Referenced in: none

Automatically associated channels: ClC1 , ClC4

Title: Muscleblind-like 2 (Mbnl2) -deficient mice as a model for myotonic dystrophy.

Authors: Minqi Hao, Kevan Akrami, Ke Wei, Carlos De Diego, Nam Che, Jeong-Hee Ku, James Tidball, Michael C Graves, Perry B Shieh, Fabian Chen

Journal, date & volume: Dev. Dyn., 2008 Feb , 237, 403-10

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18213585

Abstract
Myotonic dystrophy (DM), the most common adult-onset muscular dystrophy, is caused by CTG or CCTG microsatellite repeat expansions. Expanded DM mRNA microsatellite repeats are thought to accumulate in the nucleus, sequester Muscleblind proteins, and interfere with alternative mRNA splicing. Muscleblind2 (Mbnl2) is a member of the family of Muscleblind RNA binding proteins (that also include Mbnl1 and Mbnl3) that are known to bind CTG/CCTG RNA repeats. Recently, it was demonstrated that Mbnl1-deficient mice have characteristic features of human DM, including myotonia and defective chloride channel expression. Here, we demonstrate that Mbnl2-deficient mice also develop myotonia and have skeletal muscle pathology consistent with human DM. We also find defective expression and mRNA splicing of the chloride channel (Clcn1) in skeletal muscle that likely contributes to the myotonia phenotype. Our results support the hypothesis that Muscleblind proteins and specifically MBNL2 contribute to the pathogenesis of human DM.