Exposure to long wavelength light that improves aged mitochondrial function shifts acute cytokine expression in serum and the retina

Aged mitochondrial function can be improved with long wavelength light exposure. This reduces cellular markers of inflammation and can improve system function from fly through to human. We have previously shown that with age there are increases in cytokine expression in mouse serum. Here, we ask what impact 670nm light has on this expression using a 40 cytokine array in blood serum and retina in C57Bl6 mice. 670nm exposure was delivered daily for a week in 12 month old mice. This shifted patterns of cytokine expression in both serum and retina inducing a selective increase. In serum examples of significant increases were found in IL (interleukins) 1 & alpha;, IL-7, 10, 16, 17 along with TNF-& alpha; and CXCL (chemokines) 9 and 10. In retina the increases were again mainly in some IL's and CXCL's. A few cytokines were reduced by light exposure. Changes in serum cytokines implies that long wavelengths impact systemically even to unexposed tissues deep in the body. In the context of wider literature, increased cytokine expression may be protective. However, their upregulation by light merits further analysis as cytokines upregulation can also be negative and there are probably complex patterns of interaction in the dynamics of their expression.

Automated summary

Aged mitochondrial function can be improved with long wavelength light exposure. This study investigated the impact of 670nm light on cytokine expression in blood serum and retina in mice. The results showed that the light exposure shifted patterns of cytokine expression, selectively increasing some interleukins and chemokines. The findings suggest that long wavelengths can have systemic effects and further analysis is needed to understand the implications of cytokine upregulation by light.