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Non-classical regulation of β1- and β2-adrenoceptor-mediated inotropic responses in rat heart ventricle by the G protein Gi

Abstract

Studies suggest that increased activity of Gi contributes to the reduced β-adrenoceptor-mediated inotropic response (βAR-IR) in failing cardiomyocytes and that β2AR-IR but not β1AR-IR is blunted by dual coupling to Gs and Gi. We aimed to clarify the role of Gi upon the β1AR-IR and β2AR-IR in Sham and failing myocardium by directly measuring contractile force and cAMP accumulation. Contractility was measured ex vivo in left ventricular strips and cAMP accumulation in cardiomyocytes from rats with post-infarction heart failure (HF) or sham operates (Sham). The β2AR-IR in Sham and HF was small and was amplified by simultaneously inhibiting phosphodiesterases 3 and 4 (PDE3&4). In HF, the inotropic response and cAMP accumulation evoked by β1AR- or β2AR-stimulation were reduced. Inactivation of Gi with pertussis toxin (PTX) did not restore the β1AR-IR or β2AR-IR in HF to Sham levels but did enhance the maximal β2AR-IR. PTX increased both β1AR- and β2AR-evoked cAMP accumulation more in Sham than that in HF, and HF levels approached those in untreated Sham. The potency of agonists at β1 and at β2ARs (only under PDE3&4 inhibition) was increased in HF and by PTX in both HF and Sham. Without PDE3&4 inhibition, PTX increased only the maximal β2AR-IR, not potency. We conclude that Gi regulates both β1AR- and β2AR-IR independent of receptor coupling with Gi. Gi together with PDE3&4 tonically restrict the β2AR-IR. Gi inhibition did not restore the βAR-IR in HF despite increasing cAMP levels, suggesting that the mechanism of impairment resides downstream to cAMP signalling.

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Abbreviations

AC:

Adenylyl cyclase

ADP:

Adenosine diphosphate

βAR:

β-Adrenoceptor

βAR-IR:

β-Adrenoceptor-mediated inotropic response

Cil:

Cilostamide

(dF/dt) max :

maximal development of force

HF:

Heart failure

IBMX:

3-Isobutyl-1-methylxanthine

LVEDP:

Left ventricular end-diastolic pressure

LVSP:

Left ventricular systolic pressure

PDE:

Phosphodiesterase

PTX:

Pertussis toxin

Rol:

Rolipram

Sham:

Sham-operated

References

  • Afzal F, Aronsen JM, Moltzau LR, Sjaastad I, Levy FO, Skomedal T, Osnes JB, Qvigstad E (2011) Differential regulation of β2-adrenoceptor-mediated inotropic and lusitropic response by PDE3 and PDE4 in failing and non-failing rat cardiac ventricle. Br J Pharmacol 162:54–71

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Andersen GØ, Skomedal T, Enger M, Fidjeland A, Brattelid T, Levy FO, Osnes JB (2004) α1-AR-mediated activation of NKCC in rat cardiomyocytes involves ERK-dependent phosphorylation of the cotransporter. Am J Physiol Heart Circ Physiol 286:H1354–H1360

    CAS  PubMed  Article  Google Scholar 

  • Bristow MR, Ginsburg R, Minobe W, Cubicciotti RS, Sageman WS, Lurie K, Billingham ME, Harrison DC, Stinson EB (1982) Decreased catecholamine sensitivity and β-adrenergic-receptor density in failing human hearts. N Engl J Med 307:205–211

    CAS  PubMed  Article  Google Scholar 

  • Brown LA, Harding SE (1992) The effect of pertussis toxin on β-adrenoceptor responses in isolated cardiac myocytes from noradrenaline-treated guinea-pigs and patients with cardiac failure. Br J Pharmacol 106:115–122

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Chen-Goodspeed M, Lukan AN, Dessauer CW (2005) Modeling of Gαs and Gαi regulation of human type V and VI adenylyl cyclase. J Biol Chem 280:1808–1816

    CAS  PubMed  Article  Google Scholar 

  • Christ T, Galindo-Tovar A, Thoms M, Ravens U, Kaumann AJ (2009) Inotropy and L-type Ca2+ current, activated by β1- and β2-adrenoceptors, are differently controlled by phosphodiesterases 3 and 4 in rat heart. Br J Pharmacol 156:62–83

