Low irradiance light exposure alters the activity of key enzymes in the mitochondrial electron transport chain

Nathaniel J. Pope; Michael L. Denton

doi:10.1117/12.2546624

11 March 2020 Low irradiance light exposure alters the activity of key enzymes in the mitochondrial electron transport chain

Nathaniel J. Pope, Michael L. Denton

Author Affiliations +

Proceedings Volume 11221, Mechanisms of Photobiomodulation Therapy XV; 112210E (2020) https://doi.org/10.1117/12.2546624
Event: SPIE BiOS, 2020, San Francisco, California, United States

Abstract

Photobiomodulation (PBM) is an umbrella term for positive biological effects induced by low irradiance exposures of visible to near infrared light. Though therapeutic and protective benefits of PBM are increasingly well documented in the scientific literature, the molecular mechanisms underlying these effects remain poorly understood. The putative chromophore for these effects is cytochrome c oxidase, also known as complex IV (C-IV) of the mitochondrial electron transport chain (ETC). It is generally held that light absorption at C-IV initiates a cascade of events involving nitric oxide and reactive oxygen species (ROS) which subsequently results in increased ATP generation and improved cellular robustness. However, little is known about the mechanisms by which these pathways are initiated, and how they establish the observed beneficial outcomes. To probe these mechanisms, we have conducted low irradiance exposures of isolated mitochondria at a range of wavelengths and radiant exposures. We utilized a spectrophotometric method to make in vitro measurements of ETC complex enzyme activities, by observing changes in the redox state of the small electron carrier protein, cytochrome c. Specifically, we analyzed the enzyme kinetics of cytochrome c reductase, also known as complex III (C-III), and C-IV, with and without exposure to low irradiance light. Additionally, by utilizing C-III and C-IV inhibitors (Antimycin A and sodium cyanide, respectively) we are able to distinguish between effects acting directly on one complex or the other. In summary, this research represents a unique look at the earliest stages of PBM induction in the mitochondria, and its associated molecular mechanisms.

Citation Download Citation

Nathaniel J. Pope and Michael L. Denton "Low irradiance light exposure alters the activity of key enzymes in the mitochondrial electron transport chain", Proc. SPIE 11221, Mechanisms of Photobiomodulation Therapy XV, 112210E (11 March 2020); https://doi.org/10.1117/12.2546624

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Near infrared

Tissues

Electron transport

Proteins

Absorbance

Cyanide

Low level phototherapy

Show All Keywords

Keywords/Phrases

Search In:

Publication Years