ROS Flashes in Mitochondria Occur Concomitantly with Inner Mitochondrial Membrane Depolarization and Mitochondrial Calcium Sparks | Chapter 11 | New Frontiers in Medicine and Medical Research Vol. 16

 Using fluorescent confocal imaging, investigate complex ROS dynamics and ROS mito-flashes in distinct live cells. Analysis of mitochondrial and extra-mitochondrial ROS dynamics at the same time. Depolarization and potential of the mitochondrial membrane Analysis of mitochondrial calcium and ROS dynamics at the same time.

It is widely known that mitochondria can produce significant amounts of reactive oxygen species (ROS), which have a role in a variety of physiological and pathological processes. The complicated interrelationships between ROS, mitochondrial inner membrane potential (m), and mitochondrial Ca2+, on the other hand, were not well explored. We show that biphasic ROS dynamics exist in this study, with initial and continuous ROS increase followed by mitochondrial ROS flashes. Furthermore, there is a lot of variation in the rates of mitochondrial ROS production and the start times of ROS flashes. We proved that the processes of ROS flashes may be triggered by particular quantities of external ROS by comparing mitochondrial and extra mitochondrial fluorescence signals. Mitochondrial permeability transition pore opening (collapse of mitochondrial membrane potential, m) and mitochondrial calcium spikes are two of the mechanisms involved. Furthermore, mitochondria-to-mitochondrial contacts can be viewed as a wave of mitochondrial ROS flashes and m collapses, comparable to the phenomena of ROS-induced ROS release first observed in cardiomyocytes. Our findings suggest that excess mitochondrial ROS produced by individual mitochondrion or neighbouring mitochondria can be involved in mechanisms of mitochondrial ROS flashes activation and concomitant depolarization. This could be a common pathway in ROS-ROS and mitochondria-mitochondrial signalling, with implications for cellular and mitochondrial function.

Author (S) Details

Andrey V. Kuznetsov
Cardiac Surgery Laboratory, Department of Heart Surgery, Medical University of Innsbruck, Innsbruck, A-6020, Austria. and Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.

Judith Hagenbuchner
Department of Pediatrics II, Medical University of Innsbruck, Innsbruck, Austria.

Michael J. Ausserlechner
Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.

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