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Singh K, Teyani RL, Moniri NH. Agonists and hydrogen peroxide mediate hyperoxidation of β2-adrenergic receptor in airway epithelial cells: Implications for tachyphylaxis to β2-agonists in constrictive airway disorders. Biomed Pharmacother 2023; 168:115763. [PMID: 37865997 PMCID: PMC10842251 DOI: 10.1016/j.biopha.2023.115763] [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: 07/17/2023] [Revised: 10/06/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023] Open
Abstract
Asthma and other airway obstructive disorders are characterized by heightened inflammation and excessive airway epithelial cell reactive oxygen species (ROS), which give rise to a highly oxidative environment. After decades of use, β2-adrenergic receptor (β2AR) agonists remain at the forefront of treatment options for asthma, however, chronic use of β2-agonists leads to tachyphylaxis to the bronchorelaxant effects, a phenomenon that remains mechanistically unexplained. We have previously demonstrated that β2AR agonism increases ROS generation in airway epithelial cells, which upholds proper receptor function via feedback oxidation of β2AR cysteine thiolates to Cys-S-sulfenic acids (Cys-SOH). Our previous results also demonstrate that prevention of normal redox cycling of this post-translational oxi-modification back to the thiol prevents proper receptor function. Given that Cys-S-sulfenic acids can be irreversibly overoxidized to Cys-S-sulfinic (Cys-SO2H) or S-sulfonic (Cys-SO3H) acids, which are incapable of further participation in redox reactions, we hypothesized that β2-agonist tachyphylaxis may be explained by hyperoxidation of β2AR to S-sulfinic acids. Here, using airway epithelial cell lines and primary small airway epithelial cells from healthy and asthma-diseased donors, we show that β2AR agonism generates H2O2 in a receptor and NAPDH oxidase-dependent manner. We also demonstrate that acute and chronic receptor agonism can facilitate β2AR S-sulfination, and that millimolar H2O2 concentrations are deleterious to β2AR-mediated cAMP formation, an effect that can be rescued to a degree in the presence of the cysteine-donating antioxidant N-acetyl-L-cysteine. Our results reveal that the oxidative state of β2AR may contribute to receptor functionality and may, at least in part, explain β2-agonist tachyphylaxis.
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Affiliation(s)
- Kirti Singh
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, USA
| | - Razan L Teyani
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, USA
| | - Nader H Moniri
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, USA; Department of Biomedical Sciences, School of Medicine, Mercer University Health Sciences Center, Mercer University, Macon, GA 31207, USA.
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2
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Zhi X, Shi S, Li Y, Ma M, Long Y, Li C, Hao H, Liu H, Wang X, Wang L. S100a9 inhibits Atg9a transcription and participates in suppression of autophagy in cardiomyocytes induced by β 1-adrenoceptor autoantibodies. Cell Mol Biol Lett 2023; 28:74. [PMID: 37723445 PMCID: PMC10506287 DOI: 10.1186/s11658-023-00486-1] [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: 04/18/2023] [Accepted: 08/31/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Cardiomyocyte death induced by autophagy inhibition is an important cause of cardiac dysfunction. In-depth exploration of its mechanism may help to improve cardiac dysfunction. In our previous study, we found that β1-adrenergic receptor autoantibodies (β1-AAs) induced a decrease in myocardial autophagy and caused cardiomyocyte death, thus resulting in cardiac dysfunction. Through tandem mass tag (TMT)-based quantitative proteomics, autophagy-related S100a9 protein was found to be significantly upregulated in the myocardial tissue of actively immunized mice. However, whether S100a9 affects the cardiac function in the presence of β1-AAs through autophagy and the specific mechanism are currently unclear. METHODS In this study, the active immunity method was used to establish a β1-AA-induced mouse cardiac dysfunction model, and RT-PCR and western blot were used to detect changes in gene and protein expression in cardiomyocytes. We used siRNA to knockdown S100a9 in cardiomyocytes. An autophagy PCR array was performed to screen differentially expressed autophagy-related genes in cells transfected with S100a9 siRNA and negative control siRNA. Cytoplasmic nuclear separation, co-immunoprecipitation (Co-IP), and immunofluorescence were used to detect the binding of S100a9 and hypoxia inducible factor-1α (HIF-1α). Finally, AAV9-S100a9-RNAi was injected into mice via the tail vein to knockdown S100a9 in cardiomyocytes. Cardiac function was detected via ultrasonography. RESULTS The results showed that β1-AAs induced S100a9 expression. The PCR array indicated that Atg9a changed significantly in S100a9siRNA cells and that β1-AAs increased the binding of S100a9 and HIF-1α in cytoplasm. Knockdown of S100a9 significantly improved autophagy levels and cardiac dysfunction. CONCLUSION Our research showed that β1-AAs increased S100a9 expression in cardiomyocytes and that S100a9 interacted with HIF-1α, which prevented HIF-1α from entering the nucleus normally, thus inhibiting the transcription of Atg9a. This resulted in autophagy inhibition and cardiac dysfunction.
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Affiliation(s)
- Xiaoyan Zhi
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Shu Shi
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Yang Li
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Mingxia Ma
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Yaolin Long
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Chen Li
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Haihu Hao
- Department of Orthopaedics, Shanxi Bethune Hospital, Shanxi Academy of Medical Science, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, People's Republic of China
| | - Huirong Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, People's Republic of China
| | - Xiaohui Wang
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Li Wang
- Department of Pathology, Shanxi Medical University, No.56 Xinjian South Road, Taiyuan, Shanxi, 030001, People's Republic of China.
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3
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Sultan A, Singh J, Howarth FC. Mechanisms underlying electro-mechanical dysfunction in the Zucker diabetic fatty rat heart: a model of obesity and type 2 diabetes. Heart Fail Rev 2021; 25:873-886. [PMID: 31654177 DOI: 10.1007/s10741-019-09872-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Diabetes mellitus (DM) is a major and worsening global health problem, currently affecting over 450 million people and reducing their quality of life. Type 2 diabetes mellitus (T2DM) accounts for more than 90% of DM and the global epidemic of obesity, which largely explains the dramatic increase in the incidence and prevalence of T2DM in the past 20 years. Obesity is a major risk factor for DM which is a major cause of morbidity and mortality in diabetic patients. The electro-mechanical function of the heart is frequently compromised in diabetic patients. The aim of this review is to discuss the pathophysiology of electro-mechanical dysfunction in the diabetic heart and in particular, the Zucker diabetic fatty (ZDF) rat heart, a well-studied model of T2DM and obesity.
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Affiliation(s)
- Ahmed Sultan
- Department of Physiology, College of Medicine & Health Sciences, UAE University, P.O. Box 17666, Al Ain, UAE
| | - Jaipaul Singh
- School of Forensic and Applied Sciences, University of Central Lancashire, Preston, Lancashire, UK
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine & Health Sciences, UAE University, P.O. Box 17666, Al Ain, UAE.
