This last Tuesday 7th of September was World Duchenne Awareness Day – #WDAD2021. Duchenne Parent Project Spain, a non-profit that works to find a cure for Duchenne (DMD) and Becker Muscular Distrophy (BMD), organised as in previous years a workshop designed as a knowledge transfer activity for researchers. CBIT’s Dr Patricia Rico talked in the afternoon session, about her work to describe the role of the boron ion and the cell membrane NaBC1 ion-transporter in cell adhesion signalling and crosstalk in mechanotransduction processes. We have developed a Boron-loaded injectable hydrogel that has been shown to promote muscle regeneration after injury in a mouse model. In vitro we have seen distinctive promotion of myoblast differentiation and myotube formation. The fusion of myoblasts in myotubes is an essential phase of myogenesis for muscle repair. When myoblasts are cultured in low serum conditions inducing their differentiation, they elongate and fuse into multinucleated myotubes. We have characterised the formation of myotubes with the activation of the boron transporter.
In the figure above: Analysis of skeletal muscle regeneration after 18 days post-injury with cardiotoxin. The images show histology sections from the right tibialis anterior (TA) muscle of mice, with large regenerated eosinophilic myofibers, with centrally located nuclei (indicative of muscle regeneration), when injected with boron-loaded alginate-based systems.
In the figure above: Fluorescence images show the sarcomeric α-actinin marker after 4 days of culture under differentiation conditions. Although the initial cell seeding density was the same in both conditions, the myotube fusion index was higher in the presence of borax. In addition, the degree of maturation of the myotubes was evaluated by analyzing in detail their ultrastructure by confocal microscopy, clearly observing aligned striations of sarcomeric α-actinin in the presence of borax.
Since the maturation of the myotubes is normally associated with the appearance of these aligned structures, the results suggest that the activation of the boron transporter accelerates the fusion and maturation of the myotubes.
This work is published in » Jesús Ciriza, Ana Rodríguez-Romano, Ignacio Nogueroles, Gloria Gallego-Ferrer, Rubén Martín Cabezuelo, José Luis Pedraz, Patricia Rico. Borax-loaded injectable alginate hydrogels promote muscle regeneration in vivo after an injury. Materials Science and Engineering: C, Volume 123, 2021, 112003. https://doi.org/10.1016/j.msec.2021.112003.»
Many thanks to Dr Marisol Montolio del Olmo, Scientific Director of Duchenne Parent Project Spain, for organising this great event.