670 nm LED ameliorates inflammation in the CFH−/− mouse neural retina

•670 nm LED arrests para-inflammation in the ageing CFH−/− retina.•670 nm LED exposure alters C3 and C3b protein expression.•TLR-2 and TLR-4 expression levels dramatically decreased after 670 nm LED exposure.•670 nm LED exposure decreased calcitonin expression in the CFH−/− retina.

Para-inflammation in the neural retina is thought to contribute to the onset of some age-related retinal diseases. Continuous innate immune system activation, manifests in progressive chronic inflammation, macrophage invasion and cell loss, resulting in visual loss.We have previously shown that mitochondrial function is augmented following 670 nm LED exposure, leading to reduced retinal inflammation. Here, it was asked whether 670 nm LED regulates para-inflammation in an aged-related macular degeneration mouse model. Mutant CFH−/− mice were exposed to four 90 s exposures over 2 days for 1 week and 8 weeks. These regimes significantly reduced activated macrophage number, TNF-alpha and MIF protein expression levels. Immuno-reactivity to C3, C3b and calcitonin, all markers of inflammatory status were also altered. Finally, innate immune proteins, TLR 2 and 4, showed a marked decrease in protein expression.These findings support the notion that 670 nm LED regulates innate immunity, alleviating inflammation in the neural retina of an age-related macular degeneration mouse model.