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Schwarz R, Hofmann B, Gergs U, Neumann J. Cantharidin and sodium fluoride attenuate the negative inotropic effects of carbachol in the isolated human atrium. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2183-2202. [PMID: 37801145 PMCID: PMC10933163 DOI: 10.1007/s00210-023-02747-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 09/23/2023] [Indexed: 10/07/2023]
Abstract
Carbachol, an agonist at muscarinic receptors, exerts a negative inotropic effect in human atrium. Carbachol can activate protein phosphatases (PP1 or PP2A). We hypothesized that cantharidin or sodium fluoride, inhibitors of PP1 and PP2A, may attenuate a negative inotropic effect of carbachol. During bypass-surgery trabeculae carneae of human atrial preparations (HAP) were obtained. These trabeculae were mounted in organ baths and electrically stimulated (1 Hz). Force of contraction was measured under isometric conditions. For comparison, we studied isolated electrically stimulated left atrial preparations (LA) from mice. Cantharidin (100 µM) and sodium fluoride (3 mM) increased force of contraction in LA (n = 5-8, p < 0.05) by 113% ± 24.5% and by 100% ± 38.2% and in HAP (n = 13-15, p < 0.05) by 625% ± 169% and by 196% ± 23.5%, respectively. Carbachol (1 µM) alone exerted a rapid transient maximum negative inotropic effect in LA (n = 6) and HAP (n = 14) to 46.9% ± 3.63% and 19.4% ± 3.74%, respectively (p < 0.05). These negative inotropic effects were smaller in LA (n = 4-6) and HAP (n = 9-12) pretreated with 100 µM cantharidin and amounted to 58.0% ± 2.27% and 59.2% ± 6.19% or 3 mM sodium fluoride to 63.7% ± 9.84% and 46.3% ± 5.69%, (p < 0.05). We suggest that carbachol, at least in part, exerts a negative inotropic effect in the human atrium by stimulating the enzymatic activity of PP1 and/or PP2A.
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Affiliation(s)
- Rebecca Schwarz
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Britt Hofmann
- Department of Cardiac Surgery, Mid-German Heart Center, University Hospital Halle, Halle (Saale), Germany
| | - Ulrich Gergs
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Joachim Neumann
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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Gergs U, Wackerhagen S, Fuhrmann T, Schäfer I, Neumann J. Further investigations on the influence of protein phosphatases on the signaling of muscarinic receptors in the atria of mouse hearts. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-02973-4. [PMID: 38308688 DOI: 10.1007/s00210-024-02973-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/21/2024] [Indexed: 02/05/2024]
Abstract
The vagal regulation of cardiac function involves acetylcholine (ACh) receptor activation followed by negative chronotropic and negative as well as positive inotropic effects. The resulting signaling pathways may include Gi/o protein-coupled reduction in adenylyl cyclase (AC) activity, direct Gi/o protein-coupled activation of ACh-activated potassium current (IKACh), inhibition of L-type calcium ion channels, and/or the activation of protein phosphatases. Here, we studied the role of the protein phosphatases 1 (PP1) and 2A (PP2A) for muscarinic receptor signaling in isolated atrial preparations of transgenic mice with cardiomyocyte-specific overexpression of either the catalytic subunit of PP2A (PP2A-TG) or the inhibitor-2 (I2) of PP1 (I2-TG) or in double transgenic mice overexpressing both PP2A and I2 (DT). In mouse left atrial preparations, carbachol (CCh), cumulatively applied (1 nM-10 µM), exerted at low concentrations a negative inotropic effect followed by a positive inotropic effect at higher concentrations. This biphasic effect was noted with CCh alone as well as when CCh was added after β-adrenergic pre-stimulation with isoprenaline (1 µM). Whereas the response to stimulation of β-adrenoceptors or adenosine receptors (used as controls) was changed in PP2A-TG, the response to CCh was unaffected in atrial preparations from all transgenic models studied here. Therefore, the present data tentatively indicate that neither PP2A nor PP1, but possibly other protein phosphatases, is involved in the muscarinic receptor-induced inotropic and chronotropic effects in the mouse heart.
