Sites and Consequences of Mitochondreal ROS Production

Abstract

The thesis consists of 8 articles (6 published and 2 submitted), which may be divided into two major lines. The first (articles 1-4) deals with mitochondrial glycerophosphate dehydrogenase. We have shown that this enzyme is capable of massive ROS production and in the presented works we studied in more detail this ROS production as well as some aspects of enzyme biogenesis, so as to better understand its physiological significance. The second line (articles 5-8) represents our studies on the potential involvement of ROS in pathogenesis of mitochondrial diseases. 1. Glycerophosphate-dependent hydrogen peroxide production by brown adipose tissue mitochondria and its activation by ferricyanide; Drahota Z., Chowdhury SKR., Floryk D., Mráček T., Wilhelm J., Rauchová H., Lenaz G., Houštěk J.; J Bioenerg Biomembr. 2002; 34(2):105-13. Indeed, this was first article to demonstrate ROS production by mammalian mGPDH. We studied oxidation of glycerophosphate by brown adipose tissue mitochondria, which are known to contain high amounts of mGPDH. We found significant GP-dependent AA- stimulated production of H2O2. To further verify our findings, we used three independent methods for H2O2 measurement - fluorescence detection with p-hydroxyphenylacetic acid, antimycine A - insensitive oxygen consumption, and luminometric...