Zhang Ling-ling, Wei Wei, Wang Qing-tong, Chen Jing-yu, Chen Yin
Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui 230032, China.
Chin Med J (Engl). 2008 Nov 20;121(22):2278-83.
Signaling pathways that regulate the production of cytokines and destructive enzymes have been implicated in rheumatoid arthritis (RA) pathogenesis. There are co-relations between signaling pathways. The aim of this study was to investigate interactions and cross-talks between MEK1/2-extracellular signal-related kinase (ERK1/2) signaling and G protein-couple signaling in synoviocytes of collagen-induced arthritis (CIA) rats by the stimulation of interleukin-1 (IL-1), U0126, isoprenaline hydrochloride and aminophylline respectively.
Twenty Sprague-Dawley (SD) rats were induced by chicken type II collagen. Synoviocytes of CIA rats were isolated and cultured. The expressions of Gi, phosphorylated MEK1/2 (p-MEK1/2) and phosphorylated ERK1/2 (p-ERK1/2) were detected by Western blotting. cAMP level and protein kinase A (PKA) activity were measured by radioimmunoassay and kinase-glo luminescent kinase assay respectively.
There was remarkable inflammation in CIA rats accompanied by swelling paws, hyperplastic synovium, pannus and cartilage erosion. cAMP level and PKA activity of synoviocytes decreased. Gi, p-ERK1/2 and p-MEK1/2 increased. rIL-1alpha improved the expression of Gi, p-ERK1/2 and p-MEK1/2. cAMP and PKA increased with stimulation of rIL-1alpha. U0126 inhibited Gi, cAMP and PKA of synoviocytes stimulated by rIL-1alpha. Isoprenaline hydrochloride enhanced Gi, cAMP and PKA, but had no effects on p-MEK1/2 and p-ERK1/2. Aminophylline increased cAMP and PKA, but inhibited p-MEK1/2 and p-ERK1/2.
Mitogen-activated protein kinases (MAPKs) and G protein-couple signaling are associated with synovitis. There are cross talks between MAPKs and G protein-couple signaling. The two signaling pathways represent potential therapeutic targets for RA.
调节细胞因子和破坏酶产生的信号通路与类风湿关节炎（RA）的发病机制有关。信号通路之间存在相互关系。本研究的目的是分别通过白细胞介素-1（IL-1）、U0126、盐酸异丙肾上腺素和氨茶碱刺激，研究胶原诱导性关节炎（CIA）大鼠滑膜细胞中MEK1/2-细胞外信号调节激酶（ERK1/2）信号通路与G蛋白偶联信号通路之间的相互作用和相互影响。
20只Sprague-Dawley（SD）大鼠用鸡Ⅱ型胶原诱导。分离并培养CIA大鼠的滑膜细胞。通过蛋白质印迹法检测Gi、磷酸化MEK1/2（p-MEK1/2）和磷酸化ERK1/2（p-ERK1/2）的表达。分别通过放射免疫分析法和激酶发光法检测cAMP水平和蛋白激酶A（PKA）活性。
CIA大鼠出现明显炎症，伴有爪部肿胀、滑膜增生、血管翳和软骨侵蚀。滑膜细胞的cAMP水平和PKA活性降低。Gi、p-ERK1/2和p-MEK1/2增加。重组IL-1α改善了Gi、p-ERK1/2和p-MEK1/2的表达。rIL-1α刺激后cAMP和PKA增加。U0126抑制rIL-1α刺激的滑膜细胞的Gi、cAMP和PKA。盐酸异丙肾上腺素增强了Gi、cAMP和PKA，但对p-MEK1/2和p-ERK1/2无影响。氨茶碱增加了cAMP和PKA，但抑制了p-MEK1/2和p-ERK1/2。
丝裂原活化蛋白激酶（MAPKs）和G蛋白偶联信号通路与滑膜炎有关。MAPKs和G蛋白偶联信号通路之间存在相互影响。这两条信号通路是RA潜在的治疗靶点。
