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This Article Figures Only Full Text Full Text (PDF) Data Supplement All Versions of this Article: 01.wnl.0000306309.85301.e2v1 01.wnl.0000306309.85301.e2v2 71/4/240    most recent Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by Rodino-Klapac, L. R. Articles by Mendell, J. R. PubMed PubMed Citation Articles by Rodino-Klapac, L. R. Articles by Mendell, J. R. Related Collections All Neuromuscular Disease Muscle disease Gene therapy

Lack of toxicity of alpha-sarcoglycan overexpression supports clinical gene transfer trial in LGMD2D

From the Center for Gene Therapy (L.R.R.-K., K.R.C., J.R.M.), The Research Institute at Nationwide Children’s Hospital, Departments of Pediatrics and Neurology, Ohio State University; and the Harvard Gene Therapy Initiative (J.-S.L., R.C.M.), Department of Genetics, Harvard Medical School.

Address correspondence and reprint requests to Dr. Jerry R. Mendell, Columbus Children’s Research Institute, Room WA3011, 700 Children’s Drive, Columbus, OH 43205 Jerry.Mendell{at}NationwideChildrens.org

Background: Alpha-sarcoglycan (-SG) deficiency (limb-girdle muscular dystrophy [LGMD] type 2D) is the most common form of sarcoglycan-LGMD. No treatment is currently available. Prior studies suggest that overexpression of -SG via adeno-associated virus (AAV)-mediated gene transfer results in poorly sustained gene expression related to transgene toxicity. These findings potentially preclude gene therapy as a treatment approach for LGMD2D.

Methods: The human -SG gene (h-SG) was directly transferred to the tibialis anterior muscle of 4- to 5-week-old -SG KO mice using AAV, type 1. The gene was placed under control of either the ubiquitously expressed cytomegalovirus (CMV) promoter or muscle specific promoters that included desmin, muscle creatine kinase (MCK), and its further modification, truncated MCK (tMCK). Low (3 x 10⁹ vg) and high (3 x 10¹⁰ vg) doses of AAV1.h-SG were administered.

Results: Sustained gene expression was observed irrespective of promoters at 6 and 12 weeks post gene transfer. Quantitation of -SG gene expression by fiber counts yielded similar levels of myofiber transduction for both MCK promoters (60 to 70%), while 34% of fibers were transduced with the DES promoter. There was a trend toward lower expression at the 12-week time point with the CMV promoter. Western blot analysis revealed -SG overexpression using CMV and both the MCK promoters.

Conclusion: Our data demonstrate robust and sustained adeno-associated virus type 1 alpha-sarcoglycan gene expression under control of muscle creatine kinase promoters, without evidence of cytotoxicity. These findings support the use of gene therapy as a potential treatment approach for limb-girdle muscular dystrophy type 2D.

Abbreviations: -SG = alpha-sarcoglycan; AAV = adeno-associated virus; CMV = cytomegalovirus; DES = desmin; DGC = dystrophin-glycoprotein complex; DMD = Duchenne muscular dystrophy; FBS = fetal bovine serum; KO = knock-out; LGMD = limb-girdle muscular dystrophy; MCK = muscle creatine kinase; tMCK = truncated MCK.

Supplemental data at www.neurology.org

Editorial note, page 232

Editorial, page 234

e-Pub ahead of print on June 4, 2008, at www.neurology.org.

Supported by the Children’s Hospital Foundation (J.R.M.); NIH Wellstone Muscular Dystrophy Cooperative Research Center (AR03001 to J.R.M.); Muscular Dystrophy Association (J.R.M.); and Ruth L. Kirschstein NRSA postdoctoral fellowship (1F32AR055008 to L.R.K.).

Disclosure: The authors report no disclosures.

Received June 11, 2007. Accepted in final form November 21, 2007.

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