Mutations in the valosin-containing protein (VCP) gene cause autosomal dominant multisystem proteinopathy 1 (MSP1), characterized by a variable combination of inclusion body myopathy (IBM), Paget\'s disease of bone (PDB), and frontotemporal dementia (FTD). Here we report a novel VCP missense mutations in an Italian family with FTD as the prevalent manifestation and compare our results with those described in the literature.
We described the clinical, molecular, and imaging data of the studied family. We also conducted a systematic literature search with the aim of comparing our findings with previously reported VCP-related phenotypes.
A novel heterozygous VCP missense mutation (c 0.473 T > C/p.Met158Thr) was found in all the affected family members. The proband is a 69-year-old man affected by progressive muscle weakness since the age of 49. Muscle MRI showed patchy fatty infiltration in most muscles, and STIR sequences revealed an unusual signal increase in distal leg muscles. At age 65, he presented a cognitive disorder suggestive of behavioral variant FTD. A bone scintigraphy also revealed PDB. The patient\'s mother, his maternal aunt and her daughter had died following a history of cognitive deterioration consistent with FTD; the mother also had PDB. No relatives had any muscular impairments. Reviewing the literature data, we observed a different sex distribution of VCP-related phenotypes, being FTD prevalence higher among women as compared to men (51.2 % vs 31.2 %) and IBM prevalence higher among men as compared to women (92.1 % vs 72.8 %).
This study broadened our clinical, genetic, and imaging knowledge of VCP-related disorders.

Chikungunya virus (CHIKV) is a re-emerging mosquito-transmitted RNA virus causing joint and muscle pain. To better understand how CHIKV rewires the host cell and usurps host cell functions, we generated a systematic CHIKV-human protein-protein interaction map and revealed several novel connections that will inform further mechanistic studies. One of these novel interactions, between the viral protein E1 and STIP1 homology and U-box containing protein 1 (STUB1), was found to mediate ubiquitination of E1 and degrade E1 through the proteasome. Capsid associated with G3BP1, G3BP2 and AAA+ ​ATPase valosin-containing protein (VCP). Furthermore, VCP inhibitors blocked CHIKV infection, suggesting VCP could serve as a therapeutic target. Further work is required to fully understand the functional consequences of these interactions. Given that CHIKV proteins are conserved across alphaviruses, many virus-host protein-protein interactions identified in this study might also exist in other alphaviruses. Construction of interactome of CHIKV provides the basis for further studying the function of alphavirus biology.

OBJECTIVE: Study of the molecular mechanisms of metastasis is still the research focus for osteosarcoma (OS) prevention. This study investigates the mechanism of valosin-containing protein (VCP) promoting OS metastasis in vitro through autophagy and epithelial-mesenchymal transition (EMT).
METHODS: Different cell lines of osteosarcoma (143B and MG63) were adopted in this study. The level of VCP expression in osteosarcoma cells was changed, and the level of autophagy and the progression of the epithelial-mesenchymal transition (EMT) were observed. Then autophagy and EMT in OS cells were changed artificially, and proliferation and migration ability were observed.
RESULTS: The expression of LC3II/I was decreased, but the insolubilized P62 protein expression was increased in the VCP inhibiting group and the autophagy inhibitor treatment group. Simultaneously, E-cadherin protein expression increased while N-cadherin protein expression decreased in the VCP inhibiting group but increased in the TGF-β1 treatment group. In addition, suppressing VCP can cause a decrease in Transforming Growth Factor β1 (TGF-β1), smad2, smad3, phosphorylated smad2 (p-smad2), and phosphorylated smad3 (p-smad3). Autophagy inhibitors and agonists have no significant effect on the migration and invasion of OS cells but can significantly affect the ability of cells to resist anoikis. EMT inhibitors and agonists have a proportional effect on the migration and invasion of OS cells.
CONCLUSIONS: VCP is likely to promote the migration and invasion of OS cells by inducing EMT, possibly via TGF-β1/smad2/3 signaling pathway. In this process, VCP-mediated autophagy may contribute to successful distant metastasis of tumor cells indirectly.

We here report an autopsy case of familial amyotrophic lateral sclerosis (ALS) with p.Arg487His mutation in the valosin-containing protein (VCP) gene (VCP), in which upper motor neurons (UMNs) were predominantly involved. Moreover, our patient developed symptoms of frontotemporal dementia later in life and pathologically exhibited numerous phosphorylated transactivation response DNA-binding protein of 43 kDa (p-TDP-43)-positive neuronal cytoplasmic inclusions and short dystrophic neurites with a few lentiform neuronal intranuclear inclusions, sharing the features of frontotemporal lobar degeneration with TDP-43 pathology type A pattern. A review of previous reports of ALS with VCP mutations suggests that our case is unique in terms of its UMN-predominant lesion pattern and distribution of p-TDP-43 pathology. Thus, this case report effectively expands the clinical and pathological phenotype of ALS in patients with a VCP mutation.