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Affiliation(s)
- Ulrich Gergs
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany.
| | - Silke Wackerhagen
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Tobias Fuhrmann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Inka Schäfer
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
| | - Joachim Neumann
- Institut Für Pharmakologie Und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097, Magdeburger Str. 4, 06112, Halle, Germany
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Wang L, Feng J, Feng X, Meng D, Zhao X, Wang J, Yu P, Xu GE, Hu M, Wang T, Lehmann HI, Li G, Sluijter JPG, Xiao J. Exercise-induced circular RNA circUtrn is required for cardiac physiological hypertrophy and prevents myocardial ischaemia-reperfusion injury. Cardiovasc Res 2023; 119:2638-2652. [PMID: 37897547 DOI: 10.1093/cvr/cvad161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 08/21/2023] [Accepted: 09/04/2023] [Indexed: 10/30/2023] Open
Abstract
AIMS Regular exercise training benefits cardiovascular health and effectively reduces the risk for cardiovascular disease. Circular RNAs (circRNAs) play important roles in cardiac pathophysiology. However, the role of circRNAs in response to exercise training and biological mechanisms responsible for exercise-induced cardiac protection remain largely unknown. METHODS AND RESULTS RNA sequencing was used to profile circRNA expression in adult mouse cardiomyocytes that were isolated from mice with or without exercise training. Exercise-induced circRNA circUtrn was significantly increased in swimming-trained adult mouse cardiomyocytes. In vivo, circUtrn was found to be required for exercise-induced physiological cardiac hypertrophy. circUtrn inhibition abolished the protective effects of exercise on myocardial ischaemia-reperfusion remodelling. circUtrn overexpression prevented myocardial ischaemia-reperfusion-induced acute injury and pathological cardiac remodelling. In vitro, overexpression of circUtrn promoted H9 human embryonic stem cell-induced cardiomyocyte growth and survival via protein phosphatase 5 (PP5). Mechanistically, circUtrn directly bound to PP5 and regulated the stability of PP5 in a ubiquitin-proteasome-dependent manner. Hypoxia-inducible factor 1α-dependent splicing factor SF3B1 acted as an upstream regulator of circUtrn in cardiomyocytes. CONCLUSION The circRNA circUtrn is upregulated upon exercise training in the heart. Overexpression of circUtrn can prevent myocardial I/R-induced injury and pathological cardiac remodelling.
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Affiliation(s)
- Lijun Wang
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Jingyi Feng
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Xing Feng
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Danni Meng
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Xuan Zhao
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Jiaqi Wang
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Pujiao Yu
- Department of Cardiology, Shanghai Tongji hospital, Tongji University School of Medicine, 389 Xincun Road, Putuo District, Shanghai 200065, China
| | - Gui-E Xu
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Meiyu Hu
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - Tianhui Wang
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
| | - H Immo Lehmann
- Cardiovascular Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Guoping Li
- Cardiovascular Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Joost P G Sluijter
- Department of Cardiology, Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht 3508GA, The Netherlands
- Regenerative Medicine Center, Circulatory Health Laboratory, University Medical Center Utrecht, University Utrecht, Utrecht 3508GA, The Netherlands
| | - Junjie Xiao
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Life Science, Shanghai University, 881 Yonghe Road, Chongchuan District, Nantong 226011, China
- Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, 333 Nanchen Road, Baoshan District, Shanghai 200444, China
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Schwarz R, Hofmann B, Gergs U, Neumann J. Cantharidin increases the force of contraction and protein phosphorylation in isolated human atria. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:2613-2625. [PMID: 37097333 PMCID: PMC10497697 DOI: 10.1007/s00210-023-02483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/30/2023] [Indexed: 04/26/2023]
Abstract
Cantharidin, an inhibitor of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A), is known to increase the force of contraction and shorten the time to relaxation in human ventricular preparations. We hypothesized that cantharidin has similar positive inotropic effects in human right atrial appendage (RAA) preparations. RAA were obtained during bypass surgery performed on human patients. These trabeculae were mounted in organ baths and electrically stimulated at 1 Hz. For comparison, we studied isolated electrically stimulated left atrial (LA) preparations and isolated spontaneously beating right atrial (RA) preparations from wild-type mice. Cumulatively applied (starting at 10 to 30 µM), cantharidin exerted a positive concentration-dependent inotropic effect that plateaued at 300 µM in the RAA, LA, and RA preparations. This positive inotropic effect was accompanied by a shortening of the time to relaxation in human atrial preparations (HAPs). Notably, cantharidin did not alter the beating rate in the RA preparations. Furthermore, cantharidin (100 µM) increased the phosphorylation state of phospholamban and the inhibitory subunit of troponin I in RAA preparations, which may account for the faster relaxation observed. The generated data indicate that PP1 and/or PP2A play a functional role in human atrial contractility.
