A systematic re-examination of processing of MHCI-bound antigenic peptide precursors by ER aminopeptidase 1

Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims antigenic peptide precursors to generate mature antigenic peptides for presentation by major histocompatibility complex class I (MHCI) molecules and regulates adaptive immune responses. ERAP1 has been proposed to trim peptide precursors both in solution and in pre-formed MHCI-peptide complexes, but which mode is more relevant to its biological function remains controversial. Here, we compared ERAP1-mediated trimming of antigenic peptide precursors in solution or when bound to three MHCI alleles, HLA-B*58, HLA-B*08 and HLA-A*02. For all MHCI-peptide combinations, peptide binding onto MHCI protected against ERAP1-mediated trimming. In only a single MHCI-peptide combination, trimming of an HLA-B*08-bound 12mer progressed at a considerable rate, albeit still slower than in solution. Results from thermodynamic, kinetic and computational analyses suggested that this 12mer is highly labile and that apparent on-MHC trimming rates are always slower than that of MHCI-peptide dissociation. Both ERAP2 and leucine aminopeptidase, an enzyme unrelated to antigen processing, could trim this labile peptide from pre-formed MHCI complexes as efficiently as ERAP1. A pseudopeptide analogue with high affinity for both HLA-B*08 and the ERAP1 active site could not promote the formation of a ternary ERAP1-MHCI-peptide complex. Similarly, no interactions between ERAP1 and purified peptide loading complex (PLC) were detected in the absence or presence of a pseudopeptide trap. We conclude that MHCI binding protects peptides from ERAP1 degradation and that trimming in solution, along with the dynamic nature of peptide binding to MHCI, are sufficient to explain ERAP1 processing of antigenic peptide precursors

Correction to: LMTK3 inhibition affects microtubule stability

Correction to: Mol Cancer 20, 53 (2021) https://doi.org/10.1186/s12943-021-01345-3 Following the publication of the original article [1], the authors noticed errors on the figures introduced during the production step. Below are the errors: Fig. 2a: The labels for the y- and x-axes have been translocated upwards and need to be realigned with the axes. The x-axis should read: -Log2 (fold change). Fig. 2d: the quantification values in the NUSAP1 blots, for T47D and MDA-MB-231 cells, are no longer visible. The original article has been corrected

LMTK3 inhibition affects microtubule stability

No description supplie

Post-COVID-19 Parkinsonism and Parkinson's Disease Pathogenesis: The Exosomal Cargo Hypothesis

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease after Alzheimer's disease, globally. Dopaminergic neuron degeneration in substantia nigra pars compacta and aggregation of misfolded alpha-synuclein are the PD hallmarks, accompanied by motor and non-motor symptoms. Several viruses have been linked to the appearance of a post-infection parkinsonian phenotype. Coronavirus disease 2019 (COVID-19), caused by emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, has evolved from a novel pneumonia to a multifaceted syndrome with multiple clinical manifestations, among which neurological sequalae appear insidious and potentially long-lasting. Exosomes are extracellular nanovesicles bearing a complex cargo of active biomolecules and playing crucial roles in intercellular communication under pathophysiological conditions. Exosomes constitute a reliable route for misfolded protein transmission, contributing to PD pathogenesis and diagnosis. Herein, we summarize recent evidence suggesting that SARS-CoV-2 infection shares numerous clinical manifestations and inflammatory and molecular pathways with PD. We carry on hypothesizing that these similarities may be reflected in exosomal cargo modulated by the virus in correlation with disease severity. Travelling from the periphery to the brain, SARS-CoV-2-related exosomal cargo contains SARS-CoV-2 RNA, viral proteins, inflammatory mediators, and modified host proteins that could operate as promoters of neurodegenerative and neuroinflammatory cascades, potentially leading to a future parkinsonism and PD development

Oncology and complications.

