SEPN1/SELENON is a type II protein of the endoplasmic reticulum (ER) whose inherited defects give rise to a congenital, autosomal recessive muscle disease termed SEPN1/SELENON-related myopathy (SELENON-RM). While muscle weakness in SELENON-RM leads to life-threatening respiratory insufficiency and major scoliosis in children, incomplete understanding of its molecular mechanism and absence of biomarkers have prevented development of any disease-modifying treatment so far. Here we identify a physical and functional interaction between SELENON and the ER stress-induced oxido-reductase ERO1. SELENON and ERO1, both enriched in a region of the ER in close contact with mitochondria (mitochondria-associated membranes, MAMs), are involved in the redox regulation of proteins within the ER. Furthermore, their respective loss has opposite effects on the short-range MAMs, impinging on ER-mitochondria Ca2+ dynamics and mitochondria bioenergetics. Consistently, ERO1 depletion in SELENON knock-out cells restores ER redox, re-equilibrates short-range MAMs and rescues mitochondrial bioenergetics. This in vitro effect is reproduced in vivo, where ERO1 knock-out in a mouse background of Sepn1/Selenon loss blunts ER stress and improves multiple MAM functions, including calcium and bioenergetic signaling, thus reversing diaphragmatic weakness. The treatment of Selenon knock-out mice with the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) reduces ERO1 levels and mirrors the results of ERO1 loss. Importantly, muscle biopsies from SELENON-RM patients exhibit ERO1 induction and TUDCA-treated SELENON-RM patient-derived primary myoblasts show improvement in bioenergetic production. These findings point to the ER stress-induced ERO1 axis as both a biomarker of SEPN1-RM and a viable target for a pharmacological intervention.

Selenoprotein N (SEPN1) is a protein of the endoplasmic reticulum (ER) whose inherited defects originate SEPN1-related myopathy (SEPN1-RM). Here, we identify an interaction between SEPN1 and the ER-stress-induced oxidoreductase ERO1A. SEPN1 and ERO1A, both enriched in mitochondria-associated membranes (MAMs), are involved in the redox regulation of proteins. ERO1A depletion in SEPN1 knockout cells restores ER redox, re-equilibrates short-range MAMs, and rescues mitochondrial bioenergetics. ERO1A knockout in a mouse background of SEPN1 loss blunts ER stress and improves multiple MAM functions, including Ca2+ levels and bioenergetics, thus reversing diaphragmatic weakness. The treatment of SEPN1 knockout mice with the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) mirrors the results of ERO1A loss. Importantly, muscle biopsies from patients with SEPN1-RM exhibit ERO1A overexpression, and TUDCA-treated SEPN1-RM patient-derived primary myoblasts show improvement in bioenergetics. These findings point to ERO1A as a biomarker and a viable target for intervention and to TUDCA as a pharmacological treatment for SEPN1-RM.

Glioblastoma (GBM) is the most common primary brain tumor. Despite aggressive treatment (surgery, chemo- and radiotherapy), the prognosis is dismal (median overall survival: 14m). Actually, early diagnosis and treatment monitoring represent major unmet needs. Extracellular vesicles (EVs) are potentially optimal biomarkers owing to high stability and their presence in blood and cerebrospinal fluid. These features, combined to their genetic and proteomic composition that mirrors the intratumoral environment, highlight EV applicability as blood-based biomarkers for disease diagnosis and therapeutic monitoring. We collected plasma samples from healthy controls (n=33), GBMs (n=43) and different central nervous system malignancies (n=25). EVs were isolated and subjected to an integrated analysis relying on transmission electron microscopy, Nanoparticle Tracking Analysis, and mass spectrometry in order to assess morphology, size, concentration and protein composition. An orthotopic mouse model of human GBM was employed to confirm human plasma EV quantifications. Possible associations between plasma EV concentration and clinical features were analyzed. All statistical tests were two-sided. We observed a significant EVs enrichment in GBM patients plasma if compared to healthy control and patients harboring other CNS malignancies. GBM surgical removal was accompanied by a relevant drop in the concentration of circulating EVs followed by a re-increase at the relapse; this indicates the tumor mass as the major donor of circulating EVs in GBM patients. This phenomenon was confirmed by mouse model. The analyses of EV protein cargo revealed a specific signature, which included members of the complement/coagulation cascade and regulators of iron metabolism. Our work demonstrates the potential applicability of circulating EVs as reliable cancer biomarker for GBM patients. Furthermore we observed that EV concentration and protein cargo might provide information about response to therapies and tumor progression.

