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P2.06 Distal myopathy with rimmed vacuoles presenting with slow progression
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Abstracts / Neuromuscular Disorders 20 (2010) 596–680
P2.06 Distal myopathy with rimmed vacuoles presenting with slow progression Y. Sakai 1, Y. Manabe 1, D. Fujii 1, S. Kono 1, H. Narai 1, N. Omori 1, K. Monma 2, I. Nishino 2, K. Abe 3 1 National Hospital Organization Okayama Medical Center, Neurology, Okayama, Japan, 2 National Center of Neurology and Psychiatry, Neuromuscular Research, Kodaira, Japan, 3 Okayama University, Neurology, Okayama, Japan
Background: UDP-N-acetylglucosamine-2-epimerase and N-acetylmannosamine kinase (GNE) gene mutations have been found in patients with distal myopathy with rimmed vacuoles (DMRV). However, the correlation between GNE mutations and clinical features was not fully understood. Methods: The clinical presentation, histopathological findings, image studies, and genetic analyses of two patients with DMRV were studied. Results: Case 1: A 64-year-old man first experienced difficulty in heel gait at age 28. Distal part dominant muscle weakness and atrophy of four limbs have gradually progressed. He could stand and walk at 36 years after onset. We identified a novel compound heterozygote for a G to T transition at nucleotide position c.302 in exon 3, causing an amino acid change at codon 101 from arginine to histidine (R101H) and a A to G transition at nucleotide position c.617-4 in intron 3. Case 2: A 53-year-old woman developed first signs of finger muscle weakness at age 38. Distal part dominant muscle weakness and atrophy of four limbs have gradually progressed, too. She could stand and walk at 15 years after onset. We identified compound heterozygote for a A to T transition at nucleotide position c.527 in exon 3, causing an amino acid change at codon 176 from asparagine acid to valine (D176V) and a G to C transition at nucleotide position c.1714 in exon 10, causing an amino acid change at codon 572 from valine to leucine (V572L). Conclusions: Clinical spectrum of DMRV seems to be wider than previously thought in terms of both the severity of the disease and the pathological changes of muscles. doi:10.1016/j.nmd.2010.07.078
P2.07 Dual observation of single myofibers provide clue on dynamics of protein accumulation in distal myopathy with rimmed vacuoles (DMRV)-hereditary inclusion body myopathy (hIBM) mouse model S. Noguchi, M.C. Malicdan, I. Nonaka, I. Nishino National Institute of Neuroscience NCNP, Neuromuscular Research, Tokyo, Japan Protein aggregate myopathies are defined by the accumulation of several proteins in myofibers. Although most genetic etiologies of these diseases have already been identified, the process by which how such proteins accumulate and their contribution to disease pathogenesis have not been clarified. One of such diseases (DMRV) or (hIBM). Using the DMRV/hIBM mouse model, we have demonstrated that protein deposits and consequent RV formation in myofibers contribute to progressive muscle. To understand the dynamics of how proteins are accumulated within myofibers, we integrated findings obtained from fluorescent and electron microscopic (EM) studies using single isolated myofibers from the DMRV/hIBM mouse. Immunohistochemistry of muscle cryosections revealed that several proteins including amyloid (precursor protein and amyloid beta peptides), phosphorylated tau, eTDP-43, polyubiquitin, and p62 are accumulated in myofibers and are often accompanied by autophagic
vacuoles as evidenced by EM. As we observed that these deposits coincided with autofluorescent signals, we isolated single myofibers from mouse gastrocnemius which exhibited autofluorescence. Autofluorescent protein deposits are seen to have spatial relationship with the microtubule network system, exclusive from desmin intermediate filaments. EM observation provided further evidence on the structure of protein deposits surrounded by autophagic vacuoles. These findings suggest that protein deposits utilize the cytoskeletal motor machinery for organization and aggregation, and that these are phagocytosed by autophagic process. The distinct localization of such deposits may affect the contractile properties of muscles. Our results can support the utility of this innovative method for studying protein aggregate myopathies, and can be adapted for studying pathomechanism of disease and screening therapeutic drugs directed at clearing up such accumulations. doi:10.1016/j.nmd.2010.07.079
