-3214. [PMID: 38091184 DOI: 10.1007/s10528-023-10602-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 11/13/2023] [Indexed: 07/31/2024]
Abstract
Intracellular free Zn2+ ([Zn2+]i) is less than 1-nM in cardiomyocytes and its regulation is performed with Zn2+-transporters. However, the roles of Zn2+-transporters in cardiomyocytes are not defined exactly yet. Here, we aimed to examine the role of an overexpression and subcellular localization of a ZnT6 in insulin-resistance mimic H9c2 cardiomyoblasts (IR-cells; 50-μM palmitic acid for 24-h incubation). We used both IR-cells and ZnT6-overexpressed (ZnT6OE) cells in comparison to those of H9c2 cells (CON-cells). The IR-cells have higher ZnT6-protein levels than CON-cells while this level was similar to those of ZnT6OE-cells. The [Zn2+]i in IR-cells was increased significantly and mitochondrial localization of ZnT6 was demonstrated in these cells by using confocal microscopy visualization. Furthermore, electron microscopy analysis demonstrated abnormal morphological appearance in both IR-cells and ZnT6OE-cells characterized by irregular mitochondrion cristae and condensed and dilated cisterna in the sarcoplasmic reticulum. Mitochondria were similarly depolarized in both IR-cells and ZnT6OE-cells. The protein expression level of a mitofusin protein MFN2 in the IR-cells was decreased, significantly, whereas, it was found significantly upregulated in both ZnT6-OE-cells and IR-incubated ZnT6OE-cells, which demonstrates the role of ZnT6-overexpression but not IR. Additionally, the total protein level of a mitochondrial fission protein, dynamin-related protein 1, DRP1 was found to be increased over 1.5-fold in IR-cells while this increase was found to be higher in the ZnT6OE-cells than those of IR-cells, demonstrating an additional effect on IR-increase. ZnT6-overexpression induced also significant increases in K-acetylation, trimethylation of histone H3 lysine27, and mono-methylation of histone H3 lysine36, in a similar manner to those of IR-cells. Overall, our data point out an important contribution of ZnT6-overexpression to IR-induced cellular changes, such as alteration in mitochondria function and activation of epigenetic modifications.
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Affiliation(s)
- Irem Aktay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Deniz Billur
- Department of Histology & Embryology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey.
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2
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Chen Z, Zhang SL. Endoplasmic Reticulum Stress: A Key Regulator of Cardiovascular Disease. DNA Cell Biol 2023. [PMID: 37140435 DOI: 10.1089/dna.2022.0532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
The problems associated with economic development and social progress have led to an increase in the occurrence of cardiovascular diseases (CVDs), which affect the health of an increasing number of people and are a leading cause of disease and population mortality worldwide. Endoplasmic reticulum stress (ERS), a hot topic of interest for scholars in recent years, has been confirmed in numerous studies to be an important pathogenetic basis for many metabolic diseases and play an important role in maintaining physiological processes. The endoplasmic reticulum (ER) is a major organelle that is involved in protein folding and modification synthesis, and ERS occurs when several physiological and pathological factors allow excessive amounts of unfolded/misfolded proteins to accumulate. ERS often leads to initiation of the unfolded protein response (UPR) in a bid to re-establish tissue homeostasis; however, UPR has been documented to induce vascular remodeling and cardiomyocyte damage under various pathological conditions, leading to or accelerating the development of CVDs such as hypertension, atherosclerosis, and heart failure. In this review, we summarize the latest knowledge gained concerning ERS in terms of cardiovascular system pathophysiology, and discuss the feasibility of targeting ERS as a novel therapeutic target for the treatment of CVDs. Investigation of ERS has immense potential as a new direction for future research involving lifestyle intervention, the use of existing drugs, and the development of novel drugs that target and inhibit ERS.
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Affiliation(s)
- Zhao Chen
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Shi-Liang Zhang
- Section 4, Department of Cardiology, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
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3
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Chaoul V, Hanna R, Hachem P, El Hayek MS, Nour‐Eldine W, Abou‐Khalil P, Abi‐Ramia E, Vandecasteele G, Abi‐Gerges A. Differential changes in cyclic adenosine 3′‐5′ monophosphate (
cAMP
) effectors and major Ca
2+
handling proteins during diabetic cardiomyopathy. J Cell Mol Med 2023; 27:1277-1289. [PMID: 36967707 PMCID: PMC10148055 DOI: 10.1111/jcmm.17733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/23/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023] Open
Abstract
Diabetic cardiomyopathy (DCM) is associated with differential and time-specific regulation of β-adrenergic receptors and cardiac cyclic nucleotide phosphodiesterases with consequences for total cyclic adenosine 3'-5' monophosphate (cAMP) levels. We aimed to investigate whether these changes are associated with downstream impairments in cAMP and Ca2+ signalling in a type 1 diabetes (T1D)-induced DCM model. T1D was induced in adult male rats by streptozotocin (65 mg/kg) injection. DCM was assessed by cardiac structural and molecular remodelling. We delineated sequential changes affecting the exchange protein (Epac1/2), cAMP-dependent protein kinase A (PKA) and Ca2+ /Calmodulin-dependent kinase II (CaMKII) at 4, 8 and 12 weeks following diabetes, by real-time quantitative PCR and western blot. Expression of Ca2+ ATPase pump (SERCA2a), phospholamban (PLB) and Troponin I (TnI) was also examined. Early upregulation of Epac1 transcripts was noted in diabetic hearts at Week 4, followed by increases in Epac2 mRNA, but not protein levels, at Week 12. Expression of PKA subunits (RI, RIIα and Cα) remained unchanged regardless of the disease stage, whereas CaMKII increased at Week 12 in DCM. Moreover, PLB transcripts were upregulated in diabetic hearts, whereas SERCA2a and TnI gene expression was unchanged irrespective of the disease evolution. PLB phosphorylation at threonine-17 was increased in DCM, whereas phosphorylation of both PLB at serine-16 and TnI at serine-23/24 was unchanged. We show for the first time differential and time-specific regulations in cardiac cAMP effectors and Ca2+ handling proteins, data that may prove useful in proposing new therapeutic approaches in T1D-induced DCM.
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Affiliation(s)
- Victoria Chaoul
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
| | - Rita Hanna
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
| | - Pia Hachem
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
| | - Magali Samia El Hayek
- Signaling and Cardiovascular Pathophysiology, UMR‐S1180Université Paris‐SaclayOrsay91400France
| | - Wared Nour‐Eldine
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
| | - Pamela Abou‐Khalil
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
| | - Elias Abi‐Ramia
- School of Arts and Sciences, Department of Natural SciencesLebanese American UniversityByblosLebanon
| | - Grégoire Vandecasteele
- Signaling and Cardiovascular Pathophysiology, UMR‐S1180Université Paris‐SaclayOrsay91400France
| | - Aniella Abi‐Gerges
- Gilbert and Rose‐Marie Chagoury School of MedicineLebanese American UniversityP.O. Box 36ByblosLebanon
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4
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de Moura AL, Brum PC, de Carvalho AETS, Spadari RC. Effect of stress on the chronotropic and inotropic responses to β-adrenergic agonists in isolated atria of KOβ2 mice. Life Sci 2023; 322:121644. [PMID: 37004731 DOI: 10.1016/j.lfs.2023.121644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/06/2023] [Accepted: 03/26/2023] [Indexed: 04/03/2023]
Abstract
Altered sensitivity to the chronotropic and inotropic effects of catecholamines and reduction in β1/β2-adrenoceptor (β1/β2-AR) ratio were reported in failing and in senescent human heart, as well as in isolated atria and ventricle of rats submitted to stress. This was due to downregulation of β1-AR with or without up-regulation of β2-AR. AIMS To investigate the stress-induced behavior of β1-AR in the heart of mice expressing a non-functional β2-AR subtype. The guiding hypothesis is that the absence of β2-AR signaling will not affect the behavior of β1-AR during stress and that those are independent processes. MATERIALS AND METHODS The chronotropic and inotropic responses to β-AR agonists in isolated atria of stressed mice expressing a non-functional β2-AR were analyzed. The mRNA and protein expressions of β1- and β2-AR were also determined. KEY FINDINGS No deaths were observed in mice under stress protocol. Atria of stressed mice displayed reduced sensitivity to isoprenaline compared to the controls, an effect that was abolished by the β2- and β1-AR antagonists 50 nM ICI118,551 and 300 nM CGP20712A, respectively. Sensitivity and maximum response to the β-agonists dobutamine and salbutamol were not altered by stress or ICI118,551. The responses to dobutamine and salbutamol were prevented by CGP20712A. The expression of β1-AR was reduced at protein levels. SIGNIFICANCE Collectively, our data provide evidence that the cardiac β2-AR is not essential for survival in a stressful situation and that the stress-induced reduction of β1-AR expression was independent of the β2-AR presence.
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5
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Goktas Sahoglu S, Kazci YE, Tuncay E, Torun T, Akdeniz C, Tuzcu V, Cagavi E. Functional evaluation of the tachycardia patient-derived iPSC cardiomyocytes carrying a novel pathogenic SCN5A variant. J Cell Physiol 2022; 237:3900-3911. [PMID: 35959596 DOI: 10.1002/jcp.30843] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/29/2022] [Accepted: 07/18/2022] [Indexed: 12/11/2022]
Abstract
Tachycardia is characterized by high beating rates that can lead to life-threatening fibrillations. Mutations in several ion-channel genes were implicated with tachycardia; however, the complex genetic contributors and their modes of action are still unclear. Here, we investigated the influence of an SCN5A gene variant on tachycardia phenotype by deriving patient-specific iPSCs and cardiomyocytes (iPSC-CM). Two tachycardia patients were genetically analyzed and revealed to inherit a heterozygous p.F1465L variant in the SCN5A gene. Gene expression and immunocytochemical analysis in iPSC-CMs generated from patients did not show any significant changes in mRNA levels of SCN5A or gross NaV1.5 cellular mislocalization, compared to healthy-derived iPSC-CMs. Electrophysiological and contraction imaging analysis in patient iPSC-CMs revealed intermittent fibrillation-like states, occasional arrhythmic events, and sustained high-paced contractions that could be selectively reduced by flecainide treatment. The patch-clamp analysis demonstrated a negative shift in the voltage-dependent activation at the patient-derived iPSC-CMs compared to the healthy control line, suggestive of a gain-of-function activity associated with the SCN5A+/p.F1465L variant. Our patient-derived iPSC-CM model recapitulated the clinically relevant characteristics of tachycardia associated with a novel pathogenic SCN5A+/p.F1465L variant leading to altered Na+ channel kinetics as the likely mechanism underlying high excitability and tachycardia phenotype.
