NHSL3 controls single and collective cell migration through two distinct mechanisms.

The molecular mechanisms underlying cell migration remain incompletely understood. Here, we show that knock-out cells for NHSL3, the most recently identified member of the Nance-Horan Syndrome family, are more persistent than parental cells in single cell migration, but that, in wound healing, follower cells are impaired in their ability to follow leader cells. The NHSL3 locus encodes several isoforms.

Coxsackievirus infection induces direct pancreatic β cell killing but poor antiviral CD8 T cell responses.

Coxsackievirus B (CVB) infection of pancreatic β cells is associated with β cell autoimmunity and type 1 diabetes. We investigated how CVB affects human β cells and anti-CVB T cell responses. β cells were efficiently infected by CVB in vitro, down-regulated human leukocyte antigen (HLA) class I, and presented few, selected HLA-bound viral peptides.

ChipFilter: Microfluidic-Based Comprehensive Sample Preparation Methodology for Microbial Consortia.

The metaproteomic approach is an attractive way to describe a microbiome at the functional level, allowing the identification and quantification of proteins across a broad dynamic range as well as the detection of post-translational modifications. However, it remains relatively underutilized, mainly due to technical challenges that should be addressed, including the complexity of extracting proteins from heterogeneous microbial communities. Here, we show that a ChipFilter microfluidic device coupled to a liquid chromatography tandem mass spectrometry (LC-MS/MS) setup can be successfully used for the identification of microbial proteins.

Coxsackievirus infection induces direct pancreatic β-cell killing but poor anti-viral CD8+ T-cell responses.

Coxsackievirus B (CVB) infection of pancreatic β cells is associated with β-cell autoimmunity. We investigated how CVB impacts human β cells and anti-CVB T-cell responses. β cells were efficiently infected by CVB , downregulated HLA Class I and presented few, selected HLA-bound viral peptides.

PPP2R1A regulates migration persistence through the NHSL1-containing WAVE Shell Complex.

The RAC1-WAVE-Arp2/3 signaling pathway generates branched actin networks that power lamellipodium protrusion of migrating cells. Feedback is thought to control protrusion lifetime and migration persistence, but its molecular circuitry remains elusive. Here, we identify PPP2R1A by proteomics as a protein differentially associated with the WAVE complex subunit ABI1 when RAC1 is activated and downstream generation of branched actin is blocked.

Deciphering the Metal Speciation in Low-Molecular-Weight Complexes by IMS-MS: Application to the Detection of Manganese Superoxide Dismutase Mimics in Cell Lysates.

The detection and quantification of exogenous metal complexes are crucial to understanding their activity in intricate biological media. Mn complexes are difficult to detect and quantify because of low association constants, and high lability. The superoxide dismutase (SOD) mimic (or mimetic) labelled Mn1 is based on a 1,2-di-aminoethane functionalized with imidazole and phenolate and has good intrinsic anti-superoxide, antioxidant and anti-inflammatory activities in lipopolysaccharide (LPS)-activated intestinal epithelial HT29-MD2 cells, similar to that of its propylated analogue labelled Mn1P.

Redox proteome analysis of auranofin exposed ovarian cancer cells (A2780).

The effects of Auranofin (AF) on protein expression and protein oxidation in A2780 cancer cells were investigated through a strategy based on simultaneous expression proteomics and redox proteomics determinations. Bioinformatics analysis of the proteomics data supports the view that the most critical cellular changes elicited by AF treatment consist of thioredoxin reductase inhibition, alteration of the cell redox state, impairment of the mitochondrial functions, metabolic changes associated with conversion to a glycolytic phenotype, induction of ER stress. The occurrence of the above cellular changes was extensively validated by performing direct biochemical assays.

Candidate High-Resolution Mass Spectrometry-Based Reference Method for the Quantification of Procalcitonin in Human Serum Using a Characterized Recombinant Protein as a Primary Calibrator.

Procalcitonin (PCT) is a widely used biomarker for rapid sepsis diagnosis and antibiotic stewardship. Variability of results in commercial assays has highlighted the need for standardization of PCT measurements. An antibody-free candidate reference measurement procedure (RMP) based on the isotope dilution mass spectrometry and protein calibration approach was developed and validated to quantify PCT in human serum.

CD8 T Cells Variably Recognize Native Versus Citrullinated GRP78 Epitopes in Type 1 Diabetes.

In type 1 diabetes, autoimmune β-cell destruction may be favored by neoantigens harboring posttranslational modifications (PTMs) such as citrullination. We studied the recognition of native and citrullinated glucose-regulated protein (GRP)78 peptides by CD8 T cells. Citrullination modulated T-cell recognition and, to a lesser extent, HLA-A2 binding.

Harmonization status of procalcitonin measurements: what do comparison studies and EQA schemes tell us?

Sepsis represents a global health priority because of its high mortality and morbidity. The key to improving prognosis remains an early diagnosis to initiate appropriate antibiotic treatment. Procalcitonin (PCT) is a recognized biomarker for the early indication of bacterial infections and a valuable tool to guide and individualize antibiotic treatment.

Development of an antibody-free ID-LC MS method for the quantification of procalcitonin in human serum at sub-microgram per liter level using a peptide-based calibration.

The quantification of low abundant proteins in complex matrices by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) remains challenging. A measurement procedure based on optimized antibody-free sample preparation and isotope dilution coupled to LC-MS/MS was developed to quantify procalcitonin (PCT) in human serum at sub-microgram per liter level. A combination of sodium deoxycholate-assisted protein precipitation with acetonitrile, solid-phase extraction, and trypsin digestion assisted with Tween-20 enhanced the method sensitivity.