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Affiliation(s)
- R. Schwarz
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Straße 4, 06112 Halle (Saale), Germany
| | - B. Hofmann
- Department of Cardiac Surgery, Mid-German Heart Center, University Hospital Halle, Halle (Saale), Germany
| | - U. Gergs
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Straße 4, 06112 Halle (Saale), Germany
| | - J. Neumann
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Straße 4, 06112 Halle (Saale), Germany
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Sallam AM, Reyer H, Wimmers K, Bertolini F, Aboul-Naga A, Braz CU, Rabee AE. Genome-wide landscape of runs of homozygosity and differentiation across Egyptian goat breeds. BMC Genomics 2023; 24:573. [PMID: 37752425 PMCID: PMC10521497 DOI: 10.1186/s12864-023-09679-6] [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: 02/28/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
Understanding the genomic features of livestock is essential for successful breeding programs and conservation. This information is scarce for local goat breeds in Egypt. In the current study, genomic regions with selection signatures were identified as well as runs of homozygosity (ROH), genomic inbreeding coefficients (FROH) and fixation index (FST) were detected in Egyptian Nubian, Damascus, Barki and Boer goat breeds. A total of 46,268 SNP markers and 337 animals were available for the genomic analyses. On average, 145.44, 42.02, 87.90 and 126.95 ROHs were detected per individual in the autosomal genome of the respective breeds. The mean accumulative ROH lengths ranged from 46.5 Mb in Damascus to 360 Mb in Egyptian Nubian. The short ROH segments (< 2 Mb) were most frequent in all breeds, while the longest ROH segments (> 16 Mb) were exclusively found in the Egyptian Nubian. The highest average FROH was observed in Egyptian Nubian (~ 0.12) followed by Boer (~ 0.11), while the lowest FROH was found in Damascus (~ 0.05) and Barki breed (~ 0.03). The estimated mean FST was 0.14 (Egyptian Nubian and Boer), 0.077 (Egyptian Nubian and Barki), 0.075 (Egyptian Nubian and Damascus), 0.071 (Barki and Boer), 0.064 (Damascus and Boer), and 0.015 (Damascus and Barki), for each pair of breeds. Interestingly, multiple SNPs that accounted for high FST values were observed on chromosome 6 in regions harboring ALPK1 and KCNIP4. Genomic regions overlapping both FST and ROH harbor genes related to immunity (IL4R, PHF23, GABARAP, GPS2, and CD68), reproduction (SPATA2L, TNFSF12, TMEM95, and RNF17), embryonic development (TCF25 and SOX15) and adaptation (MC1R, KDR, and KIT), suggesting potential genetic adaptations to local environmental conditions. Our results contribute to the understanding of the genetic architecture of different goat breeds and may provide valuable information for effective preservation and breeding programs of local goat breeds in Egypt.
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Affiliation(s)
- Ahmed M Sallam
- Animal and Poultry Breeding Department, Desert Research Center, Cairo, Egypt.
