Potassium Ions Decrease Mitochondrial Matrix pH : Implications for ATP Production and Reactive Oxygen Species Generation

Potassium (K+) is the most abundant cation in the cytosol and is maintained at high concentrations within the mitochondrial matrix through potassium channels. However, many effects of K+ at such high concentrations on mitochondria and the underlying mechanisms remain unclear. This study aims to elucidate these effects and mechanisms by employing fluorescence imaging techniques to distinguish and precisely measure signals inside and outside the mitochondria. We stained the mitochondrial matrix with fluorescent dyes sensitive to K+, pH, reactive oxygen species (ROS), and membrane potential in plasma membrane-permeabilized C6 cells and isolated mitochondria from C6 cells. Fluorescence microscopy facilitated the accurate measurement of fluorescence intensity inside and outside the matrix. Increasing extramitochondrial K+ concentration from 2 mM to 127 mM led to a reduction in matrix pH and a decrease in the generation of highly reactive ROS. In addition, elevated K+ levels electrically polarized the inner membrane of the mitochondria and promoted efficient ATP synthesis via FoF1-ATPase. Introducing protons (H+) into the matrix through phosphate addition led to further mitochondrial polarization, and this effect was more pronounced in the presence of K+. K+ at high concentrations, reaching sub-hundred millimolar levels, increased H+ concentration within the matrix, suppressing ROS generation and boosting ATP synthesis. Although this study does not elucidate the role of specific types of potassium channels in mitochondria, it does suggest that mitochondrial K+ plays a beneficial role in maintaining cellular health.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:25

Enthalten in:

International journal of molecular sciences - 25(2024), 2 vom: 19. Jan.

Sprache:

Englisch

Beteiligte Personen:

Naima, Jannatul [VerfasserIn]
Ohta, Yoshihiro [VerfasserIn]

Links:

Volltext

Themen:

8L70Q75FXE
ATP production
Adenosine Triphosphate
Journal Article
Matrix pH
Mitochondria
Potassium
Potassium Channels
Potassium ions
Protons
ROS generation
RWP5GA015D
Reactive Oxygen Species

Anmerkungen:

Date Completed 29.01.2024

Date Revised 29.01.2024

published: Electronic

Citation Status MEDLINE

doi:

10.3390/ijms25021233

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367696479