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Eschenhagen T (2013) PDE4 in the human heart—major player or little helper? Br J Pharmacol 169:524–527

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Feldman AM, Cates AE, Veazey WB, Hershberger RE, Bristow MR, Baughman KL, Baumgartner WA, Van DC (1988) Increase of the 40,000-mol wt pertussis toxin substrate (G protein) in the failing human heart. J Clin Invest 82:189–197

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Gilman AG (1987) G proteins: transducers of receptor-generated signals. Annu Rev Biochem 56:615–649

    CAS  PubMed  Article  Google Scholar 

  • Gong H, Adamson DL, Ranu HK, Koch WJ, Heubach JF, Ravens U, Zolk O, Harding SE (2000) The effect of Gi-protein inactivation on basal, and β1- and β2AR-stimulated contraction of myocytes from transgenic mice overexpressing the β2-adrenoceptor. Br J Pharmacol 131:594–600

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Grimm M, Gsell S, Mittmann C, Nose M, Scholz H, Weil J, Eschenhagen T (1998) Inactivation of Giα proteins increases arrhythmogenic effects of β-adrenergic stimulation in the heart. J Mol Cell Cardiol 30:1917–1928

    CAS  PubMed  Article  Google Scholar 

  • Hadcock JR, Ros M, Watkins DC, Malbon CC (1990) Cross-regulation between G-protein-mediated pathways. Stimulation of adenylyl cyclase increases expression of the inhibitory G-protein, Giα2. J Biol Chem 265:14784–14790

    CAS  PubMed  Google Scholar 

  • Hajjar RJ, Gwathmey JK (1992) Cross-bridge dynamics in human ventricular myocardium regulation of contractility in the failing heart. Circ 86:1819–1826

    CAS  Article  Google Scholar 

  • Harvey RD, Belevych AE (2003) Muscarinic regulation of cardiac ion channels. Br J Pharmacol 139:1074–1084

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Heubach JF, Rau T, Eschenhagen T, Ravens U, Kaumann AJ (2002) Physiological antagonism between ventricular β1-adrenoceptors and α1-adrenoceptors but no evidence for β2- and β3-adrenoceptor function in murine heart. Br J Pharmacol 136:217–229

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Hussain RI, Afzal F, Mørk HK, Aronsen JM, Sjaastad I, Osnes JB, Skomedal T, Levy FO, Krobert KA (2011) Cyclic AMP-dependent inotropic effects are differentially regulated by muscarinic Gi-dependent constitutive inhibition of adenylyl cyclase in failing rat ventricle. Br J Pharmacol 162:908–916

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Hussain RI, Aronsen JM, Afzal F, Sjaastad I, Osnes JB, Skomedal T, Levy FO, Krobert KA (2013) The functional activity of inhibitory G protein Gi is not increased in failing heart ventricle. J Mol Cell Cardiol 56:129–138

    CAS  PubMed  Article  Google Scholar 

  • Janssen PM, Schillinger W, Donahue JK, Zeitz O, Emami S, Lehnart SE, Weil J, Eschenhagen T, Hasenfuss G, Prestle J (2002) Intracellular β-blockade: overexpression of Gαi2 depresses the β-adrenergic response in intact myocardium. Cardiovasc Res 55:300–308

    CAS  PubMed  Article  Google Scholar 

  • Kilts JD, Gerhardt MA, Richardson MD, Sreeram G, Mackensen GB, Grocott HP, White WD, Davis RD, Newman MF, Reves JG, Schwinn DA, Kwatra MM (2000) β2-adrenergic and several other G protein-coupled receptors in human atrial membranes activate both Gs and Gi. Circ Res 87:705–709

    CAS  PubMed  Article  Google Scholar 

  • Kompa AR, Gu XH, Evans BA, Summers RJ (1999) Desensitization of cardiac β-adrenoceptor signaling with heart failure produced by myocardial infarction in the rat evidence for the role of Gi but not Gs or phosphorylating proteins. J Mol Cell Cardiol 31:1185–1201

    CAS  PubMed  Article  Google Scholar 

  • Levy FO (2013) Cardiac PDEs and crosstalk between cAMP and cGMP signalling pathways in the regulation of contractility. Naunyn Schmiedebergs Arch Pharmacol 386:665–670

