Roles of 630 nm Red Light-Emitting Diode in Inhibition of RhoA Signal Transduction Pathway via Reducing PLEKHG5 Expression and Alleviation of Inflammatory Response in Macrophages

Abstract

Background: The joint erosion occurs due to the classically activated macrophages (M1) that mainly secrete pro-inflammatory cytokines. Existing research results show the significant efficacy of LED (light emitting diode) in promoting cell proliferation, relieving oxidative stress, and inhibiting inflammatory factors in macrophage-like cells. Methods: In this study, we performed transcriptomic analysis of the control group (Lipopolysaccharide (LPS)-treated M0 cell and M1 cell) and the experimental group, to find the role of 630 nm red LED irradiation on macrophages and their inflammatory response. To investigate the molecular mechanisms that underline the LED light radiation efficacy in the treatment of hyperimmune response of macrophages, we employed efficient molecular techniques such as western blot and qRT-PCR (Real-Time Quantitative Reverse Transcription PCR) analysis. Results: These results showed that the 630 nm red LED irradiation, reduced the inflammatory response in macrophage-like cells after inducing the inflammatory response with LPS by suppressing TNF-α (Tumor necrosis factor α), IL-1β (interleukin-1 β), IL-6 (Interleukin-6) and CCL8 (Chemokine (C-C motif) ligand 8). The 630 nm red LED irradiation reduced the expression of NF-κB (nuclear factor kappa B) p65 protein and reduced the cell stress of macrophage-like cells after treatment with LPS. Moreover, 630 nm red LED light suppressed the illicit of PLEKHG5 (Pleckstrin Homology and Rho GEF Domain Containing G5) in macrophage-like cells induced by LPS treatment and subsequently, the activation of the RhoA exchange factor and NF-κB signaling pathway. Conclusions: This study demonstrated that red LED may inhibit the hyperimmune response in macrophages via inhibiting the RhoA signaling pathway via PLEKHG5 and subsequently suppresses the illicit of proinflammatory cytokines. These findings showed that red LED light irradiation could be used to alleviate the macrophage’s immune response in RA (rheumatoid arthritis) patients.