Author: Le M1, McNeill FE1, Seymour CB1, Rusin A1, Diamond K1, Rainbow AJ1, Murphy J2, Mothersill CE3
Affiliation: <sup>1</sup>McMaster University, 1280, Main Street West, Hamilton, Ontario, Canada L8S 4K1.
<sup>2</sup>Institute of Technology Sligo, F91 YW50, Ireland.
<sup>3</sup>McMaster University, 1280, Main Street West, Hamilton, Ontario, Canada L8S 4K1. Electronic address: mothers@mcmaster.ca.
Conference/Journal: Environ Res.
Date published: 2018 Feb 7
Other:
Volume ID: 163 , Pages: 80-87 , Special Notes: doi: 10.1016/j.envres.2018.01.027. [Epub ahead of print] , Word Count: 255
Radiation-induced biophotons are an electromagnetic form of bystander signalling. In human cells, biophoton signalling is capable of eliciting effects in non-irradiated bystander cells. However, the mechanisms by which the biophotons interact and act upon the bystander cells are not clearly understood. Mitochondrial energy production and ROS are known to be involved but the precise interactions are not known. To address this question, we have investigated the effect of biophoton emission upon the function of the complexes of oxidative phosphorylation (OXPHOS). The exposure of bystander HCT116 p53 +/+ cells to biophoton signals emitted from β-irradiated HCT116 p53 +/+ cells induced significant modifications in the activity of Complex I (NADH dehydrogenase or NADH:ubiquinone oxidoreductase) such that the activity was severely diminished compared to non-irradiated controls. The enzymatic assay showed that the efficiency of NADH oxidation to NAD+ was severely compromised. It is suspected that this impairment may be linked to the photoabsorption of biophotons in the blue wavelength range (492-455 nm). The photobiomodulation to Complex I was suspected to contribute greatly to the inefficiency of ATP synthase function since it resulted in a lower quantity of H+ ions to be available for use in the process of chemiosmosis. Other reactions of the ETC were not significantly impacted. Overall, these results provide evidence for a link between biophoton emission and biomodulation of the mitochondrial ATP synthesis process. However, there are many aspects of biological modulation by radiation-induced biophotons which will require further elucidation.
KEYWORDS: Biophotons; Bystander effect; Ionising radiation; Mitochondria; Mitochondrial electron transport chain; OXPHOS
PMID: 29427954 DOI: 10.1016/j.envres.2018.01.027