    CAS  PubMed  Article  Google Scholar 

  • Levy MN (1971) Sympathetic-parasympathetic interactions in the heart. Circ Res 29:437–445

    CAS  PubMed  Article  Google Scholar 

  • Molenaar P, Christ T, Berk E, Engel A, Gillette KT, Galindo-Tovar A, Ravens U, Kaumann AJ (2014) Carvedilol induces greater control of β2- than β1-adrenoceptor-mediated inotropic and lusitropic effects by PDE3, while PDE4 has no effect in human failing myocardium. Naunyn Schmiedebergs Arch Pharmacol 387:629–640

    CAS  PubMed  Article  Google Scholar 

  • Molenaar P, Christ T, Hussain RI, Engel A, Berk E, Gillette KT, Chen L, Galindo-Tovar A, Krobert KA, Ravens U, Levy FO, Kaumann AJ (2013) PDE3, but not PDE4, reduces β1- and β2-adrenoceptor-mediated inotropic and lusitropic effects in failing ventricle from metoprolol-treated patients. Br J Pharmacol 169:528–538

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Nagata K, Communal C, Lim CC, Jain M, Suter TM, Eberli FR, Satoh N, Colucci WS, Apstein CS, Liao R (2000) Altered β-adrenergic signal transduction in nonfailing hypertrophied myocytes from Dahl salt-sensitive rats. Am J Physiol Heart Circ Physiol 279:H2502–H2508

    CAS  PubMed  Google Scholar 

  • Neumann J, Schmitz W, Scholz H, Von ML, Doring V, Kalmar P (1988) Increase in myocardial Gi-proteins in heart failure. Lancet 2:936–937

    CAS  PubMed  Article  Google Scholar 

  • Qvigstad E, Brattelid T, Sjaastad I, Andressen KW, Krobert KA, Birkeland JA, Sejersted OM, Kaumann AJ, Skomedal T, Osnes JB, Levy FO (2005) Appearance of a ventricular 5-HT4 receptor-mediated inotropic response to serotonin in heart failure. Cardiovasc Res 65:869–878

    CAS  PubMed  Article  Google Scholar 

  • Ranu HK, Mak JC, Barnes PJ, Harding SE (2000) Gi-dependent suppression of β1-adrenoceptor effects in ventricular myocytes from NE-treated guinea pigs. Am J Physiol Heart Circ Physiol 278:H1807–H1814

    CAS  PubMed  Google Scholar 

  • Rau T, Nose M, Remmers U, Weil J, Weissmuller A, Davia K, Harding S, Peppel K, Koch WJ, Eschenhagen T (2003) Overexpression of wild-type Gαi-2 suppresses β-adrenergic signaling in cardiac myocytes. FASEB J 17:523–525

    CAS  PubMed  Google Scholar 

  • Reithmann C, Werdan K (1995) Chronic muscarinic cholinoceptor stimulation increases adenylyl cyclase responsiveness in rat cardiomyocytes by a decrease in the level of inhibitory G-protein α-subunits. Naunyn Schmiedebergs Arch Pharmacol 351:27–34

    CAS  PubMed  Article  Google Scholar 

  • Richter W, Day P, Agrawal R, Bruss MD, Granier S, Wang YL, Rasmussen SG, Horner K, Wang P, Lei T, Patterson AJ, Kobilka B, Conti M (2008) Signaling from β1- and β2-adrenergic receptors is defined by differential interactions with PDE4. EMBO J 27:384–393

    CAS  PubMed Central  PubMed  Article  Google Scholar 

  • Sjaastad I, Schiander I, Sjetnan A, Qvigstad E, Bøkenes J, Sandnes D, Osnes JB, Sejersted OM, Skomedal T (2003) Increased contribution of α1- vs. β-adrenoceptor-mediated inotropic response in rats with congestive heart failure. Acta Physiol Scand 177:449–458

    CAS  PubMed  Article  Google Scholar 

  • Sjaastad I, Sejersted OM, Ilebekk A, Bjørnerheim R (2000) Echocardiographic criteria for detection of postinfarction congestive heart failure in rats. J Appl Physiol 89:1445–1454

