PMC5976715_01
a-f: Histological analysis of the muscle biopsies from patients. a, d: Hematoxylin and eosin (HE), (b, e): modified Gomori trichrome (mGt), (c, f): ATPase (pH10.6). A group of atrophic fibers was observed in both patients (a, c, d, f). mGt staining revealed the presence of rimmed vacuoles (b, e, black arrows). Bar: 50 microm. g-l: Immunostaining for valosin-containing protein (VCP: g, i, j, l) and ubiquitin (h, i, k, l). VCP positive inclusions were co-stained with ubiquitin in both the nucleus (white arrowheads, DAPI positive) and the cytoplasm (white arrows, DAPI negative). Bar: 50 microm
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Fig1
Muscle biopsy showed mixed changes, indicating myopathy and neuropathy (Fig. 1d-f) consisting of mild dystrophic change with scattered fibers with rimmed vacuoles (Fig. 1e,j-l), as well as group atrophy and fiber type grouping (Fig. 1d,f). Cytoplasmic and nuclear inclusions and rimmed vacuoles, which are common pathological changes in VCP-related myopathy, were observed in muscles from our patients (Fig. 1g-l).
PMC5976715_02
a-f: Histological analysis of the muscle biopsies from patients. a, d: Hematoxylin and eosin (HE), (b, e): modified Gomori trichrome (mGt), (c, f): ATPase (pH10.6). A group of atrophic fibers was observed in both patients (a, c, d, f). mGt staining revealed the presence of rimmed vacuoles (b, e, black arrows). Bar: 50 microm. g-l: Immunostaining for valosin-containing protein (VCP: g, i, j, l) and ubiquitin (h, i, k, l). VCP positive inclusions were co-stained with ubiquitin in both the nucleus (white arrowheads, DAPI positive) and the cytoplasm (white arrows, DAPI negative). Bar: 50 microm
41439_2018_9_Fig1_HTML.jpg
PMC5976715_02_41439_2018_9_Fig1_HTML.jpg
Fig1
Muscle biopsy showed mixed changes, indicating myopathy and neuropathy (Fig. 1d-f) consisting of mild dystrophic change with scattered fibers with rimmed vacuoles (Fig. 1e,j-l), as well as group atrophy and fiber type grouping (Fig. 1d,f). Cytoplasmic and nuclear inclusions and rimmed vacuoles, which are common pathological changes in VCP-related myopathy, were observed in muscles from our patients (Fig. 1g-l).
Results of valosin-containing protein (VCP) mutation screening.. a Two novel heterozygous substitutions were identified (c.376A>G and c.259G>T). b Schematic functional domains and mutations of VCP. The locations of substitutions in this study are denoted by red arrows. Black arrows indicate the locations of previously identified mutations with inclusion body myopathy (IBM). c Multiple alignment of the VCP amino acid sequence in different species. The substitution sites in this study (Val87 and Ile126) are highly evolutionarily conserved. d The crystal structure of VCP protein showing the locations of the mutated residues detected in IBM. The crystal structure was obtained from the Molecular Modeling Database (MMDB ID: 82738). Our substitution sites (Val87 and Ile126) and those of previously reported mutations are indicated in white and yellow, respectively
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Fig2
We identified a novel missense variant, c.376A>G (p.Ile126Val), within exon 4 in VCP (Fig. 2a). Follow-up sequencing was carried out and confirmed the variant. p.Ile126Val was located within the NTD, cofactor and ubiquitin binding function (Fig. 2b). The isoleucine residue was highly conserved from humans to yeast, except for in Drosophila melanogaster (Fig. 2c). This mutated valine is also located within the NTD (Fig. 2b) and is evolutionally conserved (Fig. 2c). ATPase domains (D1 and D2). As in almost all previous mutations, our substitution sites (Val87, Ile126) were also located in NTD and were conformationally aligned nearby (Fig. 2b,d).