Recombinant human KAI1/CD82 attenuates M1 macrophage polarization on LPS-stimulated RAW264.7 cells via blocking TLR4/JNK/NF-κB signal pathway

• Published in: BMB reports Vol. 56; no. 6; pp. 359 - 364
• Main Authors: Hyesook Lee, Jung-hwa Han, Kangbin An, Yun Jeong Kang, Hyun Hwangbo, Ji Hye Heo, Byung Hyun Choi, Jae-joon Kim, Seo Rin Kim, Soo Yong Lee, Jin Hur
• Format: Journal Article
• Language: Korean
• Published: 생화학분자생물학회 30.06.2023
• Subjects: Inflammation; JNK; KAI1; M1 macrophage polarization; NF-κB signaling pathway; TLR4; JNK/ $NF-{\kappa}B$ signaling pathway; Inflammation; KAI1; TLR4; M1 macrophage polarization
• ISSN: 1976-6696; 1976-670X

KAI1/CD82, a membrane tetraspanin protein, can prevent various cancers and retinal disorders through its anti-angiogenic and anti-metastatic capacity. However, little is known about its anti-inflammatory effect and molecular mechanism. Therefore, the present study aimed to inLPSvestigate effect of a recombinant protein of the large extracellular domain of human KAI1 (Gly 111-Leu 228, rhKAI1) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage-like cells and mouse bone marrow- derived macrophages (BMDM) and to identify its underlying mechanism. Our data showed that rhKAI1 suppressed expression levels of classically macrophages (M1) phenotyperelated surface markers F4/80 + CD86 + in LPS-stimulated BMDM and RAW264.7 cells. In addition, LPS markedly increased mRNA expression and release levels of pro-inflammatory cytokines and mediators such as interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cyclooxygenase-2, nitric oxide and prostaglandin E 2 , whereas these increases were substantially down-regulated by rhKAI1. Furthermore, LPS strongly increased expression of NF-κB p65 in the nuclei and phosphorylation of ERK, JNK, and p38 MAPK. However, nuclear translocation of NF-κB p65 and phosphorylation of JNK were greatly reversed in the presence of rhKAI1. Especially, rhKAI1 markedly suppressed expression of toll-like receptor (TLR4) and prevented binding of LPS with TLR4 through molecular docking predict analysis. Importantly, Glu 214 of rhKAI1 residue strongly interacted with Lys 360 of TLR4 residue, with a binding distance of 2.9 Å. Taken together, these findings suggest that rhKAI1 has an anti-inflammatory effect on LPS-polarized macrophages by interacting with TLR4 and down-regulating the JNK/NF-κB signaling pathway. [BMB Reports 2023; 56(6): 359-364]