    CAS  PubMed  Google Scholar 

  • Skomedal T, Borthne K, Aass H, Geiran O, Osnes JB (1997) Comparison between α1 adrenoceptor-mediated and β adrenoceptor-mediated inotropic components elicited by norepinephrine in failing human ventricular muscle. J Pharmacol Exp Ther 280:721–729

    CAS  PubMed  Google Scholar 

  • Skomedal T, Grynne B, Osnes JB, Sjetnan AE, Øye I (1980) A radioimmunoassay for cyclic AMP (cAMP) obtained by acetylation of both unlabeled and labeled (3H-cAMP) ligand, or of unlabeled ligand only. Acta Pharmacol Toxicol (Copenh) 46:200–204

    CAS  Article  Google Scholar 

  • Skomedal T, Osnes JB, Øye I (1982) Differences between α-adrenergic and β-adrenergic inotropic effects in rat heart papillary muscles. Acta Pharmacol Toxicol (Copenh) 50:1–12

    CAS  Article  Google Scholar 

  • Taussig R, Tang WJ, Hepler JR, Gilman AG (1994) Distinct patterns of bidirectional regulation of mammalian adenylyl cyclases. J Biol Chem 269:6093–6100

    CAS  PubMed  Google Scholar 

  • Ungerer M, Böhm M, Elce JS, Erdmann E, Lohse MJ (1993) Altered expression of β-adrenergic receptor kinase and β1-adrenergic receptors in the failing human heart. Circulation 87:454–463

    CAS  PubMed  Article  Google Scholar 

  • Watkins DC, Northup JK, Malbon CC (1989) Pertussis toxin treatment in vivo is associated with a decline in G-protein β-subunits. J Biol Chem 264:4186–4194

    CAS  PubMed  Google Scholar 

  • Xiao RP, Avdonin P, Zhou YY, Cheng H, Akhter SA, Eschenhagen T, Lefkowitz RJ, Koch WJ, Lakatta EG (1999) Coupling of β2-adrenoceptor to Gi proteins and its physiological relevance in murine cardiac myocytes. Circ Res 84:43–52

    CAS  PubMed  Article  Google Scholar 

  • Xiao RP, Ji X, Lakatta EG (1995) Functional coupling of the β2-adrenoceptor to a pertussis toxin-sensitive G protein in cardiac myocytes. Mol Pharmacol 47:322–329

    CAS  PubMed  Google Scholar 

  • Xiao RP, Zhang SJ, Chakir K, Avdonin P, Zhu W, Bond RA, Balke CW, Lakatta EG, Cheng H (2003) Enhanced Gi signaling selectively negates β2-adrenergic receptor (AR)–but not β1-AR-mediated positive inotropic effect in myocytes from failing rat hearts. Circulation 108:1633–1639

    CAS  PubMed  Article  Google Scholar 

  • Zhu W, Zeng X, Zheng M, Xiao RP (2005) The enigma of β2-adrenergic receptor Gi signaling in the heart: the good, the bad, and the ugly. Circ Res 97:507–509

    CAS  PubMed  Article  Google Scholar 

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Acknowledgments

We thank Iwona Gutowska Schiander for excellent technical assistance. This work was supported by the Norwegian Council on Cardiovascular Diseases, the Research Council of Norway, the Stiftelsen Kristian Gerhard Jebsen foundation, the Anders Jahre foundation for the promotion of science, the Family Blix foundation, the Simon-Fougner-Hartmann family foundation and grants from the University of Oslo.

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Correspondence to Finn Olav Levy.

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Caroline Bull Melsom and Rizwan Iqbal Hussain contributed equally to the work.

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Melsom, C.B., Hussain, R.I., Ørstavik, Ø. et al. Non-classical regulation of β1- and β2-adrenoceptor-mediated inotropic responses in rat heart ventricle by the G protein Gi . Naunyn-Schmiedeberg's Arch Pharmacol 387, 1177–1186 (2014). https://doi.org/10.1007/s00210-014-1036-7

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  • DOI: https://doi.org/10.1007/s00210-014-1036-7

Keywords

  • Contractility
  • cAMP
  • Pertussis toxin
  • Heart failure
  • Receptor signalling
  • Inhibitory G protein