This longitudinal single-center study describes the timing and risk factors for genital human papillomavirus (HPV) disease in women after allogeneic hematopoietic cell transplantation (HCT). Between 1994 and 2014, 109 females underwent HCT of whom 82 surviving transplant for >1 year had regular, comprehensive genital tract assessment and treatment of HPV disease. The cumulative proportions of any genital HPV infection at 1, 3, 5, 10 and 20 years were 4.8%, 14.9%, 28.1%, 36.7% and 40.9%, respectively. Demographic, disease-related factors, chronic GvHD (cGvHD) and its treatment were analyzed for their association with persistent, multifocal or severe genital HPV disease. Pre-transplant HPV disease was strongly associated with any posttransplant HPV (odds ratio (OR)=6.5, 95% confidence interval (CI)=1.65–25.85, P=0.008). Having either extensive or genital cGvHD was associated with increased risk of any HPV disease (OR=5.7, 95% CI=1.90–17.16, P=0.002) and a higher risk for severe genital dysplasia (CIN II–III/VIN II–III; OR=13.1, 95% CI=1.59–108.26, P=0.017), but no one developed HPV-related genital cancer. Persistent, multifocal or severe HPV disease occurred more frequently than in healthy populations. Women with extensive cGvHD, genital cGvHD or pre-transplant HPV are at greatest risk for post-transplant HPV disease. Early initiation of annual screening, comprehensive genital tract assessment and active management are cornerstones of their gynecology care.

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Cell-cell interactions promote juxtacrine signals in specific subcellular domains, which are difficult to capture in the complexity of the nervous system. For example, contact between axons and Schwann cells triggers signals required for radial sorting and myelination. Failure in this interaction causes dysmyelination and axonal degeneration. Despite its importance, few molecules at the axo-glial surface are known. To identify novel molecules in axo-glial interactions, we modified the 'pseudopodia' sub-fractionation system and isolated the projections that glia extend when they receive juxtacrine signals from axons. By proteomics we identified the signalling networks present at the glial-leading edge, and novel proteins, including members of the Prohibitin family. Glial-specific deletion of Prohibitin-2 in mice impairs axo-glial interactions and myelination. We thus validate a novel method to model morphogenesis and juxtacrine signalling, provide insights into the molecular organization of the axo-glial contact, and identify a novel class of molecules in myelination.

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal hydrolase α-galactosidase A (α-GalA) that leads to the intra-lysosomal accumulation of globotriaosylceramide (Gb3) in various organ systems. As a consequence, a multisystems disorder develops, culminating in stroke, progressive renal and cardiac dysfunction. Enzyme replacement therapy (ERT) offers a specific treatment for patients affected by FD, though the monitoring of treatment is hindered by a lack of surrogate markers of response. Remarkably, due to the high heterogeneity of the Fabry phenotype, both diagnostic testing and treatment decisions are more challenging in females than in males; thus, reliable biomarkers for Fabry disease are needed, particularly for female patients. Here, we use a proteomic approach for the identification of disease-associated markers that can be used for the early diagnosis of FD as well as for monitoring the effectiveness of ERT. Our data show that the urinary proteome of Fabry naïve patients is different from that of normal subjects. In addition, biological pathways mainly affected by FD are related to immune response, inflammation, and energetic metabolism. In particular, the up-regulation of uromodulin, prostaglandin H2 d-isomerase and prosaposin in the urine of FD patients was demonstrated; these proteins might be involved in kidney damage at the tubular level, inflammation and immune response. Furthermore, comparing the expression of these proteins in Fabry patients before and after ERT treatment, a decrease of their concentration was observed, thus demonstrating the correlation between the identified markers and the effectiveness of the pharmacological treatment.