Workshop AG Katschinski: Cardiomyocyte specific redox biosensor mice
An introduction to the cardiomyocyte specific redox biosensor mice with its potential applications
Cardiomyocytes feature a defined organization of their cytoplasm containing the sarcomeric-contractile apparatus and their confined subcellular organellar compartments. Their intracellular environment is assumed to be mostly reductive with deviations in some organelles like mitochondrial, ER, the nucleus etc. Excitation contraction coupling is thus under tight redox control. We have recently developed αMHC-driven cardiomyocyte-specific Grx1-roGFP2 sensor mice, in which the sensor is either located to the cytoplasm or targeted to the mitochondrial matrix. RoGFP2 enables real-time visualization of the EGSH towards an oxidative or reductive stimulus via disulfide formation between cysteine residues. Overall, the data demonstrates that in cardiomyocytes the cytoplasm and the mitochondrial matrix have unique EGSH under resting conditions and after stimulation. Thus, this mouse model serves as a promising tool to investigate the link between the redox status and the cellular functions.
In this workshop, we will mainly focus on the protocol for isolation of cardiomyocytes from adult mouse heart by Langendorff´s perfusion system followed by the redox measurements required to obtain the glutathione redox potential (EGSH). The possible applications of this mouse model along with the associated limitations will also be discussed along with the experimental demonstration of the technique.
Performed by Maithily Nanadikar, M.Sc. – Institute of Cardiac and Circulatory Physiology, AG Prof. Dr. med. Katschinski
Prof. Dr. Dörthe M. Katschinski
Director of the Department of Cardiovascular Physiology.