1
|
Lazzerini PE, Cupelli M, Cartocci A, Bertolozzi I, Salvini V, Accioli R, Salvadori F, Marzotti T, Verrengia D, Cevenini G, Bisogno S, Bicchi M, Donati G, Bernardini S, Laghi‐Pasini F, Acampa M, Capecchi PL, El‐Sherif N, Boutjdir M. Elevated Interleukin-6 Levels Are Associated With an Increased Risk of QTc Interval Prolongation in a Large Cohort of US Veterans. J Am Heart Assoc 2024; 13:e032071. [PMID: 38348789 PMCID: PMC11010073 DOI: 10.1161/jaha.123.032071] [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: 08/03/2023] [Accepted: 12/13/2023] [Indexed: 02/21/2024]
Abstract
BACKGROUND Although accumulating data indicate that IL-6 (interleukin-6) can promote heart rate-corrected QT interval (QTc) prolongation via direct and indirect effects on cardiac electrophysiology, current evidence comes from basic investigations and small clinical studies only. Therefore, IL-6 is still largely ignored in the clinical management of long-QT syndrome and related arrhythmias. The aim of this study was to estimate the risk of QTc prolongation associated with elevated IL-6 levels in a large population of unselected subjects. METHODS AND RESULTS An observational study using the Veterans Affairs Informatics and Computing Infrastructure was performed. Participants were US veterans who had an ECG and were tested for IL-6. Descriptive statistics and univariate and multivariate regression analyses were performed to study the relationship between IL-6 and QTc prolongation risk. Study population comprised 1085 individuals, 306 showing normal (<5 pg/mL), 376 moderately high (5-25 pg/mL), and 403 high (>25 pg/mL) IL-6 levels. Subjects with elevated IL-6 showed a concentration-dependent increase in the prevalence of QTc prolongation, and those presenting with QTc prolongation exhibited higher circulating IL-6 levels. Stepwise multivariate regression analyses demonstrated that increased IL-6 level was significantly associated with a risk of QTc prolongation up to 2 times the odds of the reference category of QTc (e.g. QTc >470 ms men/480 ms women ms: odds ratio, 2.28 [95% CI, 1.12-4.50] for IL-6 >25 pg/mL) regardless of the underlying cause. Specifically, the mean QTc increase observed in the presence of elevated IL-6 was quantitatively comparable (IL-6 >25 pg/mL:+6.7 ms) to that of major recognized QT-prolonging risk factors, such as hypokalemia and history of myocardial infarction. CONCLUSIONS Our data provide evidence that a high circulating IL-6 level is a robust risk factor for QTc prolongation in a large cohort of US veterans, supporting a potentially important arrhythmogenic role for this cytokine in the general population.
Collapse
Affiliation(s)
| | - Michael Cupelli
- VA New York Harbor Healthcare SystemNew YorkNYUSA
- SUNY Downstate Health Sciences UniversityNew YorkNYUSA
| | | | - Iacopo Bertolozzi
- Cardiology Intensive Therapy Unit, Department of Internal MedicineNuovo Ospedale San Giovanni di Dio (former Cardiology Intensive Therapy Unit, Department of Internal Medicine, Hospital of Carrara, Carrara, Italy)FlorenceItaly
| | - Viola Salvini
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Riccardo Accioli
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Fabio Salvadori
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Tommaso Marzotti
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Decoroso Verrengia
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | | | - Stefania Bisogno
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Maurizio Bicchi
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Giovanni Donati
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Sciaila Bernardini
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Franco Laghi‐Pasini
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Maurizio Acampa
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | | | - Nabil El‐Sherif
- VA New York Harbor Healthcare SystemNew YorkNYUSA
- SUNY Downstate Health Sciences UniversityNew YorkNYUSA
| | - Mohamed Boutjdir
- VA New York Harbor Healthcare SystemNew YorkNYUSA
- SUNY Downstate Health Sciences UniversityNew YorkNYUSA
- NYU Grossman School of MedicineNew YorkNYUSA
| |
Collapse
|
2
|
Fir(e)ing the Rhythm. JACC Basic Transl Sci 2023. [DOI: 10.1016/j.jacbts.2022.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
|
3
|
Islam MMT, Tarnowski D, Zhang M, Trum M, Lebek S, Mustroph J, Daniel H, Moellencamp J, Pabel S, Sossalla S, El‐Armouche A, Nikolaev VO, Shah AM, Eaton P, Maier LS, Sag CM, Wagner S. Enhanced Heart Failure in Redox-Dead Cys17Ser PKARIα Knock-In Mice. J Am Heart Assoc 2021; 10:e021985. [PMID: 34583520 PMCID: PMC8649132 DOI: 10.1161/jaha.121.021985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background PKARIα (protein kinase A type I-α regulatory subunit) is redox-active independent of its physiologic agonist cAMP. However, it is unknown whether this alternative mechanism of PKARIα activation may be of relevance to cardiac excitation-contraction coupling. Methods and Results We used a redox-dead transgenic mouse model with homozygous knock-in replacement of redox-sensitive cysteine 17 with serine within the regulatory subunits of PKARIα (KI). Reactive oxygen species were acutely evoked by exposure of isolated cardiac myocytes to AngII (angiotensin II, 1 µmol/L). The long-term relevance of oxidized PKARIα was investigated in KI mice and their wild-type (WT) littermates following transverse aortic constriction (TAC). AngII increased reactive oxygen species in both groups but with RIα dimer formation in WT only. AngII induced translocation of PKARI to the cell membrane and resulted in protein kinase A-dependent stimulation of ICa (L-type Ca current) in WT with no effect in KI myocytes. Consequently, Ca transients were reduced in KI myocytes as compared with WT cells following acute AngII exposure. Transverse aortic constriction-related reactive oxygen species formation resulted in RIα oxidation in WT but not in KI mice. Within 6 weeks after TAC, KI mice showed an enhanced deterioration of contractile function and impaired survival compared with WT. In accordance, compared with WT, ventricular myocytes from failing KI mice displayed significantly reduced Ca transient amplitudes and lack of ICa stimulation. Conversely, direct pharmacological stimulation of ICa using Bay K8644 rescued Ca transients in AngII-treated KI myocytes and contractile function in failing KI mice in vivo. Conclusions Oxidative activation of PKARIα with subsequent stimulation of ICa preserves cardiac function in the setting of acute and chronic oxidative stress.
