In vivo imaging of H2O2: characterization of the roGFP2-Orp1 mouse

• Grant number: 13/22830-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: May 03, 2014
• End date: May 02, 2015
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Angelo Rafael Carpinelli
• Grantee: Leticia Prates Roma
• Supervisor: Tobias P. Dick
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Heidelberg University, Germany
• Associated to the scholarship: 11/18993-0 - Identification and localization of reactive oxygen species during nutrient-induced insulin secretion: role of NADPH oxidase., BP.PD

Abstract

Oxidative stress has long been proposed as a unifying mechanism linking excessive nutrient intake, insulin resistance, the metabolic syndrome, and diabetes. Although in vitro studies suggest that reactive oxygen species (ROS) play an important role in the development of insulin resistance and type 2 diabetes, virtually nothing is known about how in vivo redox changes are modulated under these conditions. The development of genetically encoded redox biosensors offers a promising new way to investigate redox biology. The redox-sensitive green fluorescent proteins (roGFPs), genetically fused to redox-enzymes, allow specific measurements of either the glutathione redox potential (using the Grx1-roGFP2 probe) or of relative changes in endogenous H2O2 concentration (using the roGFP2-Orp1 probe). Using a model of insulin resistance (high-fat diet), we will assess redox changes in the mitochondria and cytosol of different tissues from animals expressing the H2O2 redox sensor roGFP2-Orp1. With this approach, we hope to determine which cells and tissue types undergo redox changes during the development of insulin resistance. (AU)