Research articleEffects of (−)-epicatechin on frontal cortex DAPC and dysbindin of the mdx mice

- The dystrophin protein complex is expressed in the frontal cortex.
- Mdx mice (lacking dystrophin) are deficient of DAPC members on average 60-75%.
- Dysbindin and the dystrophin protein complex are down-regulated in mdx mice.
- Epi treatment partially restores protein expression to that of the wild type.
- Epi treatment partially reestablishes dysbindin and the dystrophin complex co-localization.

IntroductionMultiple components of the dystrophin-associated protein complex (DAPC) are expressed in numerous tissues including the brain. Members of the DAPC and dysbindin are abnormally expressed in the brain of Duchenne Muscular Dystrophy (DMD) patients, which has been associated with cognitive impairments. However, little is known about the expression pattern of individual members of the DAPC in animal models of DMD and their relationship with dysbindin.MethodsTen mdx mice were randomly allocated into a control and intervention group [(−)-epicatechin (Epi) 1 mg/kg/day for four weeks] and results compared to a wild-type mice. After sacrifice, brain pre-frontal cortices were collected for Western blotting and immunoprecipitation assays, and sagittal sections processed for immunohistochemistry.ResultsEpi promotes a partial recovery of DAPC members [α1-Syntrophin, sarcoglycans (SG), dystrophin 71 (Dp71)], dysbindin, and utrophin protein levels. Epi also appears to restore the association of DAPC between dysbindin, and utrophin with Dp71 and ε-SG. Co-immunostaining evidence increased protein levels of dysbindin, dystrophin, and ε-SG and their colocalization.ConclusionsAltogether, results suggest that Epi is capable of restoring pre-frontal cortex DAPC and dysbindin levels of mdx mice towards that of healthy brains. The functional implications of such studies warrant further investigation.