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Affiliation(s)
- Sevilay Goktas Sahoglu
- Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Institute of Health Sciences, Neuroscience Program, Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Yusuf Enes Kazci
- Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Institute of Health Sciences, Neuroscience Program, Istanbul Medipol University, Istanbul, Turkey.,Deparment of Medical Biology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Tugce Torun
- Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Medical Biology and Genetics Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
| | - Celal Akdeniz
- Department of Pediatric Cardiology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Volkan Tuzcu
- Department of Pediatric Cardiology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Esra Cagavi
- Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey.,Deparment of Medical Biology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey.,Medical Biology and Genetics Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
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6
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Han JH, Kim MT, Myung CS. Garcinia Cambogia Improves High-Fat Diet-Induced Glucose Imbalance by Enhancing Calcium/CaMKII/AMPK/GLUT4-Mediated Glucose Uptake in Skeletal Muscle. Mol Nutr Food Res 2022; 66:e2100669. [PMID: 35213784 DOI: 10.1002/mnfr.202100669] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 02/01/2022] [Indexed: 12/20/2022]
Abstract
SCOPE Garcinia cambogia (G. cambogia) is known to have antiobesity effects. In this study, the therapeutic effects of G. cambogia on glucose homeostasis in obesity-induced diabetes are explored and the underlying mechanisms are investigated. METHODS AND RESULTS C2C12 myotubes are treated with G. cambogia; glucose uptake, intracellular Ca2+ levels, and related alterations in signaling pathways are examined. High-fat diet (HFD)-fed mice are administered G. cambogia for 8 weeks; oral glucose tolerance is evaluated, and the regulation of identified targets of signaling pathways in quadriceps skeletal muscle are examined in vivo. G. cambogia increases glucose uptake in C2C12 myotubes and induces the upregulation of AMPK, ACC, and p38 MAPK phosphorylation. Notably, G. cambogia markedly elevates both intracellular Ca2+ levels, activating CaMKII, a Ca2+ -sensing protein, and TBC1D4-mediated GLUT4 translocation, to facilitate glucose uptake. Furthermore, high-glucose-induced inhibition of glucose uptake and signal transduction is reverted by G. cambogia. In an HFD-induced diabetes mouse model, G. cambogia administration results in significant blood glucose-lowering effects, which are attributed to the regulation of targets that have been identified in vitro, in quadricep skeletal muscle. CONCLUSION These findings provide new insights into the mechanism by which G. cambogia regulates glucose homeostasis in obesity-induced diabetes.
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Affiliation(s)
- Joo-Hui Han
- Department of Pharmacology, College of Pharmacy, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Min-Tae Kim
- Department of Pharmacology, College of Pharmacy, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Chang-Seon Myung
- Department of Pharmacology, College of Pharmacy, Chungnam National University, Daejeon, 34134, Republic of Korea
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7
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Olgar Y, Tuncay E, Billur D, Turan B. Bimodal Effects of P2Y 12 Antagonism on Matrix Metalloproteinase-Associated Contractile Dysfunction in İnsulin-Resistant Mammalian Heart. Biol Trace Elem Res 2022; 200:2195-2204. [PMID: 34268701 DOI: 10.1007/s12011-021-02816-w] [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] [Received: 05/13/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022]
Abstract
The matrix metalloproteinases (MMPs) contribute to matrix remodeling in diabetes via tissue degradation; however, their contributions can be different depending on the pathology. For instance, MMPs are elevated in acute stress hyperglycemia, whereas they can be degraded in chronic hyperglycemia. Since studies emphasize the possible cardioprotective effect of ticagrelor (Tica) beyond its antiplatelet action, we aimed to examine whether Tica treatment can reverse the depressed heart function of metabolic syndrome (MetS) rats via affecting the expression levels of MMPs. Tica treatment of high-carbohydrate-induced MetS rats could not affect significantly the depressed contractile activity of Langendorff-perfused heart preparations. On the other hand, the Tica treatment provided a significant recovery in the reduced relaxation activity of the aortic preparations from the same animals. Histological examination of the hearts demonstrated marked damages in Mets rats, such as increases in the number of foamy cells and accumulation of collagen fiber and increases in the elastic lamellar irregularity of tunica media, while Tica treatment provided a slight improvement in the structure of left ventricle tissue. We also could not obtain a significant reverse in the high cytosolic labile Zn2+ ([Zn2+]i) with the treatment of cardiomyocytes with Tica. Furthermore, Tica treatment of MetS rats could not significantly reverse the degraded protein levels of MMP-2 and MMP-9 in the heart, as well. Overall, we demonstrated that Tica treatment of MetS rats has no significant benefits on the depressed heart function, although provide a significant beneficial impact on vascular relaxation. This action of Tica may be through its lack of action on both MMP degradation and high [Zn2+]i, which can further precipitate in cleavage of extracellular matrix in the heart.
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Affiliation(s)
- Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Deniz Billur
- Department of Histology and Embryology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey.
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey.
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8
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The Oxidative Balance Orchestrates the Main Keystones of the Functional Activity of Cardiomyocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7714542. [PMID: 35047109 PMCID: PMC8763515 DOI: 10.1155/2022/7714542] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 11/03/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
This review is aimed at providing an overview of the key hallmarks of cardiomyocytes in physiological and pathological conditions. The main feature of cardiac tissue is the force generation through contraction. This process requires a conspicuous energy demand and therefore an active metabolism. The cardiac tissue is rich of mitochondria, the powerhouses in cells. These organelles, producing ATP, are also the main sources of ROS whose altered handling can cause their accumulation and therefore triggers detrimental effects on mitochondria themselves and other cell components thus leading to apoptosis and cardiac diseases. This review highlights the metabolic aspects of cardiomyocytes and wanders through the main systems of these cells: (a) the unique structural organization (such as different protein complexes represented by contractile, regulatory, and structural proteins); (b) the homeostasis of intracellular Ca2+ that represents a crucial ion for cardiac functions and E-C coupling; and (c) the balance of Zn2+, an ion with a crucial impact on the cardiovascular system. Although each system seems to be independent and finely controlled, the contractile proteins, intracellular Ca2+ homeostasis, and intracellular Zn2+ signals are strongly linked to each other by the intracellular ROS management in a fascinating way to form a "functional tetrad" which ensures the proper functioning of the myocardium. Nevertheless, if ROS balance is not properly handled, one or more of these components could be altered resulting in deleterious effects leading to an unbalance of this "tetrad" and promoting cardiovascular diseases. In conclusion, this "functional tetrad" is proposed as a complex network that communicates continuously in the cardiomyocytes and can drive the switch from physiological to pathological conditions in the heart.
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9
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Yuan J, Yin X, Jiang H. Inhibition of Toll-like Receptor-4 expression for amelioration of myocardial injury in diabetes: A meta-analysis. Clinics (Sao Paulo) 2022; 77:100137. [PMID: 36434877 PMCID: PMC9700273 DOI: 10.1016/j.clinsp.2022.100137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
To understand the relationship between the inhibition of Toll-Like Receptor-4 (TLR4) expression levels and diabetic myocardial injury, studies on TLR4 and diabetic myocardial injury in the China National Knowledge Internet (CNKI), WanFang database, VIP Database, PubMed, The Cochrane Library, Web of Science, and other databases were explored (retrieval details: November 2020). A meta-analysis of the selected literature was performed using the RevMan 5.4 software to detect publication bias using funnel plots and conduct a sensitivity analysis. Nine publications were finally included in this study, of which six included data on Heart Weight/Body Weight (HW/BW) indexes, and five included data on Left Ventricular Systolic Pressure (LVSP) and Left Ventricular End-Diastolic Pressure (LVEDP) indices. The meta-analysis showed that HW/BW was significantly reduced after the suppression of TLR4 expression (Standardized Mean Difference [SMD = 1.9], 95% CI between 0.59 and 3.21, p = 0.004), LVSP was significantly improved (SMD = -2.39, 95% CI between -4.32 and -0.46, p = 0.02), and LVEDP was significantly reduced (SMD = 2.88, 95% CI between 1.05 and 4.71, p = 0.002). The TLR4 signaling pathway plays an essential role in the pathogenesis of Diabetic Cardiomyopathy (DCM). Inhibition of TLR4 expression can improve the degree of cardiac impairment. TLR4 may become a new target for the treatment of DCM, and the use of TLR4 inhibitors may prove to be a novel strategy for therapeutic research.
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Affiliation(s)
- Jinxin Yuan
- The Second Affiliated Hospital of Dalian Medical University, Liaoning, China
| | - Xingwen Yin
- The Second Affiliated Hospital of Dalian Medical University, Liaoning, China
| | - Hua Jiang
- The Second Affiliated Hospital of Dalian Medical University, Liaoning, China.
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10
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Jankauskas SS, Kansakar U, Varzideh F, Wilson S, Mone P, Lombardi A, Gambardella J, Santulli G. Heart failure in diabetes. Metabolism 2021; 125:154910. [PMID: 34627874 PMCID: PMC8941799 DOI: 10.1016/j.metabol.2021.154910] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 12/16/2022]
Abstract
Heart failure and cardiovascular disorders represent the leading cause of death in diabetic patients. Here we present a systematic review of the main mechanisms underlying the development of diabetic cardiomyopathy. We also provide an excursus on the relative contribution of cardiomyocytes, fibroblasts, endothelial and smooth muscle cells to the pathophysiology of heart failure in diabetes. After having described the preclinical tools currently available to dissect the mechanisms of this complex disease, we conclude with a section on the most recent updates of the literature on clinical management.
