A Novel Assay of Mechano-Transduction in Single Muscle Cells

Abstract

In striated muscle the tight integration of contractility and biomechanical properties with electrical, metabolic and hormonal signaling are defined as mechano-transduction signaling pathways. The great interest to define the molecular basis for mechano-transduction is underpinned by the growing number of loss-of-function disorders and diseases in which altered mechano-transduction has been identified. Intact, single cell preparations are attractive for studying mechano-transduction, however the mechanical loading of single cells requires technically challenging methods. We have recently developed MyoTak, a tenacious biological adhesive, which enables us to attach single dissociated striated myocytes (skeletal and cardiac) to force transducer and length controller units. The myocytes thus prepared can be readily imaged using an inverted microscope equipped with confocal, widefield and multiphoton fluorescence imaging systems. With this preparation we have been able to control myocyte length while assaying passive tension and electrically evoked contractility. In recent experiments we have explored the interaction of myocyte stretch and contractility with Ca2+ signaling, mitochondrial function and ROS production. We will present these new findings, the novel methods and additional experiments examining the role of microtubules as mechano-transducer elements that contribute to these interactions. Supported by RC2 NR011968 to CWW, and to WJL (NHLBI P01 HL67849 and R01-HL36974; Leducq North American-European Atrial Fibrillation Research Alliance; European Union Seventh Framework Program (FP7) “Identification and therapeutic targeting of common arrhythmia trigger mechanisms” and support from the Maryland Stem Cell Commission).