The plant alkaloid conophylline inhibits matrix formation of fibroblasts
The plant alkaloid conophylline inhibits matrix formation of fibroblasts
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DOI：
10.1074/jbc.ra118.005783
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发表时间：
2018-12-28
影响因子：
4.8
通讯作者：
Watanabe, Hideto
中科院分区：
文献类型：
--
作者：
Tezuka, Takehiko;Ota, Akinobu;Watanabe, Hideto
Conophylline是一种来自热带植物Ervatamia microphylla的叶的生物碱，并且已经显示出模拟生长和分化因子激活素A对胰腺祖细胞的作用。然而，激活素A刺激胰腺星状细胞的纤维化，而茶碱抑制它，这表明该化合物可作为抗纤维化药物。在这里，我们研究了茶碱对人包皮成纤维细胞，特别是细胞外基质（ECM）蛋白的影响。基因微阵列分析显示，茶碱显着抑制透明质酸合成酶2（HAS 2）及其反义RNA的基因的表达，而胶原蛋白基因的表达不受影响。值得注意的是，免疫染色实验显示，在用转化生长因子（TGF）处理的细胞中，Conophylline基本上抑制多功能蛋白聚糖和胶原蛋白掺入ECM中，这促进胶原蛋白合成，但在未用TGF处理的细胞中不抑制。此外，蛋白质生物合成测定公开了茶碱降低胶原蛋白生物合成，伴随着总蛋白质生物合成的降低，表明茶碱介导的纤维化抑制对胶原蛋白合成不是特异性的。Conophylline既不影响TGF诱导的SMAD家族成员2/3（SMAD 2/3）的核转位，也不影响SMAD 2的磷酸化。然而，Conophylline实质上抑制细胞外信号调节激酶1/2（ERK 1/2）的磷酸化，表明Conophylline通过TGF介导的ERK 1/2途径的活化抑制HAS 2表达。两者合计，我们的研究结果表明，茶碱可能是一个有用的抑制剂ECM形成纤维化。
Conophylline is a Vinca alkaloid from leaves of the tropical plant Ervatamia microphylla and has been shown to mimic the effect of the growth and differentiation factor activin A on pancreatic progenitor cells. However, activin A stimulates fibrosis of pancreatic stellate cells, whereas conophylline inhibits it, suggesting that this compound may serve as an antifibrotic drug. Here we investigated the effects of conophylline on human foreskin fibroblasts, especially focusing on extracellular matrix (ECM) proteins. A gene microarray analysis revealed that conophylline remarkably suppressed expression of the gene for hyaluronan synthase 2 (HAS2) and of its antisense RNA, whereas the expression of collagen genes was unaffected. Of note, immunostaining experiments revealed that conophylline substantially inhibits incorporation of versican and collagens into the ECM in cells treated with transforming growth factor (TGF), which promotes collagen synthesis, but not in cells not treated with TGF. Moreover, a protein biosynthesis assay disclosed that conophylline decreases collagen biosynthesis, concomitant with a decrease in total protein biosynthesis, indicating that conophylline-mediated inhibition of fibrosis is not specific to collagen synthesis. Conophylline affected neither TGF-induced nuclear translocation of SMAD family member 2/3 (SMAD2/3) nor phosphorylation of SMAD2. However, conophylline substantially inhibited phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), suggesting that conophylline inhibits HAS2 expression via TGF-mediated activation of the ERK1/2 pathway. Taken together, our results indicate that conophylline may be a useful inhibitor of ECM formation in fibrosis.