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Gene therapy rescues disease phenotype in a spinal muscular atrophy with respiratory distress type 1 (SMARD1) mouse model.

Nizzardo M, Simone C, Rizzo F, Salani S, Dametti S, Rinchetti P, Del Bo R, Foust K, Kaspar BK, Bresolin N, Comi GP, Corti S - Sci Adv (2015)

Bottom Line: It is caused by mutations in the IGHMBP2 gene (11q13) and presently has no cure.AAV9-IGHMBP2 administration restored protein levels and rescued motor function, neuromuscular physiology, and life span (450% increase), ameliorating pathological features in the central nervous system, muscles, and heart.To test this strategy in a human model, we transferred wild-type IGHMBP2 into human SMARD1-induced pluripotent stem cell-derived motor neurons; these cells exhibited increased survival and axonal length in long-term culture.

View Article: PubMed Central - PubMed

Affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, and Neurology Unit, IRCCS Foundation Ca' Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy.

ABSTRACT
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an autosomal recessive motor neuron disease affecting children. It is caused by mutations in the IGHMBP2 gene (11q13) and presently has no cure. Recently, adeno-associated virus serotype 9 (AAV9)-mediated gene therapy has been shown to rescue the phenotype of animal models of another lower motor neuron disorder, spinal muscular atrophy 5q, and a clinical trial with this strategy is ongoing. We report rescue of the disease phenotype in a SMARD1 mouse model after therapeutic delivery via systemic injection of an AAV9 construct encoding the wild-type IGHMBP2 to replace the defective gene. AAV9-IGHMBP2 administration restored protein levels and rescued motor function, neuromuscular physiology, and life span (450% increase), ameliorating pathological features in the central nervous system, muscles, and heart. To test this strategy in a human model, we transferred wild-type IGHMBP2 into human SMARD1-induced pluripotent stem cell-derived motor neurons; these cells exhibited increased survival and axonal length in long-term culture. Our data support the translational potential of AAV-mediated gene therapies for SMARD1, opening the door for AAV9-mediated therapy in human clinical trials.

No MeSH data available.


Related in: MedlinePlus

AAV9-IGHMBP2 improves NMJs and the size of myofibers in skeletal muscles.(A and B) NMJs in the quadriceps, gastrocnemius, and diaphragm muscles improved after gene therapy. (A) Representative images of NMJs from the quadriceps of WT, AAV9-IGHMBP2-nmd, and AAV9--nmd mice. Neurofilament Ab, green; α-bungarotoxin, red. The asterisk highlights an unoccupied NMJ. Scale bar, 20 μm. (B) Percentage of denervated NMJs in gastrocnemius, quadriceps, and diaphragm muscles (mean ± SEM; *P < 0.001). (C and D) AAV9-IGHMBP2 treatment influenced fiber caliber in nmd quadriceps, gastrocnemius, and diaphragm muscles. (C) Representative images of quadriceps and diaphragm muscle fibers at 4 weeks stained with hematoxylin and eosin (H&E). Increased numbers of perimysial and central cell nuclei were observed in untreated nmd mice; these numbers declined after AAV9-IGHMBP2 treatment. Scale bar, 100 μm. (D) Significant reductions in fiber caliber were evident in AAV9--nmd mice versus control mice; AAV9-IGHMBP2 treatment ameliorated this effect. Values are means ± SEM.
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Figure 3: AAV9-IGHMBP2 improves NMJs and the size of myofibers in skeletal muscles.(A and B) NMJs in the quadriceps, gastrocnemius, and diaphragm muscles improved after gene therapy. (A) Representative images of NMJs from the quadriceps of WT, AAV9-IGHMBP2-nmd, and AAV9--nmd mice. Neurofilament Ab, green; α-bungarotoxin, red. The asterisk highlights an unoccupied NMJ. Scale bar, 20 μm. (B) Percentage of denervated NMJs in gastrocnemius, quadriceps, and diaphragm muscles (mean ± SEM; *P < 0.001). (C and D) AAV9-IGHMBP2 treatment influenced fiber caliber in nmd quadriceps, gastrocnemius, and diaphragm muscles. (C) Representative images of quadriceps and diaphragm muscle fibers at 4 weeks stained with hematoxylin and eosin (H&E). Increased numbers of perimysial and central cell nuclei were observed in untreated nmd mice; these numbers declined after AAV9-IGHMBP2 treatment. Scale bar, 100 μm. (D) Significant reductions in fiber caliber were evident in AAV9--nmd mice versus control mice; AAV9-IGHMBP2 treatment ameliorated this effect. Values are means ± SEM.

Mentions: Mutant nmd mice had denervated motor end plates that correspond to motor neuron degeneration (Fig. 3, A and B). In these motor endplates, subsynaptic clefts and folds were not present and/or did not mature, indicating degeneration (Fig. 3A). We observed this pathological hallmark of SMARD1 disease in nearly 50% of presynaptic termini from the quadriceps, gastrocnemius, and diaphragm of AAV9--nmd animals (Fig. 3B). On the other hand, nearly 90% of neuromuscular junctions (NMJs) of the AAV9-IGHMBP2-nmd mice were innervated and did not present this abnormal structure (Fig. 3, A and B). We observed a correct “pretzel-like” structure on postsynaptic NMJs that reflected the presence of a functional network of acetylcholine receptors in AAV9-IGHMBP2-nmd mice (Fig. 3A).


