State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai, China.
Br J Pharmacol. 2011 Sep;164(2b):694-703. doi: 10.1111/j.1476-5381.2011.01464.x.
Paeoniflorin (PF) has ameliorative effects on learning and memory impairment and cerebral ischaemia in rats and has protective effects against the degeneration of dopaminergic neurons in substantia nigra. The neuroprotective effects of PF are most probably derived from its anti-inflammatory property. Abnormally high levels of intercellular adhesion molecule-1 (ICAM-1) have been found to be associated with a wide range of inflammatory and immune responses. Here we studied whether PF regulates the levels of ICAM-1 elevated in LPS-activated differentiated human monocytic U937 cells and TNF-α-stimulated human umbilical vein endothelial cells (HUVECs).
mRNA levels were evaluated by RT-PCR. Protein levels were evaluated by Western blot analysis. An immunofluorescence technique was used to estimate NF-κB translocation, and NF-κB binding to nuclear DNA was determined by EMSA.
PF inhibited ICAM-1 expression elevated in LPS-induced U937 cells and TNF-α-stimulated HUVECs. Although previous reports showed that PF's action is mediated by activating adenosine A₁ receptors, application of a selective adenosine A₁ receptor antagonist did not change the inhibitory effect of PF in our experiments. To elucidate the underlying mechanisms of the effect of PF, we studied its effect on signalling pathways upstream of ICAM-1 expression. PF suppressed the activation of the NF-κB pathway, which regulates the expression of ICAM-1. The TLR4 and MAPK pathways were shown not to be involved in the effects of PF in these cells.
PF inhibits ICAM-1 expression in LPS-treated U937 cells and TNF-α-stimulated HUVECs by suppressing the activation of the NF-κB pathway.
芍药苷（PF）可改善大鼠学习记忆障碍和脑缺血，对黑质多巴胺能神经元退化具有保护作用。PF 的神经保护作用可能源自其抗炎特性。细胞间黏附分子-1（ICAM-1）水平异常升高与广泛的炎症和免疫反应有关。在这里，我们研究了 PF 是否调节 LPS 激活的人单核细胞 U937 细胞和 TNF-α 刺激的人脐静脉内皮细胞（HUVEC）中升高的 ICAM-1 水平。
通过 RT-PCR 评估 mRNA 水平。通过 Western blot 分析评估蛋白水平。使用免疫荧光技术估计 NF-κB 易位，并通过 EMSA 测定 NF-κB 与核 DNA 的结合。
PF 抑制 LPS 诱导的 U937 细胞和 TNF-α 刺激的 HUVEC 中升高的 ICAM-1 表达。尽管先前的报告表明 PF 的作用是通过激活腺苷 A₁ 受体介导的，但在我们的实验中，应用选择性腺苷 A₁ 受体拮抗剂并没有改变 PF 的抑制作用。为了阐明 PF 作用的潜在机制，我们研究了其对 ICAM-1 表达上游信号通路的影响。PF 抑制了 NF-κB 通路的激活，该通路调节 ICAM-1 的表达。TLR4 和 MAPK 通路不参与这些细胞中 PF 的作用。
PF 通过抑制 NF-κB 通路的激活来抑制 LPS 处理的 U937 细胞和 TNF-α 刺激的 HUVEC 中 ICAM-1 的表达。
