Laminin-111 protein therapy enhances muscle regeneration and repair in the GRMD dog model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a devastating X-linked disease affecting ~1 in 5000 males. DMD patients exhibit progressive muscle degeneration and weakness, leading to loss of ambulation and premature death from cardiopulmonary failure. We previously reported that mouse Laminin-111 (msLam-111) protein could reduce muscle pathology and improve muscle function in the mdx mouse model for DMD. In this study, we examined the ability of msLam-111 to prevent muscle disease progression in the golden retriever muscular dystrophy (GRMD) dog model of DMD. The msLam-111 protein was injected into the cranial tibial muscle compartment of GRMD dogs and muscle strength and pathology were assessed. The results showed that msLam-111 treatment increased muscle fiber regeneration and repair with improved muscle strength and reduced muscle fibrosis in the GRMD model. Together, these findings support the idea that Laminin-111 could serve as a novel protein therapy for the treatment of DMD.

Human laminin-111 and laminin-211 protein therapy prevents muscle disease progression in an immunodeficient mouse model of LAMA2-CMD.

BACKGROUND: Laminin-α2-related congenital muscular dystrophy (LAMA2-CMD) is a devastating genetic disease caused by mutations in the LAMA2 gene. These mutations result in progressive muscle wasting and inflammation leading to delayed milestones, and reduced lifespan in affected patients. There is currently no cure or treatment for LAMA2-CMD. Preclinical studies have demonstrated that mouse laminin-111 can serve as an effective protein replacement therapy in a mouse model of LAMA2-CMD. METHODS: In this study, we generated a novel immunocompromised dyW mouse model of LAMA2-CMD to study the role the immune system plays in muscle disease progression. We used this immune-deficient dyW mouse model to test the therapeutic benefits of recombinant human laminin-111 and laminin-211 protein therapy on laminin-α2-deficient muscle disease progression. RESULTS: We show that immunodeficient laminin-α2 null mice demonstrate subtle differences in muscle regeneration compared to immunocompetent animals during early disease stages but overall exhibit a comparable muscle disease progression. We found human laminin-111 and laminin-211 could serve as effective protein replacement strategies with mice showing improvements in muscle pathology and function. We observed that human laminin-111 and laminin-211 exhibit differences on satellite and myoblast cell populations and differentially affect muscle repair. CONCLUSIONS: This study describes the generation of a novel immunodeficient mouse model that allows investigation of the role the immune system plays in LAMA2-CMD. This model can be used to assess the therapeutic potential of heterologous therapies that would elicit an immune response. Using this model, we show that recombinant human laminin-111 can serve as effective protein replacement therapy for the treatment of LAMA2-CMD.