Collapse
Affiliation(s)
- M. M. Towhidul Islam
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
- Department of Biochemistry and Molecular BiologyUniversity of DhakaBangladesh
| | - Daniel Tarnowski
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Min Zhang
- School of Cardiovascular Medicine & SciencesKings College London British Heart Foundation Centre of ExcellenceLondonUnited Kingdom
| | - Maximilian Trum
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Simon Lebek
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Julian Mustroph
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Henriette Daniel
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Johanna Moellencamp
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Steffen Pabel
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Samuel Sossalla
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Ali El‐Armouche
- Department of Pharmacology and ToxicologyTechnical University DresdenDresdenGermany
| | - Viacheslav O. Nikolaev
- Institute of Experimental Cardiovascular ResearchUniversity Medical Center Hamburg‐EppendorfEppendorfGermany
| | - Ajay M. Shah
- School of Cardiovascular Medicine & SciencesKings College London British Heart Foundation Centre of ExcellenceLondonUnited Kingdom
| | - Philip Eaton
- The William Harvey Research InstituteBarts and the London School of Medicine and DentistryQueen Mary University of LondonLondonUnited Kingdom
| | - Lars S. Maier
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Can Martin Sag
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| | - Stefan Wagner
- Department of Internal Medicine IIUniversity Medical Center RegensburgRegensburgGermany
| |
Collapse
|
4
|
Roybal D, Hennessey JA, Marx SO. The quest to identify the mechanism underlying adrenergic regulation of cardiac Ca 2+ channels. Channels (Austin) 2020; 14:123-131. [PMID: 32195622 PMCID: PMC7153787 DOI: 10.1080/19336950.2020.1740502] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 11/25/2022] Open
Abstract
Activation of protein kinase A by cyclic AMP results in a multi-fold upregulation of CaV1.2 currents in the heart, as originally reported in the 1970's and 1980's. Despite considerable interest and much investment, the molecular mechanisms responsible for this signature modulation remained stubbornly elusive for over 40 years. A key manifestation of this lack of understanding is that while this regulation is readily apparent in heart cells, it has not been possible to reconstitute it in heterologous expression systems. In this review, we describe the efforts of many investigators over the past decades to identify the mechanisms responsible for the β-adrenergic mediated activation of voltage-gated Ca2+ channels in the heart and other tissues.
Collapse
Affiliation(s)
- Daniel Roybal
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons
| | - Jessica A. Hennessey
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons
| |
Collapse
|
5
|
Gutiérrez A, Contreras C, Sánchez A, Prieto D. Role of Phosphatidylinositol 3-Kinase (PI3K), Mitogen-Activated Protein Kinase (MAPK), and Protein Kinase C (PKC) in Calcium Signaling Pathways Linked to the α 1-Adrenoceptor in Resistance Arteries. Front Physiol 2019; 10:55. [PMID: 30787881 PMCID: PMC6372516 DOI: 10.3389/fphys.2019.00055] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/17/2019] [Indexed: 01/07/2023] Open
Abstract
Insulin resistance plays a key role in the pathogenesis of type 2 diabetes and is also related to other health problems like obesity, hypertension, and metabolic syndrome. Imbalance between insulin vascular actions via the phosphatidylinositol 3-Kinase (PI3K) and the mitogen activated protein kinase (MAPK) signaling pathways during insulin resistant states results in impaired endothelial PI3K/eNOS- and augmented MAPK/endothelin 1 pathways leading to endothelial dysfunction and abnormal vasoconstriction. The role of PI3K, MAPK, and protein kinase C (PKC) in Ca2+ handling of resistance arteries involved in blood pressure regulation is poorly understood. Therefore, we assessed here whether PI3K, MAPK, and PKC play a role in the Ca2+ signaling pathways linked to adrenergic vasoconstriction in resistance arteries. Simultaneous measurements of intracellular calcium concentration ([Ca2+]i) in vascular smooth muscle (VSM) and tension were performed in endothelium-denuded branches of mesenteric arteries from Wistar rats mounted in a microvascular myographs. Responses to CaCl2 were assessed in arteries activated with phenylephrine (PE) and kept in Ca2+-free solution, in the absence and presence of the selective antagonist of L-type Ca2+ channels nifedipine, cyclopiazonic acid (CPA) to block sarcoplasmic reticulum (SR) intracellular Ca2+ release or specific inhibitors of PI3K, ERK-MAPK, or PKC. Activation of α1-adrenoceptors with PE stimulated both intracellular Ca2+ mobilization and Ca2+ entry along with contraction in resistance arteries. Both [Ca2+]i and contractile responses were inhibited by nifedipine while CPA abolished intracellular Ca2+ mobilization and modestly reduced Ca2+ entry suggesting that α1-adrenergic vasoconstriction is largely dependent Ca2+ influx through L-type Ca2+ channel and to a lesser extent through store-operated Ca2+ channels. Inhibition of ERK-MAPK did not alter intracellular Ca2+ mobilization but largely reduced L-type Ca2+ entry elicited by PE without altering vasoconstriction. The PI3K blocker LY-294002 moderately reduced intracellular Ca2+ release, Ca2+ entry and contraction induced by the α1-adrenoceptor agonist, while PKC inhibition decreased PE-elicited Ca2+ entry and to a lesser extent contraction without affecting intracellular Ca2+ mobilization. Under conditions of ryanodine receptor (RyR) blockade to inhibit Ca2+-induced Ca2+-release (CICR), inhibitors of PI3K, ERK-MAPK, or PKC significantly reduced [Ca2+]i increases but not contraction elicited by high K+ depolarization suggesting an activation of L-type Ca2+ entry in VSM independent of RyR. In summary, our results demonstrate that PI3K, ERK-MAPK, and PKC regulate Ca2+ handling coupled to the α1-adrenoceptor in VSM of resistance arteries and related to both contractile and non-contractile functions. These kinases represent potential pharmacological targets in pathologies associated to vascular dysfunction and abnormal Ca2+ handling such as obesity, hypertension and diabetes mellitus, in which these signaling pathways are profoundly impaired.
