Carboxyamidotriazole exerts anti-inflammatory activity in lipopolysaccharide-induced RAW264.7 macrophages by inhibiting NF-κB and MAPKs pathways

Shan Lu; Mengyuan Duan; Zehao Guo; Yongting Zhou; Danwei Wu; Xiaojuan Zhang; Yicheng Wang; Caiying Ye; Rui Ju; Juan Li; Dechang Zhang; Lei Zhu

doi:10.3892/etm.2020.8889

Carboxyamidotriazole exerts anti-inflammatory activity in lipopolysaccharide-induced RAW264.7 macrophages by inhibiting NF-κB and MAPKs pathways

Exp Ther Med. 2020 Aug;20(2):1455-1466. doi: 10.3892/etm.2020.8889. Epub 2020 Jun 12.

Authors

Shan Lu¹, Mengyuan Duan¹, Zehao Guo¹, Yongting Zhou¹, Danwei Wu², Xiaojuan Zhang¹, Yicheng Wang¹, Caiying Ye¹, Rui Ju¹, Juan Li¹, Dechang Zhang¹, Lei Zhu¹

Affiliations

¹ Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005, P.R. China.
² Department of Pharmacy, Beijing Jishuitan Hospital, Beijing 100035, P.R. China.

Abstract

Carboxyamidotriazole (CAI), originally developed as a non-cytotoxic anti-cancer drug, was shown to have anti-inflammatory activity according to recent studies in a number of animal models of inflammation. However, its mechanism of action has not been characterized. Therefore, the present study was performed to identify the anti-inflammatory action of CAI in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and to identify the signal transduction pathways involved. The in vitro results revealed that CAI had no direct effect on the activity of cyclooxygenase (COX), suggesting a different anti-inflammatory mechanism compared with that of COX-inhibiting non-steroidal anti-inflammatory drugs. Further investigation in RAW264.7 macrophages revealed that CAI decreased the production of nitric oxide via decreasing the LPS-stimulated expression of inducible nitric oxide synthase, and downregulated both mRNA and protein expression levels of the cytokines tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. CAI also significantly reduced the increased DNA-binding activity of nuclear factor (NF)-κB induced by LPS stimulation. With respect to the mechanisms involved on NF-κB activity, CAI exhibited suppression of the phosphorylation and degradation of the inhibitor of nuclear factor-κBα (IκB), and decreased the phosphorylation levels of the p65 subunit and its subsequent nuclear translocation. In addition, CAI significantly decreased the phosphorylated forms of p38, JNK and ERK, which were increased following LPS stimulation, while the total expression levels of p38, JNK and ERK remained unaltered. The results in the present study indicate that CAI alleviates the inflammatory responses of RAW 264.7 macrophages in response to LPS stimulation via attenuating the activation of NF-κB and MAPK signaling pathways and decreasing the levels of pro-inflammatory mediators. This offers a novel perspective for understanding the anti-inflammatory mechanism of CAI and suggests its potential use as a therapeutic treatment in inflammatory diseases with excessive macrophage activation.

Keywords: RAW264.7 macrophages; carboxyamidotriazole; cytokines; inducible nitric oxide synthase; mitogen-activated protein kinases; nuclear factor-κB.