| First Author | Demonbreun AR | Year | 2016 |
| Journal | Am J Pathol | Volume | 186 |
| Issue | 6 | Pages | 1610-22 |
| PubMed ID | 27070822 | Mgi Jnum | J:233700 |
| Mgi Id | MGI:5787872 | Doi | 10.1016/j.ajpath.2016.02.005 |
| Citation | Demonbreun AR, et al. (2016) Enhanced Muscular Dystrophy from Loss of Dysferlin Is Accompanied by Impaired Annexin A6 Translocation after Sarcolemmal Disruption. Am J Pathol 186(6):1610-22 |
| abstractText | Dysferlin is a membrane-associated protein implicated in membrane resealing; loss of dysferlin leads to muscular dystrophy. We examined the same loss-of-function Dysf mutation in two different mouse strains, 129T2/SvEmsJ (Dysf(129)) and C57BL/6J (Dysf(B6)). Although there are many genetic differences between these two strains, we focused on polymorphisms in Anxa6 because these variants were previously associated with modifying a pathologically distinct form of muscular dystrophy and increased the production of a truncated annexin A6 protein. Dysferlin deficiency in the C57BL/6J background was associated with increased Evan's Blue dye uptake into muscle and increased serum creatine kinase compared to the 129T2/SvEmsJ background. In the C57BL/6J background, dysferlin loss was associated with enhanced pathologic severity, characterized by decreased mean fiber cross-sectional area, increased internalized nuclei, and increased fibrosis, compared to that in Dysf(129) mice. Macrophage infiltrate was also increased in Dysf(B6) muscle. High-resolution imaging of live myofibers demonstrated that fibers from Dysf(B6) mice displayed reduced translocation of full-length annexin A6 to the site of laser-induced sarcolemmal disruption compared to Dysf(129) myofibers, and impaired translocation of annexin A6 associated with impaired resealing of the sarcolemma. These results provide one mechanism by which the C57BL/6J background intensifies dysferlinopathy, giving rise to a more severe form of muscular dystrophy in the Dysf(B6) mouse model through increased membrane leak and inflammation. |
