Long‐term treatment with TGFβ1 impairs mechanotransduction in bovine aortic endothelial cells
Long‐term treatment with TGFβ1 impairs mechanotransduction in bovine aortic endothelial cells
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DOI：
10.1038/sj.bjp.0707123
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发表时间：
2007-02
影响因子：
7.3
通讯作者：
M. Watanabe;M. Oike;Y. Ohta;Y. Ito
中科院分区：
文献类型：
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作者：
M. Watanabe;M. Oike;Y. Ohta;Y. Ito
背景与目的血管内皮细胞在机械应力的生理反应中起重要作用.转化生长因子β1（transforminggrowthfactor β1，TGFβ1）可诱导内皮细胞发生形态学改变，从而改变其机械敏感性反应。本研究旨在探讨TGFβ 1对牛主动脉内皮细胞（BAECs）低渗应激（HTS）反应的影响。实验方法将培养的BAECs用3 ng/ml TGF β 1处理24 h（24 h-TGF β1）或7 d（7 d-TGF β1）。用罗丹明-鬼笔环肽染色细胞质肌动蛋白纤维。使用fura 2测定细胞内Ca 2+浓度。酪氨酸磷酸化和RhoA表达通过蛋白质印迹法进行评估。通过真实的时间PCR评估RhoA mRNA的表达。关键结果BAECs在24 h内形成伪足样突起，并在7 d后显示成纤维细胞样外观。HTS通过内源性ATP释放在对照和24 h-TGFβ 1BAEC中诱导Ca 2+瞬变，但在7 d-TGFβ 1BAEC中不诱导。我们先前已经表明，HTS诱导的ATP释放是由RhoA和酪氨酸激酶的顺序激活介导的。7 d-TGF β 1组的RhoA基础表达量显著低于24 h-TGF β 1组和对照组。HTS使24 h-TGF β 1和对照BAEC中的膜结合RhoA增加至相同的分数水平，但其净最大量在7 d-TGF β1中显著降低。HTS诱导的RhoA活化的下游信号，即FAK和桩蛋白的酪氨酸磷酸化，在7 d-TGFβ1BAECs.Conclusions和Implications中被显著抑制这些结果表明，长期用TGFβ 1治疗不会损害BAECs中的机械感受，但通过影响RhoA膜转位而损害机械转导。British Journal of Pharmacology（2007）150，424-433。doi：10.1038/sj.bjp.0707123
Background and purposeVascular endothelial cells play a role in the physiological response to mechanical stress. Transforming growth factor β1(TGFβ1) induces morphological changes in endothelial cells, and this may alter their mechanosensitive responses. The aim of this study was to examine the effects of TGFβ1on hypotonic stress (HTS)‐induced responses in bovine aortic endothelial cells (BAECs).Experimental approachCultured BAECs were treated with 3 ng ml‐1TGFβ1for 24 h (24h‐TGFβ1) or 7 days (7d‐TGFβ1). Cytosolic actin fibres were stained with rhodamine‐phalloidin. Intracellular Ca2+concentration was measured using fura2. Tyrosine phosphorylation and RhoA expression were assessed by Western blotting. Expression of RhoA mRNA was assessed by real‐time PCR.Key resultsBAECs developed pseudopod‐like processes within 24 h and showed a fibroblast‐like appearance after 7 days. HTS induced Ca2+transients via endogenous ATP release in both control and 24h‐TGFβ1BAECs but not in 7d‐TGFβ1BAECs. We have previously shown that HTS‐induced ATP release is mediated by sequential activation of RhoA and tyrosine kinases. The basal amount of membrane‐bound RhoA was significantly lower in 7d‐TGFβ1than in 24h‐TGFβ1or control BAECs. HTS increased the membrane‐bound RhoA to the same fractional level in 24h‐TGFβ1and control BAECs, but its net maximal amount was significantly lower in 7d‐TGFβ1. HTS‐induced downstream signals of RhoA activation, i.e. the tyrosine phosphorylation of FAK and paxillin, were markedly suppressed in 7d‐TGFβ1BAECs.Conclusions and ImplicationsThese results indicate that long‐term treatment with TGFβ1does not impair mechanoreception in BAECs but impairs mechanotransduction by affecting RhoA membrane translocation.British Journal of Pharmacology(2007)150, 424–433. doi:10.1038/sj.bjp.0707123