Interleukin-1β-induced substance P release from rat cultured primary afferent neurons driven by two phospholipase A2 enzymes:: secretory type IIA and cytosolic type IV
Interleukin-1β-induced substance P release from rat cultured primary afferent neurons driven by two phospholipase A2 enzymes:: secretory type IIA and cytosolic type IV
复制标题
DOI：
10.1046/j.0022-3042.2002.00722.x
复制
发表时间：
2002-03-01
影响因子：
4.7
通讯作者：
Nakata, Y
中科院分区：
文献类型：
--
作者：
Morioka, N;Takeda, K;Nakata, Y
我们之前描述了重组白介素-1β（IL-1β）通过环氧合酶（COX）途径在原代培养的大鼠背根神经节（DRG）细胞中诱导 P 物质（SP）的显着释放。在本研究中，我们检查了两种类型的磷脂酶 A2 (PLA(2)) 酶（位于前列腺素生成途径中 COX 的上游）在 IL-1β 诱导的 DRG 细胞 SP 释放中的参与情况。在未处理的DRG细胞中，通过核糖核酸酶保护测定检测不到IIA型分泌型PLA（2）（sPLA（2）-IIA）mRNA的表达，而在与1ng/mL的IL-1β孵育的DRG细胞中，表达以时间依赖性方式诱导。另一方面，IV型胞质PLA(2) (cPLA(2)) mRNA在未处理的DRG细胞中组成型表达，并且用1ng/mL的IL-1β处理3小时显着增加了cPLA(2) mRNA的水平。 sPLA(2)抑制剂硫醚酰胺磷酰胆碱(TEA-PC)和cPLA(2)抑制剂花生四烯基三氟甲基酮(AACOCF(3))显着抑制IL-1β诱导的SP释放。此外，AACOCF(3) 抑制IL-1β 诱导的sPLA(2)-IIA mRNA 表达的诱导。这些观察结果表明，两种类型的PLA（2），sPLA（2）-IIA和cPLA（2），参与IL-1β诱导的DRG细胞SP释放，并且这两种酶之间的功能串扰可能有助于控制它们在DRG细胞中前列腺素生成系统中的活性。这些事件可能是炎症引起的脊髓初级传入神经元过度活跃的关键步骤。
We previously described that recombinant interleukin-1beta (IL-1beta) induced the significant release of substance P (SP) via a cyclooxygenase (COX) pathway in primary cultured rat dorsal root ganglion (DRG) cells. In the present study, we examined the involvement of two types of phospholipase A2 (PLA(2)) enzymes, which lie upstream of COX in the prostanoid-generating pathway, in the IL-1beta-induced release of SP from DRG cells. The expression of type IIA secretory PLA(2) (sPLA(2)-IIA) mRNA was undetectable by ribonuclease protection assay in non-treated DRG cells, while in DRG cells incubated with 1 ng/mL of IL-1beta, the expression was induced in a time-dependent manner. On the other hand, type IV cytosolic PLA(2) (cPLA(2)) mRNA was constitutively expressed in the non-treated DRG cells, and treatment with 1 ng/mL of IL-1beta for 3 h significantly increased the levels of cPLA(2) mRNA. The IL-1beta-induced SP release was significantly inhibited by the sPLA(2) inhibitor, thioetheramide phosphorylcholine (TEA-PC), and the cPLA(2) inhibitor, arachidonyl trifluoromethyl ketone (AACOCF(3)). Furthermore AACOCF(3) suppressed the induction of sPLA(2)-IIA mRNA expression induced by IL-1beta. These observations suggested that two types of PLA(2), sPLA(2)-IIA and cPLA(2), were involved in the IL-1beta-induced release of SP from DRG cells, and that the functional cross-talk between the two enzymes might help to control their activity in the prostanoid-generating system in DRG cells. These events might be key steps in the inflammation-induced hyperactivity in primary afferent neurons of spinal cord.