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Affiliation(s)
- Stanislovas S Jankauskas
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Molecular Pharmacology, Einstein Institute for Neuroimmunology and Inflammation, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Urna Kansakar
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Molecular Pharmacology, Einstein Institute for Neuroimmunology and Inflammation, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Fahimeh Varzideh
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Molecular Pharmacology, Einstein Institute for Neuroimmunology and Inflammation, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Scott Wilson
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Pasquale Mone
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Angela Lombardi
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Jessica Gambardella
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Molecular Pharmacology, Einstein Institute for Neuroimmunology and Inflammation, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA; International Translational Research and Medical Education (ITME), Department of Advanced Biomedical Science, "Federico II" University, 80131 Naples, Italy
| | - Gaetano Santulli
- Department of Medicine, Fleischer Institute for Diabetes and Metabolism (FIDAM), Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Molecular Pharmacology, Einstein Institute for Neuroimmunology and Inflammation, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA; International Translational Research and Medical Education (ITME), Department of Advanced Biomedical Science, "Federico II" University, 80131 Naples, Italy.
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11
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Alyu F, Olgar Y, Degirmenci S, Turan B, Ozturk Y. Interrelated In Vitro Mechanisms of Sibutramine-Induced Cardiotoxicity. Cardiovasc Toxicol 2021; 21:322-335. [PMID: 33389602 DOI: 10.1007/s12012-020-09622-1] [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] [Received: 08/15/2020] [Accepted: 11/24/2020] [Indexed: 11/26/2022]
Abstract
Consumption of illicit pharmaceutical products containing sibutramine has been reported to cause cardiovascular toxicity problems. This study aimed to demonstrate the toxicity profile of sibutramine, and thereby provide important implications for the development of more effective strategies in both clinical approaches and drug design studies. Action potentials (APs) were determined from freshly isolated ventricular cardiomyocytes with whole-cell configuration of current clamp as online. The maximum amplitude of APs (MAPs), the resting membrane potential (RMP), and AP duration from the repolarization phases were calculated from original records. The voltage-dependent K+-channel currents (IK) were recorded in the presence of external Cd2+ and both inward and outward parts of the current were calculated, while their expression levels were determined with qPCR. The levels of intracellular free Ca2+ and H+ (pHi) as well as reactive oxygen species (ROS) were measured using either a ratiometric micro-spectrofluorometer or confocal microscope. The mechanical activity of isolated hearts was observed with Langendorff-perfusion system. Acute sibutramine applications (10-8-10-5 M) induced significant alterations in both MAPs and RMP as well as the repolarization phases of APs and IK in a concentration-dependent manner. Sibutramine (10 μM) induced Ca2+-release from the sarcoplasmic reticulum under either electrical or caffeine stimulation, whereas it depressed left ventricular developed pressure with a marked decrease in the end-diastolic pressure. pHi inhibition by sibutramine supports the observed negative alterations in contractility. Changes in mRNA levels of different IK subunits are consistent with the acute inhibition of the repolarizing IK, affecting AP parameters, and provoke the cardiotoxicity.
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Affiliation(s)
- Feyza Alyu
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Yunus Emre Campus, 26470, Eskisehir, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
| | - Sinan Degirmenci
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, 06230, Ankara, Turkey
| | - Yusuf Ozturk
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Yunus Emre Campus, 26470, Eskisehir, Turkey.
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12
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Deng M, Chen W, Wang H, Wang Y, Zhou W, Yu T. The disappearance of IPO in myocardium of diabetes mellitus rats is associated with the increase of succinate dehydrogenase-flavin protein. BMC Cardiovasc Disord 2021; 21:142. [PMID: 33731005 PMCID: PMC7968298 DOI: 10.1186/s12872-021-01949-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/01/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The aim of the present study was to investigate whether the disappearance of ischemic post-processing (IPO) in the myocardium of diabetes mellitus (DM) is associated with the increase of succinate dehydrogenase-flavin protein (SDHA). METHODS A total of 50 Sprague Dawley rats, weighing 300-400 g, were divided into 5 groups according to the random number table method, each with 10 rats. After DM rats were fed a high-fat and -sugar diet for 4 weeks, they were injected with Streptozotocin to establish the diabetic rat model. Normal rats were fed the same regular diet for the same number of weeks. Next, the above rats were taken to establish a cardiopulmonary bypass (CPB) model. Intraperitoneal glucose tolerance test (IPGTT) and oral glucose tolerance test (OGTT) were used to detect whether the DM rat model was established successfully. Taking blood from the femoral artery to collect the blood-gas analysis indicators, and judged whether the CPB model is established. After perfusion was performed according to the experimental strategy, the area of myocardial infarction (MI), and serum creatine kinase isoenzyme (CK-MB) and cardiac troponin (CTnI) levels were measured. Finally, the relative mRNA and protein expression of SDHA was detected. RESULTS The OGTT and IPGTT suggested that the DM rat model was successfully established. The arterial blood gas analysis indicated that the CPB model was successfully established. As compared with the N group, the heart function of the IR group was significantly reduced, the levels of myocardial enzyme markers, the area of MI, as well as the relative mRNA and protein expression of SDHA, were all increased. As compared with the IR group, the CK-MB and CTnI levels in the IPO group, the MI area, relative mRNA and protein expression of SDHA decreased. As compared with the IPO group, the myocardial enzyme content in the DM + IPO group, the MI area and the relative mRNA and protein expression of SDHA increased. As compared with the DM + IPO group, in the DM + IPO + dme group, the myocardial enzyme content, area of MI and relative mRNA and protein expression were all decreased. CONCLUSION IPO can inhibit the expression of SDHA, reduce MIRI and exert a cardioprotective effect in the normal rats. However, the protective effect of IPO disappears in the diabetic rats. The inhibitor dme combined with IPO can increase the expression of SDHA and restore the protective effect of IPO in DM myocardia.
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Affiliation(s)
- Mengyuan Deng
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Huichuan District, Zunyi, 563003, Guizhou, People's Republic of China
| | - Wei Chen
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Huichuan District, Zunyi, 563003, Guizhou, People's Republic of China
| | - Haiying Wang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Huichuan District, Zunyi, 563003, Guizhou, People's Republic of China.
| | - Yan Wang
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, 149 Dalian Road, Huichuan District, Zunyi, 563003, Guizhou, People's Republic of China
| | - Wenjing Zhou
- Anesthesia Laboratory, Affiliated Hospital of Zunyi Medical University, Zunyi, People's Republic of China
| | - Tian Yu
- Zunyi Medical University, Zunyi, People's Republic of China
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Erdogan BR, Michel MC, Arioglu-Inan E. Expression and Signaling of β-Adrenoceptor Subtypes in the Diabetic Heart. Cells 2020; 9:cells9122548. [PMID: 33256212 PMCID: PMC7759850 DOI: 10.3390/cells9122548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/18/2022] Open
Abstract
Diabetes is a chronic, endocrine disorder that effects millions of people worldwide. Cardiovascular complications are the major cause of diabetes-related morbidity and mortality. Cardiac β1- and β2-adrenoceptor (AR) stimulation mediates positive inotropy and chronotropy, whereas β3-AR mediates negative inotropic effect. Changes in β-AR responsiveness are thought to be an important factor that contributes to the diabetic cardiac dysfunction. Diabetes related changes in β-AR expression, signaling, and β-AR mediated cardiac function have been studied by several investigators for many years. In the present review, we have screened PubMed database to obtain relevant articles on this topic. Our search has ended up with wide range of different findings about the effect of diabetes on β-AR mediated changes both in molecular and functional level. Considering these inconsistent findings, the effect of diabetes on cardiac β-AR still remains to be clarified.
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Affiliation(s)
- Betul R. Erdogan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Department of Pharmacology, Faculty of Pharmacy, Izmir Katip Celebi University, 35620 Izmir, Turkey
| | - Martin C. Michel
- Department of Pharmacology, Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Correspondence:
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14
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The role of labile Zn 2+ and Zn 2+-transporters in the pathophysiology of mitochondria dysfunction in cardiomyocytes. Mol Cell Biochem 2020; 476:971-989. [PMID: 33225416 DOI: 10.1007/s11010-020-03964-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/23/2020] [Indexed: 02/06/2023]
Abstract
An important energy supplier of cardiomyocytes is mitochondria, similar to other mammalian cells. Studies have demonstrated that any defect in the normal processes controlled by mitochondria can lead to abnormal ROS production, thereby high oxidative stress as well as lack of ATP. Taken into consideration, the relationship between mitochondrial dysfunction and overproduction of ROS as well as the relation between increased ROS and high-level release of intracellular labile Zn2+, those bring into consideration the importance of the events related with those stimuli in cardiomyocytes responsible from cellular Zn2+-homeostasis and responsible Zn2+-transporters associated with the Zn2+-homeostasis and Zn2+-signaling. Zn2+-signaling, controlled by cellular Zn2+-homeostatic mechanisms, is regulated with intracellular labile Zn2+ levels, which are controlled, especially, with the two Zn2+-transporter families; ZIPs and ZnTs. Our experimental studies in mammalian cardiomyocytes and human heart tissue showed that Zn2+-transporters localizes to mitochondria besides sarco(endo)plasmic reticulum and Golgi under physiological condition. The protein levels as well as functions of those transporters can re-distribute under pathological conditions, therefore, they can interplay among organelles in cardiomyocytes to adjust a proper intracellular labile Zn2+ level. In the present review, we aimed to summarize the already known Zn2+-transporters localize to mitochondria and function to stabilize not only the cellular Zn2+ level but also cellular oxidative stress status. In conclusion, one can propose that a detailed understanding of cellular Zn2+-homeostasis and Zn2+-signaling through mitochondria may emphasize the importance of new mitochondria-targeting agents for prevention and/or therapy of cardiovascular dysfunction in humans.
