Direct monitoring of cAMP at the cardiac ryanodine receptor using a novel targeted fluorescence biosensor mouse
| Autor: | Viacheslav O. Nikolaev, Stephan E. Lehnart, Ulrike Pape, K R Goetz, Cindy Meyer, Christiane Jungen, Stefan Blankenberg, Filip Berisha, Svenja Warnke, J W Wegener, Diana Lindner, Axel E. Kraft, Gerd Hasenfuss, Dirk Westermann |
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| Rok vydání: | 2019 |
| Předmět: |
Genetically modified mouse
0303 health sciences Chemistry Ryanodine receptor Phosphodiesterase chemistry.chemical_element 030204 cardiovascular system & hematology Calcium Ryanodine receptor 2 Cell biology 03 medical and health sciences 0302 clinical medicine Second messenger system cardiovascular system Protein kinase A Receptor 030304 developmental biology |
| DOI: | 10.1101/623934 |
| Popis: | RationaleCyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger which, upon β-adrenergic receptor (β-AR) stimulation, acts in microdomains to regulate cardiac excitation-contraction coupling by activating the cAMP-dependent protein kinase (PKA) phosphorylation of calcium handling proteins. One crucial microdomain is in vicinity of the cardiac ryanodine receptor type 2 (RyR2) which is associated with arrhythmogenic diastolic calcium leak from the sarcoplasmic reticulum (SR) often occurring upon RyR2 hyperphosphorylation by PKA and calcium/calmodulin-dependent kinase.ObjectiveWe sought to establish a real time approach capable of directly visualizing cAMP and its pathological changes in the vicinity of RyR2 by generating a proper targeted biosensor and transgenic mouse model to express it in adult cardiomyocytes.Methods and ResultsWe generated transgenic mice expressing a novel targeted fluorescent biosensor for RyR2-associated cAMP in adult mouse cardiomyocytes. In healthy cardiomyocytes, β1-AR but not β2-AR stimulation strongly increased local RyR2-associated cAMP levels. However, in cardiac hypertrophy induced by aortic banding, there was a marked subcellular redistribution of phosphodiesterases (PDEs) 2, 3 and 4, which included a dramatic loss of the local pool of PDE4. This was also accompanied by measurable β2-AR-induced cAMP signals, increased SR calcium leak and arrhythmia susceptibility.ConclusionsOur new targeted biosensor expressed in transgenic mice can visualize cAMP levels in the vicinity of cardiac RyR2 in healthy and diseased cardiomyocytes. In the future, this novel biosensor can be used to better understand alterations of RyR2-associated cAMP in cardiovascular diseases and local actions of new therapies. |
| Databáze: | OpenAIRE |
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