| | - Henry Reyer
- Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Klaus Wimmers
- Research Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
- Faculty of Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig-Weg 6b, 18059, Rostock, Germany
| | - Francesca Bertolini
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Adel Aboul-Naga
- Animal Production Research Institute, Agricultural Research Center, Dokki, Cairo, Egypt
| | - Camila U Braz
- Animal and Poultry Nutrition Department, Desert Research Center, Cairo, Egypt
| | - Alaa Emara Rabee
- Department of Animal Sciences, University of Illinois Urbana-Champaign, 1207 Gregory Dr, Urbana, 61801, USA
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Neumann J, Hofmann B, Dhein S, Gergs U. Role of Dopamine in the Heart in Health and Disease. Int J Mol Sci 2023; 24:ijms24055042. [PMID: 36902474 PMCID: PMC10003060 DOI: 10.3390/ijms24055042] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Dopamine has effects on the mammalian heart. These effects can include an increase in the force of contraction, and an elevation of the beating rate and the constriction of coronary arteries. Depending on the species studied, positive inotropic effects were strong, very modest, or absent, or even negative inotropic effects occurred. We can discern five dopamine receptors. In addition, the signal transduction by dopamine receptors and the regulation of the expression of cardiac dopamine receptors will be of interest to us, because this might be a tempting area of drug development. Dopamine acts in a species-dependent fashion on these cardiac dopamine receptors, but also on cardiac adrenergic receptors. We will discuss the utility of drugs that are currently available as tools to understand cardiac dopamine receptors. The molecule dopamine itself is present in the mammalian heart. Therefore, cardiac dopamine might act as an autocrine or paracrine compound in the mammalian heart. Dopamine itself might cause cardiac diseases. Moreover, the cardiac function of dopamine and the expression of dopamine receptors in the heart can be altered in diseases such as sepsis. Various drugs for cardiac and non-cardiac diseases are currently in the clinic that are, at least in part, agonists or antagonists at dopamine receptors. We define the research needs in order to understand dopamine receptors in the heart better. All in all, an update on the role of dopamine receptors in the human heart appears to be clinically relevant, and is thus presented here.
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Affiliation(s)
- Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
- Correspondence: ; Tel.: +49-345-557-1686; Fax: +49-345-557-1835
| | - Britt Hofmann
- Herzchirurgie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
| | - Stefan Dhein
- Medizinische Fakultät, Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany
| | - Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
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Abella LMR, Höhm C, Hofmann B, Gergs U, Neumann J. Effects of omecamtiv mecarbil and mavacamten in isolated human atrium. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:499-511. [PMID: 36399186 PMCID: PMC9898377 DOI: 10.1007/s00210-022-02333-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022]
Abstract
Heart failure is a syndrome that can result from impaired heart muscle contractions like in dilative cardiomyopathy but also from hypertrophic obstructive cardiomyopathy (HOCOM). A pharmacological therapy might lie in Ca2+-sensitizing or Ca2+-desensitizing drugs, respectively. Such drugs are thought to be omecamtiv mecarbil (OME) and mavacamten (MYK-461), respectively. Their function in contracting human muscle is not fully understood and was the focus of the present study. OME from 1 nM to 10 µM cumulatively applied failed to raise force of contraction in human right atrial preparations strips (HAP) or mouse left atrial preparations (LA). However, OME prolonged time to peak tension and time of relaxation in HAP and LA but did not alter the beating rate in right atrial preparations from mice (RA). In contrast, MYK-461 (10 nM to 10 µM) reduced concentration- and time-dependently force of contraction in HAP and LA. MYK-461 (10 µM) did not affect the beating rate in RA. In summary, the present data failed to detect an increase in force of contraction for OME, in human and mouse atrium. In contrast, a Ca2+ desensitizer studied for comparison was able to reduce force of contraction in HAP and LA. We conclude that putative beneficial effects of OME in dilated cardiomyopathy cannot be explained by positive inotropic effects in the HAP, whereas beneficial functional effects of MYK-461 in HOCOM can be explained by negative inotropic effects in HAP.
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Affiliation(s)
- Lina Maria Rayo Abella
- grid.9018.00000 0001 0679 2801Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany
| | - Christian Höhm
- grid.9018.00000 0001 0679 2801Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany
| | - Britt Hofmann
- grid.9018.00000 0001 0679 2801Cardiac Surgery, Medical Faculty, Martin Luther University Halle-Wittenberg, D-06097 Halle, Germany
| | - Ulrich Gergs
- grid.9018.00000 0001 0679 2801Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany
| | - Joachim Neumann
- Institute for Pharmacology and Toxicology, Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 4, D-06097, Halle, Germany.