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15
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Mitochondria-Targeting Antioxidant Provides Cardioprotection through Regulation of Cytosolic and Mitochondrial Zn 2+ Levels with Re-Distribution of Zn 2+-Transporters in Aged Rat Cardiomyocytes. Int J Mol Sci 2019; 20:ijms20153783. [PMID: 31382470 PMCID: PMC6695787 DOI: 10.3390/ijms20153783] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/12/2019] [Accepted: 06/17/2019] [Indexed: 12/29/2022] Open
Abstract
Aging is an important risk factor for cardiac dysfunction. Heart during aging exhibits a depressed mechanical activity, at least, through mitochondria-originated increases in ROS. Previously, we also have shown a close relationship between increased ROS and cellular intracellular free Zn2+ ([Zn2+]i) in cardiomyocytes under pathological conditions as well as the contribution of some re-expressed levels of Zn2+-transporters for redistribution of [Zn2+]i among suborganelles. Therefore, we first examined the cellular (total) [Zn2+] and then determined the protein expression levels of Zn2+-transporters in freshly isolated ventricular cardiomyocytes from 24-month rat heart compared to those of 6-month rats. The [Zn2+]i in the aged-cardiomyocytes was increased, at most, due to increased ZIP7 and ZnT8 with decreased levels of ZIP8 and ZnT7. To examine redistribution of the cellular [Zn2+]i among suborganelles, such as Sarco/endoplasmic reticulum, S(E)R, and mitochondria ([Zn2+]SER and [Zn2+]Mit), a cell model (with galactose) to mimic the aged-cell in rat ventricular cell line H9c2 was used and demonstrated that there were significant increases in [Zn2+]Mit with decreases in [Zn2+]SER. In addition, the re-distribution of these Zn2+-transporters were markedly changed in mitochondria (increases in ZnT7 and ZnT8 with no changes in ZIP7 and ZIP8) and S(E)R (increase in ZIP7 and decrease in ZnT7 with no changes in both ZIP8 and ZnT8) both of them isolated from freshly isolated ventricular cardiomyocytes from aged-rats. Furthermore, we demonstrated that cellular levels of ROS, both total and mitochondrial lysine acetylation (K-Acetylation), and protein-thiol oxidation were significantly high in aged-cardiomyocytes from 24-month old rats. Using a mitochondrial-targeting antioxidant, MitoTEMPO (1 µM, 5-h incubation), we provided an important data associated with the role of mitochondrial-ROS production in the [Zn2+]i-dyshomeostasis of the ventricular cardiomyocytes from 24-month old rats. Overall, our present data, for the first time, demonstrated that a direct mitochondria-targeting antioxidant treatment can be a new therapeutic strategy during aging in the heart through a well-controlled [Zn2+] distribution among cytosol and suborganelles with altered expression levels of the Zn2+-transporters.
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16
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Ulusu NN, Gok M, Erman B, Turan B. Effects of Timolol Treatment on Pancreatic Antioxidant Enzymes in Streptozotocin-induced Diabetic Rats: An Experimental and Computational Study. J Med Biochem 2019; 38:306-316. [PMID: 31156341 PMCID: PMC6534949 DOI: 10.2478/jomb-2018-0034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 09/18/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The study aimed to investigate whether timolol-treatment has a beneficial effect on pentose phosphate pathway enzyme activities such as glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGDH) enzyme activities and cAMP level in streptozotocin-induced diabetic rats in pancreatic tissues. METHODS Diabetes was induced by streptozotocin (STZ) in 3-month old male Wistar rats. The diabetic rats were treated with timolol (5 mg/kg body weight, for 12 weeks) while the control group received saline. Enzyme activities were determined in pancreas tissue. To support our results, we performed in silico calculations, using Protein Data Bank structures. RESULTS Timolol treatment of STZ-induced diabetic rats had no noteworthy effect on high blood-glucose levels. However, this treatment induced activities of G6PD and 6PGDH in diabetic rats. Timolol treatment significantly increased cAMP level in diabetic pancreatic tissue. We found that timolol cannot bind strongly to either G6PD or 6PGD, but there is a relatively higher binding affinity to adenylyl cyclase, responsible for cAMP production, serving as a regulatory signal via specific cAMP-binding proteins. CONCLUSIONS Our data point out that timolol treatment has beneficial effects on the antioxidant defence mechanism enzymes in the pancreas of STZ-induced diabetic rats.
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Affiliation(s)
- Nuriye Nuray Ulusu
- Koc University, School of Medicine, Department of Medical Biochemistry, IstanbulTurkey
| | - Muslum Gok
- Hacettepe University, Faculty of Medicine, Department of Medical Biochemistry, AnkaraTurkey
| | - Burak Erman
- Koc University, School of Engineering, Department of Chemical and Biological Engineering, IstanbulTurkey
| | - Belma Turan
- Ankara University, Faculty of Medicine, Department of Biophysics, AnkaraTurkey
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17
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Turan B. A Brief Overview from the Physiological and Detrimental Roles of Zinc Homeostasis via Zinc Transporters in the Heart. Biol Trace Elem Res 2019; 188:160-176. [PMID: 30091070 DOI: 10.1007/s12011-018-1464-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/26/2018] [Indexed: 12/15/2022]
Abstract
Zinc (mostly as free/labile Zn2+) is an essential structural constituent of many proteins, including enzymes in cellular signaling pathways via functioning as an important signaling molecule in mammalian cells. In cardiomyocytes at resting condition, intracellular labile Zn2+ concentration ([Zn2+]i) is in the nanomolar range, whereas it can increase dramatically under pathological conditions, including hyperglycemia, but the mechanisms that affect its subcellular redistribution is not clear. Therefore, overall, very little is known about the precise mechanisms controlling the intracellular distribution of labile Zn2+, particularly via Zn2+ transporters during cardiac function under both physiological and pathophysiological conditions. Literature data demonstrated that [Zn2+]i homeostasis in mammalian cells is primarily coordinated by Zn2+ transporters classified as ZnTs (SLC30A) and ZIPs (SLC39A). To identify the molecular mechanisms of diverse functions of labile Zn2+ in the heart, the recent studies focused on the discovery of subcellular localization of these Zn2+ transporters in parallel to the discovery of novel physiological functions of [Zn2+]i in cardiomyocytes. The present review summarizes the current understanding of the role of [Zn2+]i changes in cardiomyocytes under pathological conditions, and under high [Zn2+]i and how Zn2+ transporters are important for its subcellular redistribution. The emerging importance and the promise of some Zn2+ transporters for targeted cardiac therapy against pathological stimuli are also provided. Taken together, the review clearly outlines cellular control of cytosolic Zn2+ signaling by Zn2+ transporters, the role of Zn2+ transporters in heart function under hyperglycemia, the role of Zn2+ under increased oxidative stress and ER stress, and their roles in cancer are discussed.
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Affiliation(s)
- Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey.
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18
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Oikonomou E, Mourouzis K, Fountoulakis P, Papamikroulis GA, Siasos G, Antonopoulos A, Vogiatzi G, Tsalamadris S, Vavuranakis M, Tousoulis D. Interrelationship between diabetes mellitus and heart failure: the role of peroxisome proliferator-activated receptors in left ventricle performance. Heart Fail Rev 2019; 23:389-408. [PMID: 29453696 DOI: 10.1007/s10741-018-9682-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heart failure (HF) is a common cardiac syndrome, whose pathophysiology involves complex mechanisms, some of which remain unknown. Diabetes mellitus (DM) constitutes not only a glucose metabolic disorder accompanied by insulin resistance but also a risk factor for cardiovascular disease and HF. During the last years though emerging data set up, a bidirectional interrelationship between these two entities. In the case of DM impaired calcium homeostasis, free fatty acid metabolism, redox state, and advance glycation end products may accelerate cardiac dysfunction. On the other hand, when HF exists, hypoperfusion of the liver and pancreas, b-blocker and diuretic treatment, and autonomic nervous system dysfunction may cause impairment of glucose metabolism. These molecular pathways may be used as therapeutic targets for novel antidiabetic agents. Peroxisome proliferator-activated receptors (PPARs) not only improve insulin resistance and glucose and lipid metabolism but also manifest a diversity of actions directly or indirectly associated with systolic or diastolic performance of left ventricle and symptoms of HF. Interestingly, they may beneficially affect remodeling of the left ventricle, fibrosis, and diastolic performance but they may cause impaired water handing, sodium retention, and decompensation of HF which should be taken into consideration in the management of patients with DM. In this review article, we present the pathophysiological data linking HF with DM and we focus on the molecular mechanisms of PPARs agonists in left ventricle systolic and diastolic performance providing useful insights in the molecular mechanism of this class of metabolically active regiments.
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Affiliation(s)
- Evangelos Oikonomou
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece.
| | - Konstantinos Mourouzis
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Petros Fountoulakis
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Georgios Angelos Papamikroulis
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Gerasimos Siasos
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Alexis Antonopoulos
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Georgia Vogiatzi
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Sotiris Tsalamadris
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Manolis Vavuranakis
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
| | - Dimitris Tousoulis
- 1st Department of Cardiology, 'Hippokration' Hospital, National and Kapodistrian University of Athens Medical School, Vasilissis Sofias 114, TK, 115 28, Athens, Greece
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Reyes-Corral M, Sørensen NM, Thrasivoulou C, Dasgupta P, Ashmore JF, Ahmed A. Differential Free Intracellular Calcium Release by Class II Antiarrhythmics in Cancer Cell Lines. J Pharmacol Exp Ther 2019; 369:152-162. [PMID: 30655298 DOI: 10.1124/jpet.118.254375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/02/2019] [Indexed: 12/31/2022] Open
Abstract
Class II antiarrhythmics or β-blockers are antisympathetic nervous system agents that act by blocking β-adrenoceptors. Despite their common clinical use, little is known about the effects of β-blockers on free intracellular calcium (Ca2+ i), an important cytosolic second messenger and a key regulator of cell function. We investigated the role of four chemical analogs, commonly prescribed β-blockers (atenolol, metoprolol, propranolol, and sotalol), on Ca2+ i release and whole-cell currents in mammalian cancer cells (PC3 prostate cancer and MCF7 breast cancer cell lines). We discovered that only propranolol activated free Ca2+ i release with distinct kinetics, whereas atenolol, metoprolol, and sotalol did not. The propranolol-induced Ca2+ i release was significantly inhibited by the chelation of extracellular calcium with ethylene glycol tetraacetic acid (EGTA) and by dantrolene, an inhibitor of the endoplasmic reticulum (ER) ryanodine receptor channels, and it was completely abolished by 2-aminoethoxydiphenyl borate, an inhibitor of the ER inositol-1,4,5-trisphosphate (IP3) receptor channels. Exhaustion of ER stores with 4-chloro-m-cresol, a ryanodine receptor activator, or thapsigargin, a sarco/ER Ca2+ ATPase inhibitor, precluded the propranolol-induced Ca2+ i release. Finally, preincubation of cells with sotalol or timolol, nonselective blockers of β-adrenoceptors, also reduced the Ca2+ i release activated by propranolol. Our results show that different β-blockers have differential effects on whole-cell currents and free Ca2+ i release and that propranolol activates store-operated Ca2+ i release via a mechanism that involves calcium-induced calcium release and putative downstream transducers such as IP3 The differential action of class II antiarrhythmics on Ca2+ i release may have implications on the pharmacology of these drugs.
