Transcriptomic effects of adenosine 2A receptor deletion in healthy and endotoxemic murine myocardium

Abstract

Influences of adenosine 2A receptor (A 2A R) activity on the cardiac transcriptome and genesis of endotoxemic myocarditis are unclear. We applied transcriptomic profiling (39 K Affymetrix arrays) to identify A 2A R-sensitive molecules, revealed by receptor knockout (KO), in healthy and endotoxemic hearts. Baseline cardiac function was unaltered and only 37 A 2A R-sensitive genes modified by A 2A R KO (≥1.2-fold change, <5 % FDR); the five most induced are Mtr, Ppbp, Chac1, Ctsk and Cnpy2 and the five most repressed are Hp, Yipf4, Acta1, Cidec and Map3k2. Few canonical paths were impacted, with altered Gnb1, Prkar2b, Pde3b and Map3k2 (among others) implicating modified G protein/cAMP/PKA and cGMP/NOS signalling. Lipopolysaccharide (LPS; 20 mg/kg) challenge for 24 h modified >4100 transcripts in wild-type (WT) myocardium (≥1.5-fold change, FDR < 1 %); the most induced are Lcn2 (+590); Saa3 (+516); Serpina3n (+122); Cxcl9 (+101) and Cxcl1 (+89) and the most repressed are Car3 (−38); Adipoq (−17); Atgrl1/Aplnr (−14); H19 (−11) and Itga8 (−8). Canonical responses centred on inflammation, immunity, cell death and remodelling, with pronounced amplification of tolllike receptor (TLR) and underlying JAK-STAT, NFκB and MAPK pathways, and a 'cardio-depressant' profile encompassing suppressed ß-adrenergic, PKA and Ca 2+ signalling, electromechanical and mitochondrial function (and major shifts in transcripts impacting function/injury including Lcn2, S100a8/S100a9, Icam1/Vcam and Nox2 induction, and Adipoq, Igf1 and Aplnr repression). Endotoxemic responses were selectively modified by A 2A R KO, supporting inflammatory suppression via A 2A R sensitive shifts in regulators of NFκB and JAK-STAT signalling (IκBζ, IκBα, STAT1, CDKN1a and RRAS2) without impacting the cardio-depressant gene profile. Data indicate A 2A Rs exert minor effects in un-stressed myocardium and selectively suppress NFκB and JAK-STATsignalling and cardiac injury without influencing cardiac depression in endotoxemia.

Phenotyping of Mice with Heart Specific Overexpression of A2A-Adenosine Receptors: Evidence for Cardioprotective Effects of A2A-Adenosine Receptors

“…Moreover, work in isolated perfused A 2A -KO (constitutive deletion) mouse hearts clearly established that CGS 21680 a classical A 2A -receptor agonist was selective: only in WT hearts CGS 21680 (up to 1 μM) increased contractility but not in hearts from A 2A -KO mice ( Ledent et al, 1997 ). However, under basal conditions (no CGS 21680 given) contractility of WT and KO were not different ( Ledent et al, 1997 ; Ashton et al, 2017 ), suggesting that CGS 21680 is an appropriate tool to assess A 2A function in mice. Moreover, there is evidence that A 2A -receptor stimulation can protect the heart against reperfusion injury [e.g., rat ( Cargnoni et al, 1999 )].…”

Exploration and Validation of Hub Genes and Pathways in the Progression of Hypoplastic Left Heart Syndrome via Weighted Gene Co-Expression Network Analysis

“…Furthermore, there was a signi cant difference in Fbn1 expression between LV and RV for control mice. Itga8 (Integrin Subunit Alpha 8) inhibits NFκB and JAK-STAT signaling and cardiac injury in myocardium without stress [27]. Itga8 expression was signi cantly higher in LV/RV HLHS in comparison to controls both in the GSE77798 and GSE23959 datasets.…”

Role of Cardiac A2A Receptors Under Normal and Pathophysiological Conditions

“…However, what is the role of endogenous adenosine in sepsis? In A 2A -AR KO mice, sepsis was more pronounced than in WT mice ( Reichelt et al, 2013 ; Ashton et al, 2017 ) or unaltered ( Reutershan et al, 2007 ). Therefore, the role of A 2A -AR in sepsis might be quite subtle; age and gender might also be a factor, as older male KO mice exhibited a poor prognosis ( Ashton et al, 2017 ).…”

“…In A 2A -AR KO mice, sepsis was more pronounced than in WT mice ( Reichelt et al, 2013 ; Ashton et al, 2017 ) or unaltered ( Reutershan et al, 2007 ). Therefore, the role of A 2A -AR in sepsis might be quite subtle; age and gender might also be a factor, as older male KO mice exhibited a poor prognosis ( Ashton et al, 2017 ). A 2A -AR also protect against postconditioning ( Dhalla et al, 2006 ; Morrison et al, 2007 ; review; McIntosh and Lasley 2012 ) and preconditioning ( Button et al, 2005 ; Yang et al, 2005 ) and ischemia and reperfusion in vivo rats ( Kis et al, 2003 ; Ke et al, 2015 ).…”

“…Furthermore, we noted a functional role of A 2A -AR stimulation in isolated paced right atrial preparations from diseased human hearts ( Boknik et al, 2018 ). However, under basal conditions in which no CGS21680 was given, there was no difference in the contractility of WT and KO mouse hearts ( Ashton et al, 2017 ; Morrison et al, 2002 ). The stimulation of the A 2A -AR produced a positive inotropic effect ( Table 8 ; Woodiwiss et al, 1999 ; Monahan et al, 2000 ; Chan et al, 2008 ; Dobson et al, 2008 ; Tikh et al, 2008 ), which increased in the presence of additional A 1 -AR blockade DPCPX ( Fredholm et al, 2011 for selectivity of DPCPX).…”