How to Use Respiratory Chain Inhibitors in Toxicology Studies-Whole-Cell Measurements

Mitochondrial electron transport chain (ETC) inhibition is a phenomenon interesting in itself and serves as a tool for studying various cellular processes. Despite the fact that searching the term "rotenone" in PubMed returns more than 6900 results, there are many discrepancies regarding the directions of changes reported to be caused by this RTC inhibitor in the delicate redox balance of the cell. Here, we performed a multifaceted study of the popular ETC inhibitors rotenone and antimycin A, involving assessment of mitochondrial membrane potential and the production of hydrogen peroxide and superoxide anions at cellular and mitochondrial levels over a wide range of inhibitor concentrations (1 nmol/dm3-100 µmol/dm3). All measurements were performed with whole cells, with accompanying control of ATP levels. Antimycin A was more potent in hindering HepG2 cells' abilities to produce ATP, decreasing ATP levels even at a 1 nmol/dm3 concentration, while in the case of rotenone, a 10,000-times greater concentration was needed to produce a statistically significant decrease. The amount of hydrogen peroxide produced in the course of antimycin A biological activity increased rapidly at low concentrations and decreased below control level at a high concentration of 100 µmol/dm3. While both inhibitors influenced cellular superoxide anion production in a comparable manner, rotenone caused a greater increase in mitochondrial superoxide anions compared to a modest impact for antimycin A. IC50 values for rotenone and antimycin A with respect to HepG2 cell survival were of the same order of magnitude, but the survival curve of cells treated with rotenone was clearly biphasic, suggesting a concentration-dependent mode of biological action. We propose a clear experimental setup allowing for complete and credible analysis of the redox state of cells under stress conditions which allows for better understanding of the effects of ETC inhibition.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:23

Enthalten in:

International journal of molecular sciences - 23(2022), 16 vom: 13. Aug.

Sprache:

Englisch

Beteiligte Personen:

Żuberek, Mariusz [VerfasserIn]
Paciorek, Patrycja [VerfasserIn]
Rakowski, Michał [VerfasserIn]
Grzelak, Agnieszka [VerfasserIn]

Links:

Volltext

Themen:

03L9OT429T
11062-77-4
642-15-9
8L70Q75FXE
Adenosine Triphosphate
Antimycin A
BBX060AN9V
Electron transport chain inhibition
Hydrogen Peroxide
Journal Article
Mitochondrial membrane potential
Reactive oxygen species
Rotenone
Superoxides

Anmerkungen:

Date Completed 29.08.2022

Date Revised 30.08.2022

published: Electronic

Citation Status MEDLINE

doi:

10.3390/ijms23169076

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM345307313