Adenosine regulates the IL-1 beta-induced cellular functions of human gingival fibroblasts

In this study we examined the influence of adenosine on the cellular functi ons of human gingival fibroblasts (HGF), such as the production of inflamma tory cytokines and extracellular matrices (ECM), and the expression and fun ction of adhesion molecules. Concerning the expression of adenosine recepto rs, RT-PCR analysis revealed that HGF expressed adenosine receptor A1, A2a and A2b, but not A3 mRNA. Ligation of adenosine receptors by adenosine or i ts related analogue, 2-chloroadenosine (2-CADO), N-6-cyclopentyladenosine ( CPA) or CGS21680 synergistically increased IL-1 beta -induced IL-6 and IL-8 production. In terms of ECM expression, adenosine and the adenosine recept or agonists, 2-CADO and CPA, enhanced constitutive and IL-1 beta -induced e xpression of hyaluronate synthase mRNA, but not the mRNA levels of other EC M, such as collagen type I, III and fibronectin. Moreover, the adherence of IL-1 beta -stimulated HGF to activated lymphocytes was also inhibited by a denosine, which is in part explained by the fact that adenosine down-regula ted the IL-1 beta -induced expression of ICAM-1 on HGF. These results provi de new evidence for the possible involvement of adenosine in the regulation of inflammatory responses in periodontal tissues.