Journal: Antioxidants

Article Title: Near-Infrared Light Exposure Triggers ROS to Downregulate Inflammatory Cytokines Induced by SARS-CoV-2 Spike Protein in Human Cell Culture

doi: 10.3390/antiox12101824

Figure Lengend Snippet: Effect of NIR light treatment on inflammatory cytokine and macrophage polarization. Schematic diagram for LPS-induced activation of TLR4/NF-κB inflammation pathway and NIR light treatment, in ( A ) HAECs and ( B ) PMA-differentiated THP-1 macrophage cell line. ( A ) HAECs were LPS-induced for the inflammatory response and maintained in an inflamed state following two additional LPS boosts (blue arrows), and subjected to brief 10-min intervals of NIR light exposure (red arrows), repeated once every 12 h, over a 48-h trial period. ( B ) PMA-differentiated THP-1 macrophage cell line was LPS-induced for the inflammatory response and maintained in an inflamed state following three additional LPS boosts (blue arrows) and subjected to brief 10-min intervals of NIR light exposure (red arrows), repeated once every 12 h, over a 96-h trial period. ( A , B ) Cells cultured without LPS induction were used as controls. For quantification of cytokine gene transcription via qRT-PCR, all cells were harvested 3 h after the last LPS boost. For ELISA quantification of IL6 secretion, cell supernatants were harvested 6 h after the last LPS boost. ( C ) Gene expression of inflammatory cytokines for HAEC control cells (grey bars) and LPS-induced HAECs with (red bars) or without (blue bars) NIR light treatment. ( D ) Gene expression of inflammatory and anti-inflammatory cytokines for THP-1 control cells (grey bars) and LPS-induced THP-1 with (red bars) or without (blue bars) NIR light treatment. Measurement of IL-6 protein release via ELISA, from ( E ) control and LPS-induced HAECs not treated (black bars) or NIR light-treated (red bars) and from ( F ) THP-1 control cells (grey bars) and LPS-induced THP-1 with (red bars) or without (blue bars) NIR light treatment. For ( C , D ), n = 4 to 6. For ( E , F ), n = 3. For ( C – F ), data are shown as standard error of the mean ± SEM; ** p < 0.01; **** p < 0.0001.

Article Snippet: Six hours after the last boost of the NIR light exposure protocol, HAECs and THP-1 cell supernatants were harvested, and IL-6 secreted into the medium during the final 6 h of the experiment was measured using a Human IL-6 DuoSet ELISA kit, according to the manufacturers’ instructions (R&D SYSTEMS a Bio-Techne brand, San Jose, CA 95134, USA).

Techniques: Activation Assay, Cell Culture, Quantitative RT-PCR, Enzyme-linked Immunosorbent Assay, Gene Expression, Control