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Affiliation(s)
- Marta Reyes-Corral
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
| | - Naja M Sørensen
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
| | - Christopher Thrasivoulou
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
| | - Prokar Dasgupta
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
| | - Jonathan F Ashmore
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
| | - Aamir Ahmed
- Centre for Stem Cells and Regenerative Medicine (M.R.-C., A.A.) and MRC Centre for Transplantation (P.D.), King's College London, London, United Kingdom; Sophion Bioscience A/S, Ballerup, Denmark (N.M.S.); and Departments of Cell and Developmental Biology (C.T.) and Neuroscience, Physiology and Pharmacology, and The Ear Institute (J.F.A.), University College London, London, United Kingdom
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20
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Wang JL, Chou CT, Liang WZ, Wu CJ, Kuo CC, Hao LJ, Shieh P, Jan CR. Effects of timolol on Ca2+ handling and viability in human prostate cancer cells. Toxicol Mech Methods 2019; 29:138-145. [DOI: 10.1080/15376516.2018.1540024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Jue-Long Wang
- Department of Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Chiang-Ting Chou
- Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi, Taiwan
| | - Wei-Zhe Liang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- Department of Pharmacy, Tajen University, Pingtung, Taiwan
- Yuh-Ing Junior College of Health Care & Management, Kaohsiung, Taiwan
| | - Cherng-Jer Wu
- Department of Pharmacy, Kaohsiung Veterans General Hospital Pingtung Branch, Pingtung, Taiwan
| | - Chun-Chi Kuo
- Department of Nursing, Tzu Hui Institute of Technology, Pingtung, Taiwan
| | - Lyh-Jyh Hao
- Department of Metabolism, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, Taiwan
| | - Pochuen Shieh
- Department of Pharmacy, Tajen University, Pingtung, Taiwan
| | - Chung-Ren Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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Tuncay E, Olgar Y, Durak A, Degirmenci S, Bitirim CV, Turan B. β 3 -adrenergic receptor activation plays an important role in the depressed myocardial contractility via both elevated levels of cellular free Zn 2+ and reactive nitrogen species. J Cell Physiol 2019; 234:13370-13386. [PMID: 30613975 DOI: 10.1002/jcp.28015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/11/2018] [Indexed: 12/27/2022]
Abstract
Role of β3 -AR dysregulation, as either cardio-conserving or cardio-disrupting mediator, remains unknown yet. Therefore, we examined the molecular mechanism of β3 -AR activation in depressed myocardial contractility using a specific agonist CL316243 or using β3 -AR overexpressed cardiomyocytes. Since it has been previously shown a possible correlation between increased cellular free Zn2+ ([Zn2+ ]i ) and depressed cardiac contractility, we first demonstrated a relation between β3 -AR activation and increased [Zn2+ ]i , parallel to the significant depolarization in mitochondrial membrane potential in rat ventricular cardiomyocytes. Furthermore, the increased [Zn2+ ]i induced a significant increase in messenger RNA (mRNA) level of β3 -AR in cardiomyocytes. Either β3 -AR activation or its overexpression could increase cellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) levels, in line with significant changes in nitric oxide (NO)-pathway, including increases in the ratios of pNOS3/NOS3 and pGSK-3β/GSK-3β, and PKG expression level in cardiomyocytes. Although β3 -AR activation induced depression in both Na+ - and Ca2+ -currents, the prolonged action potential (AP) seems to be associated with a marked depression in K+ -currents. The β3 -AR activation caused a negative inotropic effect on the mechanical activity of the heart, through affecting the cellular Ca2+ -handling, including its effect on Ca2+ -leakage from sarcoplasmic reticulum (SR). Our cellular level data with β3 -AR agonism were supported with the data on high [Zn2+ ]i and β3 -AR protein-level in metabolic syndrome (MetS)-rat heart. Overall, our present data can emphasize the important deleterious effect of β3 -AR activation in cardiac remodeling under pathological condition, at least, through a cross-link between β3 -AR activation, NO-signaling, and [Zn2+ ]i pathways. Moreover, it is interesting to note that the recovery in ER-stress markers with β3 -AR agonism in hyperglycemic cardiomyocytes is favored. Therefore, how long and to which level the β3 -AR agonism would be friend or become foe remains to be mystery, yet.
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Affiliation(s)
- Erkan Tuncay
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Sinan Degirmenci
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | | | - Belma Turan
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
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22
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Tuncay E, Bitirim CV, Olgar Y, Durak A, Rutter GA, Turan B. Zn2+-transporters ZIP7 and ZnT7 play important role in progression of cardiac dysfunction via affecting sarco(endo)plasmic reticulum-mitochondria coupling in hyperglycemic cardiomyocytes. Mitochondrion 2019; 44:41-52. [DOI: 10.1016/j.mito.2017.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/13/2017] [Accepted: 12/27/2017] [Indexed: 12/20/2022]
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Zyśk M, Gapys B, Ronowska A, Gul-Hinc S, Erlandsson A, Iwanicki A, Sakowicz-Burkiewicz M, Szutowicz A, Bielarczyk H. Protective effects of voltage-gated calcium channel antagonists against zinc toxicity in SN56 neuroblastoma cholinergic cells. PLoS One 2018; 13:e0209363. [PMID: 30571745 PMCID: PMC6301650 DOI: 10.1371/journal.pone.0209363] [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: 07/10/2018] [Accepted: 12/04/2018] [Indexed: 12/13/2022] Open
Abstract
One of the pathological site effects in excitotoxic activation is Zn2+ overload to postsynaptic neurons. Such an effect is considered to be equivalent to the glutamate component of excitotoxicity. Excessive uptake of Zn2+ by active voltage-dependent transport systems in these neurons may lead to significant neurotoxicity. The aim of this study was to investigate whether and which antagonists of the voltage gated calcium channels (VGCC) might modify this Zn2+-induced neurotoxicity in neuronal cells. Our data demonstrates that depolarized SN56 neuronal cells may take up large amounts of Zn2+ and store these in cytoplasmic and mitochondrial sub-fractions. The mitochondrial Zn2+ excess suppressed pyruvate uptake and oxidation. Such suppression was caused by inhibition of pyruvate dehydrogenase complex, aconitase and NADP-isocitrate dehydrogenase activities, resulting in the yielding of acetyl-CoA and ATP shortages. Moreover, incoming Zn2+ increased both oxidized glutathione and malondialdehyde levels, known parameters of oxidative stress. In depolarized SN56 cells, nifedipine treatment (L-type VGCC antagonist) reduced Zn2+ uptake and oxidative stress. The treatment applied prevented the activities of PDHC, aconitase and NADP-IDH enzymes, and also yielded the maintenance of acetyl-CoA and ATP levels. Apart from suppression of oxidative stress, N- and P/Q-type VGCCs presented a similar, but weaker protective influence. In conclusion, our data shows that in the course of excitotoxity, impairment to calcium homeostasis is tightly linked with an excessive neuronal Zn2+ uptake. Hence, the VGCCs types L, N and P/Q share responsibility for neuronal Zn2+ overload followed by significant energy-dependent neurotoxicity. Moreover, Zn2+ affects the target tricarboxylic acid cycle enzymes, yields acetyl-CoA and energy deficits as well.
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Affiliation(s)
- Marlena Zyśk
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
- * E-mail:
| | - Beata Gapys
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Anna Ronowska
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Sylwia Gul-Hinc
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Anna Erlandsson
- Department of Public Health & Caring Sciences/Molecular Geriatrics, Uppsala University, Uppsala, Sweden
| | - Adam Iwanicki
- Department of Molecular Bacteriology, University of Gdańsk & Medical University of Gdańsk, Gdansk, Poland
| | | | - Andrzej Szutowicz
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Hanna Bielarczyk
- Department of Laboratory Medicine, Medical University of Gdansk, Gdansk, Poland
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Olgar Y, Turan B. A sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin comparison with insulin shows important effects on Zn 2+-transporters in cardiomyocytes from insulin-resistant metabolic syndrome rats through inhibition of oxidative stress 1. Can J Physiol Pharmacol 2018; 97:528-535. [PMID: 30444646 DOI: 10.1139/cjpp-2018-0466] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors showed significant effects in patients with diabetes or metabolic syndrome (MetS) with high cardiovascular risk. Although the increased intracellular Zn2+ level ([Zn2+]i), oxidative stress, and altered cardiac matrix metalloproteinases (MMPs) in diabetic cardiomyopathy can intersect with different signaling pathways, the exact mechanisms are not known yet. Since either MMPs or SGLT2 have important roles in cardiac-fibrosis under hyperglycemia, we aimed to examine the role of SGLT2 inhibitor dapagliflozin (DAP) on cardiac Zn2+-transporters responsible for [Zn2+]i-regulation, comparison to insulin (INS), together with MMP levels and systemic oxidative stress status in MetS-rats. High-carbohydrated diet-induced MetS-rats received DAP or INS for 2 weeks. DAP but not INS in MetS-rats significantly decreased high blood-glucose levels, while both treatments exerted benefits on increased total oxidative status and decreased total antioxidant status in MetS-rat plasma as well as in heart tissue. Protein levels of Zn2+-transporters, responsible for Zn2+-influx into cytosol, ZIP7 and ZIP14 were increased with significant decrease in ZIP8 of MetS-rat cardiomyoctes, while Zn2+-transporters, responsible for cytosolic Zn2+-efflux, ZnT7 was decreased with no change in ZnT8. Both treatments induced significant beneficial effects on altered ZIP14, ZIP8, and ZnT7 levels. Furthermore, both treatments exerted benefits on depressed gelatin-zymography and protein expression levels of MMP-2 and MMP-9 in MetS-rat ventricular cardiomyocytes. The direct effect of DAP on heart was also confirmed with measurements of left ventricular developed pressure. Overall, we showed that DAP has important antioxidant-like cardio-protective effects in MetS-rats, similar to INS-effect, affecting Zn2+-regulation via Zn2+-transporters, MMPs, and oxidative stress. Therefore one can suggest that SGLT2 inhibitors can be new therapeutic agents for cardio-protection not only in hyperglycemia but also in failing heart.
