Caveolin-3 regulates compartmentation of cardiomyocyte beta2-adrenergic receptor-mediated cAMP signaling

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• 作者：Peter T. Wright ; Viacheslav O. Nikolaev ; Thomas O'Hara ; Ivan Diakonov ; Anamika Bhargava ; Sergiy Tokar ; Sophie Schobesberger ; Andrew I. Shevchuk ; Markus B. Sikkel ; Ross Wilkinson ; Natalia A. Trayanova ; Alex ; er R. Lyon ; Sian E. Harding ; Julia Gorelik
• 关键词：尾-AR ; 尾-adrenergic receptor ; ARVM ; adult rat ventricular myocytes ; Cav3 ; caveolin-3 ; Cav3DN ; caveolin-3 dominant negative mutant ; FRET ; fluorescence resonance energy transfer ; HF ; heart failure ; M尾CD ; methyl-尾-cyclodextrin ; SICM ; scanning ion conductance microscopy
• 刊名：Journal of Molecular and Cellular Cardiology
• 出版年：February, 2014
• 年：2014
• 卷：67
• 期：Complete
• 页码：38-48
• 全文大小：1619 K

文摘

The purpose of this study was to investigate whether caveolin-3 (Cav3) regulates localization of 尾₂-adrenergic receptor (尾₂AR) and its cAMP signaling in healthy or failing cardiomyocytes. We co-expressed wildtype Cav3 or its dominant-negative mutant (Cav3DN) together with the F枚rster resonance energy transfer (FRET)-based cAMP sensor Epac2-camps in adult rat ventricular myocytes (ARVMs). FRET and scanning ion conductance microscopy were used to locally stimulate 尾₂AR and to measure cytosolic cAMP. Cav3 overexpression increased the number of caveolae and decreased the magnitude of 尾₂AR-cAMP signal. Conversely, Cav3DN expression resulted in an increased 尾₂AR-cAMP response without altering the whole-cell L-type calcium current. Following local stimulation of Cav3DN-expressing ARVMs, 尾₂AR response could only be generated in T-tubules. However, the normally compartmentalized 尾₂AR-cAMP signal became diffuse, similar to the situation observed in heart failure. Finally, overexpression of Cav3 in failing myocytes led to partial 尾₂AR redistribution back into the T-tubules. In conclusion, Cav3 plays a crucial role for the localization of 尾₂AR and compartmentation of 尾₂AR-cAMP signaling to the T-tubules of healthy ARVMs, and overexpression of Cav3 in failing myocytes can partially restore the disrupted localization of these receptors.