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4
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Song Y, Xu C, Liu J, Li Y, Wang H, Shan D, Wainer IW, Hu X, Zhang Y, Woo AYH, Xiao RP. Heterodimerization With 5-HT 2BR Is Indispensable for β 2AR-Mediated Cardioprotection. Circ Res 2021; 128:262-277. [PMID: 33208036 DOI: 10.1161/circresaha.120.317011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE The β2-adrenoceptor (β2-AR), a prototypical GPCR (G protein-coupled receptor), couples to both Gs and Gi proteins. Stimulation of the β2-AR is beneficial to humans and animals with heart failure presumably because it activates the downstream Gi-PI3K-Akt cell survival pathway. Cardiac β2-AR signaling can be regulated by crosstalk or heterodimerization with other GPCRs, but the physiological and pathophysiological significance of this type of regulation has not been sufficiently demonstrated. OBJECTIVE Here, we aim to investigate the potential cardioprotective effect of β2-adrenergic stimulation with a subtype-selective agonist, (R,R')-4-methoxy-1-naphthylfenoterol (MNF), and to decipher the underlying mechanism with a particular emphasis on the role of heterodimerization of β2-ARs with another GPCR, 5-hydroxytryptamine receptors 2B (5-HT2BRs). METHODS AND RESULTS Using pharmacological, genetic and biophysical protein-protein interaction approaches, we studied the cardioprotective effect of the β2-agonist, MNF, and explored the underlying mechanism in both in vivo in mice and cultured rodent cardiomyocytes insulted with doxorubicin, hydrogen peroxide (H2O2) or ischemia/reperfusion. In doxorubicin (Dox)-treated mice, MNF reduced mortality and body weight loss, while improving cardiac function and cardiomyocyte viability. MNF also alleviated myocardial ischemia/reperfusion injury. In cultured rodent cardiomyocytes, MNF inhibited DNA damage and cell death caused by Dox, H2O2 or hypoxia/reoxygenation. Mechanistically, we found that MNF or another β2-agonist zinterol markedly promoted heterodimerization of β2-ARs with 5-HT2BRs. Upregulation of the heterodimerized 5-HT2BRs and β2-ARs enhanced β2-AR-stimulated Gi-Akt signaling and cardioprotection while knockdown or pharmacological inhibition of the 5-HT2BR attenuated β2-AR-stimulated Gi signaling and cardioprotection. CONCLUSIONS These data demonstrate that the β2-AR-stimulated cardioprotective Gi signaling depends on the heterodimerization of β2-ARs and 5-HT2BRs.
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MESH Headings
- Adrenergic beta-2 Receptor Agonists/pharmacology
- Animals
- Cardiomyopathies/chemically induced
- Cardiomyopathies/metabolism
- Cardiomyopathies/pathology
- Cardiomyopathies/prevention & control
- Cardiotoxicity
- Cell Death/drug effects
- Cells, Cultured
- Disease Models, Animal
- Doxorubicin
- Ethanolamines/pharmacology
- Fenoterol/analogs & derivatives
- Fenoterol/pharmacology
- Fibrosis
- Hydrogen Peroxide
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Myocardial Reperfusion Injury/metabolism
- Myocardial Reperfusion Injury/pathology
- Myocardial Reperfusion Injury/prevention & control
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Protein Multimerization
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT2B/genetics
- Receptor, Serotonin, 5-HT2B/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction
- Mice
- Rats
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Affiliation(s)
- Ying Song
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
| | - Chanjuan Xu
- Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China (C.X., J.L.)
| | - Jianfeng Liu
- Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China (C.X., J.L.)
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China (Y.L., H.W.)
- Peking-Tsinghua Center for Life Sciences, Beijing, China (Y.L., H.W., R.-P.X.)
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China (Y.L., H.W.)
| | - Huan Wang
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
| | - Dan Shan
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
| | | | - Xinli Hu
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
| | - Yan Zhang
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
| | - Anthony Yiu-Ho Woo
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, China (A.Y.-H.W.)
| | - Rui-Ping Xiao
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, China (Y.S., D.S., X.H., Y.Z., A.Y.-H.W., R.-P.X.)
- Peking-Tsinghua Center for Life Sciences, Beijing, China (Y.L., H.W., R.-P.X.)
- Beijing City Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, China (R.-P.X.)
- PKU-Nanjing Institute of Translational Medicine, China (R.-P.X.)
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5
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Ma XE, Liu B, Zhao CX. Modulation of Ca 2+-induced Ca 2+ release by ubiquitin protein ligase E3 component n-recognin UBR3 and 6 in cardiac myocytes. Channels (Austin) 2020; 14:326-335. [PMID: 32988261 PMCID: PMC7757829 DOI: 10.1080/19336950.2020.1824957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Ca2+-induced Ca2+ release (CICR) from sarcoplasmic reticulum is a finely tuned process responsible for cardiac excitation and contraction. The ubiquitin–proteasome system (UPS) as a major degradative system plays a crucial role in the maintenance of Ca2+ homeostasis. The E3 component N-recognin (UBR) subfamily is a part of the UPS; however, the role of UBR in regulating cardiac CICR is unknown. In the present study, we found that among the UBR family, single knockdown of UBR3 or UBR6 significantly elevated the amplitude of sarcoplasmic reticulum Ca2+ release without affecting Ca2+ transient decay time in neonatal rat ventricular myocytes. The protein expression of alpha 1 C subunit of L-type voltage-dependent Ca2+ channel (Cav1.2) was increased after UBR3/6 knockdown, whereas the protein levels of RyR2, SERCA2a, and PLB remained unchanged. In line with the increase in Cav1.2 proteins, the UBR3/6 knockdown enhanced the current of Cav1.2 channels. Furthermore, the increase in Cav1.2 proteins caused by UBR3/6 reduction was not counteracted by a protein biosynthesis inhibitor, cycloheximide, suggesting a degradative regulation of UBR3/6 on Cav1.2 channels. Our results indicate that UBR3/6 modulates cardiac CICR via targeting Cav1.2 protein degradation.
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Affiliation(s)
- Xiu-E Ma
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine , Shanghai, China
| | - Bei Liu
- Department of Cardiology, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University , Shanghai, China
| | - Chun-Xia Zhao
- Department of Cardiology, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University , Shanghai, China
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6
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Minervini G, Pennuto M, Tosatto SCE. The pVHL neglected functions, a tale of hypoxia-dependent and -independent regulations in cancer. Open Biol 2020; 10:200109. [PMID: 32603638 PMCID: PMC7574549 DOI: 10.1098/rsob.200109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The von Hippel–Lindau protein (pVHL) is a tumour suppressor mainly known for its role as master regulator of hypoxia-inducible factor (HIF) activity. Functional inactivation of pVHL is causative of the von Hippel–Lindau disease, an inherited predisposition to develop different cancers. Due to its impact on human health, pVHL has been widely studied in the last few decades. However, investigations mostly focus on its role in degrading HIFs, whereas alternative pVHL protein–protein interactions and functions are insistently surfacing in the literature. In this review, we analyse these almost neglected functions by dissecting specific conditions in which pVHL is proposed to have differential roles in promoting cancer. We reviewed its role in regulating phosphorylation as a number of works suggest pVHL to act as an inhibitor by either degrading or promoting downregulation of specific kinases. Further, we summarize hypoxia-dependent and -independent pVHL interactions with multiple protein partners and discuss their implications in tumorigenesis.
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Affiliation(s)
- Giovanni Minervini
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| | - Maria Pennuto
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.,Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy
| | - Silvio C E Tosatto
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
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7
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Rambacher KM, Moniri NH. Cysteine redox state regulates human β2-adrenergic receptor binding and function. Sci Rep 2020; 10:2934. [PMID: 32076070 PMCID: PMC7031529 DOI: 10.1038/s41598-020-59983-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 02/05/2020] [Indexed: 01/08/2023] Open
Abstract
Bronchoconstrictive airway disorders such as asthma are characterized by inflammation and increases in reactive oxygen species (ROS), which produce a highly oxidative environment. β2-adrenergic receptor (β2AR) agonists are a mainstay of clinical therapy for asthma and provide bronchorelaxation upon inhalation. We have previously shown that β2AR agonism generates intracellular ROS, an effect that is required for receptor function, and which post-translationally oxidizes β2AR cysteine thiols to Cys-S-sulfenic acids (Cys-S-OH). Furthermore, highly oxidative environments can irreversibly oxidize Cys-S-OH to Cys-S-sulfinic (Cys-SO2H) or S-sulfonic (Cys-SO3H) acids, which are incapable of further participating in homeostatic redox reactions (i.e., redox-deficient). The aim of this study was to examine the vitality of β2AR-ROS interplay and the resultant functional consequences of β2AR Cys-redox in the receptors native, oxidized, and redox-deficient states. Here, we show for the first time that β2AR can be oxidized to Cys-S-OH in situ, moreover, using both clonal cells and a human airway epithelial cell line endogenously expressing β2AR, we show that receptor redox state profoundly influences β2AR orthosteric ligand binding and downstream function. Specifically, homeostatic β2AR redox states are vital toward agonist-induced cAMP formation and subsequent CREB and G-protein-dependent ERK1/2 phosphorylation, in addition to β-arrestin-2 recruitment and downstream arrestin-dependent ERK1/2 phosphorylation and internalization. On the contrary, redox-deficient β2AR states exhibit decreased ability to signal via either Gαs or β-arrestin. Together, our results demonstrate a β2AR-ROS redox axis, which if disturbed, interferes with proper receptor function.
