Dataset Information

Transgenic overexpression of the ?7 integrin reduces muscle pathology and improves viability in the dy(W) mouse model of merosin-deficient congenital muscular dystrophy type 1A.

ABSTRACT: Merosin-deficient congenital muscular dystrophy 1A (MDC1A) is a devastating neuromuscular disease that results in children being confined to a wheelchair, requiring ventilator assistance to breathe and premature death. MDC1A is caused by mutations in the LAMA2 gene, which results in the partial or complete loss of laminin-211 and laminin-221, the major laminin isoforms found in the basal lamina of skeletal muscle. MDC1A patients exhibit reduced ?7?1 integrin; however, it is unclear how the secondary loss of ?7?1 integrin contributes to MDC1A disease progression. To investigate whether restoring ?7 integrin expression can alleviate the myopathic phenotype observed in MDC1A, we produced transgenic mice that overexpressed the ?7 integrin in the skeletal muscle of the dy(W?/?) mouse model of MDC1A. Enhanced expression of the ?7 integrin restored sarcolemmal localization of the ?7?1 integrin to laminin-?2-deficient myofibers, changed the composition of the muscle extracellular matrix, reduced muscle pathology, maintained muscle strength and function and improved the life expectancy of dy(W?/?) mice. Taken together, these results indicate that enhanced expression of ?7 integrin prevents muscle disease progression through augmentation and/or stabilization of the existing extracellular matrix in laminin-?2-deficient mice, and strategies that increase ?7 integrin in muscle might provide an innovative approach for the treatment of MDC1A.

SUBMITTER: Doe JA

PROVIDER: S-EPMC3113674 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

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Transgenic overexpression of the α7 integrin reduces muscle pathology and improves viability in the dy(W) mouse model of merosin-deficient congenital muscular dystrophy type 1A.

Doe Jinger A JA Wuebbles Ryan D RD Allred Erika T ET Rooney Jachinta E JE Elorza Margaret M Burkin Dean J DJ

Journal of cell science 20110607 Pt 13

Merosin-deficient congenital muscular dystrophy 1A (MDC1A) is a devastating neuromuscular disease that results in children being confined to a wheelchair, requiring ventilator assistance to breathe and premature death. MDC1A is caused by mutations in the LAMA2 gene, which results in the partial or complete loss of laminin-211 and laminin-221, the major laminin isoforms found in the basal lamina of skeletal muscle. MDC1A patients exhibit reduced α7β1 integrin; however, it is unclear how the secon ...[more]

PMID: 21652631

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Project description:Merosin deficient congenital muscular dystrophy 1A (MDC1A) is a very rare autosomal recessive disorder caused by mutations in the LAMA2 gene leading to severe and progressive muscle weakness and atrophy. Although over 350 causative mutations have been identified for MDC1A, no treatment is yet available. There are many therapeutic approaches in development, but the lack of natural history data of the mouse model and standardized outcome measures makes it difficult to transit these pre-clinical findings to clinical trials. Therefore, in the present study, we collected natural history data and assessed pre-clinical outcome measures for the dy2J/dy2J mouse model using standardized operating procedures available from the TREAT-NMD Alliance. Wild type and dy2J/dy2J mice were subjected to five different functional tests from the age of four to 32 weeks. Non-tested control groups were taken along to assess whether the functional test regime interfered with muscle pathology. Respiratory function, body weights and creatine kinase levels were recorded. Lastly, skeletal muscles were collected for further histopathological and gene expression analyses. Muscle function of dy2J/dy2J mice was severely impaired at four weeks of age and all mice lost the ability to use their hind limbs. Moreover, respiratory function was altered in dy2J/dy2J mice. Interestingly, the respiration rate was decreased and declined with age, whereas the respiration amplitude was increased in dy2J/dy2J mice when compared to wild type mice. Creatine kinase levels were comparable to wild type mice. Muscle histopathology and gene expression analysis revealed that there was a specific regional distribution pattern of muscle damage in dy2J/dy2J mice. Gastrocnemius appeared to be the most severely affected muscle with a high proportion of atrophic fibers, increased fibrosis and inflammation. By contrast, triceps was affected moderately and diaphragm only mildly. Our study presents a complete natural history dataset which can be used in setting up standardized studies in dy2J/dy2J mice.

Dataset Information

Transgenic overexpression of the ?7 integrin reduces muscle pathology and improves viability in the dy(W) mouse model of merosin-deficient congenital muscular dystrophy type 1A.

Publications

Transgenic overexpression of the α7 integrin reduces muscle pathology and improves viability in the dy(W) mouse model of merosin-deficient congenital muscular dystrophy type 1A.

Similar Datasets

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