title: Telomere shortening in diaphragm and tibialis anterior muscles of aged mdx mice.
abstract: The progression of Duchenne muscular dystrophy (DMD) is, in part, due to satellite cell senescence driven by high replicative pressure as these muscle stem cells repeatedly divide and fuse to damaged muscle fibers. We hypothesize that telomere shortening in satellite cells underlies their senescence. To test this hypothesis, we evaluated the diaphragm and a leg muscle from dystrophic mice of various ages for telomere dynamics. We found 30% telomere shortening in tibialis anterior muscles from 600-day-old mdx mice relative to age-matched wildtype mice. We also found a more severe shortening of telomere length in diaphragm muscles of old mdx mice. In those muscles, telomeres were shortened by approximately 15% and 40% in 100- and 600-day-old mdx mice, respectively. These findings indicate that satellite cells undergo telomere erosion, which may contribute to the inability of these cells to perpetually repair DMD muscle.
authors.affiliation: Pediatric Hematology-Oncology and Blood and Marrow Transplant Program, University of Minnesota, School of Medicine, Minneapolis, Minnesota 55455, USA.
authors.forename: Troy C
authors.initials: TC
authors.lastname: Lund
authors.forename: Robert W
authors.initials: RW
authors.lastname: Grange
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Lowe
mesh_terms: D000367:Age Factors; D000818:Animals; D016922:Cellular Senescence / Q000235:genetics*; D003964:Diaphragm / Q000378:metabolism*; D051379:Mice; D018101:Mice, Inbred mdx; D018482:Muscle, Skeletal / Q000378:metabolism*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics*; D032496:Satellite Cells, Skeletal Muscle / Q000737:chemistry / Q000378:metabolism; D016615:Telomere / Q000737:chemistry / Q000378:metabolism*; D013977:Tibia