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Affiliation(s)
- Yusuf Olgar
- Departments of Biophysics and Internal Medicine, Faculty of Medicine, Ankara University, Ankara, Turkey.,Departments of Biophysics and Internal Medicine, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Departments of Biophysics and Internal Medicine, Faculty of Medicine, Ankara University, Ankara, Turkey.,Departments of Biophysics and Internal Medicine, Faculty of Medicine, Ankara University, Ankara, Turkey
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Aging related functional and structural changes in the heart and aorta: MitoTEMPO improves aged-cardiovascular performance. Exp Gerontol 2018; 110:172-181. [DOI: 10.1016/j.exger.2018.06.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/30/2018] [Accepted: 06/11/2018] [Indexed: 12/19/2022]
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Degirmenci S, Olgar Y, Durak A, Tuncay E, Turan B. Cytosolic increased labile Zn 2+ contributes to arrhythmogenic action potentials in left ventricular cardiomyocytes through protein thiol oxidation and cellular ATP depletion. J Trace Elem Med Biol 2018; 48:202-212. [PMID: 29773183 DOI: 10.1016/j.jtemb.2018.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 02/06/2023]
Abstract
Intracellular labile (free) Zn2+-level ([Zn2+]i) is low and increases markedly under pathophysiological conditions in cardiomyocytes. High [Zn2+]i is associated with alterations in excitability and ionic-conductances while exact mechanisms are not clarified yet. Therefore, we examined the elevated-[Zn2+]i on some sarcolemmal ionic-mechanisms, which can mediate cardiomyocyte dysfunction. High-[Zn2+]i induced significant changes in action potential (AP) parameters, including depolarization in resting membrane-potential and prolongations in AP-repolarizing phases. We detected also the time-dependent effects such as induction of spontaneous APs at the time of ≥ 3 min following [Zn2+]i increases, a manner of cellular ATP dependent and reversible with disulfide-reducing agent dithiothreitol, DTT. High-[Zn2+]i induced inhibitions in voltage-dependent K+-channel currents, such as transient outward K+-currents, Ito, steady-state currents, Iss and inward-rectifier K+-currents, IK1, reversible with DTT seemed to be responsible from the prolongations in APs. We, for the first time, demonstrated that lowering cellular ATP level induced significant decreaeses in both Iss and IK1, while no effect on Ito. However, the increased-[Zn2+]i could induce marked activation in ATP-sensitive K+-channel currents, IKATP, depending on low cellular ATP and thiol-oxidation levels of these channels. The mRNA levels of Kv4.3, Kv1.4 and Kv2.1 were depressed markedly with increased-[Zn2+]i with no change in mRNA level of Kv4.2, while the mRNA level of IKATP subunit, SUR2A was increased significantly with increased-[Zn2+]i, being reversible with DTT. Overall we demonstrated that high-[Zn2+]i, even if nanomolar levels, alters cardiac function via prolonged APs of cardiomyocytes, at most, due to inhibitions in voltage-dependent K+-currents, although activation of IKATP is playing cardioprotective role, through some biochemical changes in cellular ATP- and thiol-oxidation levels. It seems, a well-controlled [Zn2+]i can be novel therapeutic target for cardiac complications under pathological conditions including oxidative stress.
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Affiliation(s)
- Sinan Degirmenci
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey.
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Olgar Y, Durak A, Tuncay E, Bitirim CV, Ozcinar E, Inan MB, Tokcaer-Keskin Z, Akcali KC, Akar AR, Turan B. Increased free Zn 2+ correlates induction of sarco(endo)plasmic reticulum stress via altered expression levels of Zn 2+ -transporters in heart failure. J Cell Mol Med 2018; 22:1944-1956. [PMID: 29333637 PMCID: PMC5824399 DOI: 10.1111/jcmm.13480] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 10/29/2017] [Indexed: 12/14/2022] Open
Abstract
Zn2+ -homoeostasis including free Zn2+ ([Zn2+ ]i ) is regulated through Zn2+ -transporters and their comprehensive understanding may be important due to their contributions to cardiac dysfunction. Herein, we aimed to examine a possible role of Zn2+ -transporters in the development of heart failure (HF) via induction of ER stress. We first showed localizations of ZIP8, ZIP14 and ZnT8 to both sarcolemma and S(E)R in ventricular cardiomyocytes (H9c2 cells) using confocal together with calculated Pearson's coefficients. The expressions of ZIP14 and ZnT8 were significantly increased with decreased ZIP8 level in HF. Moreover, [Zn2+ ]i was significantly high in doxorubicin-treated H9c2 cells compared to their controls. We found elevated levels of ER stress markers, GRP78 and CHOP/Gadd153, confirming the existence of ER stress. Furthermore, we measured markedly increased total PKC and PKCα expression and PKCα-phosphorylation in HF. A PKC inhibition induced significant decrease in expressions of these ER stress markers compared to controls. Interestingly, direct increase in [Zn2+ ]i using zinc-ionophore induced significant increase in these markers. On the other hand, when we induced ER stress directly with tunicamycin, we could not observe any effect on expression levels of these Zn2+ transporters. Additionally, increased [Zn2+ ]i could induce marked activation of PKCα. Moreover, we observed marked decrease in [Zn2+ ]i under PKC inhibition in H9c2 cells. Overall, our present data suggest possible role of Zn2+ transporters on an intersection pathway with increased [Zn2+ ]i and PKCα activation and induction of HF, most probably via development of ER stress. Therefore, our present data provide novel information how a well-controlled [Zn2+ ]i via Zn2+ transporters and PKCα can be important therapeutic approach in prevention/treatment of HF.
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Affiliation(s)
- Yusuf Olgar
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | | | - Evren Ozcinar
- Department of Cardiovascular Surgery, Heart Center, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Mustafa Bahadir Inan
- Department of Cardiovascular Surgery, Heart Center, Ankara University Faculty of Medicine, Ankara, Turkey
| | | | - Kamil Can Akcali
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Ahmet Ruchan Akar
- Department of Cardiovascular Surgery, Heart Center, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Ankara University Faculty of Medicine, Ankara, Turkey
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28
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Turan B, Tuncay E. Impact of Labile Zinc on Heart Function: From Physiology to Pathophysiology. Int J Mol Sci 2017; 18:ijms18112395. [PMID: 29137144 PMCID: PMC5713363 DOI: 10.3390/ijms18112395] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/02/2017] [Accepted: 11/08/2017] [Indexed: 12/15/2022] Open
Abstract
Zinc plays an important role in biological systems as bound and histochemically reactive labile Zn2+. Although Zn2+ concentration is in the nM range in cardiomyocytes at rest and increases dramatically under stimulation, very little is known about precise mechanisms controlling the intracellular distribution of Zn2+ and its variations during cardiac function. Recent studies are focused on molecular and cellular aspects of labile Zn2+ and its homeostasis in mammalian cells and growing evidence clarified the molecular mechanisms underlying Zn2+-diverse functions in the heart, leading to the discovery of novel physiological functions of labile Zn2+ in parallel to the discovery of subcellular localization of Zn2+-transporters in cardiomyocytes. Additionally, important experimental data suggest a central role of intracellular labile Zn2+ in excitation-contraction coupling in cardiomyocytes by shaping Ca2+ dynamics. Cellular labile Zn2+ is tightly regulated against its adverse effects through either Zn2+-transporters, Zn2+-binding molecules or Zn2+-sensors, and, therefore plays a critical role in cellular signaling pathways. The present review summarizes the current understanding of the physiological role of cellular labile Zn2+ distribution in cardiomyocytes and how a remodeling of cellular Zn2+-homeostasis can be important in proper cell function with Zn2+-transporters under hyperglycemia. We also emphasize the recent investigations on Zn2+-transporter functions from the standpoint of human heart health to diseases together with their clinical interest as target proteins in the heart under pathological condition, such as diabetes.
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Affiliation(s)
- Belma Turan
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey.
| | - Erkan Tuncay
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey.