Collapse
Affiliation(s)
- Alejandro Gutiérrez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Cristina Contreras
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ana Sánchez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| |
Collapse
|
6
|
Sánchez A, Contreras C, Climent B, Gutiérrez A, Muñoz M, García-Sacristán A, López M, Rivera L, Prieto D. Impaired Ca 2+ handling in resistance arteries from genetically obese Zucker rats: Role of the PI3K, ERK1/2 and PKC signaling pathways. Biochem Pharmacol 2018; 152:114-128. [PMID: 29574066 DOI: 10.1016/j.bcp.2018.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/20/2018] [Indexed: 01/12/2023]
Abstract
The impact of obesity on vascular smooth muscle (VSM) Ca2+ handling and vasoconstriction, and its regulation by the phosphatidylinositol 3-kinase (PI3K), mitogen activated protein kinase (MAPK) and protein kinase C (PKC) were assessed in mesenteric arteries (MA) from obese Zucker rats (OZR). Simultaneous measurements of intracellular Ca2+ ([Ca2+]i) and tension were performed in MA from OZR and compared to lean Zucker rats (LZR), and the effects of selective inhibitors of PI3K, ERK-MAPK kinase and PKC were assessed on the functional responses of VSM voltage-dependent L-type Ca2+ channels (CaV1.2). Increases in [Ca2+]i induced by α1-adrenoceptor activation and high K+ depolarization were not different in arteries from LZR and OZR although vasoconstriction was enhanced in OZR. Blockade of the ryanodine receptor (RyR) and of Ca2+ release from the sarcoplasmic reticulum (SR) markedly reduced depolarization-induced Ca2+ responses in arteries from lean but not obese rats, suggesting impaired Ca2+-induced Ca2+ release (CICR) from SR in arteries from OZR. Enhanced Ca2+ influx after treatment with ryanodine was abolished by nifedipine and coupled to up-regulation of CaV1.2 channels in arteries from OZR. Increased activation of ERK-MAPK and up-regulation of PI3Kδ, PKCβ and δ isoforms were associated to larger inhibitory effects of PI3K, MAPK and PKC blockers on VSM L-type channel Ca2+ entry in OZR. Changes in arterial Ca2+ handling in obesity involve SR Ca2+ store dysfunction and enhanced VSM Ca2+ entry through L-type channels, linked to a compensatory up-regulation of CaV1.2 proteins and increased activity of the ERK-MAPK, PI3Kδ and PKCβ and δ, signaling pathways.
Collapse
Affiliation(s)
- Ana Sánchez
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Cristina Contreras
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Belén Climent
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Alejandro Gutiérrez
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Mercedes Muñoz
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Albino García-Sacristán
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Luis Rivera
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Dolores Prieto
- Department of Physiology, School of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| |
Collapse
|
7
|
Rocha-Resende C, Guedes de Jesus IC, Roman-Campos D, Miranda AS, Alves F, Resende RR, Dos Santos Cruz J, Machado FS, Guatimosim S. Absence of suppressor of cytokine signaling 2 turns cardiomyocytes unresponsive to LIF-dependent increases in Ca 2+ levels. Am J Physiol Cell Physiol 2017; 312:C478-C486. [PMID: 28122728 DOI: 10.1152/ajpcell.00004.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 01/12/2023]
Abstract
Little is known regarding the role of suppressor of cytokine signaling (SOCS) in the control of cytokine signaling in cardiomyocytes. We investigated the consequences of SOCS2 ablation for leukemia inhibitory factor (LIF)-induced enhancement of intracellular Ca2+ ([Ca2+]i) transient by performing experiments with cardiomyocytes from SOCS2-knockout (ko) mice. Similar levels of SOCS3 transcripts were seen in cardiomyocytes from wild-type and SOCS2-ko mice, while SOCS1 mRNA was reduced in SOCS2-ko. Immunoprecipitation experiments showed increased SOCS3 association with gp130 receptor in SOCS2-ko myocytes. Measurements of Ca2+ in wild-type myocytes exposed to LIF showed a significant increase in the magnitude of the Ca2+ transient. This change was absent in LIF-treated SOCS2-ko cells. LIF activation of ERK and STAT3 was observed in both wild-type and SOCS2-ko cells, indicating that in SOCS2-ko, LIF receptors were functional, despite the lack of effect in the Ca2+ transient. In wild-type cells, LIF-induced increase in [Ca2+]i and phospholamban Thr17 [PLN(Thr17)] phosphorylation was inhibited by KN-93, indicating a role for CaMKII in LIF-induced Ca2+ raise. LIF-induced phosphorylation of PLN(Thr17) was abrogated in SOCS2-ko myocytes. In wild-type cardiomyocytes, LIF treatment increased L-type Ca2+ current (ICa,L), a key activator of CaMKII in response to LIF. Conversely, SOCS2-ko myocytes failed to activate ICa,L in response to LIF, providing a rationale for the lack of LIF effect on Ca2+ transient. Our data show that absence of SOCS2 turns cardiomyocytes unresponsive to LIF-induced [Ca2+] raise, indicating that endogenous levels of SOCS2 are crucial for full activation of LIF signaling in the heart.