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8
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Manilall A, Mokotedi L, Gunter S, Le Roux R, Fourie S, Flanagan CA, Millen AME. Increased protein phosphatase 5 expression in inflammation-induced left ventricular dysfunction in rats. BMC Cardiovasc Disord 2022; 22:539. [PMID: 36494772 PMCID: PMC9732989 DOI: 10.1186/s12872-022-02977-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Titin phosphorylation contributes to left ventricular (LV) diastolic dysfunction. The independent effects of inflammation on the molecular pathways that regulate titin phosphorylation are unclear. METHODS We investigated the effects of collagen-induced inflammation and subsequent tumor necrosis factor-α (TNF-α) inhibition on mRNA expression of genes involved in regulating titin phosphorylation in 70 Sprague-Dawley rats. LV diastolic function was assessed with echocardiography. Circulating inflammatory markers were quantified by enzyme-linked immunosorbent assay and relative LV gene expression was assessed by Taqman® polymerase chain reaction. Differences in normally distributed variables between the groups were determined by two-way analysis of variance (ANOVA), followed by Tukey post-hoc tests. For non-normally distributed variables, group differences were determined by Kruskal-Wallis tests. RESULTS Collagen inoculation increased LV relative mRNA expression of vascular cell adhesion molecule 1 (VCAM1), pentraxin 3 (PTX3), and inducible nitric oxide synthase (iNOS) compared to controls, indicating local microvascular inflammation. Collagen inoculation decreased soluble guanylate cyclase alpha-2 (sGCα2) and soluble guanylate cyclase beta-2 (sGCβ2) expression, suggesting downregulation of nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) signaling. Inhibiting TNF-α prevented collagen-induced changes in VCAM1, iNOS, sGCα2 and sGCβ2 expression. Collagen inoculation increased protein phosphatase 5 (PP5) expression. Like LV diastolic dysfunction, increased PP5 expression was not prevented by TNF-α inhibition. CONCLUSION Inflammation-induced LV diastolic dysfunction may be mediated by a TNF-α-independent increase in PP5 expression and dephosphorylation of the N2-Bus stretch element of titin, rather than by TNF-α-induced downregulation of NO-sGC-cGMP pathway-dependent titin phosphorylation. The steady rise in number of patients with inflammation-induced diastolic dysfunction, coupled with low success rates of current therapies warrants a better understanding of the systemic signals and molecular pathways responsible for decreased titin phosphorylation in development of LV diastolic dysfunction. The therapeutic potential of inhibiting PP5 upregulation in LV diastolic dysfunction requires investigation.
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Affiliation(s)
- Ashmeetha Manilall
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Lebogang Mokotedi
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Sulè Gunter
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Regina Le Roux
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Serena Fourie
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Colleen A. Flanagan
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
| | - Aletta M. E. Millen
- grid.11951.3d0000 0004 1937 1135Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
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Kokot T, Köhn M. Emerging insights into serine/threonine-specific phosphoprotein phosphatase function and selectivity. J Cell Sci 2022; 135:277104. [DOI: 10.1242/jcs.259618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
ABSTRACT
Protein phosphorylation on serine and threonine residues is a widely distributed post-translational modification on proteins that acts to regulate their function. Phosphoprotein phosphatases (PPPs) contribute significantly to a plethora of cellular functions through the accurate dephosphorylation of phosphorylated residues. Most PPPs accomplish their purpose through the formation of complex holoenzymes composed of a catalytic subunit with various regulatory subunits. PPP holoenzymes then bind and dephosphorylate substrates in a highly specific manner. Despite the high prevalence of PPPs and their important role for cellular function, their mechanisms of action in the cell are still not well understood. Nevertheless, substantial experimental advancements in (phospho-)proteomics, structural and computational biology have contributed significantly to a better understanding of PPP biology in recent years. This Review focuses on recent approaches and provides an overview of substantial new insights into the complex mechanism of PPP holoenzyme regulation and substrate selectivity.
