Essential role of EGFR in cardioprotection and signaling responses to A₁ adenosine receptors and ischemic preconditioning

Abstract

Transactivation of epidermal growth factor receptor (EGFR) may contribute to specific protective responses (e.g. mediated by δ-opioid, bradykinin, or muscarinic receptors). No studies have assessed EGFR involvement in cardioprotection mediated by adenosine receptors (ARs), and the role of EGFR in ischemic preconditioning (IPC) is unclear. We tested EGFR, matrix metalloproteinase (MMP), and heparin-binding EGF (HB-EGF) dependencies of functional protection via A1AR agonism or IPC. Pretreatment of mouse hearts with 100 nM of A1AR agonist 2-chloro- N6-cyclopentyladenosine (CCPA) or IPC (3 × 1.5-min ischemia/2-min reperfusion) substantially improved recovery from 25-min ischemia, reducing left ventricular diastolic dysfunction up to 50% and nearly doubling pressure development and positive change in pressure over time (+dP/d t). Benefit with both CCPA and IPC was eliminated by inhibitors of EGFR tyrosine kinase (0.3 μM AG1478), MMP (0.3 μM GM6001), or HB-EGF ligand (0.3 ng/ml CRM197), none of which independently altered postischemic outcome. Phosphorylation of myocardial EGFR, Erk1/2, and Akt increased two- to threefold during A1AR agonism, with responses blocked by AG1478, GM6001, and CRM197. Studies in HL-1 myocytes confirm A1AR-dependent Erk1/2 phosphorylation is negated by AG1478 or GM6001, and reduced with CRM197 (as was Akt activation). These data collectively reveal that A1AR- and IPC-mediated functional protection is entirely EGFR and MMP dependent, potentially involving the HB-EGF ligand. Myocardial survival kinase activation (Erk1/2, Akt) by A1AR agonism is similarly MMP/HB-EGF/EGFR dependent. Thus MMP-mediated EGFR activation appears essential to cardiac protection and signaling via A1ARs and preconditioning.

Potential prognostic biomarker CD73 regulates epidermal growth factor receptor expression in human breast cancer

“…Recently, other studies have assessed EGFR involvement in cardioprotection mediated by adenosine receptors (ARs). Moreover, A1AR agonist 2-chloro-N6-cyclopentyladenosine substantially increased cardiac EGFR phosphorylation, while total expression of EGFR was unchanged (29). Our study showed that CD73 regulated EGFR expression through A2AR.…”

Transactivation of the epidermal growth factor receptor in responses to myocardial stress and cardioprotection

“…More specific analyses confirms an essential role for EGFR in preconditioning: chronic inhibition of EGFR with AG1478 attenuates ischaemic preconditioning by 50% or more (Benter et al, 2005a); and acute inhibition of EGFR, MMP or HB-EGF negates protection via preconditioning, though no effects were observed on intrinsic I-R tolerance (Williams-Pritchard et al, 2011).…”

“…Studies in cancer cells similarly supported sequestration of active EGFR within caveolae (Abulrob et al, 2004), while there is also evidence for signalling via both caveolar and non-caveolar EGFR (with prolonged ERK1/2 activation by extra-caveolar EGFR vs. transient ERK1/2 activation by caveolar EGFR) (Rimoldi et al, 2003). Interestingly, the protective A1 adenosine receptor, implicated in preconditioning responses and shown to protect via EGFR transactivation (Williams-Pritchard et al, 2011), appears to translocate out of myocardial caveolae upon activation (Lasley et al, 2000), though there is evidence A1 activation also translocates other signal elements, including PKC, into caveolae (Yang et al, 2009).…”

“…In cardiac cells, EGFR transactivation has been linked to angiotensin (Rakesh et al, 2010), muscarinic (Krieg et al, 2002;Krieg et al, 2004;Miao et al, 2015), endothelin (Kodama et al, 2002;Chen et al, 2006), opioid (Cao et al, 2005;Cohen et al, 2007;Forster et al, 2007;Zhang et al, 2015), bradykinin (Methner et al, 2009), adrenergic (Noma et al, 2007;Grisanti et al, 2014), adenosine (Williams-Pritchard et al, 2011), and sphoingosine-1 phosphate (S1P) (Hofmann et al, 2009) GPCRs, with transactivation via angiotensin II (Ang II) perhaps the most well studied. Several Gq-linked receptors (Ang II, ET-1, -ARs) may promote cardiac hypertrophy/remodelling, whereas transactivation by adenosine, opioid, bradykinin or muscarinic receptors may be protective, enhancing cell survival.…”

“…This transactivation appears essential to cardioprotection triggered by S1P receptor agonists. Cardiac protection and survival kinase activation in response to adenosine receptor agonism (and ischaemic preconditioning) is also associated with EGFR phosphorylation and blocked by EGFR, MMP or HB-EGF inhibitors (Williams-Pritchard et al, 2011). Finally, mechanical stress has been shown to trigger β-arrestin-dependent AT1 receptor activation, leading to EGFR transactivation and protection of cardiac myocytes from apoptosis (Rakesh et al, 2010).…”