Collapse
Affiliation(s)
- Cibele Rocha-Resende
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Itamar Couto Guedes de Jesus
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Danilo Roman-Campos
- Department of Biophysics, Paulista School of Medicine, Universidade Federal de São Paulo, Sao Paulo, Brazil
| | - Artur S Miranda
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; and
| | - Fabiana Alves
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Ribeiro Resende
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; and
| | - Jader Dos Santos Cruz
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; and
| | - Fabiana Simão Machado
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; and
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil;
| |
Collapse
|
8
|
Regulation of TRPM7 Function by IL-6 through the JAK2-STAT3 Signaling Pathway. PLoS One 2016; 11:e0152120. [PMID: 27010689 PMCID: PMC4806911 DOI: 10.1371/journal.pone.0152120] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 03/09/2016] [Indexed: 12/25/2022] Open
Abstract
Aims Previous studies have demonstrated that expression of the TRPM7 channel, which may induce delayed cell death by mediating calcium influx, is precisely regulated. However, functional regulation of TRPM7 channels by endogenous molecules has not been elucidated. The proinflammatory cytokine IL-6 contributes to regulation of Ca2+ influx in cerebral ischemia, but the role of IL-6 in regulating TRPM7 functioning is unknown. Thus, we here investigated the interaction between IL-6 and TRPM7 channels and the relevant mechanisms. Materials and Methods Using whole-cell patch-clamping, we first investigated the effect of IL-6 on TRPM7-like currents in primary cultured cortical neurons. Next, TRPM7-overexpressing HEK293 cells were used to confirm the effect of IL-6/sIL-6R on TRPM7. Finally, we used specific signaling pathway inhibitors to investigate the signaling pathways involved. Results IL-6 or IL-6/sIL-6R dose-dependently inhibited inward TRPM7 currents, in both primary cultured neurons and HEK293 cells overexpressing TRPM7. In intracellular Mg2+-free conditions, extracellular Ca2+ or the α-kinase domain of TRPM7 did not participate in this regulation. The inhibitory effect of IL-6 on TRPM7 could be blocked by specific inhibitors of the JAK2−STAT3 pathway, but not of the PI3K, ERK1/2, or PLC pathways. Conclusions IL-6 inhibits the inward TRPM7 current via the JAK2−STAT3 signaling pathway.
Collapse
|
9
|
Abstract
Stress-response kinases, the mitogen-activated protein kinases (MAPKs) are activated in response to the challenge of a myriad of stressors. c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERKs), and p38 MAPKs are the predominant members of the MAPK family in the heart. Extensive studies have revealed critical roles of activated MAPKs in the processes of cardiac injury and heart failure and many other cardiovascular diseases. Recently, emerging evidence suggests that MAPKs also promote the development of cardiac arrhythmias. Thus, understanding the functional impact of MAPKs in the heart could shed new light on the development of novel therapeutic approaches to improve cardiac function and prevent arrhythmia development in the patients. This review will summarize the recent findings on the role of MAPKs in cardiac remodeling and arrhythmia development and point to the critical need of future studies to further elucidate the fundamental mechanisms of MAPK activation and arrhythmia development in the heart.
Collapse
|
10
|
Ai X. SR calcium handling dysfunction, stress-response signaling pathways, and atrial fibrillation. Front Physiol 2015; 6:46. [PMID: 25745402 PMCID: PMC4333799 DOI: 10.3389/fphys.2015.00046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/30/2015] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia. It is associated with a markedly increased risk of premature death due to embolic stroke and also complicates co-existing cardiovascular diseases such as heart failure. The prevalence of AF increases dramatically with age, and aging has been shown to be an independent risk of AF. Due to an aging population in the world, a growing body of AF patients are suffering a diminished quality of life and causing an associated economic burden. However, effective pharmacologic treatments and prevention strategies are lacking due to a poor understanding of the molecular and electrophysiologic mechanisms of AF in the failing and/or aged heart. Recent studies suggest that altered atrial calcium handling contributes to the onset and maintenance of AF. Here we review the role of stress-response kinases and calcium handling dysfunction in AF genesis in the aged and failing heart.
Collapse
Affiliation(s)
- Xun Ai
- Department of Cell and Molecular Physiology, Loyola University Chicago Maywood, IL, USA
| |
Collapse
|
11
|
Engineering Angiogenesis for Myocardial Infarction Repair: Recent Developments, Challenges, and Future Directions. Cardiovasc Eng Technol 2014. [DOI: 10.1007/s13239-014-0193-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
12
|
Abstract
Multiple studies have shown that the cytokine leukemia inhibitory factor (LIF) is protective of the myocardium in the acute stress of ischemia-reperfusion. All three major intracellular signaling pathways that are activated by LIF in cardiac myocytes have been linked to actions that protect against oxidative stress and cell death, either at the level of the mitochondrion or via nuclear transcription. In addition, LIF has been shown to contribute to post-myocardial infarction cardiac repair and regeneration, by stimulating the homing of bone marrow-derived cardiac progenitors to the injured myocardium, the differentiation of resident cardiac stem cells into endothelial cells, and neovascularization. Whether LIF offers protection to the heart under chronic stress such as hypertension-induced cardiac remodeling and heart failure is not known. However, mice with cardiac myocyte restricted knockout of STAT3, a principal transcription factor activated by LIF, develop heart failure with age, and cardiac STAT3 levels are reported to be decreased in heart failure patients. In addition, endogenously produced LIF has been implicated in the cholinergic transdiffrentiation that may serve to attenuate sympathetic overdrive in heart failure and in the peri-infarct region of the heart after myocardial infarction. Surprisingly, therapeutic strategies to exploit the beneficial actions of LIF on the injured myocardium have received scant attention. Nor is it established whether the purported so-called adverse effects of LIF observed in isolated cardiac myocytes have physiological relevance in vivo. Here we present an overview of the actions of LIF in the heart with the goal of stimulating further research into the translational potential of this pleiotropic cytokine.
