New cardiac expression of two adenosine-2A receptor isoforms in dysfunctioning minipigs

• Published in: Journal of receptors and signal transduction Vol. 37; no. 4; p. 379
• Main Authors: Cabiati, Manuela, Svezia, Benedetta, Matteucci, Marco, Panchetti, Luca, Burchielli, Silvia, Morales, Maria-Aurora, Del Ry, Silvia
• Format: Journal Article
• Language: English
• Published: England 04.07.2017
• Subjects: Adenosine - metabolism; Animals; Heart Ventricles - metabolism; Heart Ventricles - pathology; Humans; Myocardium - metabolism; Myocardium - pathology; Protein Isoforms - genetics; Receptor, Adenosine A2A - genetics; Swine; Swine, Miniature; Ventricular Dysfunction, Left - genetics; Ventricular Dysfunction, Left - metabolism; Ventricular Dysfunction, Left - pathology; Adenosine-2A receptor; left ventricular dysfunction; Sus scrofa; cardiac mRNA expression; sequencing
• ISSN: 1532-4281
• DOI: 10.1080/10799893.2017.1286677

Eight A R variants are reported in humans while no A R isoforms in pigs. The aim of this study was to evaluate potential isoforms presence in cardiac pig tissue to better define possible involvement of A R in the cardiovascular pathophysiology. In adult male minipigs (n = 4) left ventricular dysfunction (LVD) was induced by pacing at 200 bpm in the right ventricular (RV) apex. In these animals and in sham operated pigs (C-SHAM, n = 4) cardiac tissue was collected from LV-septal wall (LV-SW)-close to pacing site-and from lateral (opposite) site (LV-OSW). A R specific primers, derived from Sus scrofa AY772412 sequence, were used for Real-Time PCR. The DNA was sequenced using the Sanger method. Histological analysis was also performed. In LV-SW of LVD minipigs the A R melting curves were characterized by a sharp peak between 87 and 91 °C (short isoform, 1-94 bp) on the right of the principal peak corresponding to a long A R isoform (GenBank: JQ229674.1) 1-213 bp. As for C-SHAM only one peak was observed in LV-OSW region of LVD animals. The short isoform had an alternative promoter region and a specific translated protein. Histology showed in LVD-LV-SW prominent Purkinje cells compared to LV-OSW and C-SHAM. No difference in A R expression was observed between LVD animals and C-SHAM although a slight decrease was observed in LVD-LV-OSW. The presence of two different isoforms in the myocardium close to the insertion of pacing is suggestive of a differential state-specific expression of A R in cardiac tissue.