Lin Hugo You-Hsien, Chang Kai-Ting, Hung Chi-Chih, Kuo Chang-Hung, Hwang Shang-Jyh, Chen Hung-Chun, Hung Chih-Hsing, Lin Sheng-Fung
BMC Immunol. 2014 Sep 26;15:37. doi: 10.1186/s12865-014-0037-0.
Mammalian target of rapamycin (mTOR) inhibitors, such as sirolimus and its derivative, everolimus, are potent immunosuppressive and antiproliferative drugs. Inflammatory diseases are characterized by immunological dysfunction, and monocyte recruitment underlies the mechanism of cell damage. Chemokines attract inflammatory cells to sites of inflammation. Interleukin-8 (IL-8/CXCL8); the monocyte chemoattractant protein-1 (MCP-1/CCL2); the regulated on activation, normal T cell expressed, presumably secreted protein (RANTES/CCL5); the macrophage inflammatory protein (MIP)-1α (CCL3); and MIP-1β (CCL4) are involved in the pathogenesis of inflammation. However, whether mTOR inhibitors moderate the production of chemokines in monocytes remains unclear.
A human monocyte cell line, THP-1, and primary monocytes obtained from human volunteers, were stimulated using lipopolysaccharide (LPS), and then treated with sirolimus. The expression of the MCP-1, RANTES, IL-8, MIP-1α, MIP-1β, and TNF-α proteins was measured using enzyme-linked immunosorbent assays, and intracellular signalling was examined using western blotting.
Sirolimus significantly suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1β in the THP-1 cells and human primary monocytes. The mitogen-activated protein kinase (MAPK) inhibitors that were examined suppressed the LPS-induced expression of MCP-1, IL-8, RANTES, MIP-1α, and MIP-1β. In addition, sirolimus suppressed the LPS-induced phosphorylation of p38 and p65 in the THP-1 and human primary monocytes.
Sirolimus downregulates the expression of chemokines in monocytes, including MCP-1, RANTES, IL-8, MIP-1α, and MIP-1β, by inhibiting the NF-κB-p65 and MAPK-p38 signalling pathways.
雷帕霉素的哺乳动物靶点（mTOR）抑制剂，如西罗莫司及其衍生物依维莫司，是强效的免疫抑制和抗增殖药物。炎症性疾病以免疫功能障碍为特征，单核细胞募集是细胞损伤机制的基础。趋化因子将炎症细胞吸引到炎症部位。白细胞介素-8（IL-8/CXCL8）、单核细胞趋化蛋白-1（MCP-1/CCL2）、活化调节正常T细胞表达和可能分泌的蛋白（RANTES/CCL5）、巨噬细胞炎性蛋白（MIP）-1α（CCL3）和MIP-1β（CCL4）参与炎症的发病机制。然而，mTOR抑制剂是否能调节单核细胞中趋化因子的产生仍不清楚。
使用脂多糖（LPS）刺激人单核细胞系THP-1和从人类志愿者获得的原代单核细胞，然后用西罗莫司处理。使用酶联免疫吸附测定法测量MCP-1、RANTES、IL-8、MIP-1α、MIP-1β和TNF-α蛋白的表达，并使用蛋白质印迹法检查细胞内信号传导。
西罗莫司显著抑制LPS诱导的THP-1细胞和人原代单核细胞中MCP-1、IL-8、RANTES、MIP-1α和MIP-1β的表达。所检测的丝裂原活化蛋白激酶（MAPK）抑制剂抑制LPS诱导的MCP-1、IL-8、RANTES、MIP-1α和MIP-1β的表达。此外，西罗莫司抑制LPS诱导的THP-1和人原代单核细胞中p38和p – 65的磷酸化。结论：西罗莫司通过抑制NF-κB-p65和MAPK-p38信号通路下调单核细胞中趋化因子的表达，包括MCP-1、RANTES、IL-8、MIP-1α和MIP-1β。