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Affiliation(s)
- Kalyn M Rambacher
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA30341, United States
| | - Nader H Moniri
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA30341, United States.
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8
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Rambacher KM, Moniri NH. The β2-adrenergic receptor-ROS signaling axis: An overlooked component of β2AR function? Biochem Pharmacol 2019; 171:113690. [PMID: 31697929 DOI: 10.1016/j.bcp.2019.113690] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/31/2019] [Indexed: 02/07/2023]
Abstract
β2-Adrenergic receptor (β2AR) agonists are clinically used to elicit rapid bronchodilation for the treatment of bronchospasms in pulmonary diseases such as asthma and COPD, both of which exhibit characteristically high levels of reactive oxygen species (ROS); likely secondary to over-expression of ROS generating enzymes and chronically heightened inflammation. Interestingly, β2AR has long-been linked to ROS, yet the involvement of ROS in β2AR function has not been as vigorously studied as other aspects of β2AR signaling. Herein, we discuss the existing body of evidence linking β2AR activation to intracellular ROS generation and importantly, the role of ROS in regulating β2AR function. The reciprocal interplay of the β2AR and ROS appear to endow this receptor with the ability to self-regulate signaling efficacy and ligand binding, hereby unveiling a redox-axis that may be unfavorably altered in pathological states contributing to both disease progression and therapeutic drug responses.
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Affiliation(s)
- Kalyn M Rambacher
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, USA
| | - Nader H Moniri
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, USA.
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9
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Cook RF, Bussey CT, Fomison‐Nurse IC, Hughes G, Bahn A, Cragg PA, Lamberts RR. β
2
‐Adrenoceptors indirectly support impaired β
1
‐adrenoceptor responsiveness in the isolated type 2 diabetic rat heart. Exp Physiol 2019; 104:808-818. [DOI: 10.1113/ep087437] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/18/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Rosalind F. Cook
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Carol T. Bussey
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Ingrid C. Fomison‐Nurse
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Gillian Hughes
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Andrew Bahn
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Patricia A. Cragg
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Regis R. Lamberts
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
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10
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Bussey CT, Thaung HPA, Hughes G, Bahn A, Lamberts RR. Cardiac β-adrenergic responsiveness of obese Zucker rats: The role of AMPK. Exp Physiol 2018; 103:1067-1075. [PMID: 29873129 DOI: 10.1113/ep087054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/30/2018] [Indexed: 01/30/2023]
Abstract
NEW FINDINGS What is the central question of the study? Is the reduced signalling of AMP-activated protein kinase (AMPK), a key regulator of energy homeostasis in the heart, responsible for the reduced β-adrenergic responsiveness of the heart in obesity? What is the main finding and its importance? Inhibition of AMPK in isolated hearts prevented the reduced cardiac β-adrenergic responsiveness of obese rats, which was accompanied by reduced phosphorylation of AMPK, a proxy of AMPK activity. This suggests a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart, and it suggests that AMPK might be an important target to restore the β-adrenergic responsiveness in the heart in obesity. ABSTRACT The obesity epidemic impacts heavily on cardiovascular health, in part owing to changes in cardiac metabolism. AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis in the heart and is regulated by β-adrenoceptors (β-ARs) in normal conditions. In obesity, chronic sympathetic overactivation leads to impaired cardiac β-AR responsiveness, although it is unclear whether AMPK signalling, downstream of β-ARs, contributes to this dysfunction. Therefore, we aimed to determine whether reduced AMPK signalling is responsible for the reduced β-AR responsiveness in obesity. In isolated hearts of lean and obese Zucker rats, we tested β-AR responsiveness to the β1 -AR agonist isoprenaline (ISO, 1 × 10-10 to 5 × 10-8 m) in the absence and presence of the AMPK inhibitor, compound C (CC, 10 μm). The β1 -AR expression and AMPK phosphorylation were assessed by Western blot. β-Adrenergic responsiveness was reduced in the hearts of obese rats (logEC50 of ISO-developed pressure dose-response curves: lean -8.53 ± 0.13 × 10x m versus obese -8.35 ± 0.10 × 10x m ; P < 0.05 lean versus obese, n = 6 per group). This difference was not apparent after AMPK inhibition (logEC50 of ISO-developed pressure curves: lean CC -8.19 ± 0.12 × 10x m versus obese CC 8.17 ± 0.13 × 10x m, P < 0.05, n = 6 per group). β1 -Adrenergic receptor expression and AMPK phosphorylation were reduced in hearts of obese rats (AMPK at Thr172 : lean 1.73 ± 0.17 a.u. versus lean CC 0.81 ± 0.13 a.u., and obese 1.18 ± 0.09 a.u. versus obese CC 0.81 ± 0.16 a.u., P < 0.05, n = 6 per group). Thus, a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart exists, and AMPK might be an important target to restore the reduced cardiac β-adrenergic responsiveness in obesity.
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Affiliation(s)
- Carol T Bussey
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - H P Aye Thaung
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew Bahn
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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11
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Cook RF, Bussey CT, Mellor KM, Cragg PA, Lamberts RR. β1-Adrenoceptor, but not β2-adrenoceptor, subtype regulates heart rate in type 2 diabetic ratsin vivo. Exp Physiol 2017; 102:911-923. [DOI: 10.1113/ep086293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/16/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Rosalind F. Cook
- Department of Physiology, Otago School of Medical Sciences, HeartOtago; University of Otago; Dunedin New Zealand
| | - Carol T. Bussey
- Department of Physiology, Otago School of Medical Sciences, HeartOtago; University of Otago; Dunedin New Zealand
| | - Kimberley M. Mellor
- Department of Physiology, Faculty of Medical and Health Sciences; University of Auckland; Auckland New Zealand
| | - Patricia A. Cragg
- Department of Physiology, Otago School of Medical Sciences, HeartOtago; University of Otago; Dunedin New Zealand
| | - Regis R. Lamberts
- Department of Physiology, Otago School of Medical Sciences, HeartOtago; University of Otago; Dunedin New Zealand
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12
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Odnoshivkina UG, Sytchev VI, Nurullin LF, Giniatullin AR, Zefirov AL, Petrov AM. β2-adrenoceptor agonist-evoked reactive oxygen species generation in mouse atria: implication in delayed inotropic effect. Eur J Pharmacol 2015; 765:140-53. [PMID: 26297975 DOI: 10.1016/j.ejphar.2015.08.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/05/2015] [Accepted: 08/17/2015] [Indexed: 12/20/2022]
Abstract
Fenoterol, a β2-adrenoceptor agonist, has anti-apoptotic action in cardiomyocytes and induces a specific pattern of downstream signaling. We have previously reported that exposure to fenoterol (5 μM) results in a delayed positive inotropic effect which is related to changes in both Ca2+ transient and NO. Here, the changes in reactive oxygen species (ROS) production in response to the fenoterol administration and the involvement of ROS in effect of this agonist on contractility were investigated in mouse isolated atria. Stimulation of β2-adrenoceptor increases a level of extracellular ROS, while intracellular ROS level rises only after removal of fenoterol from the bath. NADPH-oxidase inhibitor (apocynin) prevents the increase in ROS production and the Nox2 isoform is immunofluorescently colocalized with β2-adrenoceptor at the atrial myocytes. Treatments with antioxidants (N-acetyl-L-cysteine, NADPH inhibitors, exogenous catalases) significantly inhibit the fenoterol induced increase in the contraction amplitude, probably by attenuating Ca2+ transient and up-regulating NO production. ROS generated in a β2-adrenoceptor-dependent manner can potentiate the activity of some Ca2+ channels. Indeed, inhibition of ryanodine receptors, TRPV-or L-type Ca2+- channels shows a similar efficacy in reduction of positive inotropic effect of both fenoterol and H2O2. In addition, detection of mitochondrial ROS indicates that fenoterol triggers a slow increase in ROS which is prevented by rotenone, but rotenone has no impact on the inotropic effect of fenoterol. We suggest that stimulation of β2-adrenoceptor with fenoterol causes the activation of NADPH-oxidase and after the agonist removal extracellularly generated ROS penetrates into the cell, increasing the atrial contractions probably via Ca2+ channels.
