Meng Chen, Liu Zhen, Liu Gui-Lin, Fu Li-Sha, Zhang Min, Zhang Zhao, Xia Hui-Min, Zhang Shi-Hai, Xu You-Nian
Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
J Huazhong Univ Sci Technolog Med Sci. 2015 Jun;35(3):419-425. doi: 10.1007/s11596-015-1447-9. Epub 2015 Jun 14.
Ketamine (KTM), a N-methyl-D-aspartate (NMDA) receptor antagonist, was found to has an anti-inflammatory effect, but some patients suffered from exacerbated pro-inflammatory reactions after anesthesia with KTM. The present study was aimed to examine the underlying mechanism of pro-inflammatory effects of KTM. In this study, RAW264.7 cells were exposed to KTM and NMDA alone or combined for 30 min before lipopolysaccharide (LPS) stimulation. The expression levels of IL-6 and TNF-α were detected by RT-PCR and ELISA, and those of NMDA receptors by RT-PCR in RAW264.7 cells. Additionally, the TLR4 expression was determined by RT-PCR and flow cytometry, respectively. The results showed that in RAW264.7 cells, KTM alone promoted the TLR4 expression, but did not increase the expression of IL-6 or TNF-α. In the presence of LPS, KTM caused a significantly higher expression of IL-6 and TNF-α than LPS alone. NMDA could neither alter the IL-6 and TNF-α mRNA expression, nor reverse the enhanced expression of IL-6 and TNF-α mRNA by KTM in LPS-challenged cells. After TLR4-siRNA transfection, RAW264.7 cells pretreated with KTM no longer promoted the IL-6 and TNF-α expression in the presence of LPS. In conclusion, KTM accelerated LPS-induced inflammation in RAW264.7 cells by promoting TLR4 expression, independent of NMDA receptor.
氯胺酮（KTM）是一种N-甲基-D-天冬氨酸（NMDA）受体拮抗剂，已被发现具有抗炎作用，但一些患者在接受KTM麻醉后出现促炎反应加剧的情况。本研究旨在探讨KTM促炎作用的潜在机制。在本研究中，在脂多糖（LPS）刺激前，将RAW264.7细胞单独或联合暴露于KTM和NMDA 30分钟。通过RT-PCR和ELISA检测RAW264.7细胞中IL-6和TNF-α的表达水平，通过RT-PCR检测NMDA受体的表达水平。此外，分别通过RT-PCR和流式细胞术测定TLR4的表达。结果表明，在RAW264.7细胞中，单独使用KTM可促进TLR4表达，但不增加IL-6或TNF-α的表达。在存在LPS的情况下，KTM导致IL-6和TNF-α的表达明显高于单独使用LPS。NMDA既不能改变IL-6和TNF-α mRNA的表达，也不能逆转KTM在LPS刺激的细胞中增强的IL-6和TNF-α mRNA的表达。在TLR4-siRNA转染后，用KTM预处理的RAW264.7细胞在存在LPS的情况下不再促进IL-6和TNF-α的表达。总之，KTM通过促进TLR4表达加速RAW264.7细胞中LPS诱导的炎症，与NMDA受体无关。
