Extracellular ATP is an autocrine/paracrine regulator of hypoxia-induced adventitial fibroblast growth - Signaling through extracellular signal-regulated kinase-1/2 and the Egr-1 transcription factor
Extracellular ATP is an autocrine/paracrine regulator of hypoxia-induced adventitial fibroblast growth - Signaling through extracellular signal-regulated kinase-1/2 and the Egr-1 transcription factor
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DOI：
10.1074/jbc.m203012200
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发表时间：
2002-11-22
影响因子：
4.8
通讯作者：
Stenmark, KR
中科院分区：
文献类型：
--
作者：
Gerasimovskaya, EV;Ahmad, S;Stenmark, KR
腺嘌呤核苷酸的重要自分泌/旁分泌功能已在几种组织中提出。我们探讨了细胞外ATP调节/介导缺氧诱导的外膜成纤维细胞生长的可能性。急性缺氧（3%O ~（-2），10-60 min）可使肺外膜成纤维细胞和肺微血管内皮细胞的细胞外ATP浓度升高，慢性缺氧（3%O ~（-2），14-30 d）可显著降低外核苷酸酶对细胞外ATP的水解速率。与UTP、ADP β、2-甲硫基腺苷三磷酸、腺苷5 '-（α，β-亚甲基）三磷酸和苯甲酰苯甲酰-ATP（2'-3 '-O-（4-苯甲酰苯甲酰）-ATP）一样，外源性ATP刺激成纤维细胞中[H-3]胸苷掺入，表明P2 Y和P2 X嘌呤受体均可介导促有丝分裂反应。苏拉明（100 μ M）、汽巴蓝3GA（100 μ M）和磷酸吡哆醛-6-偶氮苯基-2 '，-4'-二磺酸（100 μ M）以及腺苷三磷酸双磷酸酶（5单位/ml）减弱缺氧和ATP诱导的DNA合成，表明在缺氧条件下嘌呤受体的激活和功能作用。ATP诱导的DNA合成增加缺氧的添加剂的方式，而ATP和缺氧协同增加生长因子诱导的DNA合成，再次表明，ATP和缺氧利用类似的信号通路，以诱导增殖。事实上，我们发现ATP（100 pm）和缺氧（3%O2）诱导Egr-1转录因子的表达和激活，这两种刺激部分通过Galalpha（i）/ERK 1/2依赖性信号通路起作用。苏拉明、汽巴蓝3GA和腺苷三磷酸双磷酸酶减弱缺氧诱导的ERK 1/2激活和Egr-1表达。我们的结论是，缺氧诱导内皮细胞和成纤维细胞的ATP释放和P2嘌呤受体的激活参与缺氧条件下成纤维细胞的DNA合成的调节。
Important autocrine/paracrine functions for the adenine nucleotides have been proposed in several tissues. We addressed the possibility that extracellular ATP would modulate/mediate hypoxia-induced adventitial fibroblast growth. Acute hypoxia (3% O-2, 10-60 min) increased extracellular ATP concentrations in adventitial fibroblasts and in lung microvascular endothelial cells, and chronic hypoxia (3% O-2, 14-30 days) markedly attenuated the rate of extracellular ATP hydrolysis by ecto-nucleotidase(s). Exogenous ATP stimulated [H-3]thymidine incorporation in fibroblasts as did UTP, ADPbeta, 2-methylthioadenosine triphosphate, adenosine 5'-(alpha,beta-methylene)triphosphate, and benzoylbenzoyl-ATP (2'-3'-O-(4-benzoylbenzoyl)-ATP), indicating that both P2Y and P2X purinoceptors can mediate mitogenic responses. Suramin (100 muM), Cibacron blue 3GA (100 pm), and pyridoxalphosphate-6-azophenyl-2',-4'-disulfonic acid (100 muM) as well as apyrase (5 units/ml) attenuated hypoxia- and ATP-induced and DNA synthesis, indicating activation and a functional role of purinoceptors under hypoxic conditions. ATP-induced DNA synthesis was augmented by hypoxia in an additive fashion, whereas ATP and hypoxia synergistically increased growth factor-induced DNA synthesis, again suggesting that ATP and hypoxia utilize similar signaling pathways to induce proliferation. Indeed, we found that ATP (100 pm) and hypoxia (3% 02) induced expression and activation of Egr-1 transcription factor, and both stimuli acted, in part, through a Galpha(i)/ERK1/2-dependent signaling pathway. Suramin, Cibacron blue 3GA, and apyrase attenuated hypoxia-induced ERK1/2 activation and Egr-1 expression. We conclude that hypoxia induces ATP release from endothelial cells and fibroblasts and that the activation of P2 purinoceptors is involved in the regulation of DNA synthesis by fibroblasts under hypoxic conditions.