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Affiliation(s)
- Ulia G Odnoshivkina
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Vaycheslav I Sytchev
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Leniz F Nurullin
- Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center of Russian Academy of Sciences, Laboratory of Biophysics of Synaptic Processes, Lobatchevsky str. 2/31, P.O. 30, Kazan 420111, Russia
| | - Arthur R Giniatullin
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Andrei L Zefirov
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia
| | - Alexey M Petrov
- Department of Normal Physiology, Kazan State Medical University, Butlerova st., 49, Kazan 420012, Russia.
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13
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Thaung HPA, Baldi JC, Wang HY, Hughes G, Cook RF, Bussey CT, Sheard PW, Bahn A, Jones PP, Schwenke DO, Lamberts RR. Increased Efferent Cardiac Sympathetic Nerve Activity and Defective Intrinsic Heart Rate Regulation in Type 2 Diabetes. Diabetes 2015; 64:2944-56. [PMID: 25784543 DOI: 10.2337/db14-0955] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 03/09/2015] [Indexed: 11/13/2022]
Abstract
Elevated sympathetic nerve activity (SNA) coupled with dysregulated β-adrenoceptor (β-AR) signaling is postulated as a major driving force for cardiac dysfunction in patients with type 2 diabetes; however, cardiac SNA has never been assessed directly in diabetes. Our aim was to measure the sympathetic input to and the β-AR responsiveness of the heart in the type 2 diabetic heart. In vivo recording of SNA of the left efferent cardiac sympathetic branch of the stellate ganglion in Zucker diabetic fatty rats revealed an elevated resting cardiac SNA and doubled firing rate compared with nondiabetic rats. Ex vivo, in isolated denervated hearts, the intrinsic heart rate was markedly reduced. Contractile and relaxation responses to β-AR stimulation with dobutamine were compromised in externally paced diabetic hearts, but not in diabetic hearts allowed to regulate their own heart rate. Protein levels of left ventricular β1-AR and Gs (guanine nucleotide binding protein stimulatory) were reduced, whereas left ventricular and right atrial β2-AR and Gi (guanine nucleotide binding protein inhibitory regulatory) levels were increased. The elevated resting cardiac SNA in type 2 diabetes, combined with the reduced cardiac β-AR responsiveness, suggests that the maintenance of normal cardiovascular function requires elevated cardiac sympathetic input to compensate for changes in the intrinsic properties of the diabetic heart.
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Affiliation(s)
- H P Aye Thaung
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - J Chris Baldi
- Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Heng-Yu Wang
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Rosalind F Cook
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Carol T Bussey
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Phil W Sheard
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew Bahn
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Peter P Jones
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Daryl O Schwenke
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
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14
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Zhao C, Wang L, Ma X, Zhu W, Yao L, Cui Y, Liu Y, Li J, Liang X, Sun Y, Li L, Chen YH. Cardiac Nav 1.5 is modulated by ubiquitin protein ligase E3 component n-recognin UBR3 and 6. J Cell Mol Med 2015; 19:2143-52. [PMID: 26059563 PMCID: PMC4568919 DOI: 10.1111/jcmm.12588] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 03/03/2015] [Indexed: 11/29/2022] Open
Abstract
The voltage-gated Na+ channel Nav1.5 is essential for action potential (AP) formation and electrophysiological homoeostasis in the heart. The ubiquitin–proteasome system (UPS) is a major degradative system for intracellular proteins including ion channels. The ubiquitin protein ligase E3 component N-recognin (UBR) family is a part of the UPS; however, their roles in regulating cardiac Nav1.5 channels remain elusive. Here, we found that all of the UBR members were expressed in cardiomyocytes. Individual knockdown of UBR3 or UBR6, but not of other UBR members, significantly increased Nav1.5 protein levels in neonatal rat ventricular myocytes, and this effect was verified in HEK293T cells expressing Nav1.5 channels. The UBR3/6-dependent regulation of Nav1.5 channels was not transcriptionally mediated, and pharmacological inhibition of protein biosynthesis failed to counteract the increase in Nav1.5 protein caused by UBR3/6 reduction, suggesting a degradative modulation of UBR3/6 on Nav1.5. Furthermore, the effects of UBR3/6 knockdown on Nav1.5 proteins were abolished under the inhibition of proteasome activity, and UBR3/6 knockdown reduced Nav1.5 ubiquitylation. The double UBR3–UBR6 knockdown resulted in comparable increases in Nav1.5 proteins to that observed for single knockdown of either UBR3 or UBR6. Electrophysiological recordings showed that UBR3/6 reduction-mediated increase in Nav1.5 protein enhanced the opening of Nav1.5 channels and thereby the amplitude of the AP. Thus, our findings indicate that UBR3/6 regulate cardiomyocyte Nav1.5 channel protein levels via the ubiquitin–proteasome pathway. It is likely that UBR3/6 have the potential to be a therapeutic target for cardiac arrhythmias.
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Affiliation(s)
- Chunxia Zhao
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Lijie Wang
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiue Ma
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Weidong Zhu
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China
| | - Lei Yao
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China
| | - Yingyu Cui
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China.,Institute of Medical Genetics, Tongji University, Shanghai, China
| | - Yi Liu
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Institute of Medical Genetics, Tongji University, Shanghai, China
| | - Jun Li
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Institute of Medical Genetics, Tongji University, Shanghai, China
| | - Xingqun Liang
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China
| | - Yunfu Sun
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China
| | - Li Li
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China.,Institute of Medical Genetics, Tongji University, Shanghai, China
| | - Yi-Han Chen
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.,Research Center for Translational Medicine, Tongji University School of Medicine, Shanghai, China.,Department of Pathology and Pathophysiology, Tongji University School of Medicine, Shanghai, China.,Institute of Medical Genetics, Tongji University, Shanghai, China
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15
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Imbrogno S, Gattuso A, Mazza R, Angelone T, Cerra MC. β3 -AR and the vertebrate heart: a comparative view. Acta Physiol (Oxf) 2015; 214:158-75. [PMID: 25809182 DOI: 10.1111/apha.12493] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/04/2014] [Accepted: 03/16/2015] [Indexed: 01/13/2023]
Abstract
Recent cardiovascular research showed that, together with β1- and β2-adrenergic receptors (ARs), β3-ARs contribute to the catecholamine (CA)-dependent control of the heart. β3-ARs structure, function and ligands were investigated in mammals because of their applicative potential in human cardiovascular diseases. Only recently, the concept of a β3-AR-dependent cardiac modulation was extended to non-mammalian vertebrates, although information is still scarce and fragmentary. β3-ARs were structurally described in fish, showing a closer relationship to mammalian β1-AR than β2-AR. Functional β3-ARs are present in the cardiac tissue of teleosts and amphibians. As in mammals, activation of these receptors elicits a negative modulation of the inotropic performance through the involvement of the endothelium endocardium (EE), Gi/0 proteins and the nitric oxide (NO) signalling. This review aims to comparatively analyse data from literature on β3-ARs in mammals, with those on teleosts and amphibians. The purpose is to highlight aspects of uniformity and diversity of β3-ARs structure, ligands activity, function and signalling cascades throughout vertebrates. This may provide new perspectives aimed to clarify the biological relevance of β3-ARs in the context of the nervous and humoral control of the heart and its functional plasticity.
