Encapsulated engineered myoblasts can cure Hurler syndrome: preclinical experiments in the mouse model

Mucopolysaccharidosis type I (MPSI) is an autosomic recessive, lysosomal storage disorder due to the deficit of the enzyme α-L-iduronidase (IDUA). The disease accounts for a general impairment of tissue and organ functions, mainly including heart disease, corneal clouding, organomegaly, skeletal malformations and joint stiffness. Neurological deterioration affects the severe forms. Both haemopoietic stem cell transplantation and enzyme replacement therapy can be applied to the treatment of the disorder; however, they both present several limitations. Thus, the search for alternative strategies to complement the present procedures is highly desirable. A murine myoblast cell line engineered to overexpress IDUA was generated and enclosed in alginate microcapsules, which were intra-peritoneally implanted in the MPSI mouse model. Plasma and tissue enzyme activity induced by the treatment and urinary and tissue glycosaminoglycan content were monitored in the animals, progressively sacrificed up to 4 months after implantation. Significant induction of enzyme activity and reduction of glycosaminoglycan accumulation were detected in the implanted animals, complete normalization of deposits was achieved in two animals. Intra-peritoneal implantation of alginate microcapsule confirms to be a valid approach as an endogenous enzyme replacement procedure.