P2.08 GNE is involved in the early development of skeletal and cardiac muscles I. Milman, S. Mitrani-Rosenbaum Hadassah Hebrew University Medical Center, Goldyne Savad Institute of Gene Therapy, Jerusalem, Israel Mutations in GNE, the key enzyme in the biosynthesis of sialic acid, cause Hereditary Inclusion Body Myopathy (HIBM), an adult onset, slowly progressive distal and proximal primary myopathy. Although the importance of sialylation in brain development has been well established, nothing is known about the mechanism leading from GNE mutations to specific muscle defects. In this study we show that ES cells from normal (GNE+/+) and from GNE KO (KO) mice- who die at day E8.5 – have different patterns of differentiation. Morphological examination of mouse ES cells at various differentiation stages (from day 1 to day 45) as well as mRNA and immunohistochemistry analyses of various markers specific for each lineage, were concordant in illustrating major differences in early development between GNE+/+ and GNE KO cells: as expected, neuronal differentiation is defective, begins later and stops earlier in GNE KO cells than in GNE+/+ cells. Interestingly, cardiac muscle differentiates normally at the beginning of the process and cardiac cells reach normal beating function, but the process is then completely disrupted in GNE KO cells, the number of beating cells and their beating rate is dramatically reduced. Finally, GNE KO cells show a severe delay and defect in the development of skeletal muscle cells: rare differentiated skeletal muscle cells (MHC positive) derived from GNE KO ES can be spotted in these cultures, but even those do not reach a fully differentiated stage. This data shows a direct and drastic effect of GNE in early skeletal and cardiac muscle development, and could open new avenues in the understanding of the pathophysiology of HIBM. doi:10.1016/j.nmd.2010.07.080
P2.09 A non-viral, GNE-lipoplex treatment to correct sialylation defects in hereditary inclusion body myopathy (HIBM) T. Yardeni 1, I. Manoli 1, C. Ciccone 1, S. Hoogstraten-Miller 2, D. Darvish 3, Y. Anikster 4, P. Maples 5, C.M. Jay 5, W.A. Gahl 1, J. Nemunaitis 5, M. Huizing 1 1
NHGRI, NIH, Bethesda, United States, 2 NHGRI, NIH, OLAM, Bethesda, United States, 3 HIBM Research group, Encino, United States, 4 Tel – Aviv
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
P2.06 Distal myopathy with rimmed vacuoles presenting with slow progression Y. Sakai 1, Y. Manabe 1, D. Fujii 1, S. Kono 1, H. Narai 1, N. Omori 1, K. Monma 2, I. Nishino 2, K. Abe 3 1 National Hospital Organization Okayama Medical Center, Neurology, Okayama, Japan, 2 National Center of Neurology and Psychiatry, Neuromuscular Research, Kodaira, Japan, 3 Okayama University, Neurology, Okayama, Japan
Background: UDP-N-acetylglucosamine-2-epimerase and N-acetylmannosamine kinase (GNE) gene mutations have been found in patients with distal myopathy with rimmed vacuoles (DMRV). However, the correlation between GNE mutations and clinical features was not fully understood. Methods: The clinical presentation, histopathological findings, image studies, and genetic analyses of two patients with DMRV were studied. Results: Case 1: A 64-year-old man first experienced difficulty in heel gait at age 28. Distal part dominant muscle weakness and atrophy of four limbs have gradually progressed. He could stand and walk at 36 years after onset. We identified a novel compound heterozygote for a G to T transition at nucleotide position c.302 in exon 3, causing an amino acid change at codon 101 from arginine to histidine (R101H) and a A to G transition at nucleotide position c.617-4 in intron 3. Case 2: A 53-year-old woman developed first signs of finger muscle weakness at age 38. Distal part dominant muscle weakness and atrophy of four limbs have gradually progressed, too. She could stand and walk at 15 years after onset. We identified compound heterozygote for a A to T transition at nucleotide position c.527 in exon 3, causing an amino acid change at codon 176 from asparagine acid to valine (D176V) and a G to C transition at nucleotide position c.1714 in exon 10, causing an amino acid change at codon 572 from valine to leucine (V572L). Conclusions: Clinical spectrum of DMRV seems to be wider than previously thought in terms of both the severity of the disease and the pathological changes of muscles. doi:10.1016/j.nmd.2010.07.078
