Research projects

The specific objectives are:

1.- Study the activation of innate immunity in dysferlin-deficient cell cultures. We had developed a new protocol to differentiate to myotubes TE671 cell line. Using CRIPR/Cas9 methodology we develop a new TE671 cell line dysferlin-deficient. This cell line contain the following mutations in exon 29 of DYSF gene: c.3103_3112del, c.3112dup, c.3147T>G and c.3150C>G (reference sequence NM_3494.3). This cell line reproduces the myogenin reduction, TSP1 increase and deficient membrane repair observed in dysferlin-deficient primary cultures.

2.- To study the efficacy of treatment in cell cultures.

2.1 Drug therapy: Treatment with proteasome inhibitors and EB1089 resulted in a slight increase of dysferlin expression which was accompanied by a low increase of myogenin expression. Also, EB1089 and proteasome inhibitors reduced the release of TSP-1 in myotubes from a dysferlinopathy patient. However, the increase of dysferlin had no effect on the repair of muscle membrane after injury. Our findings indicate that the ubiquitin-proteasome system might not be the main mechanism of mutant dysferlin degradation. However, its inhibition could help to improve muscle inflammation by reducing TSP-1 release. 

2.2 TLR4 analysis and inhibition: Dysferlin-deficient myotubes have an increased TLR4 levels compared to Control myotubes. Second messengers from TLR4 signaling pathways were also activated. Atorvastatin treatment, reduced neither TLR4 levels nor secondary inflammatory messengers, but increased dysferlin levels. Actually, we are testing other TLR4 inhibitors to interfere with inflammation signaling pathways, which are constitutively activated in dysferlin-deficient cells.