Collapse
|
13
|
Zgheib C, Zouein FA, Kurdi M, Booz GW. Differential STAT3 signaling in the heart: Impact of concurrent signals and oxidative stress. JAKSTAT 2013; 1:101-10. [PMID: 23904970 PMCID: PMC3670289 DOI: 10.4161/jkst.19776] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Multiple lines of evidence suggest that the transcription factor STAT3 is linked to a protective and reparative response in the heart. Thus, increasing duration or intensity of STAT3 activation ought to minimize damage and improve heart function under conditions of stress. Two recent studies using genetic mouse models, however, report findings that appear to refute this proposition. Unfortunately, studies often approach the question of the role of STAT3 in the heart from the perspective that all STAT3 signaling is equivalent, particularly when it comes to signaling by IL-6 type cytokines, which share the gp130 signaling protein. Moreover, STAT3 activation is typically equated with phosphorylation of a critical tyrosine residue. Yet, STAT3 transcriptional behavior is subject to modulation by serine phosphorylation, acetylation, and redox status of the cell. Unphosphorylated STAT3 is implicated in gene induction as well. Thus, how STAT3 is activated and also what other signaling events are occurring at the same time is likely to impact on the outcome ultimately linked to STAT3. Notably STAT3 may serve as a scaffold protein allowing it to interact with other singling pathways. In this context, canonical gp130 cytokine signaling may function to integrate STAT3 signaling with a protective PI3K/AKT signaling network via mutual involvement of JAK tyrosine kinases. Differences in the extent of integration may occur between those cytokines that signal through gp130 homodimers and those through heterodimers of gp130 with a receptor α chain. Signal integration may have importance not only for deciding the particular gene profile linked to STAT3, but for the newly described mitochondrial stabilization role of STAT3 as well. In addition, disruption of integrated gp130-related STAT3 signaling may occur under conditions of oxidative stress, which negatively impacts on JAK catalytic activity. For these reasons, understanding the importance of STAT3 signaling to heart function requires a greater appreciation of the plasticity of this transcription factor in the context in which it is investigated.
Collapse
Affiliation(s)
- Carlos Zgheib
- Department of Pharmacology and Toxicology; School of Medicine; and the Center for Excellence in Cardiovascular-Renal Research; The University of Mississippi Medical Center; Jackson, MS USA
| | | | | | | |
Collapse
|
14
|
Chronic treatment of mice with leukemia inhibitory factor does not cause adverse cardiac remodeling but improves heart function. Eur Cytokine Netw 2013; 23:191-7. [PMID: 23291613 DOI: 10.1684/ecn.2012.0319] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent evidence suggests that the IL-6 family cytokine, leukemia inhibitory factor (LIF) is produced by cardiac cells under stress conditions including myocardial infarction and heart failure. Additionally, short-term delivery of LIF has been shown to have preconditioning effects on the heart and to limit infarct size. However, cell culture studies have suggested that LIF may exert harmful effects on cardiac myocytes, including pathological hypertrophy and contractile dysfunction. Long-term effects of LIF on the heart in vivo have not been reported and were the focus of this study. Adult male mice were injected daily with LIF (2 μg/30 g) or saline for 10 days. LIF treatment caused an approximate 11% loss in body weight. Cardiac function as assessed by echocardiography was improved in LIF-treated mice. Ejection fraction and fractional shortening were increased by 21% and 32%, respectively. No cardiac hypertrophy was seen on histology in LIF-treated mice,, there was no change in the heart-to-tibia length ratio, and no cardiac fibrosis was observed. STAT3 was markedly activated by LIF in the left ventricle. Different effects of LIF were seen in protein levels of genes associated with STAT3 in the left ventricle: levels of SOD2 and Bcl-xL were unchanged, but levels of total STAT3 and MCP-1 were increased. There was a trend towards increased expression of miR-17, miR-21, and miR-199 in the left ventricle of LIF-treated mice, but these changes were not statistically significant. In conclusion, effects of chronic LIF treatment on the heart, although modest, were positive for systolic function: adverse cardiac remodeling was not observed. Our findings thus lend further support to recent proposals that LIF may have therapeutic utility in preventing injury to or repairing the myocardium.
Collapse
|
15
|
Nathanson NM. Regulation of neurokine receptor signaling and trafficking. Neurochem Int 2012; 61:874-8. [PMID: 22306348 DOI: 10.1016/j.neuint.2012.01.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 01/08/2012] [Accepted: 01/12/2012] [Indexed: 01/17/2023]
Abstract
Leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) are neurally active cytokines, or neurokines. LIF signals through a receptor consisting of gp130 and the low affinity LIF receptor (LIFR), while the CNTF receptor consists of gp130, LIFR, and the low affinity CNTF receptor (CNTFR). Ser1044 of the LIFR is phosphorylated by Erk1/2 MAP kinase. Stimulation of neural cells with growth factors which strongly activate Erk1/2 decreases LIF-mediated signal transduction due to increased degradation of the LIFR as a consequence of Erk1/2-dependent phosphorylation of the receptor at Ser1044. The gp130 receptor subunit is phosphorylated, at least in part by calmodulin-dependent protein kinase II, at Ser782, which is adjacent to a dileucine internalization motif. Ser782 appears to negatively regulate cytokine receptor expression, as mutagenesis of Ser782 results in increased gp130 expression and cytokine-induced neuropeptide gene transcription. The LIFR and gp130 are transmembrane proteins, while CNTFR is a peripheral membrane protein attached to the cell surface via a glycosylphosphatidylinositol tail. In unstimulated cells, CNTFR but not LIFR and gp130 is localized to detergent-resistant lipid rafts. Stimulation of cells with CNTFR causes translocation of LIFR and gp130 into the lipid rafts, while stimulation with LIF does not induce receptor translocation, raising the possibility that CNTF could induce different patterns of signaling and/or receptor trafficking than caused by LIF. We used a compartmentalized culture system to examine the mechanisms for retrograde signaling by LIF and CNTF from distal neurites to the cell bodies of mouse sympathetic neurons. Stimulation with neurokines of the distal neurites of sympathetic neurons grown in a compartmentalized culture system resulted in the activation and nuclear translocation of the transcription factor Stat3. Retrograde signaling required Jak kinase activity in the cell body but not the distal neurites, and could be blocked by inhibitors of microtubule but not microfilament function. The results are consistent with a signaling endosomes model in which the ctyokine/receptor complex is transported back to the cell body where Stat3 is activated. While both LIF and CNTF mediate retrograde activation of Stat3, the kinetics for retrograde signaling differ for the two neurokines.
