Understanding structural changes at the molecular level in disease models can provide new insights into underlying disease mechanisms. The authors of this week’s paper used single molecule localization super resolution microscopy to study the effect of cardiac failure on the sarcomeric cytoskeleton after cardiac failure.
Canine cardiomyocytes were used as a model system to study structural changes in the sarcomere associated cytoskeletal protein, alpha-actinin, after inducing synchronous or dyssynchronous heart failure (SHF or DHF) and following cardiac resynchronization therapy (CRT). In control cells the organization of alpha-actinin was found to be in a regular, pararell, transverse sheet pattern consistent with the arrangement found in striated muscle. In heart failure and CRT cells there was a reduction in the overall spatial regularity of alpha-actinin and increase in the presence of longitudinal alpha-actinin depositions connecting adjacent parallel alpha-actinin sheets. This decreased regularity was most pronounced in DHF.