Effects of Laser Radiation on Mitochondria and Mitochondrial Proteins Subjected to Nitric Oxide.

Anatoly N Osipov,Evgeny A Buravlev,Yury A Vladimirov,Tatiana V Machneva

doi:10.3389/fmed.2018.00112

Abstract

The biological roles of heme and nonheme nitrosyl complexes in physiological and pathophysiological conditions as metabolic key players are considered in this study. Two main physiological functions of protein nitrosyl complexes are discussed—(1) a depot and potential source of free nitric oxide (NO) and (2) a controller of crucial metabolic processes. The first function is realized through the photolysis of nitrosyl complexes (of hemoglobin, cytochrome c, or mitochondrial iron–sulfur proteins). This reaction produces free NO and subsequent events are due to the NO physiological functions. The second function is implemented by the possibility of NO to bind heme and nonheme proteins and produce corresponding nitrosyl complexes. Enzyme nitrosyl complex formation usually results in the inhibition (or enhancement in the case of guanylate cyclase) of its enzymatic activity. Photolysis of protein nitrosyl complexes, in this case, will restore the original enzymatic activity. Thus, cytochrome c acquires peroxidase activity in the presence of anionic phospholipids, and this phenomenon can be assumed as a key step in the programmed cell death. Addition of NO induces the formation of cytochrome c nitrosyl complexes, inhibits its peroxidase activity, and hinders apoptotic reactions. In this case, photolysis of cytochrome c nitrosyl complexes will reactivate cytochrome c peroxidase activity and speed up apoptosis. Control of mitochondrial respiration by NO by formation or photolytic decay of iron–sulfur protein nitrosyl complexes is an effective instrument to modulate mitochondrial metabolism. These questions are under discussion in this study.

Highlights

The mechanisms of physiological activity of nitric oxide (NO) have been the crucial questions in the NO metabolic pathways in the latest two decades
The green (532 nm) laser and red (650 nm) LED were much less effective, and the decreased relative oxygen consumption can be explained by the existence of iron–sulfur protein nitrosyl complexes undestroyed upon laser irradiation. These results prove that in experimental endotoxic shock model laser radiation can serve as a powerful instrument to improve mitochondrial respiration as it destroys nitrosyl complexes formed in the case of excessive NO production
Due to the photosensitivity of these complexes, we can expect that low power laser radiation can serve as an effective instrument to locally produce free NO in cells and tissues

Summary

Introduction

The mechanisms of physiological activity of nitric oxide (NO) have been the crucial questions in the NO metabolic pathways in the latest two decades. One of the main questions was how NO, a short-lived free radical could survive in cell and perform its physiological activity? It was found that NO can exist in cells in complexes with thiols (nitrosothiols) or heme and nonheme iron compounds (heme and nonheme nitrosyl complexes), etc. The physiological role of nitrosyl complexes in mitochondria and cells has been the main goal for researchers for many years [5,6,7]. It becomes clear that mitochondrion nitrosyl complexes can play various roles from NO depot up to enzymatic activity controller. An important question regarding the physiological role of nitrosyl complexes, in this case, could be the issue of nitrosyl complex stability as well as how to release free NO from these species

Objectives

Conclusion