Thromboxane A2-stimulated phospholipase D in osteoblast-like cells: possible involvement of PKC.
Thromboxane A2-stimulated phospholipase D in osteoblast-like cells: possible involvement of PKC.
复制标题
成骨细胞样细胞中血栓素 A2 刺激的磷脂酶 D：可能涉及 PKC。
DOI：
10.1152/ajpendo.1995.269.3.e524
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
O. Kozawa
中科院分区：
文献类型：
--
作者：
J. Shinoda;A. Suzuki;Y. Oiso;O. Kozawa
我们研究了血栓素A2（TxA 2）对成骨样MC 3 T3-E1细胞中磷脂酰胆碱水解磷脂酶D活性的影响。9，11-Epithio-11，12-methanothromoxane A2（STA 2）是TxA 2的稳定类似物，在10 nM和10 μ M之间的范围内以剂量依赖性方式刺激胆碱和肌醇磷酸的形成。STA 2和12-O-十四烷酰基佛波醇13-乙酸酯（TPA）（一种蛋白激酶C激活佛波酯）组合刺激的胆碱形成不具有相加性。1-（5-异喹啉磺酰基）-2-甲基哌嗪（H-7）是一种蛋白激酶抑制剂，抑制由STA 2和TPA诱导的胆碱的形成，但20 μ M N-（2-胍基乙基）-5-异喹啉磺酰胺（HA-1004），作为蛋白激酶C抑制剂H-7的对照，几乎没有影响。Calphostin C是一种有效且特异性的蛋白激酶C抑制剂，也抑制了由STA 2诱导的胆碱的形成。用乙二醇-双（β-氨基-乙醚）-N，N，N '，N'-四乙酸螯合细胞外Ca ~（2+）可显著降低STA_2诱导的胆碱形成。STA 2剂量依赖性地刺激细胞外45 Ca ~（2+）内流。STA 2刺激MC 3 T3-E1细胞的DNA合成，并增加这些细胞的数量。这些结果表明，TxA 2刺激成骨样细胞中的磷脂酶D，导致其增殖的方向，并且蛋白激酶C的激活参与磷脂酶D的刺激。
We examined the effect of thromboxane A2 (TxA2) on phosphatidylcholine-hydrolyzing phospholipase D activity in osteoblast-like MC3T3-E1 cells. 9,11-Epithio-11,12-methanothromboxane A2 (STA2), a stable analogue of TxA2, stimulated the formations of both choline and inositol phosphates in a dose-dependent manner in the range between 10 nM and 10 microM. The formation of choline stimulated by a combination of STA2 and 12-O-tetradecanoylphorbol 13-acetate (TPA), a protein kinase C-activating phorbol ester, was not additive. 1-(5-Isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7), an inhibitor of protein kinases, suppressed the formation of choline induced by STA2 as well as that by TPA, but 20 microM N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004), a control for H-7 as a protein kinase C inhibitor, had little effect. Calphostin C, a potent and specific inhibitor of protein kinase C, also suppressed the formation of choline induced by STA2. The STA2-induced formation of choline was significantly reduced by chelating extracellular Ca2+ with ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid. STA2 dose dependently stimulated 45Ca2+ influx from extracellular space. STA2 stimulated DNA synthesis of MC3T3-E1 cells and increased the number of these cells. These results suggest that TxA2 stimulates phospholipase D in osteoblast-like cells, resulting in the direction of their proliferation, and that the activation of protein kinase C is involved in the stimulation of phospholipase D.