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Affiliation(s)
- S. Imbrogno
- Department of Biology, Ecology and Earth Sciences; University of Calabria; Arcavacata di Rende Italy
| | - A. Gattuso
- Department of Biology, Ecology and Earth Sciences; University of Calabria; Arcavacata di Rende Italy
| | - R. Mazza
- Department of Biology, Ecology and Earth Sciences; University of Calabria; Arcavacata di Rende Italy
| | - T. Angelone
- Department of Biology, Ecology and Earth Sciences; University of Calabria; Arcavacata di Rende Italy
- National Institute of Cardiovascular Research; Bologna Italy
| | - M. C. Cerra
- Department of Biology, Ecology and Earth Sciences; University of Calabria; Arcavacata di Rende Italy
- National Institute of Cardiovascular Research; Bologna Italy
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16
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Sun Y, Wang Y, Zhang L, Xu C, Liu Y, Kang S, Yan C, Li D, Sun H. Prevention of cardiac events caused by surgical stress in aged rats: simultaneously activating β2-adrenoceptor and inhibiting β1-adrenoceptor. Stress 2014; 17:373-81. [PMID: 24754893 DOI: 10.3109/10253890.2014.915392] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Increased plasma catecholamine levels are associated with a high risk of perioperative cardiac events in aged individuals undergoing non-cardiac surgical interventions. Given the different effects of β1-adrenoreceptor (β1AR) and β2-adrenoreceptor (β2AR) stimulation by catecholamine in cardiomyocytes, this study evaluated whether simultaneous inhibition of β1AR and activation of β2AR is better than separate application in reducing the risk of perioperative cardiac events in aged rats undergoing non-cardiac surgery. Male aged Sprague-Dawley (SD) rats were divided into five groups. Normal group received no treatment. Surgery group received an abdominal surgery with hypoxia. β1- group, β2+ group, β2+ group and β1+β2+ group received surgery and hypoxia with metoprolol (100 mg/kg·d), fenoterol (250 μg/kg·d) or both, respectively. The drugs were given three days before surgery with treatment continued through post-surgical day 7. The results showed that simultaneous activation of β2AR with a β2AR agonist and inhibition of β1AR with a selective β1AR blocker normalized myocardial oxygen consumption, decreased myocardial damage, augmented cardiomyocyte survival, improved cardiac function, reduced the incidence of arrhythmia, thus decreasing the occurrence of cardiac events in perioperative aged rats undergoing non-cardiac surgery. The results demonstrated that combined use of β2AR agonist and β1AR blocker achieved better general effects than use of either one alone. Our results provide a new insight into preventing perioperative cardiac events for elderly patients undergoing surgical stress.
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17
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Yamazaki S, Miyoshi N, Kawabata K, Yasuda M, Shimoi K. Quercetin-3-O-glucuronide inhibits noradrenaline-promoted invasion of MDA-MB-231 human breast cancer cells by blocking β₂-adrenergic signaling. Arch Biochem Biophys 2014; 557:18-27. [PMID: 24929186 DOI: 10.1016/j.abb.2014.05.030] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 05/16/2014] [Accepted: 05/27/2014] [Indexed: 01/31/2023]
Abstract
Endogenous catecholamines such as adrenaline (A) and noradrenaline (NA) are released from the adrenal gland and sympathetic nervous system during exposure to stress. The adrenergic system plays a central role in stress signaling, and excessive stress was found to be associated with increased production of reactive oxygen species (ROS). Overproduction of ROS induces oxidative damage in tissues and causes the development of diseases such as cancer. In this study, we investigated the effects of quercetin-3-O-glucuronide (Q3G), a circulating metabolite of quercetin, which is a type of natural flavonoid, on the catecholamine-induced β2-adrenergic receptor (β2-AR)-mediated response in MDA-MB-231 human breast cancer cells expressing β2-AR. Treatment with A or NA at concentrations above 1μM generated significant levels of ROS, and NA treatment induced the gene expression of heme oxygenase-1 (HMOX1), and matrix metalloproteinase-2 (MMP-2) and -9 (MMP9). Inhibitors of p38 MAP kinase (SB203580), cAMP-dependent protein kinase (PKA) (H-89), activator protein-1 (AP-1) transcription factor (SR11302), and NF-κB and AP-1 (Tanshinone IIA) decreased MMP2 and MMP9 gene expression. NA also enhanced cAMP induction, RAS activation and phosphorylation of ERK1/2. These results suggested that the cAMP-PKA, MAPK, and ROS-NF-κB pathways are involved in β2-AR signaling. Treatment with 0.1μM Q3G suppressed ROS generation, cAMP and RAS activation, phosphorylation of ERK1/2 and the expression of HMOX1, MMP2, and MMP9 genes. Furthermore, Q3G (0.1μM) suppressed invasion of MDA-MB-231 breast cancer cells and MMP-9 induction, and inhibited the binding of [(3)H]-NA to β2-AR. These results suggest that Q3G may function to suppress invasion of breast cancer cells by controlling β2-adrenergic signaling, and may be a dietary chemopreventive factor for stress-related breast cancer.
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Affiliation(s)
- Shunsuke Yamazaki
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Noriyuki Miyoshi
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kyuichi Kawabata
- Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195, Japan
| | - Michiko Yasuda
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kayoko Shimoi
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan; Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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18
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Anavi S, Hahn-Obercyger M, Madar Z, Tirosh O. Mechanism for HIF-1 activation by cholesterol under normoxia: a redox signaling pathway for liver damage. Free Radic Biol Med 2014; 71:61-69. [PMID: 24632196 DOI: 10.1016/j.freeradbiomed.2014.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 02/03/2014] [Accepted: 03/04/2014] [Indexed: 12/12/2022]
Abstract
Cholesterol and chronic activation of hypoxia-inducible factor-1 (HIF-1) have been separately implicated in the pathogenesis and progression of liver diseases. In AML12 hepatocytes increased HIF-1α protein accumulation was evident after 2 h of incubation with cholesterol, whereas enhanced HIF-1 transcriptional activity was observed after 6 h. Investigations into the molecular mechanism have shown that cholesterol inhibited HIF-1α degradation. Mitochondrial dysfunction and enhanced mitochondrial reactive oxygen species (ROS) generation were observed in 2-h cholesterol-treated cells along with augmented nitric oxide (NO) levels. Further analysis indicated that HIF-1α stabilization at later time (6h), but not after 2h, of incubation with cholesterol was dependent on NO production. To elucidate the role of mitochondrial dysfunction in HIF-1α stabilization, mitochondrial DNA-depleted hepatocytes were prepared. In these cells the ability of cholesterol to activate the HIF-1 pathway was abolished. Similarly, catalase overexpression also attenuated cholesterol-induced HIF-1α accumulation. These results demonstrate that cholesterol promotes HIF-1 activation in a ROS- and NO-dependent manner. Chronic liver activation of HIF-1 by cholesterol may mediate its deleterious effects in the liver.
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Affiliation(s)
- Sarit Anavi
- The Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Michal Hahn-Obercyger
- The Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Zecharia Madar
- The Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Oren Tirosh
- The Robert H. Smith Faculty of Agriculture, Food, and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
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19
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Kwon HJ, Ohmiya Y, Yasuda K. Simultaneous monitoring of intracellular ATP and oxygen levels in chondrogenic differentiation using a dual-color bioluminescence reporter. LUMINESCENCE 2013; 29:1194-8. [PMID: 24150901 DOI: 10.1002/bio.2598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 07/17/2013] [Accepted: 09/09/2013] [Indexed: 01/08/2023]
Abstract
A number of assay methods which measure cellular metabolic activity have only measured intracellular ATP levels because it has been speculated that ATP production and oxygen consumption are obligatorily coupled to each other under normal conditions. However, there exist many cases in which ATP production and oxygen consumption are uncoupled. Therefore, measurement of only intracellular ATP levels has a limit for understanding the overall metabolic states during various cellular functions. Here, we report a novel system for simultaneously monitoring intracellular ATP and oxygen levels using a red-emitting Phrixothrix hirtus luciferase (PxRe) and a blue-emitting Renilla luciferase (Rluc). Using this system, we monitored the dynamic changes in both intracellular ATP and oxygen levels during chondrogenesis. We found that the oxygen level oscillated at twice the frequency of ATP in chondrogenesis and the oxygen oscillations have an antiphase mode to the ATP oscillations; we also found an independent mode for the ATP oscillations. This result indicates that both mitochondrial and non-mitochondrial respiration oscillate and thus play a role in chondrogenesis. This dual-color monitoring system is useful for studying metabolic regulations that underlie diverse cellular processes.