Gene therapy rescues disease phenotype in a spinal muscular atrophy with respiratory distress type 1 (SMARD1) mouse model.

Nizzardo M, Simone C, Rizzo F, Salani S, Dametti S, Rinchetti P, Del Bo R, Foust K, Kaspar BK, Bresolin N, Comi GP, Corti S - Sci Adv (2015)

AAV9-IGHMBP2 improves NMJs and the size of myofibers in skeletal muscles.(A and B) NMJs in the quadriceps, gastrocnemius, and diaphragm muscles improved after gene therapy. (A) Representative images of NMJs from the quadriceps of WT, AAV9-IGHMBP2-nmd, and AAV9--nmd mice. Neurofilament Ab, green; α-bungarotoxin, red. The asterisk highlights an unoccupied NMJ. Scale bar, 20 μm. (B) Percentage of denervated NMJs in gastrocnemius, quadriceps, and diaphragm muscles (mean ± SEM; *P < 0.001). (C and D) AAV9-IGHMBP2 treatment influenced fiber caliber in nmd quadriceps, gastrocnemius, and diaphragm muscles. (C) Representative images of quadriceps and diaphragm muscle fibers at 4 weeks stained with hematoxylin and eosin (H&E). Increased numbers of perimysial and central cell nuclei were observed in untreated nmd mice; these numbers declined after AAV9-IGHMBP2 treatment. Scale bar, 100 μm. (D) Significant reductions in fiber caliber were evident in AAV9--nmd mice versus control mice; AAV9-IGHMBP2 treatment ameliorated this effect. Values are means ± SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 3: AAV9-IGHMBP2 improves NMJs and the size of myofibers in skeletal muscles.(A and B) NMJs in the quadriceps, gastrocnemius, and diaphragm muscles improved after gene therapy. (A) Representative images of NMJs from the quadriceps of WT, AAV9-IGHMBP2-nmd, and AAV9--nmd mice. Neurofilament Ab, green; α-bungarotoxin, red. The asterisk highlights an unoccupied NMJ. Scale bar, 20 μm. (B) Percentage of denervated NMJs in gastrocnemius, quadriceps, and diaphragm muscles (mean ± SEM; *P < 0.001). (C and D) AAV9-IGHMBP2 treatment influenced fiber caliber in nmd quadriceps, gastrocnemius, and diaphragm muscles. (C) Representative images of quadriceps and diaphragm muscle fibers at 4 weeks stained with hematoxylin and eosin (H&E). Increased numbers of perimysial and central cell nuclei were observed in untreated nmd mice; these numbers declined after AAV9-IGHMBP2 treatment. Scale bar, 100 μm. (D) Significant reductions in fiber caliber were evident in AAV9--nmd mice versus control mice; AAV9-IGHMBP2 treatment ameliorated this effect. Values are means ± SEM.
Mentions: Mutant nmd mice had denervated motor end plates that correspond to motor neuron degeneration (Fig. 3, A and B). In these motor endplates, subsynaptic clefts and folds were not present and/or did not mature, indicating degeneration (Fig. 3A). We observed this pathological hallmark of SMARD1 disease in nearly 50% of presynaptic termini from the quadriceps, gastrocnemius, and diaphragm of AAV9--nmd animals (Fig. 3B). On the other hand, nearly 90% of neuromuscular junctions (NMJs) of the AAV9-IGHMBP2-nmd mice were innervated and did not present this abnormal structure (Fig. 3, A and B). We observed a correct “pretzel-like” structure on postsynaptic NMJs that reflected the presence of a functional network of acetylcholine receptors in AAV9-IGHMBP2-nmd mice (Fig. 3A).

Bottom Line: It is caused by mutations in the IGHMBP2 gene (11q13) and presently has no cure.AAV9-IGHMBP2 administration restored protein levels and rescued motor function, neuromuscular physiology, and life span (450% increase), ameliorating pathological features in the central nervous system, muscles, and heart.To test this strategy in a human model, we transferred wild-type IGHMBP2 into human SMARD1-induced pluripotent stem cell-derived motor neurons; these cells exhibited increased survival and axonal length in long-term culture.

View Article: PubMed Central - PubMed

Affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, and Neurology Unit, IRCCS Foundation Ca' Granda, Ospedale Maggiore Policlinico, 20122 Milan, Italy.

ABSTRACT
Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an autosomal recessive motor neuron disease affecting children. It is caused by mutations in the IGHMBP2 gene (11q13) and presently has no cure. Recently, adeno-associated virus serotype 9 (AAV9)-mediated gene therapy has been shown to rescue the phenotype of animal models of another lower motor neuron disorder, spinal muscular atrophy 5q, and a clinical trial with this strategy is ongoing. We report rescue of the disease phenotype in a SMARD1 mouse model after therapeutic delivery via systemic injection of an AAV9 construct encoding the wild-type IGHMBP2 to replace the defective gene. AAV9-IGHMBP2 administration restored protein levels and rescued motor function, neuromuscular physiology, and life span (450% increase), ameliorating pathological features in the central nervous system, muscles, and heart. To test this strategy in a human model, we transferred wild-type IGHMBP2 into human SMARD1-induced pluripotent stem cell-derived motor neurons; these cells exhibited increased survival and axonal length in long-term culture. Our data support the translational potential of AAV-mediated gene therapies for SMARD1, opening the door for AAV9-mediated therapy in human clinical trials.

No MeSH data available.


Related in: MedlinePlus