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29
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Bitirim CV, Tuncay E, Turan B. Demonstration of subcellular migration of CK2α localization from nucleus to sarco(endo)plasmic reticulum in mammalian cardiomyocytes under hyperglycemia. Mol Cell Biochem 2017; 443:25-36. [DOI: 10.1007/s11010-017-3207-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/14/2017] [Indexed: 12/16/2022]
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30
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Induction of endoplasmic reticulum stress and changes in expression levels of Zn 2+-transporters in hypertrophic rat heart. Mol Cell Biochem 2017; 440:209-219. [PMID: 28849306 DOI: 10.1007/s11010-017-3168-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/16/2017] [Indexed: 12/15/2022]
Abstract
Clinical and experimental studies have shown an association between intracellular free Zn2+ ([Zn2+]i)-dyshomeostasis and cardiac dysfunction besides [Ca2+]i-dyshomeostasis. Since [Zn2+]i-homeostasis is regulated through Zn2+-transporters depending on their subcellular distributions, one can hypothesize that any imbalance in Zn2+-homeostasis via alteration in Zn2+-transporters may be associated with the induction of ER stress and apoptosis in hypertrophic heart. We used a transverse aortic constriction (TAC) model to induce hypertrophy in young male rat heart. We confirmed the development of hypertrophy with a high ratio of heart to body weight and cardiomyocyte capacitance. The expression levels of ER stress markers GRP78, CHOP/Gadd153, and calnexin are significantly high in TAC-group in comparison to those of controls (SHAM-group). Additionally, we detected high expression levels of apoptotic status marker proteins such as the serine kinase GSK-3β, Bax-to-Bcl-2 ratio, and PUMA in TAC-group in comparison to SHAM-group. The ratios of phospho-Akt to Akt and phospho-NFκB to the NFκB are significantly higher in TAC-group than in SHAM-group. Furthermore, we observed markedly increased phospho-PKCα and PKCα levels in TAC-group. We, also for the first time, determined significantly increased ZIP7, ZIP14, and ZnT8 expressions along with decreased ZIP8 and ZnT7 levels in the heart tissue from TAC-group in comparison to SHAM-group. Furthermore, a roughly calculated total expression level of ZIPs responsible for Zn2+-influx into the cytosol (increased about twofold) can be also responsible for the markedly increased [Zn2+]i detected in hypertrophic cardiomyocytes. Taking into consideration the role of increased [Zn2+]i via decreased ER-[Zn2+] in the induction of ER stress in cardiomyocytes, our present data suggest that differential changes in the expression levels of Zn2+-transporters can underlie mechanical dysfunction, in part due to the induction of ER stress and apoptosis in hypertrophic heart via increased [Zn2+]i- besides [Ca2+]i-dyshomeostasis.
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31
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Tuncay E, Bitirim VC, Durak A, Carrat GRJ, Taylor KM, Rutter GA, Turan B. Hyperglycemia-Induced Changes in ZIP7 and ZnT7 Expression Cause Zn 2+ Release From the Sarco(endo)plasmic Reticulum and Mediate ER Stress in the Heart. Diabetes 2017; 66:1346-1358. [PMID: 28232492 DOI: 10.2337/db16-1099] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 02/10/2017] [Indexed: 11/13/2022]
Abstract
Changes in cellular free Zn2+ concentration, including those in the sarco(endo)plasmic reticulum [S(E)R], are primarily coordinated by Zn2+ transporters (ZnTs) whose identity and role in the heart are not well established. We hypothesized that ZIP7 and ZnT7 transport Zn2+ in opposing directions across the S(E)R membrane in cardiomyocytes and that changes in their activity play an important role in the development of ER stress during hyperglycemia. The subcellular S(E)R localization of ZIP7 and ZnT7 was determined in cardiomyocytes and in isolated S(E)R preparations. Markedly increased mRNA and protein levels of ZIP7 were observed in ventricular cardiomyocytes from diabetic rats or high-glucose-treated H9c2 cells while ZnT7 expression was low. In addition, we observed increased ZIP7 phosphorylation in response to high glucose in vivo and in vitro. By using recombinant-targeted Förster resonance energy transfer sensors, we show that hyperglycemia induces a marked redistribution of cellular free Zn2+, increasing cytosolic free Zn2+ and lowering free Zn2+ in the S(E)R. These changes involve alterations in ZIP7 phosphorylation and were suppressed by small interfering RNA-mediated silencing of CK2α. Opposing changes in the expression of ZIP7 and ZnT7 were also observed in hyperglycemia. We conclude that subcellular free Zn2+ redistribution in the hyperglycemic heart, resulting from altered ZIP7 and ZnT7 activity, contributes to cardiac dysfunction in diabetes.
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Affiliation(s)
- Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Verda C Bitirim
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Gaelle R J Carrat
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Kathryn M Taylor
- School of Pharmacy and Pharmaceutical Sciences, College of Biomedical and Life Sciences, Cardiff University, Cardiff, U.K
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, U.K
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
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Billur D, Tuncay E, Okatan EN, Olgar Y, Durak AT, Degirmenci S, Can B, Turan B. Interplay Between Cytosolic Free Zn 2+ and Mitochondrion Morphological Changes in Rat Ventricular Cardiomyocytes. Biol Trace Elem Res 2016; 174:177-188. [PMID: 27107885 DOI: 10.1007/s12011-016-0704-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/12/2016] [Indexed: 12/11/2022]
Abstract
The Zn2+ in cardiomyocytes is buffered by structures near T-tubulus and/or sarcoplasmic/endoplasmic reticulum (S(E)R) while playing roles as either an antioxidant or a toxic agent, depending on the concentration. Therefore, we aimed first to examine a direct effect of ZnPO4 (extracellular exposure) or Zn2+ pyrithione (ZnPT) (intracellular exposure) application on the structure of the mitochondrion in ventricular cardiomyocytes by using histological investigations. The light microscopy data demonstrated that Zn2+ exposure induced marked increases on cellular surface area, an indication of hypertrophy, in a concentration-dependent manner. Furthermore, a whole-cell patch-clamp measurement of cell capacitance also supported the hypertrophy in the cells. We observed marked increases in mitochondrial matrix/cristae area and matrix volume together with increased lysosome numbers in ZnPO4- or ZnPT-incubated cells by using transmission electron microscopy, again in a concentration-dependent manner. Furthermore, we observed notable clustering and vacuolated mitochondrion, markedly disrupted and damaged myofibrils, and electron-dense small granules in Zn2+-exposed cells together with some implications of fission-fusion defects in the mitochondria. Moreover, we observed marked depolarization in mitochondrial membrane potential during 1-μM ZnPT minute applications by using confocal microscopy. We also showed that 1-μM ZnPT incubation induced significant increases in the phosphorylation levels of GSK3β (Ser21 and Ser9), Akt (Ser473), and NFκB (Ser276 and Thr254) together with increased expression levels in ER stress proteins such as GRP78 and calregulin. Furthermore, a new key player at ER-mitochondria sites, promyelocytic leukemia protein (PML) level, was markedly increased in ZnPT-incubated cells. As a summary, our present data suggest that increased cytosolic free Zn2+ can induce marked alterations in mitochondrion morphology as well as depolarization in mitochondrion membrane potential and changes in some cytosolic signaling proteins as well as a defect in ER-mitochondria cross talk.
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Affiliation(s)
- Deniz Billur
- Department of Histology-Embryology, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Esma Nur Okatan
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Aysegul Toy Durak
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Sinan Degirmenci
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Belgin Can
- Department of Histology-Embryology, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey.
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Tuncay E, Turan B. Intracellular Zn(2+) Increase in Cardiomyocytes Induces both Electrical and Mechanical Dysfunction in Heart via Endogenous Generation of Reactive Nitrogen Species. Biol Trace Elem Res 2016; 169:294-302. [PMID: 26138011 DOI: 10.1007/s12011-015-0423-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/23/2015] [Indexed: 12/23/2022]
Abstract
Oxidants increase intracellular free Zn(2+) concentration ([Zn(2+)]i) in ventricular myocytes, which contributes to oxidant-induced alterations in excitation-contraction coupling (ECC). However, it is not clear whether increased [Zn(2+)]i in cardiomyocytes via increased reactive nitrogen species (RNS) has a role on heart function under pathological conditions, such as hyperglycemia. In this study, first we aimed to investigate the role of increased [Zn(2+)]i under in vitro condition in the development of both electrical and mechanical dysfunction of isolated papillary muscle strips from rat heart via exposed samples to a Zn(2+)-ionophore (Zn-pyrithione; 1 μM) for 20 min. Under simultaneous measurement of intracellular action potential and contractile activity in these preparations, Zn-pyrithione exposure caused marked prolongation in action potential repolarization phase and slowdown in both contraction and relaxation rates of twitch activity. Second, in order to demonstrate an association between increased [Zn(2+)]i and increased RNS, we monitored intracellular [Zn(2+)]i under an acute exposure of nitric oxide (NO) donor sodium nitroprusside, SNP, in freshly isolated quiescent cardiomyocytes loaded with FluoZin-3. Resting level of free Zn(2+) is significantly higher in cardiomyocytes under hyperglycemic condition compared to those of the controls, which seems to be associated with increased level of RNS production in hyperglycemic cardiomyocytes. Western blot analysis showed that Zn-pyrithione exposure induced a marked decrease in the activity of protein phosphatase 1 and 2A, member of macromolecular protein complex of cardiac ryanodine receptors, RyR2, besides significant increase in the phosphorylation level of extracellular signal-regulated kinase1/2 as a concentration-dependent manner. Overall, the present data demonstrated that there is a cross-relationship between increased RNS production and increased [Zn(2+)]i level in cardiomyocytes under pathological conditions such as hyperglycemia.
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Affiliation(s)
- Erkan Tuncay
- Department of Biophysics, Ankara University Faculty of Medicine, 06100, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Ankara University Faculty of Medicine, 06100, Ankara, Turkey.
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Lee SR, Noh SJ, Pronto JR, Jeong YJ, Kim HK, Song IS, Xu Z, Kwon HY, Kang SC, Sohn EH, Ko KS, Rhee BD, Kim N, Han J. The Critical Roles of Zinc: Beyond Impact on Myocardial Signaling. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:389-99. [PMID: 26330751 PMCID: PMC4553398 DOI: 10.4196/kjpp.2015.19.5.389] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 12/15/2022]
Abstract
Zinc has been considered as a vital constituent of proteins, including enzymes. Mobile reactive zinc (Zn(2+)) is the key form of zinc involved in signal transductions, which are mainly driven by its binding to proteins or the release of zinc from proteins, possibly via a redox switch. There has been growing evidence of zinc's critical role in cell signaling, due to its flexible coordination geometry and rapid shifts in protein conformation to perform biological reactions. The importance and complexity of Zn(2+) activity has been presumed to parallel the degree of calcium's participation in cellular processes. Whole body and cellular Zn(2+) levels are largely regulated by metallothioneins (MTs), Zn(2+) importers (ZIPs), and Zn(2+) transporters (ZnTs). Numerous proteins involved in signaling pathways, mitochondrial metabolism, and ion channels that play a pivotal role in controlling cardiac contractility are common targets of Zn(2+). However, these regulatory actions of Zn(2+) are not limited to the function of the heart, but also extend to numerous other organ systems, such as the central nervous system, immune system, cardiovascular tissue, and secretory glands, such as the pancreas, prostate, and mammary glands. In this review, the regulation of cellular Zn(2+) levels, Zn(2+)-mediated signal transduction, impacts of Zn(2+) on ion channels and mitochondrial metabolism, and finally, the implications of Zn(2+) in health and disease development were outlined to help widen the current understanding of the versatile and complex roles of Zn(2+).
