Abstract | BACKGROUND: METHODS: Herein we characterize the impact of FIG4 on skeletal muscle development and function using the spontaneously occurring mouse mutant pale tremor (plt), a mouse line with a loss of function mutation in Fig4. RESULTS: In plt mice, we characterized abnormalities in skeletal muscle, including reduced muscle size and specific force generation. We also uncovered ultrastructural abnormalities and increased programmed cell death. Conversely, we detected no structural or functional abnormalities to suggest impairment of excitation-contraction coupling, a process previously shown to be influenced by PI(3,5)P2 levels. Conditional rescue of Fig4 mutation in neurons prevented overt muscle weakness and the development of obvious muscle abnormalities, suggesting that the changes observed in the plt mice were primarily related to denervation of skeletal muscle. On the basis of the ability of reduced FIG4 levels to rescue aspects of Mtmr2-dependent neuropathy, we evaluated the effect of Fig4 haploinsufficiency on the myopathy of Mtm1-knockout mice. Male mice with a compound Fig4+/-/Mtm1-/Y genotype displayed no improvements in muscle histology, muscle size or overall survival, indicating that FIG4 reduction does not ameliorate the Mtm1-knockout phenotype. CONCLUSIONS: Overall, these data indicate that loss of Fig4 impairs skeletal muscle function but does not significantly affect its structural development.
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Authors | Aaron Reifler, Guy M Lenk, Xingli Li, Linda Groom, Susan V Brooks, Desmond Wilson, Michyla Bowerson, Robert T Dirksen, Miriam H Meisler, James J Dowling |
Journal | Skeletal muscle
(Skelet Muscle)
Vol. 3
Issue 1
Pg. 21
(Sep 01 2013)
ISSN: 2044-5040 [Print] England |
PMID | 24004519
(Publication Type: Journal Article)
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