Carcinoma-associated fibroblasts are fibroblasts activated by surrounding cancer cells. Carcinoma-associated fibroblasts exhibit enhanced cell migration, which plays an important role in cancer metastasis. Previously, we demonstrated enhanced migration of NIH3T3 fibroblasts when they were cultured in the presence of MCF7 breast cancer cells. Human fibroblasts displayed a similar phenomenon even when they were co-cultured with cancer cells other than MCF7 cells. In this study, we screened ∼16,000 compounds from the RIKEN Natural Products Depository chemical library for inhibitors of enhanced NIH3T3 cell migration in the presence of MCF7. We identified NPD8733 as an inhibitor of cancer cell-enhanced fibroblast migration. This inhibition was observed not only in a wound-healing co-culture assay but also in a Transwell migration assay. Using NPD8733 and a structurally similar but inactive derivative, NPD8126, on immobilized beads, we found that NPD8733, but not NPD8126, specifically binds to valosin-containing protein (VCP)/p97, a member of the ATPase-associated with diverse cellular activities (AAA+) protein family. Using VCP truncation variants, we found that NPD8733 binds to the D1 domain of VCP. Because VCP\'s D1 domain is important for its function, we concluded that NPD8733 may act on VCP by binding to this domain. siRNA-mediated silencing of VCP in NIH3T3 fibroblasts, but not in MCF7 cells, reduced the migration of the co-cultured NIH3T3 fibroblasts. These results indicate that MCF7 activates the migration of NIH3T3 cells through VCP and that NPD8733 binds VCP and thereby inhibits its activity.

The transport of nascent very low density lipoprotein (VLDL) particles from the endoplasmic reticulum (ER) to the Golgi determines their secretion by the liver and is mediated by a specialized ER-derived vesicle, the VLDL transport vesicle (VTV). Our previous studies have shown that the formation of ER-derived VTV requires proteins in addition to coat complex II proteins. The VTV proteome revealed that a 9-kDa protein, small valosin-containing protein-interacting protein (SVIP), is uniquely present in these specialized vesicles. Our biochemical and morphological data indicate that the VTV contains SVIP. Using confocal microscopy and co-immunoprecipitation assays, we show that SVIP co-localizes with apolipoprotein B-100 (apoB100) and specifically interacts with VLDL apoB100 and coat complex II proteins. Treatment of ER membranes with myristic acid in the presence of cytosol increases SVIP recruitment to the ER in a concentration-dependent manner. Furthermore, we show that myristic acid treatment of hepatocytes increases both VTV budding and VLDL secretion. To determine the role of SVIP in VTV formation, we either blocked the SVIP protein using specific antibodies or silenced SVIP by siRNA in hepatocytes. Our results show that both blocking and silencing of SVIP lead to significant reduction in VTV formation. Additionally, we show that silencing of SVIP reduces VLDL secretion, suggesting a physiological role of SVIP in intracellular VLDL trafficking and secretion. We conclude that SVIP acts as a novel regulator of VTV formation by interacting with its cargo and coat proteins and has significant implications in VLDL secretion by hepatocytes.

The ubiquitous AAA+ ATPase p97 functions as a dynamic molecular machine driving several cellular processes. It is essential in regulating protein homeostasis, and it represents a potential drug target for cancer, particularly when there is a greater reliance on the endoplasmic reticulum-associated protein degradation pathway and ubiquitin-proteasome pathway to degrade an overabundance of secreted proteins. Here, we report a case study for using fragment-based ligand design approaches against this large and dynamic hexamer, which has multiple potential binding sites for small molecules. A screen of a fragment library was conducted by surface plasmon resonance (SPR) and followed up by nuclear magnetic resonance (NMR), two complementary biophysical techniques. Virtual screening was also carried out to examine possible binding sites for the experimental hits and evaluate the potential utility of fragment docking for this target. Out of this effort, 13 fragments were discovered that showed reversible binding with affinities between 140 µM and 1 mM, binding stoichiometries of 1:1 or 2:1, and good ligand efficiencies. Structural data for fragment-protein interactions were obtained with residue-specific [U-(2)H] (13)CH3-methyl-labeling NMR strategies, and these data were compared to poses from docking. The combination of virtual screening, SPR, and NMR enabled us to find and validate a number of interesting fragment hits and allowed us to gain an understanding of the structural nature of fragment binding.