P2.07 Dual observation of single myofibers provide clue on dynamics of protein accumulation in distal myopathy with rimmed vacuoles (DMRV)-hereditary inclusion body myopathy (hIBM) mouse model S. Noguchi, M.C. Malicdan, I. Nonaka, I. Nishino National Institute of Neuroscience NCNP, Neuromuscular Research, Tokyo, Japan Protein aggregate myopathies are defined by the accumulation of several proteins in myofibers. Although most genetic etiologies of these diseases have already been identified, the process by which how such proteins accumulate and their contribution to disease pathogenesis have not been clarified. One of such diseases (DMRV) or (hIBM). Using the DMRV/hIBM mouse model, we have demonstrated that protein deposits and consequent RV formation in myofibers contribute to progressive muscle. To understand the dynamics of how proteins are accumulated within myofibers, we integrated findings obtained from fluorescent and electron microscopic (EM) studies using single isolated myofibers from the DMRV/hIBM mouse. Immunohistochemistry of muscle cryosections revealed that several proteins including amyloid (precursor protein and amyloid beta peptides), phosphorylated tau, eTDP-43, polyubiquitin, and p62 are accumulated in myofibers and are often accompanied by autophagic
vacuoles as evidenced by EM. As we observed that these deposits coincided with autofluorescent signals, we isolated single myofibers from mouse gastrocnemius which exhibited autofluorescence. Autofluorescent protein deposits are seen to have spatial relationship with the microtubule network system, exclusive from desmin intermediate filaments. EM observation provided further evidence on the structure of protein deposits surrounded by autophagic vacuoles. These findings suggest that protein deposits utilize the cytoskeletal motor machinery for organization and aggregation, and that these are phagocytosed by autophagic process. The distinct localization of such deposits may affect the contractile properties of muscles. Our results can support the utility of this innovative method for studying protein aggregate myopathies, and can be adapted for studying pathomechanism of disease and screening therapeutic drugs directed at clearing up such accumulations. doi:10.1016/j.nmd.2010.07.079
P2.08 GNE is involved in the early development of skeletal and cardiac muscles I. Milman, S. Mitrani-Rosenbaum Hadassah Hebrew University Medical Center, Goldyne Savad Institute of Gene Therapy, Jerusalem, Israel Mutations in GNE, the key enzyme in the biosynthesis of sialic acid, cause Hereditary Inclusion Body Myopathy (HIBM), an adult onset, slowly progressive distal and proximal primary myopathy. Although the importance of sialylation in brain development has been well established, nothing is known about the mechanism leading from GNE mutations to specific muscle defects. In this study we show that ES cells from normal (GNE+/+) and from GNE KO (KO) mice- who die at day E8.5 – have different patterns of differentiation. Morphological examination of mouse ES cells at various differentiation stages (from day 1 to day 45) as well as mRNA and immunohistochemistry analyses of various markers specific for each lineage, were concordant in illustrating major differences in early development between GNE+/+ and GNE KO cells: as expected, neuronal differentiation is defective, begins later and stops earlier in GNE KO cells than in GNE+/+ cells. Interestingly, cardiac muscle differentiates normally at the beginning of the process and cardiac cells reach normal beating function, but the process is then completely disrupted in GNE KO cells, the number of beating cells and their beating rate is dramatically reduced. Finally, GNE KO cells show a severe delay and defect in the development of skeletal muscle cells: rare differentiated skeletal muscle cells (MHC positive) derived from GNE KO ES can be spotted in these cultures, but even those do not reach a fully differentiated stage. This data shows a direct and drastic effect of GNE in early skeletal and cardiac muscle development, and could open new avenues in the understanding of the pathophysiology of HIBM. doi:10.1016/j.nmd.2010.07.080
P2.09 A non-viral, GNE-lipoplex treatment to correct sialylation defects in hereditary inclusion body myopathy (HIBM) T. Yardeni 1, I. Manoli 1, C. Ciccone 1, S. Hoogstraten-Miller 2, D. Darvish 3, Y. Anikster 4, P. Maples 5, C.M. Jay 5, W.A. Gahl 1, J. Nemunaitis 5, M. Huizing 1 1
NHGRI, NIH, Bethesda, United States, 2 NHGRI, NIH, OLAM, Bethesda, United States, 3 HIBM Research group, Encino, United States, 4 Tel – Aviv