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Affiliation(s)
- Hyuck Joon Kwon
- Department of Physical Therapy, College of Health Science, Eulji University, Gyeonggi-do, Korea
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20
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Ciccarelli M, Santulli G, Pascale V, Trimarco B, Iaccarino G. Adrenergic receptors and metabolism: role in development of cardiovascular disease. Front Physiol 2013; 4:265. [PMID: 24106479 PMCID: PMC3789271 DOI: 10.3389/fphys.2013.00265] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/08/2013] [Indexed: 01/08/2023] Open
Abstract
Activation of the adrenergic system has a profound effects on metabolism. Increased circulating catecholamine and activation of the different adrenergic receptors deployed in the various organs produce important metabolic responses which include: (1) increased lipolysis and elevated levels of fatty acids in plasma, (2) increased gluconeogenesis by the liver to provide substrate for the brain, and (3) moderate inhibition of insulin release by the pancreas to conserve glucose and to shift fuel metabolism of muscle in the direction of fatty acid oxidation. These physiological responses, typical of the stress conditions, are demonstrated to be detrimental for the functioning of different organs like the cardiac muscle when they become chronic. Indeed, a common feature of many pathological conditions involving over-activation of the adrenergic system is the development of metabolic alterations which can include insulin resistance, altered glucose and lipid metabolism and mitochondrial dysfunction. These patterns are involved with a variably extent among the different pathologies, however, they are in general strictly correlated to the level of activation of the adrenergic system. Here we will review the effects of the different adrenergic receptors subtypes on the metabolic variation observed in important disease like Heart Failure.
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Affiliation(s)
- Michele Ciccarelli
- Department of Medicine and Surgery, University of Salerno Salerno, Italy ; Center for Translational Medicine, Department of Pharmacology, Temple University of Philadelphia PA, USA
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21
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Peterson YK, Cameron RB, Wills LP, Trager RE, Lindsey CC, Beeson CC, Schnellmann RG. β2-Adrenoceptor agonists in the regulation of mitochondrial biogenesis. Bioorg Med Chem Lett 2013; 23:5376-81. [PMID: 23954364 DOI: 10.1016/j.bmcl.2013.07.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 01/14/2023]
Abstract
The stimulation of mitochondrial biogenesis (MB) via cell surface G-protein coupled receptors is a promising strategy for cell repair and regeneration. Here we report the specificity and chemical rationale of a panel of β2-adrenoceptor agonists with regards to MB. Using primary cultures of renal cells, a diverse panel of β2-adrenoceptor agonists elicited three distinct phenotypes: full MB, partial MB, and non-MB. Full MB compounds had efficacy in the low nanomolar range and represent two chemical scaffolds containing three distinct chemical clusters. Interestingly, the MB phenotype did not correlate with reported receptor affinity or chemical similarity. Chemical clusters were then subjected to pharmacophore modeling creating two models with unique and distinct features, consisting of five conserved amongst full MB compounds were identified. The two discrete pharmacophore models were coalesced into a consensus pharmacophore with four unique features elucidating the spatial and chemical characteristics required to stimulate MB.
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Affiliation(s)
- Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States
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22
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Yaniv Y, Spurgeon HA, Ziman BD, Lyashkov AE, Lakatta EG. Mechanisms that match ATP supply to demand in cardiac pacemaker cells during high ATP demand. Am J Physiol Heart Circ Physiol 2013; 304:H1428-38. [PMID: 23604710 DOI: 10.1152/ajpheart.00969.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The spontaneous action potential (AP) firing rate of sinoatrial node cells (SANCs) involves high-throughput signaling via Ca(2+)-calmodulin activated adenylyl cyclases (AC), cAMP-mediated protein kinase A (PKA), and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent phosphorylation of SR Ca(2+) cycling and surface membrane ion channel proteins. When the throughput of this signaling increases, e.g., in response to β-adrenergic receptor activation, the resultant increase in spontaneous AP firing rate increases the demand for ATP. We hypothesized that an increase of ATP production to match the increased ATP demand is achieved via a direct effect of increased mitochondrial Ca(2+) (Ca(2+)m) and an indirect effect via enhanced Ca(2+)-cAMP/PKA-CaMKII signaling to mitochondria. To increase ATP demand, single isolated rabbit SANCs were superfused by physiological saline at 35 ± 0.5°C with isoproterenol, or by phosphodiesterase or protein phosphatase inhibition. We measured cytosolic and mitochondrial Ca(2+) and flavoprotein fluorescence in single SANC, and we measured cAMP, ATP, and O₂ consumption in SANC suspensions. Although the increase in spontaneous AP firing rate was accompanied by an increase in O₂ consumption, the ATP level and flavoprotein fluorescence remained constant, indicating that ATP production had increased. Both Ca(2+)m and cAMP increased concurrently with the increase in AP firing rate. When Ca(2+)m was reduced by Ru360, the increase in spontaneous AP firing rate in response to isoproterenol was reduced by 25%. Thus, both an increase in Ca(2+)m and an increase in Ca(2+) activated cAMP-PKA-CaMKII signaling regulate the increase in ATP supply to meet ATP demand above the basal level.
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Affiliation(s)
- Yael Yaniv
- Laboratory of Cardiovascular Science, Gerontology Research Center, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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Flint MS, Baum A, Episcopo B, Knickelbein KZ, Liegey Dougall AJ, Chambers WH, Jenkins FJ. Chronic exposure to stress hormones promotes transformation and tumorigenicity of 3T3 mouse fibroblasts. Stress 2013; 16:114-21. [PMID: 22506837 PMCID: PMC3652531 DOI: 10.3109/10253890.2012.686075] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epinephrine and norepinephrine are produced during psychological stress and can directly bind to cells to induce DNA damage. These effects may have more long-lasting consequences such as DNA mutations resulting in an increased potential for cellular transformation and/or tumor progression. This study examined the molecular effects of a chronic (24 h) in vitro exposure to these stress hormones on murine 3T3 cells. Long exposures (24 h) in dose-response experiments with norepinephrine or epinephrine induced significant increases in DNA damage in treated cells compared to that of untreated controls as measured by the alkaline comet assay. Pre-treatment with a blocking agent (the β-adrenergic receptor antagonist propranolol) eliminated this increase in damage. In addition, both norepinephrine and epinephrine increased cellular transformation, as assessed by growth in soft agar, and 3T3 cells pre-treated with either norepinephrine or epinephrine induced a more rapid onset of tumors and more aggressive tumor growth in nude mice. In summary, incubation of 3T3 cells with catecholamines results in long-term DNA damage as measured by increased transformed phenotypes and tumor progression, indicating that they are important mediators of stress effects on genomic instability and vulnerability to tumor formation.
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Affiliation(s)
- Melanie S Flint
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15237, USA
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Pérez-Schindler J, Philp A, Hernandez-Cascales J. Pathophysiological relevance of the cardiac β2-adrenergic receptor and its potential as a therapeutic target to improve cardiac function. Eur J Pharmacol 2012. [PMID: 23183106 DOI: 10.1016/j.ejphar.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
β-adrenoceptors are members of the G protein-coupled receptor superfamily which play a key role in the regulation of myocardial function. Their activation increases cardiac performance but can also induce deleterious effects such as cardiac arrhythmias or myocardial apoptosis. In fact, inhibition of β-adrenoceptors exerts a protective effect in patients with sympathetic over-stimulation during heart failure. Although β(2)-adrenoceptor is not the predominant subtype in the heart, it seems to importantly contribute to the cardiac effects of adrenergic stimulation; however, the mechanism by which this occurs is not fully understood. This review summarizes the current knowledge on the role of β(2)-adrenoceptors in the regulation of cardiac contractility, metabolism, cardiomyocyte survival and cardiac arrhythmias. In addition, therapeutic considerations relating to stimulation of the β(2)-adrenoceptor such as an increase in cardiac contractility with low arrythmogenic effect, protection of the myocardium again apoptosis or positive regulation of heart metabolism are discussed.
