Multiple adenosine receptor subtypes stimulate wound healing in human EA.hy926 endothelial cells

Wound healing is an important outcome of tissue damage and can be stimulated by adenosine released from cells during events such as tissue injury, ischaemia or tumour growth. The aim of this research was to determine the potency and efficacy of adenosine A 1 , A 2A and A 2B receptor agonists on the rate of wound healing and cell proliferation in human EA.hy926 endothelial cells. Real-time PCR data showed that only adenosine A 1 , A 2A and A 2B receptor mRNA were expressed in this cell line. All three adenosine receptor agonists, CPA, CGS21680 and NECA, significantly increased the rate of wound healing in human EAhy926 endothelial cells with the following order of potency CGS21680>CPA>NECA and efficacy CPA>NECA>CGS21680. The selective adenosine A 1 , A 2A and A 2B receptor antagonists, DPCPX, ZM241385 and MRS1754 (all at 10 nM), reversed the effects of their respective agonists. EAhy926 endothelial cell proliferation was also significantly increased with the adenosine A 1 and A 2B receptor agonists, CPA and NECA. Western blot analysis demonstrated that adenosine A 2A and A 1 receptor protein levels were highly expressed compared with the adenosine A 2B receptors in the EAhy926 endothelial cell lines. While all three adenosine A 1 , A 2A and A 2B receptor subtypes contribute to cell proliferation and wound healing in human EAhy926 endothelial cells, treatments selectively targeting receptor subtypes may further enhance wound healing.