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Elucidation of the mechanisms of okadaic acid-induced apoptosis and cleavage of nucleolar proteins in osteoblasts

阐明冈田酸诱导成骨细胞凋亡和核仁蛋白裂解的机制

基本信息

批准号：
17591915
负责人：
HANEJI Tatsuji
金额：
$ 2.18万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Protein phosphorylation and dephosphorylation has been recognized as a key mechanism in cell function. Okadaic acid (OA) is a potent inhibitor of protein phosphatases and induces apoptosis in human osteoblasts. Nuclear factor-kappa B (NF-κB) is an essential transcription factor in the control of expression of genes involved in cell growth and differentiation. Treatment of human osteoblastic MG63 cells with OA enhanced the phosphorylation level of NF-κB on serine 536, as judged from the results of Western analysis and a k protein phosphatase dephosphorylation assay. OA stimulated the transcriptional activity of NF-κB in MG63 cells by a luciferase assay. These findings indicate that OA elicit phosphorylation of NF-κB on serine 536 in MG63 cells, resulting in the translocation of phospho-NF-κB to the nucleus, thereby promoting transcriptional activity of genes.Nucleolin is an abundantly expressed nucleolar phosphoprotein and is located mainly in the nucleolus. The staining pattern of nucleolin in cultured cells is similar to that of protein phosphatase1δ. (PP1δ). Nucleolin was demonstrated to bind to PP1δ in nucleolus in human osteoblasts by using immunocytochemical and immunoprecipitation methods. AgNORs and nucleolin disappeared from the nuclei of the osteoblasts treated with OA. A major band, 110 kDa, was detected in the proteins obtained from osteoblastic cells. The level of the 110 kDa protein decreased in the apoptotic osteoblasts, whereas an additional band, 80 kDa, appeared and the level of this protein increased in the proteins prepared from OA-induced apoptotic osteoblasts. The present results indicate that PP18 directly binds to nucleolin in the nucleolus of osteoblasts and that nucleolin is cleaved during apoptosis in osteoblasts.

蛋白质磷酸化和去磷酸化已被认为是细胞功能的关键机制。冈田酸（OA）是一种有效的蛋白磷酸酶抑制剂，可诱导人成骨细胞凋亡。核因子-κ B（NF-κB）是调控细胞生长和分化相关基因表达的重要转录因子。Western分析和K蛋白磷酸酶去磷酸化试验结果显示OA处理人成骨细胞MG 63后，NF-κB丝氨酸536位的磷酸化水平增加。荧光素酶法检测OA对MG 63细胞NF-κB转录活性的影响。结果表明，OA可诱导MG 63细胞NF-κB B磷酸化，使磷酸化NF-κ B B转位至细胞核，从而促进基因转录活性。核仁素是一种在核仁中大量表达的磷蛋白，主要定位于核仁。核仁素在培养细胞中的染色模式与蛋白磷酸酶1 δ相似。(PP1δ）。用免疫细胞化学和免疫沉淀方法证实核仁素与人成骨细胞核仁中的PP 1 δ结合。OA处理组成骨细胞核内AgNORs和核仁素消失。从成骨细胞获得的蛋白质中检测到一条主要条带，110 kDa。110 kDa的蛋白质的水平下降，在凋亡的成骨细胞，而一个额外的带，80 kDa，出现和这种蛋白质的水平增加，从OA诱导的凋亡的成骨细胞制备的蛋白质。目前的结果表明，PP 18直接结合到成骨细胞核仁中的核仁素，并且核仁素在成骨细胞凋亡过程中被切割。

项目成果

期刊论文数量（20）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The transcriptional factor Osterix directly interacts with RNA helicase A

DOI：
10.1016/j.bbrc.2007.01.150
发表时间：
2007-04-06
期刊：
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
影响因子：
3.1
作者：
Amorim, Bruna Rabelo;Okamura, Hirohiko;Haneji, Tatsuji
通讯作者：
Haneji, Tatsuji

Okadaic acid induces phosphorylation of p65NF-κB on serine 536 and activates NF-κB transcriptional activity in human osteoblastic MG63 cells

冈田酸诱导人成骨细胞 MG63 细胞中 p65NF-κB 丝氨酸 536 磷酸化并激活 NF-κB 转录活性

DOI：
发表时间：
2006
期刊：
Journal of Cellular Biochemistry 99・5
影响因子：
0
作者：
Sato;T.;Watanabe;K.;Masuhara;M.;Hada;N.;Hakeda;Y.;Ozaki A
通讯作者：
Ozaki A

Association of protein phosphatase 1 delta with nucleolin in osteoblastic cells and cleavage of nucleolin in apoptosis-induced cells

成骨细胞中蛋白磷酸酶 1 δ 与核仁素的关联以及凋亡诱导细胞中核仁素的裂解

DOI：
发表时间：
期刊：
Acta Histochemica et Cytochemica (in press)
影响因子：
0
作者：
小川;郁子他;Ogawa I. et al.;小川郁子;Hirohiko Okamura;Hirohiko Okamura;Michi Fujita;Hiroyuki Morimoto;Hiroyuki Morimoto;Kikuji Yamashita;Kikuji Yamashita;羽地達次;Tatsuji Haneji T.
通讯作者：
Tatsuji Haneji T.

Arachidonic acid inhibits osteoblast differentiation through cytosolic phospholipase A_z-dependent pathway

花生四烯酸通过胞质磷脂酶A_z依赖性途径抑制成骨细胞分化