Collapse
Affiliation(s)
- Neil M Nathanson
- Department of Pharmacology, Box 357750, University of Washington, Seattle, WA 98195-7750, United States.
| |
Collapse
|
16
|
Robin E, Sabourin J, Benoit R, Pedretti S, Raddatz E. Adenosine A1 receptor activation is arrhythmogenic in the developing heart through NADPH oxidase/ERK- and PLC/PKC-dependent mechanisms. J Mol Cell Cardiol 2011; 51:945-54. [PMID: 21907719 DOI: 10.1016/j.yjmcc.2011.08.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 08/06/2011] [Accepted: 08/24/2011] [Indexed: 11/25/2022]
Abstract
Whether adenosine, a crucial regulator of the developing cardiovascular system, can provoke arrhythmias in the embryonic/fetal heart remains controversial. Here, we aimed to establish a mechanistic basis of how an adenosinergic stimulation alters function of the developing heart. Spontaneously beating hearts or dissected atria and ventricle obtained from 4-day-old chick embryos were exposed to adenosine or specific agonists of the receptors A(1)AR (CCPA), A(2A)AR (CGS-21680) and A(3)AR (IB-MECA). Expression of the receptors was determined by quantitative PCR. The functional consequences of blockade of NADPH oxidase, extracellular signal-regulated kinase (ERK), phospholipase C (PLC), protein kinase C (PKC) and L-type calcium channel (LCC) in combination with adenosine or CCPA, were investigated in vitro by electrocardiography. Furthermore, the time-course of ERK phosphorylation was determined by western blotting. Expression of A(1)AR, A(2A)AR and A(2B)AR was higher in atria than in ventricle while A(3)AR was equally expressed. Adenosine (100μM) triggered transient atrial ectopy and second degree atrio-ventricular blocks (AVB) whereas CCPA induced mainly Mobitz type I AVB. Atrial rhythm and atrio-ventricular propagation fully recovered after 60min. These arrhythmias were prevented by the specific A(1)AR antagonist DPCPX. Adenosine and CCPA transiently increased ERK phosphorylation and induced arrhythmias in isolated atria but not in ventricle. By contrast, A(2A)AR and A(3)AR agonists had no effect. Interestingly, the proarrhythmic effect of A(1)AR stimulation was markedly reduced by inhibition of NADPH oxidase, ERK, PLC, PKC or LCC. Moreover, NADPH oxidase inhibition or antioxidant MPG prevented both A(1)AR-mediated arrhythmias and ERK phosphorylation. These results suggest that pacemaking and conduction disturbances are induced via A(1)AR through concomitant stimulation of NADPH oxidase and PLC, followed by downstream activation of ERK and PKC with LCC as possible target.
Collapse
Affiliation(s)
- Elodie Robin
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, CH-1005, Switzerland.
| | | | | | | | | |
Collapse
|
17
|
Rose BA, Force T, Wang Y. Mitogen-activated protein kinase signaling in the heart: angels versus demons in a heart-breaking tale. Physiol Rev 2010; 90:1507-46. [PMID: 20959622 PMCID: PMC3808831 DOI: 10.1152/physrev.00054.2009] [Citation(s) in RCA: 546] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Among the myriad of intracellular signaling networks that govern the cardiac development and pathogenesis, mitogen-activated protein kinases (MAPKs) are prominent players that have been the focus of extensive investigations in the past decades. The four best characterized MAPK subfamilies, ERK1/2, JNK, p38, and ERK5, are the targets of pharmacological and genetic manipulations to uncover their roles in cardiac development, function, and diseases. However, information reported in the literature from these efforts has not yet resulted in a clear view about the roles of specific MAPK pathways in heart. Rather, controversies from contradictive results have led to a perception that MAPKs are ambiguous characters in heart with both protective and detrimental effects. The primary object of this review is to provide a comprehensive overview of the current progress, in an effort to highlight the areas where consensus is established verses the ones where controversy remains. MAPKs in cardiac development, cardiac hypertrophy, ischemia/reperfusion injury, and pathological remodeling are the main focuses of this review as these represent the most critical issues for evaluating MAPKs as viable targets of therapeutic development. The studies presented in this review will help to reveal the major challenges in the field and the limitations of current approaches and point to a critical need in future studies to gain better understanding of the fundamental mechanisms of MAPK function and regulation in the heart.
Collapse
Affiliation(s)
- Beth A Rose
- Departments of Anesthesiology, Physiology, and Medicine, David Geffen School of Medicine, Molecular Biology, Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
18
|
Smani T, Calderón-Sanchez E, Gómez-Hurtado N, Fernández-Velasco M, Cachofeiro V, Lahera V, Ordoñez A, Delgado C. Mechanisms underlying the activation of L-type calcium channels by urocortin in rat ventricular myocytes. Cardiovasc Res 2010; 87:459-66. [DOI: 10.1093/cvr/cvq063] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
|
19
|
Calderón-Sanchez E, Delgado C, Ruiz-Hurtado G, Domínguez-Rodríguez A, Cachofeiro V, Rodríguez-Moyano M, Gomez AM, Ordóñez A, Smani T. Urocortin induces positive inotropic effect in rat heart. Cardiovasc Res 2009; 83:717-25. [DOI: 10.1093/cvr/cvp161] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
20
|
Lee DI, Klein MG, Zhu W, Xiao RP, Gerzanich V, Xu KY. Activation of (Na+ + K+)-ATPase modulates cardiac L-type Ca2+ channel function. Mol Pharmacol 2009; 75:774-81. [PMID: 19122004 DOI: 10.1124/mol.108.052597] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cellular Ca(2+) signaling underlies diverse vital biological processes, including muscle contractility, memory encoding, fertilization, cell survival, and cell death. Despite extensive studies, the fundamental control mechanisms that regulate intracellular Ca(2+) movement remain enigmatic. We have found recently that activation of the (Na(+)+K(+))-ATPase markedly potentiates intracellular Ca(2+) transients and contractility of rat heart cells. Little is known about the pathway responsible for the activation of the (Na(+)+K(+))-ATPase-initiated Ca(2+) signaling. Here, we demonstrate a novel mechanism in which activation of the (Na(+)+K(+))-ATPase is coupled to increased L-type Ca(2+) channel function through a signaling cascade involving Src and ERK1/2 but not well established regulators of the channel, such as adrenergic receptor system or activation of PKA or CaMKII. We have also identified Ser(1928), a phosphorylation site for the alpha1 subunit of the L-type Ca(2+) channel that may participate in the activation of the (Na(+)+K(+))-ATPase-mediated Ca(2+) signaling. The findings reported here uncover a novel molecular cross-talk between activation of the (Na(+)+K(+))-ATPase and L-type Ca(2+) channel and provide new insights into Ca(2+) signaling mechanisms for deeper understanding of the nature of cellular Ca(2+) handling in heart.
