In vitro immunomodulation of magnesium on monocytic cell toward anti-inflammatory macrophages
Lei Sun, Xiaoyu Li, Menghan Xu, Fenghe Yang, Wei Wang, Xufeng Niu
Abstract
Abstract Biodegradable magnesium (Mg) has shown great potential advantages over current bone fixation devices and vascular scaffold technologies; however, there are few reports on the immunomodulation of corrosive Mg products, the micron-sized Mg particles (MgMPs). Human monocytic leukemia cell line THP-1 was set as the in vitro cell model to estimate the immunomodulation of MgMPs on cell proliferation, apoptosis, polarization and inflammatory reaction. Our results indicated high-concentration of Mg2+ demoted the proliferation of the THP-1 cells and, especially, THP-1-derived macrophages, which was a potential factor that could affect cell function, but meanwhile, cell apoptosis was almost not affected by Mg2+. In particular, the inflammation regulatory effects of MgMPs were investigated. Macrophages exposed to Mg2+ exhibited down-regulated expressions of M1 subtype markers and secretions of pro-inflammatory cytokines, up-regulated expression of M2 subtype marker and secretion of anti-inflammatory cytokine. These results indicated Mg2+ could convert macrophages from M0 to M2 phenotype, and the bioeffects of MgMPs on human inflammatory cells were most likely due to the Mg2+-induced NF-κB activation reduction. Together, our results proved Mg2+ could be used as a new anti-inflammatory agent to suppress inflammation in clinical applications, which may provide new ideas for studying the immunomodulation of Mg-based implants on human immune system.