A further aspect of interest in mutations in this area of the dystrophin gene is the fact that they disrupt the production of the dp260 isoform of dystrophin that is expressed in the retina

(19), and it is possible to determine whether AOs that restore reading frame in these mice are effective in the appropriate retinal layer. Mdx-3cv is also an interesting animal model to test exon skipping because it is the only mouse model with a mutation in the cysteine rich domain (20) due to a deletion within intron 65. This alters mRNA processing such that several transcripts are produced, Inhibitors,research,lifescience,medical predominantly one lacking the whole exon of exon 66. AOs targeting exon 65 (and 66) could result in exon skipped products with restored reading frame. Importantly, the cysteine rich domain is responsible Inhibitors,research,lifescience,medical for dystroglycan binding, so it would be interesting to test whether dystrophin lacking this region can ameliorate the Mdx-3cv phenotypes. Additionally, the dystrophin isoform Dp71, which among known dystrophic animals is

lacking only in mdx-3cv, is thought to play an important role in brain. Vorinostat price Haenggy et al. (21) previously investigated mice lacking either utrophin (utrophin0/0) or dystrophin isoforms (including Dp71) (i.e. mdx3Cv), and found Inhibitors,research,lifescience,medical three distinct complexes: (i) DAPs associated with utrophin in the basolateral membrane of the choroid plexus epithelium; (ii) DAPs associated Inhibitors,research,lifescience,medical with utrophin in vascular endothelial cells; and (iii) DAPs associated with Dp71 in the glial end-feet. The composition and localization of the Dystrophin associated proteins (DAPs) are dependent upon the anchoring proteins. Upon ablation of utrophin or Dp71, the corresponding DAPs were disrupted and no compensation of the missing protein by its homologue was observed. Inhibitors,research,lifescience,medical Association of the water channel aquaporin-4 with the glial DAPs likewise was also disrupted in mdx3Cv mice (21). Aquaporin-4 is known to be localized by alpha1-syntrophin, a dystrophin associated protein, at glial astrocyte endfeet,

and involved in generation Oxalosuccinic acid of cerebrospinal fluid (CSF) and brain edema (22). Thus, restoration of Dp71 by AOs could localize DAPs, including alpha1-syntrophin which is associated with the C-terminal domain of Dp71, then, in turn, restore the localization of aquaporin-4 at the blood-brain barrier (BBB) (23). Importantly, AO sequences against the equivalent dystrophin region in human and animal models (mouse or dog) show few differences across species. Development of gene-modified mice, possessing the human instead of mouse dystrophin gene has proved a useful tool to test the efficacy of AO sequences in vivo as demonstrated by Arechavala-Gomeza et al. for comparative analysis targeting exon 51 (24).