Collapse
Affiliation(s)
- Dong I Lee
- Department of Biochemistry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | | | | | | |
Collapse
|
21
|
Barry SP, Davidson SM, Townsend PA. Molecular regulation of cardiac hypertrophy. Int J Biochem Cell Biol 2008; 40:2023-39. [PMID: 18407781 DOI: 10.1016/j.biocel.2008.02.020] [Citation(s) in RCA: 213] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 02/13/2008] [Accepted: 02/15/2008] [Indexed: 01/05/2023]
Abstract
Heart failure is one of the leading causes of mortality in the western world and encompasses a wide spectrum of cardiac pathologies. When the heart experiences extended periods of elevated workload, it undergoes hypertrophic enlargement in response to the increased demand. Cardiovascular disease, such as that caused by myocardial infarction, obesity or drug abuse promotes cardiac myocyte hypertrophy and subsequent heart failure. A number of signalling modulators in the vasculature milieu are known to regulate heart mass including those that influence gene expression, apoptosis, cytokine release and growth factor signalling. Recent evidence using genetic and cellular models of cardiac hypertrophy suggests that pathological hypertrophy can be prevented or reversed and has promoted an enormous drive in drug discovery research aiming to identify novel and specific regulators of hypertrophy. In this review we describe the molecular characteristics of cardiac hypertrophy such as the aberrant re-expression of the fetal gene program. We discuss the various molecular pathways responsible for the co-ordinated control of the hypertrophic program including: natriuretic peptides, the adrenergic system, adhesion and cytoskeletal proteins, IL-6 cytokine family, MEK-ERK1/2 signalling, histone acetylation, calcium-mediated modulation and the exciting recent discovery of the role of microRNAs in controlling cardiac hypertrophy. Characterisation of the signalling pathways leading to cardiac hypertrophy has led to a wealth of knowledge about this condition both physiological and pathological. The challenge will be translating this knowledge into potential pharmacological therapies for the treatment of cardiac pathologies.
Collapse
Affiliation(s)
- Sean P Barry
- Medical Molecular Biology Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N IEH, United Kingdom.
| | | | | |
Collapse
|
22
|
Damon DH. TH and NPY in sympathetic neurovascular cultures: role of LIF and NT-3. Am J Physiol Cell Physiol 2007; 294:C306-12. [PMID: 18032527 DOI: 10.1152/ajpcell.00214.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The sympathetic nervous system is an important determinant of vascular function. The effects of the sympathetic nervous system are mediated via release of neurotransmitters and neuropeptides from postganglionic sympathetic neurons. The present study tests the hypothesis that vascular smooth muscle cells (VSM) maintain adrenergic neurotransmitter/neuropeptide expression in the postganglionic sympathetic neurons that innervate them. The effects of rat aortic and tail artery VSM (AVSM and TAVSM, respectively) on neuropeptide Y (NPY) and tyrosine hydroxylase (TH) were assessed in cultures of dissociated sympathetic neurons. AVSM decreased TH (39 +/- 12% of control) but did not affect NPY. TAVSM decreased TH (76 +/- 10% of control) but increased NPY (153 +/- 20% of control). VSM expressed leukemia inhibitory factor (LIF) and neurotrophin-3 (NT-3), which are known to modulate NPY and TH expression. Sympathetic neurons innervating blood vessels expressed LIF and NT-3 receptors. Inhibition of LIF inhibited the effect of AVSM on TH. Inhibition of neurotrophin-3 (NT-3) decreased TH and NPY in neurons grown in the presence of TAVSM. These data suggest that vascular-derived LIF decreases TH and vascular-derived NT-3 increases or maintains NPY and TH expression in postganglionic sympathetic neurons. NPY and TH in vascular sympathetic nerves are likely to modulate NPY and/or norepinephrine release from these nerves and are thus likely to affect blood flow and blood pressure. The present studies suggest a novel mechanism whereby VSM would modulate sympathetic control of vascular function.
Collapse
Affiliation(s)
- Deborah H Damon
- Dept. of Pharmacology, Univ. of Vermont, 89 Beaumont Ave., Given Bldg., Burlington, VT 05405, USA.
| |
Collapse
|
23
|
Hagiwara Y, Miyoshi S, Fukuda K, Nishiyama N, Ikegami Y, Tanimoto K, Murata M, Takahashi E, Shimoda K, Hirano T, Mitamura H, Ogawa S. SHP2-mediated signaling cascade through gp130 is essential for LIF-dependent I CaL, [Ca2+]i transient, and APD increase in cardiomyocytes. J Mol Cell Cardiol 2007; 43:710-6. [PMID: 17961593 DOI: 10.1016/j.yjmcc.2007.09.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 08/30/2007] [Accepted: 09/10/2007] [Indexed: 02/08/2023]
Abstract
Leukemia inhibitory factor (LIF), a cardiac hypertrophic cytokine, increases L-type Ca(2+) current (I(CaL)) via ERK-dependent and PKA-independent phosphorylation of serine 1829 in the Cav(1.2) subunit. The signaling cascade through gp130 is involved in this augmentation. However, there are two major cascades downstream of gp130, i.e. JAK/STAT3 and SHP2/ERK. In this study, we attempted to clarify which of these two cascades plays a more important role. Knock-in mouse line, in which the SHP2 signal was disrupted (gp130(F759/F759) group), and wild-type mice (WT group) were used. A whole-cell patch clamp experiment was performed, and intracellular Ca(2+) concentration ([Ca(2+)](i) transient) was monitored. The I(CaL) density and [Ca(2+)](i) transient were measured from the untreated cells and the cells treated with LIF or IL-6 and soluble IL-6 receptor (IL-6+sIL-6r). Action potential duration (APD) was also recorded from the ventricle of each mouse, with or without LIF. Both LIF and IL-6+sIL-6r increased I(CaL) density significantly in WT (+27.0%, n=16 p<0.05, and +32.2%, n=15, p<0.05, respectively), but not in gp130(F759/F759) (+9.4%, n=16, NS, and -6.1%, n=13, NS, respectively). Administration of LIF and IL-6+sIL-6r increased [Ca(2+)](i) transient significantly in WT (+18.8%, n=13, p<0.05, and +32.0%, n=21, p<0.05, respectively), but not in gp130(F759/F759) (-3.8%, n=7, NS, and -6.4%, n=10, NS, respectively). LIF prolonged APD(80) significantly in WT (10.5+/-4.3%, n=12, p<0.05), but not in gp130(F759/F759) (-2.1+/-11.2%, n=7, NS). SHP2-mediated signaling cascade is essential for the LIF and IL-6+sIL-6r-dependent increase in I(CaL), [Ca(2+)](i) transient and APD.
