Ethanol activates NFkappaB DNA binding and p56lck protein tyrosine kinase in human osteoblast-like cells.
Ethanol activates NFkappaB DNA binding and p56lck protein tyrosine kinase in human osteoblast-like cells.
复制标题
乙醇激活人成骨细胞样细胞中的 NFkappaB DNA 结合和 p56lck 蛋白酪氨酸激酶。
DOI：
10.1016/s8756-3282(00)00425-7
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发表时间：
2001
期刊：
影响因子：
4.1
通讯作者：
Keller,ET
中科院分区：
文献类型：
--
作者：
Yao,Z;Zhang,J;Dai,J;Keller,ET
酗酒者经常遭受中度到严重的骨质流失，导致骨折。骨生成的减少和骨吸收的增加都被认为是乙醇（ETOH）介导的骨质流失的原因。骨吸收是由几种促炎细胞因子如白细胞介素-1和-6诱导的。这些细胞因子的表达是由转录因子NFκB诱导的，而转录因子NFκB又被几种激酶激活。由此可见，蛋白激酶和NFκB的激活可能有助于etoh诱导的骨质流失。因此，我们试图确定ETOH是否激活人成骨细胞样细胞系（HOBIT）中的蛋白酪氨酸激酶（PTK）和NFκB DNA结合。50和100 mmol/L的乙醇（反映慢性酒精中毒患者血液中乙醇水平）作用24小时不改变HOBIT细胞活力。相比之下，200 mmol/L乙醇使细胞活力降低40%。100 mmol/L ETOH处理HOBIT细胞诱导细胞核nf - κ b:DNA复合物形成和nf - κ b活性。50mmol /L和100mmol /L ETOH培养HOBIT细胞30min后，PTK活性分别提高2.5倍和4.2倍。用抑制p56lck的damnacanthal （DAM）预孵育HOBIT细胞，阻断etoh介导的PTK活性；而用抑制pp60src的herbimycin A预孵育则没有作用。DAM抑制乙醇诱导的HOBIT细胞nf - κ b活化和人原代成骨细胞中白细胞介素-6的表达。最后，用蛋白激酶C抑制剂双吲哚马来酰亚胺I HCl （BIS）预孵育，降低了etoh介导的PTK活性；而与蛋白激酶A抑制剂H89预孵育则没有。这些数据表明，ETOH通过p56lckin HOBIT细胞诱导NFκB核易位。BIS对PTK激活的抑制表明ETOH通过蛋白激酶c依赖性途径激活PTK。这些数据表明，ETOH可能通过激活信号转导，导致成骨细胞产生破骨细胞因子（即白细胞介素-6），从而导致骨质流失。
Alcoholics frequently suffer from moderate to severe bone loss that results in bone fractures. Both decreased bone production and increased bone resorption have been postulated to contribute to ethanol (ETOH)-mediated bone loss. Bone resorption is induced by several proinflammatory cytokines such as interleukin-1 and -6. The expression of these cytokines is induced by the transcription factor NFκB, which, in turn, is activated by several kinases. It follows that protein kinase and NFκB activation may contribute to ETOH-induced bone loss. Accordingly, we sought to determine if ETOH activates protein tyrosine kinases (PTK) and NFκB DNA binding in a human osteoblast-like cell line (HOBIT). Ethanol at 50 and 100 mmol/L (reflective of blood ethanol levels reached in chronic alcoholics) for 24 h did not alter HOBIT cell viability. In contrast, 200 mmol/L ethanol decreased cell viability by 40%. Treatment of HOBIT cells with 100 mmol/L ETOH induced nuclear NFκB:DNA complex formation and NFκB activity. Incubation of HOBIT cells with ETOH at 50 and 100 mmol/L for 30 min induced a 2.5- and 4.2-fold increase in PTK activity, respectively. Preincubation of HOBIT cells with damnacanthal (DAM), which inhibits p56lck, blocked ETOH-mediated PTK activity; whereas, preincubation with herbimycin A, which inhibits pp60src, did not. DAM inhibited both ethanol-induced NFκB activation in HOBIT cells and interleukin-6 expression in primary human osteoblasts. Finally, preincubation with the protein kinase C inhibitor, bisindolylmaleimide I HCl (BIS), diminished ETOH-mediated PTK activity; whereas, preincubation with the protein kinase A inhibitor, H89, did not. These data demonstrate that ETOH induces NFκB nuclear translocation through p56lckin HOBIT cells. BIS′ inhibition of PTK activation suggests that ETOH activates PTK through a protein kinase C-dependent pathway. These data suggest that ETOH may contribute to bone loss through activation of signal transduction that results in production of an osteoclastogenic cytokine (i.e., interleukin-6) in osteoblasts.