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Affiliation(s)
- Sung Ryul Lee
- Department of Integrated Biomedical Science, Cardiovascular and Metabolic disease Center, College of Medicine, Inje University, Busan 614-735, Korea
| | - Su Jin Noh
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Julius Ryan Pronto
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Yu Jeong Jeong
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Hyoung Kyu Kim
- Department of Integrated Biomedical Science, Cardiovascular and Metabolic disease Center, College of Medicine, Inje University, Busan 614-735, Korea
| | - In Sung Song
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Zhelong Xu
- Department of Physiology and Pathophysiology, Tianjin Medical University, Tainjin 300070, P.R. China
| | - Hyog Young Kwon
- Soonchunhyang Institute of Medio-bio Science (SIMS), Soonchunhyang University, Cheonan 336-745, Korea
| | - Se Chan Kang
- Department of Life Science, Gachon University, Seongnam 461-701, Korea
| | - Eun-Hwa Sohn
- Department of Herbal Medicine Resource, Kangwon National University, Samcheok 245-711, Korea
| | - Kyung Soo Ko
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Byoung Doo Rhee
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Nari Kim
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Jin Han
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
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Okatan EN, Tuncay E, Hafez G, Turan B. Profiling of cardiac β-adrenoceptor subtypes in the cardiac left ventricle of rats with metabolic syndrome: Comparison with streptozotocin-induced diabetic rats. Can J Physiol Pharmacol 2015; 93:517-25. [DOI: 10.1139/cjpp-2014-0507] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Little is known about metabolic syndrome (MetS)-associated cardiomyopathy, especially in relation to the role and contribution of beta-adrenoceptor (β-AR) subtypes. Therefore, we examined the roles of β-AR subtypes in the cardiac function of rats with MetS (MetS group) and compared it with that of rats with streptozotocin (STZ)-induced diabetes (STZ group). Compared with the normal control rats, the protein levels of cardiac β1- and β2-AR in the MetS group were significantly decreased and with no changes in their mRNA levels, whereas the protein levels of β3-AR were similar to those of the controls. However, as shown previously, the protein levels of cardiac β1- and β2-AR in the STZ group were decreased, whereas the β3-AR levels were significantly increased by comparison with the controls. Additionally, the mRNA levels of β2- and β3-AR were increased, but β1-AR mRNA was decreased in the STZ group. Furthermore, left ventricular developed pressure responses to β3-AR agonist BRL37344 were increased in the STZ group but not in the MetS group, whereas for both groups, the responses to noradrenaline were not different from those of the controls. However, the response to stimulation with high concentrations of fenoterol was depressed in the MetS group, compared with the controls, but not in the STZ group. Consequently, our data suggest that the contribution of the β-AR system to cardiac dysfunction in the rats with MetS is not the same as that in the STZ group, although they have similar cardiac dysfunction with similar ultrastructural changes to the myocardium.
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Affiliation(s)
- Esma N. Okatan
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
| | - Gaye Hafez
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
- Department of Biophysics, Ankara University, Faculty of Medicine, 06100 Ankara, Turkey
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Examining a new role for zinc in regulating calcium release in cardiac muscle. Biochem Soc Trans 2015; 43:359-63. [DOI: 10.1042/bst20140285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
It is well established that mammalian cells contain a small but measurable pool of free or labile zinc in the cytosol that is buffered in the high picomolar range. Recent attention has focused on the fact that this pool of free zinc has signalling effects that can be evoked through extracellular stimuli posing the question as to whether zinc should be regarded as a second messenger. Our knowledge of the targets, the biological significance and the molecular mechanisms of zinc signalling is limited but recent evidence suggests that zinc homoeostasis may be intimately linked to intracellular calcium signalling. In this review, we discuss the role of zinc as an intracellular signalling molecule with an emphasis on the potential role of zinc in shaping calcium-dynamics in cardiac muscle. We also consider the evidence that the cardiac ryanodine receptor (RyR2) is a potential zinc signalling target.
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Güzel D, Dursun AD, Fıçıcılar H, Tekin D, Tanyeli A, Akat F, Topal Çelikkan F, Sabuncuoğlu B, Baştuğ M. Effect of intermittent hypoxia on the cardiac HIF-1/VEGF pathway in experimental type 1 diabetes mellitus. Anatol J Cardiol 2015; 16:76-83. [PMID: 26467365 PMCID: PMC5336740 DOI: 10.5152/akd.2015.5925] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE High altitude and hypoxic preconditioning have cardioprotective effects by increasing coronary vascularity, reducing post-ischemic injury, and improving cardiac function. Our purpose was to examine if intermittent hypoxia treatment has any restoring effects related to the possible role of the HIF-1/VEGF pathway on diabetic cardiomyopathy. METHODS Wistar Albino male rats (n=34) were divided into four groups: control (C), intermittent hypoxia (IH), diabetes mellitus (DM), and diabetes mellitus plus intermittent hypoxia (DM+IH). Following a streptozotocin (STZ) injection (50 mg/kg, i.p.), blood glucose levels of 250 mg/dL and above were considered as DM. IH and DM+IH groups were exposed to hypoxia 6 h/day for 42 days at a pressure corresponding to 3000 m altitude. Twenty-four hours after the IH protocol, hearts were excised. Hematoxylin and eosin-stained apical parts of the left ventricles were evaluated. Hypoxia inducible factor-1 (HIF-1), vascular endothelial growth factor 164 (VEGF164), and VEGF188 polymerase chain reaction products were run in agarose gel electrophoresis. Band density analysis of UV camera images was performed using Image J. The data were compared by one-way ANOVA, repeated measures two-way ANOVA, and the Kruskal-Wallis test. RESULTS The percent weight change was lower in the DM group than in the controls (p=0.004). The tissue injury was the highest in the DM group and the least in the IH group. Diabetes decreased, whereas the IH treatment increased the vascularity. A decrease was observed in the VEGF188 mRNA levels in the DM+IH group compared with the C group, but there were no difference in HIF-1α and VEGF164 mRNA levels between the groups. CONCLUSION The IH treatment restored the diabetic effects on the heart by reducing tissue injury and increasing the capillarity without transcriptional changes in HIF-1/VEGF correspondingly.
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Affiliation(s)
- Derya Güzel
- Department of Physiology, Faculty of Medicine, Sakarya University; Sakarya-Turkey.
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Beta-blocker timolol alleviates hyperglycemia-induced cardiac damage via inhibition of endoplasmic reticulum stress. J Bioenerg Biomembr 2014; 46:377-87. [PMID: 25064604 DOI: 10.1007/s10863-014-9568-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/11/2014] [Indexed: 01/08/2023]
Abstract
Current data support that pharmacological modulators of endoplasmic reticulum stress (ERS) have therapeutic potential for diabetic individuals. Therefore, we aimed to examine whether timolol, having free radical-scavenger action, besides being a β-blocker, exerts a cardioprotective effect via inhibition of ERS response in diabetic rats in a comparison with an antioxidant N-acetylcysteine (NAC). Histopathological data showed that either timolol- or NAC-treatment of diabetic rats prevented the changes in mitochondria and nucleus of the cardiac tissue while they enhanced the cellular redox-state in heart as well. The levels of ER-targeted cytoprotective chaperones GRP78 and calnexin, unfolded protein response signaling protein CHO/Gadd153 besides the levels of calpain, BCL-2, phospho-Akt, PUMA, and PML in the hearts from diabetic rats, treated with either timolol or NAC, are found to be similar among these groups, although all these parameters were markedly preserved in the untreated diabetics compared to those of the controls. Taken into consideration how important a balanced-ratio between anti-apoptotic and pro-apoptotic proteins for the maintenance mitochondria/ER function, our results suggest that ERS in diabetic rat heart is mediated by increased oxidative damage, which in turn triggers cardiac dysfunction. Moreover, we also demonstrated that timolol treatment of diabetic rats, similar to NAC treatment, induced a well-controlled redox-state and apoptosis in cardiac myocardium. We, thus for the first time, report that cardioprotective effect of timolol seems to be associated with normalization of ER function due to its antioxidant action in cardiomyocytes even under hyperglycemia.
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Gokturk H, Ulusu NN, Gok M, Tuncay E, Can B, Turan B. Long-term treatment with a beta-blocker timolol attenuates renal-damage in diabetic rats via enhancing kidney antioxidant-defense system. Mol Cell Biochem 2014; 395:177-86. [DOI: 10.1007/s11010-014-2123-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 06/02/2014] [Indexed: 12/22/2022]
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Antioxidant drug therapy approaches for neuroprotection in chronic diseases of the retina. Int J Mol Sci 2014; 15:1865-86. [PMID: 24473138 PMCID: PMC3958826 DOI: 10.3390/ijms15021865] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/18/2014] [Accepted: 01/21/2014] [Indexed: 12/31/2022] Open
Abstract
The molecular pathways contributing to visual signal transduction in the retina generate a high energy demand that has functional and structural consequences such as vascularization and high metabolic rates contributing to oxidative stress. Multiple signaling cascades are involved to actively regulate the redox state of the retina. Age-related processes increase the oxidative load, resulting in chronically elevated levels of oxidative stress and reactive oxygen species, which in the retina ultimately result in pathologies such as glaucoma or age-related macular degeneration, as well as the neuropathic complications of diabetes in the eye. Specifically, oxidative stress results in deleterious changes to the retina through dysregulation of its intracellular physiology, ultimately leading to neurodegenerative and potentially also vascular dysfunction. Herein we will review the evidence for oxidative stress-induced contributions to each of the three major ocular pathologies, glaucoma, age-related macular degeneration, and diabetic retinopathy. The premise for neuroprotective strategies for these ocular disorders will be discussed in the context of recent clinical and preclinical research pursuing novel therapy development approaches.
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