Bone marrow transplantation increases efficacy of central nervous system-directed enzyme replacement therapy in the murine model of globoid cell leukodystrophy
ABSTRACT Globoid cell leukodystrophy (GLD, Krabbe disease), is an autosomal recessive, neurodegenerative disease caused by the deficiency of the lysosomal enzyme galactocerebrosidase (GALC). In the absence of GALC, the toxic metabolite psychosine accumulates in the brain and causes the death of the myelin-producing cells, oligodendrocytes. Currently, the only therapy for GLD is hematopoietic stem cell transplantation using bone marrow (BMT) or umbilical cord blood. However, this is only partially effective. Previous studies have shown that enzyme replacement therapy (ERT) provides some therapeutic benefit in the murine model of GLD, the Twitcher mouse. Experiments have also shown that two disparate therapies can produce synergistic effects when combined. The current study tests the hypothesis that BMT will increase the therapeutic effects of ERT when these two treatments are combined. Twitcher mice were treated with either ERT alone or both ERT and BMT during the first 2-4days of life. Recombinant enzyme was delivered by intracerebroventricular (ICV) and intrathecal (IT) injections. Twitcher mice receiving ERT had supraphysiological levels of GALC activity in the brain 24h after injection. At 36days of age, ERT-treated Twitcher mice had reduced psychosine levels, reduced neuroinflammation, improved motor function, and increased lifespan. Twitcher mice receiving both ERT and BMT had significantly increased lifespan, improved motor function, reduced psychosine levels, and reduced neuroinflammation in certain areas of the brain compared to untreated or ERT-treated Twitcher mice. Together, these results indicate that BMT enhances the efficacy of ERT in GLD.
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ABSTRACT: Globoid cell leukodystrophy (GLD) or Krabbe disease is an autosomal recessive disorder resulting from the defective lysosomal enzyme galactocerebrosidase (GALC). The lack of GALC enzyme leads to severe neurological symptoms. While most human patients are infants who do not survive beyond 2years of age, older patients are also diagnosed. In addition to human patients, several naturally occurring animal models, including dog, mouse, and monkey, have also been identified. The mouse model of Krabbe disease, twitcher (twi) mouse has been used for many treatment trials including gene therapy. Using the combination of intracerebroventricular, intracerebellar, and intravenous (iv) injection of the adeno-associated virus serotype rh10 (AAVrh10) expressing mouse GALC in neonate twi mice we previously have demonstrated a significantly extended normal life and exhibition of normal behavior in treated mice. In spite of the prolonged healthy life of these treated mice and improved myelination, it is unlikely that using multiple injection sites for viral administration will be approved for treatment of human patients. In this study, we have explored the outcome of the single iv injection of viral vector at post-natal day 10 (PND10). This has resulted in increased GALC activity in the central nervous system (CNS) and high GALC activity in the peripheral nervous system (PNS). As we have shown previously, an iv injection of AAVrh10 at PND2 results in a small extension of life beyond the typical lifespan of the untreated twi mice (~40days). In this study, we report that mice receiving a single iv injection at PND10 had no tremor and continued to gain weight until a few weeks before they died. On average, they lived 20-25days longer than untreated mice. We anticipate that this strategy in combination with other therapeutic options may be beneficial and applicable to treatment of human patients. Copyright © 2014 Elsevier Inc. All rights reserved.Molecular Genetics and Metabolism 12/2014; 114(3). DOI:10.1016/j.ymgme.2014.12.300 · 2.83 Impact Factor
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ABSTRACT: Natural killer (NK) cells exert important immunoregulatory functions by releasing several inflammatory molecules, such as IFN-γ and members of chemokines, which include CCL3/MIP-1α and CCL4/MIP-1β. These cells also express heptahelical receptors, which are coupled to heterotrimeric G proteins that guide them into inflamed and injured tissues. NK cells have been shown to recognize and destroy transformed cells and virally-infected cells, but their roles in neurodegenerative diseases have not been examined in detail. In this review, I will summarize the effects of NK cells in two neurodegenerative diseases, namely multiple sclerosis and globoid cell leukodystrophy. It is hoped that the knowledge obtained from these diseases may facilitate building rational protocols for treating these and other neurodegenerative or autoimmune diseases using NK cells and drugs that activate them as therapeutic tools.Toxins 03/2013; 5(2):363-75. DOI:10.3390/toxins5020363 · 2.48 Impact Factor
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ABSTRACT: Globoid cell leukodystrophy (GLD) is a common neurodegenerative lysosomal storage disorder caused by a deficiency in galactocerebrosidase (GALC), an enzyme that cleaves galactocerebroside during myelination. Bone marrow transplantation has shown promise when administered to late-onset GLD patients. However, the side effects (e.g., graft versus host disease), harsh conditioning regimens (e.g., myelosuppression), and variable therapeutic effects make this an unsuitable option for infantile GLD patients. We previously reported modest improvements in the twitcher mouse model of GLD after intracerebroventricular (ICV) injections of a low dose of multipotent stromal cells (MSCs). Goals of this study were to improve bone marrow-derived MSC (BMSC) therapy for GLD by increasing the cell dosage and comparing cell type (e.g., transduced v. native), treatment timing (e.g., single v. weekly), and administration route (e.g., ICV v. intraperitoneal). Neonatal twitcher mice received (1) 2x10(5) BMSCs by ICV injection, (2) 1x10(6) BMSCs by intraperitoneal (IP) injection, (3) weekly IP injections of 1x10(6) BMSCs, or (4) 1x10(6) lentiviral-transduced BMSCs overexpressing GALC (GALC-BMSC) by IP injection. All treated mice lived longer than untreated mice. However, the mice receiving peripheral MSC therapy had improved motor function (e.g., hind limb strength and rearing ability), twitching symptoms, and weight compared to both the untreated and ICV-treated mice. Inflammatory cell, globoid cell, and apoptotic cell levels in the sciatic nerves were significantly decreased as a result of the GALC-BMSC or weekly IP injections. The results of this study indicate a promising future for peripheral MSC therapy as a non-invasive, adjunct therapy for patients affected with GLD.Stem Cells 08/2013; 31(8). DOI:10.1002/stem.1397 · 7.70 Impact Factor