functional substitution by tat-utrophin in dystrophin-deficient mice功能替代的tat-utrophin dystrophin-deficient老鼠.pdfVIP

Functional Substitution by TAT-Utrophin in Dystrophin- Deficient Mice 1 1 1 1 2 Kevin J. Sonnemann , Hanke Heun-Johnson , Amy J. Turner , Kristen A. Baltgalvis , Dawn A. Lowe , James M. Ervasti1* 1 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America, 2 Program in Physical Therapy, University of Minnesota, Minneapolis, Minnesota, United States of America Abstract Background: The loss of dystrophin compromises muscle cell membrane stability and causes Duchenne muscular dystrophy and/or various forms of cardiomyopathy. Increased expression of the dystrophin homolog utrophin by gene delivery or pharmacologic up-regulation has been demonstrated to restore membrane integrity and improve the phenotype in the dystrophin-deficient mdx mouse. However, the lack of a viable therapy in humans predicates the need to explore alternative methods to combat dystrophin deficiency. We investigated whether systemic administration of recombinant full-length utrophin (Utr) or DR4-21 ‘‘micro’’ utrophin (mUtr) protein modified with the cell-penetrating TAT protein transduction domain could attenuate the phenotype of mdx mice. Methods and Findings: Recombinant TAT-Utr and TAT-mUtr proteins were expressed using the baculovirus system and purified using FLAG-affinity chromatography. Age-matched mdx mice received six twice-weekly intraperitoneal injections of either recombinant protein or PBS. Three days after the final injection, mice were analyzed for several phenotypic para