The Effect of Nrf2 on Inflammatory Responses of Human Monocytic Cells After Blue Light Exposure

Abstract

Blue light treatment alters cellular signaling and affects intracellular biochemical processes in tissues. PURPOSE: This study determined the ability of blue light to modulate Nrf2 and decrease LPS-induced secretion of pro-inflammatory cytokines from cultured, human monocytic cells. METHODS: Cultured THP-1 human monocytic cells were exposed to LPS and blue light treatment. Western Blot analyses, EMSA, and ELISA were used to evaluate NF?B, Nrf2, HO-1, TNF-?, IL-6 and IL-8 production. RESULTS: Light treatment increased nuclear Nrf2 and increased HO-1. Cells pretreated with light had no detectable NF?B-DNA binding. LPS treatment increased nuclear NF?B, and had little effect on Nrf2. Light pre-treatment significantly decreased the amount of TNF-? by 63% and IL-8 by 55%. CONCLUSIONS: Blue light increases the production of Nrf2 and HO-1, decreases the ability of Nf?B to bind in the nucleus, and leads to a decrease in the secretion of pro-inflammatory proteins in human monocytic cells.