Dickenson John M, Reeder Steve, Rees Bob, Alexander Steve, Kendall Dave
Department of Life Sciences, Faculty of Science and Mathematics, School of Science, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK.
Eur J Pharmacol. 2003 Aug 1;474(1):43-51. doi: 10.1016/s0014-2999(03)02041-7.
There is increasing evidence to suggest that adenosine receptors can modulate the function of cells involved in the immune system. For example, human dendritic cells derived from blood monocytes have recently been described to express functional adenosine A1, A2A and A3 receptors. Therefore, in the present study, we have investigated whether the recently established murine dendritic cell line XS-106 expresses functional adenosine receptors. The selective adenosine A3 receptor agonist 1-[2-chloro-6[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-1-deoxy-N-methyl-beta-D-ribofuranuronamide (2-Cl-IB-MECA) inhibited forskolin-mediated [3H]cyclic AMP accumulation and stimulated concentration-dependent increases in p42/p44 mitogen-activated protein kinase (MAPK) phosphorylation. The selective adenosine A2A receptor agonist 4-[2-[[-6-amino-9-(N-ethyl-beta-D-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzene-propanoic acid (CGS 21680) stimulated a robust increase in [3H]cyclic AMP accumulation and p42/p44 MAPK phosphorylation. In contrast, the selective adenosine A1 receptor agonist CPA (N6-cyclopentyladenosine) did not inhibit forskolin-mediated [3H]cyclic AMP accumulation or stimulate increases in p42/p44 MAPK phosphorylation. These observations suggest that XS-106 cells express functional adenosine A2A and A3 receptors. The non-selective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) inhibited lipopolysaccharide-induced tumour necrosis factor-alpha (TNF-alpha) release from XS-106 cells in a concentration-dependent fashion. Furthermore, treatment with Cl-IB-MECA (1 microM) or CGS 21680 (1 microM) alone produced a partial inhibition of lipopolysaccharide-induced TNF-alpha release (when compared to NECA), whereas a combination of both agonists resulted in the inhibition of TNF-alpha release comparable to that observed with NECA alone. Treatment of cells with the adenosine A2A receptor selective antagonists 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5ylamino]ethyl)phenol (ZM 241385; 100 nM) and 5-amino-2-(2-furyl)-7-phenylethyl-pyrazolo[4,3-e]-1,2,4-triazolo[1,5c]pyrimidine (SCH 58261; 100 nM) and the adenosine A3 receptor selective antagonist N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-benzeneacetamide (MRS 1220; 100 nM) partially blocked the inhibitory effects of NECA on lipopolysaccharide-induced TNF-alpha release. Combined addition of MRS 1220 and SCH 58261 completely blocked the inhibitory effects of NECA on lipopolysaccharide-induced TNF-alpha release. In conclusion, we have shown that the mouse dendritic cell line XS-106 expresses functional adenosine A2A and A3 receptors, which are capable of modulating TNF-alpha release.
越来越多的证据表明，腺苷受体可以调节参与免疫系统的细胞的功能。例如，最近有研究描述从血液单核细胞衍生而来的人树突状细胞表达功能性腺苷A1、A2A和A3受体。因此，在本研究中，我们调查了最近建立的小鼠树突状细胞系XS-106是否表达功能性腺苷受体。选择性腺苷A3受体激动剂1-[2-氯-6-[[(3-碘苯基)甲基]氨基]-9H-嘌呤-9-基]-1-脱氧-N-甲基-β-D-核糖呋喃脲苷（2-Cl-IB-MECA）抑制福斯可林介导的[3H]环磷酸腺苷（cAMP）积累，并刺激p42/p44丝裂原活化蛋白激酶（MAPK）磷酸化呈浓度依赖性增加。选择性腺苷A2A受体激动剂4-[2-[[-6-氨基-9-(N-乙基-β-D-核糖呋喃脲苷基)-9H-嘌呤-2-基]氨基]乙基]苯丙酸（CGS 21680）刺激[3H]cAMP积累和p42/p44 MAPK磷酸化显著增加。相比之下，选择性腺苷A1受体激动剂CPA（N6-环戊基腺苷）既不抑制福斯可林介导的[3H]cAMP积累，也不刺激p42/p44 MAPK磷酸化增加。这些观察结果表明，XS-106细胞表达功能性腺苷A2A和A3受体。非选择性腺苷受体激动剂5'-N-乙基羧酰胺腺苷（NECA）以浓度依赖性方式抑制脂多糖诱导的XS-106细胞释放肿瘤坏死因子-α（TNF-α）。此外，单独用Cl-IB-MECA（1 microM）或CGS 21680（1 microM）处理可部分抑制脂多糖诱导的TNF-α释放（与NECA相比），而两种激动剂联合使用导致的TNF-α释放抑制效果与单独使用NECA时相当。用腺苷A2A受体选择性拮抗剂4-(2-[7-氨基-2-(2-呋喃基)[1,2,4]三唑并[2,3-a][1,3,5]三嗪-5-基氨基]乙基)苯酚（ZM 241385；100 nM）和5-氨基-2-(2-呋喃基)-7-苯乙基-吡唑并[4,3-e]-1,2,4-三唑并[1,5-c]嘧啶（SCH 58261；100 nM）以及腺苷A3受体选择性拮抗剂N-[9-氯-2-(2-呋喃基)[1,2,4]-三唑并[1,5-c]喹唑啉-5-苯乙酰胺（MRS 1220；100 nM）处理细胞，可部分阻断NECA对脂多糖诱导的TNF-α释放的抑制作用。联合添加MRS 1220和SCH 58261可完全阻断NECA对脂多糖诱导的TNF-α释放的抑制作用。总之，我们已经表明，小鼠树突状细胞系XS-106表达功能性腺苷A2A和A3受体，它们能够调节TNF-α的释放。
