Division of Immunology and Allergy, Hans Wilsdorf Laboratory, Inflammation and Allergy Research Group, Department of Internal Medicine, University Hospital and Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland.
Proc Natl Acad Sci U S A. 2010 Oct 12;107(41):17692-7. doi: 10.1073/pnas.1009443107. Epub 2010 Sep 27.
Glatiramer acetate (GA), an immunomodulator used in multiple sclerosis (MS) therapy, induces the production of secreted IL-1 receptor antagonist (sIL-1Ra), a natural inhibitor of IL-1β, in human monocytes, and in turn enhances sIL-1Ra circulating levels in MS patients. GA is a mixture of peptides with random Glu, Lys, Ala, and Tyr sequences of high polarity and hydrophilic nature that is unlikely to cross the blood-brain barrier. In contrast, sIL-1Ra crosses the blood-brain barrier and, in turn, may mediate GA anti-inflammatory activities within the CNS by counteracting IL-1β activities. Here we identify intracellular signaling pathways induced by GA that control sIL-1Ra expression in human monocytes. By using kinase knockdown and specific inhibitors, we demonstrate that GA induces sIL-1Ra production via the activation of PI3Kδ, Akt, MEK1/2, and ERK1/2, demonstrating that both PI3Kδ/Akt and MEK/ERK pathways rule sIL-1Ra expression in human monocytes. The pathways act in parallel upstream glycogen synthase kinase-3α/β (GSK3α/β), the knockdown of which enhances sIL-1Ra production. Together, our findings demonstrate the existence of signal transduction triggered by GA, further highlighting the mechanisms of action of this drug in MS.
醋酸格拉替雷(GA)是一种用于多发性硬化症(MS)治疗的免疫调节剂,可诱导人单核细胞产生白细胞介素 1 受体拮抗剂(sIL-1Ra),这是白细胞介素 1β 的天然抑制剂,继而增加 MS 患者的循环 sIL-1Ra 水平。GA 是一种具有随机 Glu、Lys、Ala 和 Tyr 序列的多肽混合物,具有高极性和亲水性,不太可能穿过血脑屏障。相比之下,sIL-1Ra 可以穿过血脑屏障,并且可以通过拮抗 IL-1β 的活性在中枢神经系统中介导 GA 的抗炎活性。在这里,我们确定了 GA 诱导的细胞内信号通路,这些通路控制人单核细胞中 sIL-1Ra 的表达。通过使用激酶敲低和特定抑制剂,我们证明 GA 通过激活 PI3Kδ、Akt、MEK1/2 和 ERK1/2 诱导 sIL-1Ra 的产生,表明 PI3Kδ/Akt 和 MEK/ERK 通路均控制人单核细胞中 sIL-1Ra 的表达。这些通路在糖原合酶激酶-3α/β(GSK3α/β)上游平行作用,敲低 GSK3α/β 会增强 sIL-1Ra 的产生。总之,我们的发现证明了 GA 触发的信号转导的存在,进一步强调了这种药物在 MS 中的作用机制。