High Glucose-Induced Mitochondrial Reactive Oxygen Species in Cerebral Pericytes and Their Attenuation by Pharmacological Inhibition of Mitochondrial Carbonic Anhydrases

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 758-775-Beta Cells, Glucose Control & Complications
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-769
Tulin O. Price1, Ana Luiza Ribeiro Diogo*2, William A Banks3 and Gul N. Shah4
1Saint Louis Univeristy, Saint Louis, MO, 2Superior School of Health Sciences, Edifício Fepecs, Brazil, 3University of Washington School of Medicine, Seattle, WA, 4Saint Louis University, St. Louis, MO
Chronic hyperglycemia during diabetes mellitus leads to overproduction of mitochondrial reactive oxygen species (ROS) and oxidative stress. Mitochondrial ROS are considered as one of the central mechanism in the diabetes-specific microvascular pathology, in a variety of insulin-insensitive tissues such as the brain. Pericytes in the microvasculature of the brain are especially sensitive to mitochondrial ROS-induced oxidative stress. ROS primarily are produced during mitochondrial oxidative metabolism of glucose. The mitochondrial carbonic anhydrases CA VA and CA VB regulate the glucose metabolism and therefore regulate the ROS production and oxidative stress. We have recently shown that inhibition of mitochondrial carbonic anhydrases reduces high glucose-induced oxidative stress in cerebral pericytes and rescues them from apoptosis (1). Since oxidative stress is caused by mitochondrial ROS, in this study, we measure mitochondrial ROS in cerebral pericytes exposed to high glucose and investigate the effect of the pharmacological inhibition of mitochondrial carbonic anhydrases on high glucose-induced ROS production.

The cerebral pericytes were grown overnight in low glucose (LG, 5.7 mM) with or without mitochondrial carbonic anhydrases inhibitors, ethoxyzolamide or topiramate and then treated with high glucose (HG, 40.7 mM). Mitochondrial ROS was detected by treatment with MitoSOX followed by fluorescence imaging. The cell treated with high glucose showed an increase in mitochondrial ROS. Pretreatment with both ethoxyzolamide and topiramate significantly reduced high glucose-induced intracellular ROS overproduction. For the quantification a fluorimetric assay kit was used. A significant increase in ROS was reversed by pharmacological inhibition of mitochondrial carbonic anhydrases. The cell viability was unaffected by treatment with either ethoxyzolamide or topiramate.

These results provide the first evidence that high glucose induces excess mitochondrial ROS in cerebral pericytes, and pharmacologic inhibition of mitochondrial carbonic anhydrases attenuates high glucose-induced mitochondrial ROS in mouse cerebral pericytes.

(1) Shah GN et al., J Pharmacol Exp Ther. 2012; Dec 17. [Epub ahead of print] PMID:23249625

Nothing to Disclose: TOP, ALRD, WAB, GNS

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