RESUMEN
Limb girdle muscular dystrophy 2B (LGMD2B) is without treatment and caused by mutations in the dysferlin gene (DYSF). One-third is missense mutations leading to dysferlin aggregation and amyloid formation, in addition to defects in sarcolemmal repair and progressive muscle wasting. Dysferlin-null mouse models do not allow study of the consequences of missense mutations. We generated a new mouse model (MMex38) carrying a missense mutation in exon 38 in analogy to a clinically relevant human DYSF variant (DYSF p.Leu1341Pro). The targeted mutation induces all characteristics of missense mutant dysferlinopathy, including a progressive dystrophic pattern, amyloid formation, and defects in membrane repair. We chose U7 small nuclear RNA (snRNA)-based splice switching to demonstrate a possible exon-skipping strategy in this new animal model. We show that Dysf exons 37 and 38 can successfully be skipped in vivo. Overall, the MMex38 mouse model provides an ideal tool for preclinical development of treatment strategies for dysferlinopathy.
RESUMEN
Peptide Nucleic Acids (PNAs) are molecules combining structural features of proteins and nucleic acid. They resemble DNA or RNA by forming helical polyamides containing nitrogen bases attached to the backbone consisting of N-(2-aminoethyl)-glycine monomers, which mimics the alternating ribose-phosphodiester-backbone of a nucleic acid. Because PNAs bind exceptionally strong to complementary DNA or RNA sequences obeying Watson-Crick base paring, they became attractive candidates for antisense and antigen therapies. PNAs are also being tested as novel antibiotics, gene-activating agents, and as molecular probes for FISH and imaging or biosensors used in diagnostics. Although PNAs offer many exiting medical applications, improving their cellular uptake and developing specific delivery strategies is crucial for a successful entry in the clinic in the near future.