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Prolyl hydroxylase domain protein 2 regulates the intracellular cyclic AMP level in cardiomyocytes through its interaction with phosphodiesterase 4D. Biochem Biophys Res Commun 2012; 427:73-9. [PMID: 22975349 DOI: 10.1016/j.bbrc.2012.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/03/2012] [Indexed: 01/19/2023]
Abstract
Cyclic adenosine 3',5'-monophosphate (cAMP), which is synthesized by adenylyl cyclase (AC) and degraded by phosphodiesterase (PDE), plays crucial roles in the regulation of multiple cellular functions and physiological processes. Prolyl hydroxylase domain (PHD) proteins, which belong to a family of dioxygenases that function as oxygen sensors through their hydroxylation activity, have been implicated in multiple signaling pathways. Here, we aimed to determine whether PHD played a role in regulating intracellular cAMP level in cardiomyocytes. Through the overexpression/knockdown of the PHD gene and the measurement of the cAMP content, we found that PHD2, but not PHD1 or PHD3, acts as a regulator of intracellular cAMP. In neonatal rat cardiomyocytes and H9c2 cells, the overexpression of PHD2 increased the intracellular cAMP level, whereas the PHD2 knockdown reduced it. There was no alteration in the AC expression or activity in cells that overexpressed or downregulated PHD2. The overexpression of PHD2 decreased both the protein expression and the activity of phosphodiesterase 4D (PDE4D), whereas the PHD2 knockdown increased the PDE4D expression and activity. Co-immunoprecipitation experiments revealed a direct binding between PHD2 and PDE4D and liquid chromatography-tandem mass spectrometry analyses identified the specific hydroxylation sites on PDE4D. In conclusion, PHD2 may directly interact with PDE4D to function as a novel regulator of the intracellular cAMP levels in cardiomyocytes.
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Salie R, Moolman JA, Lochner A. The mechanism of beta-adrenergic preconditioning: roles for adenosine and ROS during triggering and mediation. Basic Res Cardiol 2012; 107:281. [PMID: 22797560 DOI: 10.1007/s00395-012-0281-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 06/15/2012] [Accepted: 06/29/2012] [Indexed: 12/11/2022]
Abstract
The aim of this study was to investigate the mechanism of beta-adrenergic preconditioning (BPC). The roles of adenosine and its receptor subtypes, the generation of oxygen free radicals (ROS) and activation of the K(ATP) channels as well as the phosphoinositide-3-kinase (PI(3)K)/PKB/Akt and extracellular signal-regulated kinase (ERK) signal transduction pathways during the triggering and mediation phases were evaluated. Using the isolated working rat heart, BPC was elicited by administration of denopamine (beta1 adrenergic receptor agonist, 10(-7) M), isoproterenol (beta1/beta2 adrenergic receptor agonist, 10(-7) M) or formoterol (beta2 adrenergic receptor agonist, 10(-9) M) for 5 min followed by 5 min washout. Index ischaemia was 35 min regional ischaemia and infarct size determined using the tetrazolium method. The role of adenosine was studied using adenosine deaminase and selective antagonists as well as the PI(3)K and ERK inhibitors, wortmannin and PD98,059, bracketing the triggering and mediating phases. Involvement of ROS, PKC, the mitochondrial K(ATP) channels, release of endogenous opioids and bradykinin was studied by administration of N-acetyl cysteine (NAC), bisindolylmaleimide, the K(ATP) channel blocker 5-hydroxydecanoate (5-HD), naloxone or HOE140, respectively. Activation of PKB/Akt and ERKp44/p42 during triggering and reperfusion was determined by Western blot. Preconditioning with all three beta-adrenergic receptor agonists caused a reduction in infarct size and an improvement in postischaemic function. BPC preconditioning with isoproterenol, denopamine or formoterol was abolished by the adenosine A3 receptor antagonist MRS1191 during both the triggering and mediation phases. Isoproterenol-induced preconditioning (beta1/beta2 PC) was attenuated by MRS1754, an adenosine A(2B) receptor antagonist, during the triggering phase and abolished during reperfusion. The mediation phase of beta1/beta2 PC was also abolished by ZM241385, an adenosine A(2A) antagonist. The free radical scavenger NAC caused a significant attenuation of cardioprotection induced by isoproterenol when administered during both trigger and mediation phases, while being effective during the trigger phase with denopamine and during reperfusion in formoterol preconditioned hearts. The mitochondrial K(ATP) channel blocker, 5-HD, was without effect on beta1/beta2 PC during both triggering and mediation phases. BPC in rat hearts is dependent on activation of the A(3) adenosine receptors by endogenously produced adenosine and production of free radicals during the triggering and mediation phases while the A(2A) and A(2B) adenosine receptors participate mainly during reperfusion. The mitochondrial K(ATP) channels do not contribute to cardioprotection at any stage. Activation of ERK and PI3K/PKB/Akt during the triggering and reperfusion phases is associated with cardioprotection.
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Affiliation(s)
- Ruduwaan Salie
- Division Medical Physiology, Department Biomedical Sciences, Faculty of Health Sciences, University of Stellenbosch, Tygerberg, Republic of South Africa
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Reactive oxygen species are required for β2 adrenergic receptor-β-arrestin interactions and signaling to ERK1/2. Biochem Pharmacol 2012; 84:661-9. [PMID: 22728070 DOI: 10.1016/j.bcp.2012.06.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 06/08/2012] [Accepted: 06/13/2012] [Indexed: 12/13/2022]
Abstract
The β2-adrenergic receptor (β2AR) is the prototypical member of the heptahelical G protein-coupled receptor (GPCR) superfamily and is well-known to elicit biological effects through both G protein-dependent and G protein-independent signaling cascades. Agonism of β2AR has been described to promote phosphorylation and activation of extracellular signal-regulated kinases (ERK1/2) via a G-protein/PKA pathway that transpires rapidly upon receptor agonism, as well as by a distinct β-arrestin-mediated pathway that occurs at later time points. We have previously shown that β2AR agonism promotes generation of intracellular reactive oxygen species (ROS) and that β2AR-associated G protein signaling is dependent on ROS formation. It has also been suggested that β2AR-mediated ROS generation occurs via recruitment of β-arrestins. In this study, we confirm the effects of β-arrestin on β2AR-induced ROS generation, and investigate the ROS-dependency of β-arrestin-linked β2AR signaling. In HEK293 cells, both coimmunoprecipitation and BRET studies reveal that ROS are vital for the physical interaction of β2AR with β-arrestin partner proteins. Using phosphorylation of ERK1/2 as a functional endpoint to assess the role of ROS in β2AR-β-arrestin signaling, our results show that inhibition of intracellular ROS abrogates both the β-arrestin and G protein-mediated phosphorylation of ERK1/2 upon agonism of β2AR. Importantly, both the G protein and β-arrestin components were reversed upon exogenous administration of ROS, suggesting a critical role for oxidants in stabilization of β2AR. Taken together, our data signify that ROS serve purposeful roles in stabilizing both G protein- and β-arrestin-mediated β2AR signaling in HEK293 cells.
