Stimulation of P2Y receptors activates c-fos gene expression and inhibits DNA synthesis in cultured cardiac fibroblasts

• Published in: Cardiovascular research 1998-03, Vol.37 (3), p.718-728
• Main Authors: ZHENG, J.-S, O'NEILL, L, XILIN LONG, WEBB, T. E, BARNARD, E. A, LAKATTA, E. G, BOLUYT, M. O
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - pharmacology; Animals; Biological and medical sciences; Blotting, Northern; Calcium - metabolism; Cells, Cultured; Chelating Agents - pharmacology; DNA - analysis; DNA - biosynthesis; Egtazic Acid - analogs & derivatives; Egtazic Acid - pharmacology; Fibroblasts - drug effects; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Genes, fos; Heart; Myocardium - cytology; Myocardium - metabolism; Norepinephrine - pharmacology; Rats; Rats, Wistar; Receptors, Purinergic P2 - drug effects; Signal Transduction - drug effects; Sympathomimetics - pharmacology; Vertebrates: cardiovascular system
• ISSN: 0008-6363; 1755-3245
• DOI: 10.1016/s0008-6363(97)00245-9

The aims of this study were to determine (1) whether neonatal rat cardiac fibroblasts (CAFB) express P2Y receptors; (2) whether CAFB respond to extracellular ATP by inducing expression of c-fos mRNA; and (3) whether extracellular ATP modulates norepinephrine (NE)-stimulated cell growth in CAFB. Expression of P2Y1 and P2Y2 receptors and induction of c-fos were examined by Northern blot analysis. CAFB growth was assessed by measuring [3H]thymidine incorporation and DNA content. P2Y receptor pharmacology was studied using various ATP analogues. Northern blot analysis of polyA enriched RNA confirmed that at least 2 subtypes of P2Y receptors (P2Y1 and P2Y2) are expressed in cultured CAFB. Extracellular ATP induced the expression of c-fos mRNA through a pathway that was sensitive to inhibitors of protein kinase C (PKC), but not to inhibitors of intracellular Ca2+ signaling. Extracellular ATP inhibited the NE-stimulated increases in DNA content and in [3H]thymidine incorporation into DNA. Whereas the potency order for stimulation of c-fos expression was ATP = UTP > ADP > adenosine, the potency order to inhibit the NE-induced increase of [3H]thymidine incorporation into DNA was ATP > ADP > UTP > adenosine. These data demonstrate that CAFB express both P2Y1 and P2Y2 receptor mRNA and that CAFB respond to P2Y receptor stimulation by induction of c-fos and inhibition of DNA synthesis. These findings suggest that the effects of ATP on [3H]thymidine incorporation into DNA and on expression of c-fos mRNA are exerted via distinct P2Y receptor subtypes.