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Affiliation(s)
- Thomas Kokot
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
| | - Maja Köhn
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg 1 , Freiburg 79104 , Germany
- University of Freiburg, 2 Faculty of Biology , Freiburg 79104 , Germany
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10
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Gergs U, Jahn T, Schulz N, Großmann C, Rueckschloss U, Demus U, Buchwalow IB, Neumann J. Protein Phosphatase 2A Improves Cardiac Functional Response to Ischemia and Sepsis. Int J Mol Sci 2022; 23:ijms23094688. [PMID: 35563079 PMCID: PMC9101092 DOI: 10.3390/ijms23094688] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 11/16/2022] Open
Abstract
Reversible protein phosphorylation is a posttranslational modification of regulatory proteins involved in cardiac signaling pathways. Here, we focus on the role of protein phosphatase 2A (PP2A) for cardiac gene expression and stress response using a transgenic mouse model with cardiac myocyte-specific overexpression of the catalytic subunit of PP2A (PP2A-TG). Gene and protein expression were assessed under basal conditions by gene chip analysis and Western blotting. Some cardiac genes related to the cell metabolism and to protein phosphorylation such as kinases and phosphatases were altered in PP2A-TG compared to wild type mice (WT). As cardiac stressors, a lipopolysaccharide (LPS)-induced sepsis in vivo and a global cardiac ischemia in vitro (stop-flow isolated perfused heart model) were examined. Whereas the basal cardiac function was reduced in PP2A-TG as studied by echocardiography or as studied in the isolated work-performing heart, the acute LPS- or ischemia-induced cardiac dysfunction deteriorated less in PP2A-TG compared to WT. From the data, we conclude that increased PP2A activity may influence the acute stress tolerance of cardiac myocytes.
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Affiliation(s)
- Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097 Halle, Germany; (T.J.); (N.S.); (J.N.)
- Correspondence: ; Tel.: +49-345-557-4093
| | - Tina Jahn
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097 Halle, Germany; (T.J.); (N.S.); (J.N.)
| | - Nico Schulz
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097 Halle, Germany; (T.J.); (N.S.); (J.N.)
| | - Claudia Großmann
- Julius-Bernstein-Institut für Physiologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097 Halle, Germany;
| | - Uwe Rueckschloss
- Institut für Anatomie und Zellbiologie, Julius-Maximilians-Universität Würzburg, D-97070 Würzburg, Germany;
| | - Uta Demus
- Gesellschaft zur Förderung von Medizin-, Bio-und Umwelttechnologien e. V., D-06120 Halle, Germany;
| | - Igor B. Buchwalow
- Institut für Hämatopathologie, D-22547 Hamburg, Germany;
- Scientific and Educational Resource Center for Molecular Morphology, Peoples’ Friendship University of Russia, Moscow 117198, Russia
| | - Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, D-06097 Halle, Germany; (T.J.); (N.S.); (J.N.)
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Neumann J, Kirchhefer U, Dhein S, Hofmann B, Gergs U. The Roles of Cardiovascular H 2-Histamine Receptors Under Normal and Pathophysiological Conditions. Front Pharmacol 2022; 12:732842. [PMID: 34987383 PMCID: PMC8720924 DOI: 10.3389/fphar.2021.732842] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/02/2021] [Indexed: 12/11/2022] Open
Abstract
This review addresses pharmacological, structural and functional relationships among H2-histamine receptors and H1-histamine receptors in the mammalian heart. The role of both receptors in the regulation of force and rhythm, including their electrophysiological effects on the mammalian heart, will then be discussed in context. The potential clinical role of cardiac H2-histamine-receptors in cardiac diseases will be examined. The use of H2-histamine receptor agonists to acutely increase the force of contraction will be discussed. Special attention will be paid to the potential role of cardiac H2-histamine receptors in the genesis of cardiac arrhythmias. Moreover, novel findings on the putative role of H2-histamine receptor antagonists in treating chronic heart failure in animal models and patients will be reviewed. Some limitations in our biochemical understanding of the cardiac role of H2-histamine receptors will be discussed. Recommendations for further basic and translational research on cardiac H2-histamine receptors will be offered. We will speculate whether new knowledge might lead to novel roles of H2-histamine receptors in cardiac disease and whether cardiomyocyte specific H2-histamine receptor agonists and antagonists should be developed.
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Affiliation(s)
- Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Stefan Dhein
- Landratsamt Altenburger Land, Altenburg, Germany
| | - Britt Hofmann
- Herzchirurgie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
| | - Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
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