Formyl peptide-receptor like-1 requires lipid raft and extracellular signal-regulated protein kinase to activate inhibitor-κB kinase in human U87 astrocytoma cells
Formyl peptide-receptor like-1 requires lipid raft and extracellular signal-regulated protein kinase to activate inhibitor-κB kinase in human U87 astrocytoma cells
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DOI：
10.1111/j.1471-4159.2007.04876.x
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发表时间：
2007-11-01
影响因子：
4.7
通讯作者：
Wong, Yung H.
中科院分区：
文献类型：
--
作者：
Kam, Angel Y. F.;Liu, Andrew M. F.;Wong, Yung H.
甲酰基肽受体样物-1 （FPRL-1）可能在阿尔茨海默病、趋化和神经毒素释放中发挥关键作用，可能通过调节核因子κ B （NF κ B）。本研究表明，在人U87星形细胞瘤或稳定表达该受体的中国仓鼠卵巢细胞中，FPRL-1的激活可导致κ B激酶抑制剂（IKK）的磷酸化，IKK是NF κ B信号级联的起始激酶。FPRL-1选择性六肽Trp-Lys-Tyr-Met-Val-Met （WKYMVM）以时间和剂量依赖的方式促进IKK磷酸化，而百日咳毒素预处理消除了G α (i/o)依赖性刺激。fprl -1介导的IKK磷酸化需要细胞外信号调节蛋白激酶（ERK）、磷脂酰肌醇3-激酶和细胞Src (c-Src)，但不需要c-Jun n-末端激酶和p38丝裂原活化蛋白激酶。尽管它具有动员Ca2+的能力，但WKYMVM不需要Ca2+来调节IKK磷酸化。FPRL-1的激活也诱导NF κ b驱动的荧光素酶表达。有趣的是，甲基- β -环糊精从质膜上消耗胆固醇消除了FPRL-1刺激的IKK磷酸化，表明脂筏完整性在FPRL-1到IKK信号传导中起重要作用。此外，我们发现在U87细胞中，FPRL-1-IKK通路中的几个信号中间体，包括G α (i2)、c-Src和ERK，组成性地定位于筏微域。WKYMVM给药不仅导致更多的ERK募集到筏区，而且特异性地刺激筏相关的c-Src和ERK磷酸化。综上所述，这些结果表明FPRL-1能够通过IKK磷酸化激活NF κ B信号，这可能作为FPRL-1相关疾病的有用治疗靶点。
Formyl peptide-receptor like-1 (FPRL-1) may possess critical roles in Alzheimer's diseases, chemotaxis and release of neurotoxins, possibly through its regulation of nuclear factor-kappa B (NF kappa B). Here we illustrate that activation of FPRL-1 in human U87 astrocytoma or Chinese hamster ovary cells stably expressing the receptor resulted in the phosphorylations of inhibitor-kappa B kinase (IKK), an onset kinase for NF kappa B signaling cascade. FPRL-1 selective hexapeptide Trp-Lys-Tyr-Met-Val-Met (WKYMVM) promoted IKK phosphorylations in time- and dose-dependent manners while pre-treatment of pertussis toxin abrogated the G alpha(i/o)-dependent stimulations. The FPRL-1-mediated IKK phosphorylation required extracellular signal-regulated protein kinase (ERK), phosphatidylinositol 3-kinase and cellular Src (c-Src), but not c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Despite its ability to mobilize Ca2+, WKYMVM did not require Ca2+ for the modulation of IKK phosphorylation. Activation of FPRL-1 also induced NF kappa B-driven luciferase expression. Interestingly, cholesterol depletion from plasma membrane by methyl-beta-cyclodextrin abolished the FPRL-1-stimulated IKK phosphorylation, denoting the important role of lipid raft integrity in the FPRL-1 to IKK signaling. Furthermore, we demonstrated that in U87 cells, several signaling intermediates in the FPRL-1-IKK pathway including G alpha(i2), c-Src and ERK were constitutively localized at the raft microdomains. WKYMVM administration not only resulted in higher amount of ERK recruitment to the raft region, but also specifically stimulated raft-associated c-Src and ERK phosphorylations. Taken together, these results demonstrate that FPRL-1 is capable of activating NF kappa B signaling through IKK phosphorylation and this may serve as a useful therapeutical target for FPRL-1-related diseases.