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Branco AF, Pereira SL, Moreira AC, Holy J, Sardão VA, Oliveira PJ. Isoproterenol cytotoxicity is dependent on the differentiation state of the cardiomyoblast H9c2 cell line. Cardiovasc Toxicol 2011; 11:191-203. [PMID: 21455642 DOI: 10.1007/s12012-011-9111-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
H9c2 cells are used as a surrogate for cardiac cells in several toxicological studies, which are usually performed with cells in their undifferentiated state, raising questions on the applicability of the results to adult cardiomyocytes. Since H9c2 myoblasts have the capacity to differentiate into skeletal and cardiac muscle cells under different conditions, the hypothesis of the present work was that cells in different differentiation states differ in their susceptibility to toxicants. In order to test the hypothesis, the effects of the cardiotoxicant isoproterenol (ISO) were investigated. The present work demonstrates that differentiated H9c2 cells are more susceptible to ISO toxicity. Cellular content of beta(1)-adrenergic receptors (AR), beta(3)-AR, and calcineurin is decreased as cells differentiate, as opposed to the content on the mitochondrial voltage-dependent anion channel (VDAC) and phosphorylated p38-MAPK, which increase. After ISO treatment, the pro-apoptotic protein Bax increases in all experimental groups, although only undifferentiated myoblasts up-regulate the anti-apoptotic Bcl-2. Calcineurin is decreased in differentiated H9c2 cells, which suggests an important role against ISO-induced cell death. The results indicate that the differentiation state of H9c2 myoblasts influence ISO toxicity, which may involve calcineurin, p38-MAPK, and Bax/Bcl-2 alterations. The data also provide new insights into cardiovascular toxicology during early development.
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MESH Headings
- Adrenergic beta-Agonists/toxicity
- Animals
- Calcineurin/metabolism
- Cell Differentiation
- Cell Line
- Dose-Response Relationship, Drug
- Isoproterenol/toxicity
- Myoblasts, Cardiac/drug effects
- Myoblasts, Cardiac/metabolism
- Myoblasts, Cardiac/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phosphorylation
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Rats
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/metabolism
- Voltage-Dependent Anion Channels/metabolism
- bcl-2-Associated X Protein/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Ana F Branco
- Center for Neuroscience and Cell Biology, Department of Life Sciences, University of Coimbra, 3004-517 Coimbra, Portugal
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Burns RN, Moniri NH. Agonist- and hydrogen peroxide-mediated oxidation of the β2 adrenergic receptor: evidence of receptor s-sulfenation as detected by a modified biotin-switch assay. J Pharmacol Exp Ther 2011; 339:914-21. [PMID: 21917560 DOI: 10.1124/jpet.111.185975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)), have recently been shown to be generated upon agonism of several members of the G protein-coupled receptor (GPCR) superfamily, including β(2)-adrenergic receptors (β(2)ARs). Previously, we have demonstrated that inhibition of intracellular ROS generation mitigates β(2)AR signaling, suggesting that β(2)AR-mediated ROS generation is capable of feeding back to regulate receptor function. Given that ROS, specifically H(2)O(2), are able to post-translationally oxidize protein cysteine sulfhydryls to cysteine-sulfenic acids, the goal of the current study was to assess whether ROS are capable of S-sulfenating β(2)AR. Using a modified biotin-switch assay that is selective for cysteine-sulfenic acids, our results demonstrate for the first time that H(2)O(2) treatment facilitates S-sulfenation of transiently overexpressed β(2)AR in human embryonic kidney 293 cells. It is noteworthy that stimulation of cells with the β-agonist isoproterenol produces both dose- and time-dependent S-sulfenation of β(2)AR, an effect that is receptor-dependent, and demonstrates that receptor-generated ROS are also capable of oxidizing the β(2)AR. Receptor-dependent S-sulfenation was inhibited by the chemoselective sulfenic acid alkylator dimedone and the cysteine antioxidant N-acetyl-l-cysteine. Moreover, our results reveal that receptor oxidation occurs in cells that endogenously express physiologically relevant levels of β(2)AR, because treatment of human alveolar epithelial A549 cells with either H(2)O(2) or the β(2)-selective agonist formoterol promoted receptor S-sulfenation. These findings provide the first evidence, to our knowledge, that a mammalian GPCR can be oxidized by S-sulfenation and signify an important first step toward shedding light on the overlooked role of ROS in the regulation of β(2)AR function.
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Affiliation(s)
- Rebecca N Burns
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Mercer University, 3001 Mercer University Drive, Atlanta, GA 30341, USA
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Day RM, Lee YH, Han L, Kim YC, Feng YH. Angiotensin II activates AMPK for execution of apoptosis through energy-dependent and -independent mechanisms. Am J Physiol Lung Cell Mol Physiol 2011; 301:L772-81. [PMID: 21856818 DOI: 10.1152/ajplung.00072.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
At the cellular level, 5'-AMP-activated protein kinase (AMPK) serves as a critical link between energy homeostasis and the regulation of fundamental biological activities, including apoptosis. Angiotensin (Ang) II plays a key role in fibrotic lung remodeling. We recently demonstrated that Ang II induces apoptosis in pulmonary artery endothelial cells (PAEC) through the Ang type 2 receptor (AT(2)). AT(2) activates Src-homology two-domain-containing phosphatase-2 (SHP-2) in a signaling cascade leading to Bcl-x(L) mRNA destabilization and initiation of intrinsic apoptosis. We investigated the requirement of AMPK and ATP generation for Ang II-induced apoptosis in PAEC. Ang II activated AMPK, which was required for ATP generation. Inhibition of ATP production by compound C, an AMPK inhibitor, or by oligomycin suppressed Ang II-induced apoptosis. Experiments in Chinese hamster ovary-K1 cells expressing ectopic AT(2) (wild-type, mutant D90A, or carboxy terminal truncated mutant tC319) demonstrated that AT(2) activation of AMPK required the active conformation of the receptor and the carboxy terminal 44 amino acids. AMPK associated with and activated SHP-2 and was required for Bcl-x(L) mRNA destabilization. These are the first findings demonstrating that AMPK is activated by Ang II to produce ATP required for apoptosis. Our data also indicate that AMPK plays an energy-independent role by mediating SHP-2 activation.
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Affiliation(s)
- Regina M Day
- Dept. of Pharmacology, Uniformed Services Univ. of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814-4799, USA.
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Regulation of contractility and metabolic signaling by the β2-adrenergic receptor in rat ventricular muscle. Life Sci 2011; 88:892-7. [PMID: 21466811 DOI: 10.1016/j.lfs.2011.03.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 03/08/2011] [Accepted: 03/25/2011] [Indexed: 01/12/2023]
Abstract
AIMS Cardiac function is modulated by the sympathetic nervous system through β-adrenergic receptor (β-AR) activity and this represents the main regulatory mechanism for cardiac performance. To date, however, the metabolic and molecular responses to β(2)-agonists are not well characterized. Therefore, we studied the inotropic effect and signaling response to selective β(2)-AR activation by tulobuterol. MAIN METHODS Strips of rat right ventricle were electrically stimulated (1Hz) in standard Tyrode solution (95% O(2), 5% CO(2)) in the presence of the β(1)-antagonist CGP-20712A (1μM). A cumulative dose-response curve for tulobuterol (0.1-10μM), in the presence or absence of the phosphodiesterase (PDE) inhibitor IBMX (30μM), or 10min incubation (1μM) with the β(2)-agonist tulobuterol was performed. KEY FINDINGS β(2)-AR stimulation induced a positive inotropic effect (maximal effect=33±3.3%) and a decrease in the time required for half relaxation (from 45±0.6 to 31±1.8ms, -30%, p<0.001) after the inhibition of PDEs. After 10min of β(2)-AR stimulation, p-AMPKα(T172) (54%), p-PKB(T308) (38%), p-AS160(T642) (46%) and p-CREB(S133) (63%) increased, without any change in p-PKA(T197). SIGNIFICANCE These results suggest that the regulation of ventricular contractility is not the primary function of the β(2)-AR. Rather, β(2)-AR could function to activate PKB and AMPK signaling, thereby modulating muscle mass and energetic metabolism of rat ventricular muscle.
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Biary N, Akar FG. A brighter side of ROS revealed by selective activation of beta-adrenergic receptor subtypes. J Physiol 2010; 588:2973-4. [PMID: 20710039 DOI: 10.1113/jphysiol.2010.195743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Nora Biary
- The Cardiovascular Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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