• Julien Ochala, Olli Carpén, and Lars Larsson.
• Department of Clinical Neurophysiology, Uppsala University Hospital, Sweden. julien.ochala@neuro.uu.se
• Ups. J. Med. Sci. 2009 Jan 1; 114 (4): 235-41.

BackgroundMyofibrillar myopathies constitute a rare group of congenital neuromuscular disorders, frequently associated with mutations in Z-disc proteins such as myotilin. Myotilin location and interactions with other Z-disc proteins are clearly defined, but its role in the regulation of muscle structure and function remains unknown. The present study aims at investigating this specific role of myotilin.MethodsSkeletal and cardiac muscles were collected from adult mice with a targeted deletion of myotilin (myo(-/-)) and wild-type animals (myo(+/+)).Results And ConclusionSimilar skeletal and cardiac muscle weights were observed in myo(-/-) and myo(+/+) mice. At the muscle cell level, the size and force production of single membrane permeabilized fibers were identical between myo(-/-) and myo(+/+) rodents. Thus, myotilin does not have a significant influence on muscle mass, muscle fiber size, or regulation of muscle contraction. Alternatively, compensatory over-expressions of other elements including proteins from the same subfamily, or Z-disc proteins such as telethonin, or intermediate filaments may compensate for the lack of myotilin.

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