Graduate Institute of Natural Products, College of Medicine, Chang-Gung University, Tao-Yuan, Taiwan, Republic of China; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Taoyuan 333, Taiwan, Republic of China; Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou, Taiwan, Republic of China.
Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
Eur J Pharmacol. 2018 Jun 15;829:26-37. doi: 10.1016/j.ejphar.2018.03.037. Epub 2018 Mar 28.
This study investigates the effect and the underlying mechanism of 2',3-dihydroxy-5-methoxybiphenyl (RIR-2), a lignan extracted from the roots of Rhaphiolepis indica (L.) Lindl. ex Ker var. tashiroi Hayata ex Matsum. & Hayata (Rosaceae), on N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced respiratory burst and cathepsin G in human neutrophils. Signaling pathways regulated by RIR-2 which modulated fMLP-induced respiratory burst were evaluated by an interaction between β subunit of G-protein (Gβ) with downstream signaling induced by fMLP and by immunoblotting analysis of the downstream targets of Gβ-protein. RIR-2 inhibited fMLP-induced superoxide anion production (IC:2.57 ± 0.22 μM), cathepsin G release (IC:18.72 ± 3.76 μM) and migration in a concentration dependent manner. RIR-2 specifically suppresses fMLP-induced Src family kinases phosphorylation by inhibiting the interaction between Gβ-protein with Src kinases without inhibiting Src kinases activities, therefore, RIR-2 attenuated the downstream targets of Src kinase, such as phosphorylation of Raf/ERK, AKT, P38, PLCγ2, PKC and translocation Tec, p47° and P40° from the cytosol to the inner leaflet of the plasma membrane. Furthermore, RIR-2 attenuated fMLP-induced intracellular calcium mobilization by inhibiting the interaction between Gβ-protein with PLCβ2. RIR-2 was not a competitive or allosteric antagonist of fMLP. On the contrary, phorbol 12-myristate 13-acetate (PMA)-induced phosphorylation of Src, AKT, P38, PKC and membrane localization of p47° and P40° remained unaffected. RIR-2 specifically modulates fMLP-mediated neutrophil superoxide anion production and cathepsin G release by inhibiting the interaction between Gβ-protein with downstream signaling which subsequently interferes with the activation of intracellular calcium, PLCγ2, AKT, p38, PKC, ERK, p47° and p40.
本研究探讨了 2',3-二羟基-5-甲氧基联苯（RIR-2），一种从罗菲莱皮斯 indica（L.）林德尔根中提取的木脂素的作用及其作用机制。（Rosaceae），对 N-甲酰基-L-甲硫氨酰基-L-亮氨酰基-L-苯丙氨酸（fMLP）诱导的人嗜中性粒细胞呼吸爆发和组织蛋白酶 G 的影响。通过 G 蛋白β亚基（Gβ）与 fMLP 诱导的下游信号之间的相互作用以及 Gβ-蛋白下游靶标的免疫印迹分析，评估了 RIR-2 调节的调节 fMLP 诱导的呼吸爆发的信号通路。RIR-2 以浓度依赖的方式抑制 fMLP 诱导的超氧阴离子产生（IC：2.57±0.22μM）、组织蛋白酶 G 释放（IC：18.72±3.76μM）和迁移。RIR-2 通过抑制 Gβ-蛋白与Src 激酶之间的相互作用特异性抑制 fMLP 诱导的 Src 家族激酶磷酸化，而不抑制 Src 激酶活性，因此，RIR-2 减弱了 Src 激酶的下游靶标，如 Raf/ERK、AKT、P38、PLCγ2、PKC 和 Tec 的磷酸化，p47°和 P40°从细胞质转移到质膜的内叶。此外，RIR-2 通过抑制 Gβ-蛋白与 PLCβ2 的相互作用来减弱 fMLP 诱导的细胞内钙动员。RIR-2 不是 fMLP 的竞争性或变构拮抗剂。相反，佛波醇 12-肉豆蔻酸 13-醋酸盐（PMA）诱导的 Src、AKT、P38、PKC 的磷酸化和 p47°和 P40°的膜定位不受影响。RIR-2 通过抑制 Gβ-蛋白与下游信号之间的相互作用特异性调节 fMLP 介导的嗜中性粒细胞超氧阴离子产生和组织蛋白酶 G 释放，随后干扰细胞内钙、PLCγ2、AKT、p38、PKC、ERK、p47°和 p40 的激活。
