A PiggyBac-mediated approach for muscle gene transfer or cell therapy.

An emerging therapeutic approach for Duchenne muscular dystrophy is the transplantation of autologous myogenic progenitor cells genetically modified to express dystrophin. The use of this approach is challenged by the difficulty in maintaining these cells ex vivo while keeping their myogenic potential, and ensuring sufficient transgene expression following their transplantation and myogenic differentiation in vivo. We investigated the use of the piggyBac transposon system to achieve stable gene expression when transferred to cultured mesoangioblasts and into murine muscles.

Assessing dystrophies and other muscle diseases at the nanometer scale by atomic force microscopy.

Aim: Atomic force microscopy nanoindentation of myofibers was used to assess and quantitatively diagnose muscular dystrophies from human patients.

Materials & Methods: Myofibers were probed from fresh or frozen muscle biopsies from human dystrophic patients and healthy volunteers, as well as mice models, and Young's modulus stiffness values were determined.

Results: Fibers displaying abnormally low mechanical stability were detected in biopsies from patients affected by 11 distinct muscle diseases, and Young's modulus values were commensurate to the severity of the disease.

MAR-mediated integration of plasmid vectors for in vivo gene transfer and regulation.

Background: The in vivo transfer of naked plasmid DNA into organs such as muscles is commonly used to assess the expression of prophylactic or therapeutic genes in animal disease models.

Results: In this study, we devised vectors allowing a tight regulation of transgene expression in mice from such non-viral vectors using a doxycycline-controlled network of activator and repressor proteins. Using these vectors, we demonstrate proper physiological response as consequence of the induced expression of two therapeutically relevant proteins, namely erythropoietin and utrophin.

Cloning of the IL-1β3 gene and IL-1β4 pseudogene in salmonids uncovers a second type of IL-1β gene in teleost fish.

To date two closely related interleukin-1β genes (IL-1β1 and IL-β2) have been found in salmonids. The cloning of trout and salmon IL-1β3, and a salmon IL-1β4 pseudogene reveals that two types of IL-1β genes exist in teleost species. Type I teleost IL-1β genes, including salmonid IL-1β3, share a similar 6 coding exon structure as in tetrapods.