Purpose of Review: The goal of this review is to summarize the unique regenerative milieu within mature mammalian extraocular muscles (EOMs). This will aid in understanding disease propensity for and sparing of EOMs in skeletal muscle diseases as well as the recalcitrance of the EOM to injury. Recent Findings: The EOMs continually remodel throughout life and contain an extremely enriched number of myogenic precursor cells that differ in number and functional characteristics from those in limb skeletal muscle. The EOMs also contain a large population of Pitx2-positive myogenic precursor cells that provide the EOMs with many of their unusual biological characteristics, such as myofiber remodeling and skeletal muscle disease sparing. This environment provides for rapid and efficient remodeling and regeneration after various types of injury. In addition, the EOMs show a remarkable ability to respond to perturbations of single muscles with coordinated changes in the other EOMs that move in the same plane. Summary: These data will inform ophthalmologists as they work toward developing new treatments for eye movement disorders, new approaches for repair after nerve or direct EOM injury, as well as suggest potential explanations for the unusual disease propensity and disease-sparing characteristics of human EOM.
Bibliographical noteFunding Information:
This work was supported by NIH EY15313 (L.K.M.), NIH RA066454 (M.V.), NIH P30 EY11375, NIH P30AR0507220, Minnesota Lions Foundation, and an unrestricted grant to the Department of Ophthalmology and Visual Sciences from Research to Prevent Blindness, Inc. In addition, this work was supported in part by NIH P30 CA77598 supporting the University Flow Cytometry Resource.
© 2017, Springer Science + Business Media New York.
- Extraocular muscle
- Satellite cells
- Strabismus surgery