Collapse
Affiliation(s)
- Yoko Hagiwara
- Division of Cardiology, Department of Medicine, Keio University School of Medicine, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Furukawa T, Kurokawa J. Potassium channel remodeling in cardiac hypertrophy. J Mol Cell Cardiol 2006; 41:753-61. [PMID: 16962130 DOI: 10.1016/j.yjmcc.2006.07.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Revised: 07/28/2006] [Accepted: 07/31/2006] [Indexed: 10/24/2022]
Abstract
Cardiac hypertrophy is an adaptive process against increased work loads; however, hypertrophy also presents substrates for lethal ventricular arrhythmias, resulting in sudden arrhythmic deaths that account for about one third of deaths in cardiac hypertrophy. To maintain physiological cardiac function in the face of increased work loads, hypertrophied cardiomyocytes undergo K(+) channel remodeling that provides a prolongation in action potential duration and an increase in Ca(2+) entry. Increased Ca(2+) entry, in turn, activates signaling mechanisms including a calcineruin/NFAT pathway to permit remodeling of the K(+) channels. This results in a positive feedback loop between the K(+) channel remodeling and altered Ca(2+) handling; this loop may represent a potential therapeutic target against sudden arrhythmic deaths in cardiac hypertrophy. The purposes of this review are to: (1) discuss types of K(+) channels and their mRNA that undergo remodeling in cardiac hypertrophy; (2) report on recent research on molecular mechanisms of K(+) channel remodeling; and (3) address physiological events underlying new therapeutic modalities to ameliorate arrhythmias and sudden death in cardiac hypertrophy.
Collapse
Affiliation(s)
- Tetsushi Furukawa
- Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Japan.
| | | |
Collapse
|
25
|
Ganesan AN, Maack C, Johns DC, Sidor A, O'Rourke B. Beta-adrenergic stimulation of L-type Ca2+ channels in cardiac myocytes requires the distal carboxyl terminus of alpha1C but not serine 1928. Circ Res 2006; 98:e11-8. [PMID: 16397147 PMCID: PMC2692538 DOI: 10.1161/01.res.0000202692.23001.e2] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Beta-adrenoceptor stimulation robustly increases cardiac L-type Ca2+ current (ICaL); yet the molecular mechanism of this effect is still not well understood. Previous reports have shown in vitro phosphorylation of a consensus protein kinase A site at serine 1928 on the carboxyl terminus of the alpha1C subunit; however, the functional role of this site has not been investigated in cardiac myocytes. Here, we examine the effects of truncating the distal carboxyl terminus of the alpha1C subunit at amino acid residue 1905 or mutating the putative protein kinase A site at serine 1928 to alanine in adult guinea pig myocytes, using novel dihydropyridine-insensitive alpha1C adenoviruses, coexpressed with beta2 subunits. Expression of alpha1C truncated at 1905 dramatically attenuated the increase of peak ICaL induced by isoproterenol. However, the point mutation S1928A did not significantly attenuate the beta-adrenergic response. The findings indicate that the distal carboxyl-terminus of alpha1C plays an important role in beta-adrenergic upregulation of cardiac L-type Ca2+ channels, but that phosphorylation of serine 1928 is not required for this effect.
Collapse
Affiliation(s)
- Anand N Ganesan
- Institute of Molecular Cardiobiology, The Johns Hopkins University, Baltimore, MD 21205, USA
| | | | | | | | | |
Collapse
|
26
|
Gibson RM, Laszlo GS, Nathanson NM. Calmodulin-dependent protein kinases phosphorylate gp130 at the serine-based dileucine internalization motif. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1714:56-62. [PMID: 16036214 DOI: 10.1016/j.bbamem.2005.05.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 05/18/2005] [Accepted: 05/23/2005] [Indexed: 11/29/2022]
Abstract
The receptor for leukemia inhibitory factor (LIF) consists of two polypeptides, the low affinity LIF receptor (LIFR) and gp130. We previously demonstrated that LIF stimulation caused phosphorylation of gp130 at Ser782, adjacent to a dileucine internalization motif, and that transient expression of a mutant receptor lacking Ser782 resulted in increased cell surface expression and increased LIF-stimulated gene expression compared to wild-type receptor. Phosphorylation of Ser782 on gp130 fusion protein by LIF-stimulated 3T3-L1 cell extracts was inhibited 61% by autocamtide-2-related inhibitory peptide (AIP), a highly specific and highly effective inhibitor of calmodulin-dependent protein kinase type II (CaMKII). Purified rat forebrain CaMKII was also able to phosphorylate gp130 fusion protein at Ser782 in vitro. Furthermore, antibodies targeting CaMKII and CaMKIV were able to immunoprecipitate gp130 phosphorylating activity from LIF-stimulated 3T3-L1 lysates. While pretreatment of cells with the MAPKK inhibitors PD98059 and U0126 blocked phosphorylation of Ser782 prior to LIF stimulation, these inhibitors did not block Ser782 phosphorylation by LIF-stimulated 3T3-L1 cell extracts in vitro. These results show that CaMKII and possibly CaMKIV phosphorylate Ser782 in the serine-based dileucine internalization motif of gp130 via a MAPK-dependent pathway.
Collapse
Affiliation(s)
- Robin M Gibson
- Department of Pharmacology, University of Washington, Box 357750, Seattle, WA 98195-7750, USA
| | | | | |
Collapse
|