Anti-Inflammatory Effects of the Novel PIM Kinase Inhibitor KMU‐470 in RAW 264.7 Cells Through the TLR4‐NF‐κB‐NLRP3 Pathway

• Main Authors: Hye Suk Baek, Hyeon Ji Min, Victor Sukbong Hong, Taeg Kyu Kwon, Jong Wook Park, Jinho Lee, Shin Kim
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: International Journal of Molecular Sciences
• Subjects: KMU-470; PIM kinase; TLR4; LPS; inflammation; NF‐κB
• Online Access: https://www.mdpi.com/1422-0067/21/14/5138
• ISSN: 1661-6596; 1422-0067

PIM kinases, a small family of serine/threonine kinases, are important intermediates in the cytokine signaling pathway of inflammatory disease. In this study, we investigated whether the novel PIM kinase inhibitor KMU-470, a derivative of indolin-2-one, inhibits lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells. We demonstrated that KMU-470 suppressed the production of nitric oxide and inducible nitric oxide synthases that are induced by LPS in RAW 264.7 cells. Furthermore, KMU-470 inhibited LPS-induced up-regulation of TLR4 and MyD88, as well as the phosphorylation of IκB kinase and NF-κB in RAW 264.7 cells. Additionally, KMU-470 suppressed LPS-induced up-regulation at the transcriptional level of various pro-inflammatory cytokines such as IL-1β, TNF-α, and IL-6. Notably, KMU-470 inhibited LPS-induced up-regulation of a major component of the inflammasome complex, NLRP3, in RAW 264.7 cells. Importantly, PIM-1 siRNA transfection attenuated up-regulation of NLRP3 and pro-IL-1β in LPS-treated RAW 264.7 cells. Taken together, these findings indicate that PIM-1 plays a key role in inflammatory signaling and that KMU-470 is a potential anti-inflammatory agent.