This collection of cases describes some unusual urological tumors and complications related to urological tumors and their treatment. Case 1: A case of uretero-arterial fistula in a patient with long-term ureteral stenting for ureteral oncological stricture and a second case associated to retroperitoneal fibrosis were described. Abdominal CT, pyelography, cystoscopy were useful to show the origin of the bleeding. Angiography is useful for confirming the diagnosis and for subsequent positioning of an endovascular prosthesis which represents a safe approach with reduced post-procedural complications. Case 2: A case of patient who suffered from interstitial pneumonitis during a cycle of intravesical BCG instillations for urothelial cancer. The patient was hospitalized for more than two weeks in a COVID ward for a suspected of COVID-19 pneumonia, but he did not show any evidence of SARS-CoV-2 infection during his hospital stay. Case 3: A case of a young man with a functional urinary bladder paraganglioma who was successfully managed with complete removal of the tumor, leaving the urinary bladder intact. Case 4: A case of a 61 year old male suffering from muscle invasive bladder cancer who was admitted for a radical cystectomy and on the eighth postoperative day developed microangiopathic hemolytic anemia and thrombocytopenia, which clinically defines thrombotic microangiopathy

Guideline Assessment Project II: statistical calibration informed the development of an AGREE II extension for surgical guidelines

OBJECTIVE: To inform the development of an AGREE II extension specifically tailored for surgical guidelines. AGREE II was designed to inform the development, reporting, and appraisal of clinical practice guidelines. Previous research has suggested substantial room for improvement of the quality of surgical guidelines. METHODS: A previously published search in MEDLINE for clinical practice guidelines published by surgical scientific organizations with an international scope between 2008 and 2017, resulted in a total of 67 guidelines. The quality of these guidelines was assessed using AGREE II. We performed a series of statistical analyses (reliability, correlation and Factor Analysis, Item Response Theory) with the objective to calibrate AGREE II for use specifically in surgical guidelines. RESULTS: Reliability/correlation/factor analysis and Item Response Theory produced similar results and suggested that a structure of 5 domains, instead of 6 domains of the original instrument, might be more appropriate. Furthermore, exclusion and re-arrangement of items to other domains was found to increase the reliability of AGREE II when applied in surgical guidelines. CONCLUSIONS: The findings of this study suggest that statistical calibration of AGREE II might improve the development, reporting, and appraisal of surgical guidelines

AGREE-S: AGREE II extension for surgical interventions - United European Gastroenterology and European Association for Endoscopic Surgery methodological guide

The Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument has been developed to inform the methodology, reporting and appraisal of clinical practice guidelines. Evidence suggests that the quality of surgical guidelines can be improved, and the structure and content of AGREE II can be modified to help enhance the quality of guidelines of surgical interventions

Fake news and Social Media: How Greek users identify and curb misinformation online

The issue of fake news and its impact has become very prominent in recent years. Despite the fact that fake news is not a new phenomenon, technological advances have constructed a fertile environment for the fake news to be spread rapidly. Social media platforms, such as Facebook, Twitter or YouTube, offer ground for generation and distribution of fake news. Consequently, it is important to study the way social media operates, how fake news is produced and spread through social network sites and what is the role users play. In particular, this study examines the methods and tools Greek users implement in order to spot fake news on social media and counter its spread. Moreover, this research contributes to the theory of fake news by addressing the issue of users’ interaction with news and users’ collaboration in the information era. The data presented in this research was collected from the members of the Ellinika Hoaxes Facebook group, an online Greek community where users exchange knowledge and insights and they collaborate to spot fake news and counter its spread

Digital Communication and Interactive Storytelling in Wikipedia : A Study of Greek Users’ Interaction and Experience

Wikipedia consists of an online encyclopedia created by users worldwide who collaborate to distribute knowledge and edit information in real-time. Although Wikipedia's accuracy has been a disputable and debatable issue in many recent studies, little academic research has systematically addressed how users interact with the platform's storytelling tools and how do they perceive and use Wikipedia's infrastructure, such as interactive tools. This exploratory study fulfills this gap and sheds light on users' perceptions about Wikipedia's interactivity. Moreover, Wikipedia is approached as an online community where collaboration, co-creation, and knowledge distribution play an important role. Therefore, it can be studied under the scope of Digital Humanities as well. The theoretical framework of interactive storytelling and digital communication suggests that hyperlinks, page preview bottoms, or interactive catalogs are applied in Wikipedia's environment to help users absorb information and construct their narratives. The findings of this thesis offer practical insights on how Wikipedia's interactive storytelling tools empower users with the ability to develop their stories and become editors/authors and provide a foundation for further academic research on user experience and how to improve interactivity and digital communication in Wikipedi