Lifestyle-specific S-nitrosylation of protein cysteine thiols regulates Escherichia coli biofilm formation and resistance to oxidative stress.

Communities of bacteria called biofilms are characterized by reduced diffusion, steep oxygen, and redox gradients and specific properties compared to individualized planktonic bacteria. In this study, we investigated whether signaling via nitrosylation of protein cysteine thiols (S-nitrosylation), regulating a wide range of functions in eukaryotes, could also specifically occur in biofilms and contribute to bacterial adaptation to this widespread lifestyle. We used a redox proteomic approach to compare cysteine S-nitrosylation in aerobic and anaerobic biofilm and planktonic Escherichia coli cultures and we identified proteins with biofilm-specific S-nitrosylation status.

Evaluation of the necessity and the feasibility of the standardization of procalcitonin measurements: Activities of IFCC WG-PCT with involvement of all stakeholders.

Procalcitonin (PCT) is an important biomarker for sepsis diagnosis and management. To date, there is no higher-order reference measurement procedure (RMP) and certified reference material to achieve global standardization of results and results traceability to the SI units. Although efforts have been made to harmonize PCT results, a number of comparison studies and external quality assessment (EQA) schemes show conflicting results regarding results comparability and to date, equivalence of PCT results across the assays remains questionable in absence of studies relying on commutable EQA materials.

Potential of Fourier Transform Mass Spectrometry (Orbitrap and Ion Cyclotron Resonance) for Speciation of the Selenium Metabolome in Selenium-Rich Yeast.

The evolution of the field of element speciation, from the targeted analysis for specific element species toward a global exploratory analysis for the entirety of metal- or metalloid-related compounds present in a biological system (metallomics), requires instrumental techniques with increasing selectivity and sensitivity. The selectivity of hyphenated techniques, combining chromatography, and capillary electrophoresis with element-specific detection (usually inductively coupled plasma mass spectrometry, ICP MS), is often insufficient to discriminate all the species of a given element in a sample. The necessary degree of specificity can be attained by ultrahigh-resolution (R >100,000 in the < 1,000 range for a 1 s scan) mass spectrometry based on the Fourier transformation of an image current of the ions moving in an Orbitrap or an ion cyclotron resonance (ICR) cell.

Peptides Derived From Insulin Granule Proteins Are Targeted by CD8 T Cells Across MHC Class I Restrictions in Humans and NOD Mice.

The antigenic peptides processed by β-cells and presented through surface HLA class I molecules are poorly characterized. Each HLA variant (e.g.

Deciphering shell proteome within different Baltic populations of mytilid mussels illustrates important local variability and potential consequences in the context of changing marine conditions.

Molluscs defend themselves against predation and environmental stressors through the possession of mineralized shells. Mussels are widely used to predict the effects of abiotic factors such as salinity and pH on marine calcifiers in the context of changing ocean conditions. Shell matrix proteins are part of the molecular control regulating the biomineralization processes underpinning shell production.

The zoonotic pathogen Leptospira interrogans mitigates environmental stress through cyclic-di-GMP-controlled biofilm production.

The zoonotic bacterium Leptospira interrogans is the aetiological agent of leptospirosis, a re-emerging infectious disease that is a growing public health concern. Most human cases of leptospirosis result from environmental infection. Biofilm formation and its contribution to the persistence of virulent leptospires in the environment or in the host have scarcely been addressed.

On-Chip Sample Preparation Using a ChipFilter Coupled to NanoLC-MS/MS for Bottom-Up Proteomics.

Sample preparation is a crucial step in bottom-up proteomics. Analytical performances of bottom-up proteomics can be improved by the miniaturization of sample preparation. Many microfluidic devices have been designed in the field of proteomics, but many of them are not capable of handling complex samples and do not integrate the processing and digestion steps.

S-nitrosylation affects TRAP1 structure and ATPase activity and modulates cell response to apoptotic stimuli.

The mitochondrial chaperone TRAP1 has been involved in several mitochondrial functions, and modulation of its expression/activity has been suggested to play a role in the metabolic reprogramming distinctive of cancer cells. TRAP1 posttranslational modifications, i.e.

Development of Immobilized Enzyme Reactors for the characterization of the glycosylation heterogeneity of a protein.

The mapping of post-translational modifications (PTMs) of proteins can be addressed by bottom-up proteomics strategy using proteases to achieve the enzymatic digestion of the biomolecule. Glycosylation is one of the most challenging PTM to characterize due to its large structural heterogeneity. In this work, two Immobilized Enzyme Reactors (IMERs) based on trypsin and pepsin protease were used for the first time to fasten and improve the reliability of the specific mapping of the N-glycosylation heterogeneity of glycoproteins.

Investigation of serum proteome homeostasis during radiation therapy by a quantitative proteomics approach.

The purpose of the present study is to analyze the serum proteome of patients receiving Radiation Therapy (RT) at different stages of their treatment to discovery candidate biomarkers of the radiation-induced skin lesions and the molecular pathways underlying the radiation signatures. Six stages of RT treatment were monitored from patients treated because of brain cancer: before starting the treatment, during the treatment (four time points), and at 4 weeks from the last RT dose. Serum samples were analyzed by a proteomics approach based on the Data Independent Acquisition (DIA) mass spectrometry (MS).