Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using murine models, we have previously demonstrated that recombinant adeno-associated virus (rAAV)-mediated microdystrophin gene transfer is a promising approach to treatment of Duchenne muscular dystrophy (DMD). To examine further therapeutic effects and the safety issue of rAAV-mediated microdystrophin gene transfer using larger animal models, such as dystrophic dog models, we first investigated transduction efficiency of rAAV in wild-type canine muscle cells, and found that rAAV2 encoding beta-galactosidase effectively transduces canine primary myotubes in vitro. Subsequent rAAV2 transfer into skeletal muscles of normal dogs, however, resulted in low and transient expression of beta-galactosidase together with intense cellular infiltrations in vivo, where cellular and humoral immune responses were remarkably activated. In contrast, rAAV2 expressing no transgene elicited no cellular infiltrations. Co-administration of immunosuppressants, cyclosporine and mycophenolate mofetil could partially improve rAAV2 transduction. Collectively, these results suggest that immune responses against the transgene product caused cellular infiltration and eliminated transduced myofibers in dogs. Furthermore, in vitro interferon-gamma release assay showed that canine splenocytes respond to immunogens or mitogens more susceptibly than murine ones. Our results emphasize the importance to scrutinize the immune responses to AAV vectors in larger animal models before applying rAAV-mediated gene therapy to DMD patients.
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PMID:Injection of a recombinant AAV serotype 2 into canine skeletal muscles evokes strong immune responses against transgene products. 1758 97

Recombinant adeno-associated virus (rAAV)-mediated gene transfer is an attractive approach to the treatment of Duchenne muscular dystrophy (DMD). We investigated the muscle transduction profiles and immune responses associated with the administration of rAAV2 and rAAV8 in normal and canine X-linked muscular dystrophy in Japan (CXMD(J)) dogs. rAAV2 or rAAV8 encoding the lacZ gene was injected into the skeletal muscles of normal dogs. Two weeks after the injection, we detected a larger number of beta-galactosidase-positive fibers in rAAV8-transduced canine skeletal muscle than in rAAV2-transduced muscle. Although immunohistochemical analysis using anti-CD4 and anti-CD8 antibodies revealed less T-cell response to rAAV8 than to rAAV2, beta-galactosidase expression in rAAV8-injected muscle lasted for <4 weeks with intramuscular transduction. Canine bone marrow-derived dendritic cells (DCs) were activated by both rAAV2 and rAAV8, implying that innate immunity might be involved in both cases. Intravenous administration of rAAV8-lacZ into the hind limb in normal dogs and rAAV8-microdystrophin into the hind limb in CXMD(J) dogs resulted in improved transgene expression in the skeletal muscles lasting over a period of 8 weeks, but with a declining trend. The limb perfusion transduction protocol with adequate immune modulation would further enhance the rAAV8-mediated transduction strategy and lead to therapeutic benefits in DMD gene therapy.
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PMID:Transduction efficiency and immune response associated with the administration of AAV8 vector into dog skeletal muscle. 1894 41

Duchenne muscular dystrophy is a lethal neuromuscular disease that currently has no effective therapy. Transgenic overexpression of the alpha7 integrin in mdx/utrn(-/-) mice, a model of Duchenne muscular dystrophy ameliorates the disease. We have isolated and used alpha7(+/-) muscle cells expressing beta-galactosidase, driven by the endogenous alpha7 promoter, to identify compounds that increase alpha7 integrin levels. Valproic acid (VPA) was found to enhance alpha7 integrin levels, induce muscle hypertrophy, and inhibit apoptosis in myotubes by activating the Akt/mTOR/p70S6K pathway. This activation of the Akt pathway occurs within 1 hour of treatment and is mediated by phosphatidylinositol 3-OH kinase. To evaluate the potential use of VPA to treat muscular dystrophy, mdx/utrn(-/-) mice were injected with the drug. Treatment with VPA lowered collagen content and fibrosis, and decreased hind limb contractures. VPA-treated mice also had increased sarcolemmal integrity and decreased damage, decreased CD8-positive inflammatory cells, and higher levels of activated Akt in their muscles. Thus, VPA has important biological effects that may be applicable for the treatment of muscular dystrophy.
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PMID:Valproic acid activates the PI3K/Akt/mTOR pathway in muscle and ameliorates pathology in a mouse model of Duchenne muscular dystrophy. 1917 9


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