Muscle spindles exhibit core lesions and extensive degeneration of intrafusal fibers in the Ryr1I4895TSwt mouse model of core myopathy

作者：Zvaritch Elena; MacLennan David H^*

来源：Biochemical and Biophysical Research Communications, 2015, 460(1): 34-39.

DOI：10.1016/j.bbrc.2015.01.056

• Core myopathy
• Ryanodine receptor type 1
• Muscle spindle
• Intrafusal fibers
• Muscle weakness
• Mouse model

Muscle spindles from the hind limb muscles of adult Ryr(1I4895T/wt) (IT/+) mice exhibit severe structural abnormalities. Up to 85% of the spindles are separated from skeletal muscle fascicles by a thick layer of connective tissue. Many intrafusal fibers exhibit degeneration, with Z-line streaming, compaction and collapse of myofibrillar bundles, mitochondrial clumping, nuclear shrinkage and pyknosis. The lesions resemble cores observed in the extrafusal myofibers of this animal model and of core myopathy patients. Spindle abnormalities precede those in extrafusal fibers, indicating that they are a primary pathological feature in this murine Ryr1-related core myopathy. Muscle spindle involvement, if confirmed for human core myopathy patients, would provide an explanation for an array of devastating clinical features characteristic of these diseases and provide novel insights into the pathology of RYR1 -related myopathies.

• 出版日期2015-4-24