Spatial analysis of the glioblastoma proteome reveals specific molecular signatures and markers of survival

Molecular heterogeneity is a key feature of glioblastoma that impedes patient stratification and leads to large discrepancies in mean patient survival. Here, we analyze a cohort of 96 glioblastoma patients with survival ranging from a few months to over 4 years. 46 tumors are analyzed by mass spectrometry-based spatially-resolved proteomics guided by mass spectrometry imaging. Integration of protein expression and clinical information highlights three molecular groups associated with immune, neurogenesis, and tumorigenesis signatures with high intra-tumoral heterogeneity. Furthermore, a set of proteins originating from reference and alternative ORFs is found to be statistically significant based on patient survival times. Among these proteins, a 5-protein signature is associated with survival. The expression of these 5 proteins is validated by immunofluorescence on an additional cohort of 50 patients. Overall, our work characterizes distinct molecular regions within glioblastoma tissues based on protein expression, which may help guide glioblastoma prognosis and improve current glioblastoma classification

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Genome-wide association analyses identify new Brugada syndrome risk loci and highlight a new mechanism of sodium channel regulation in disease susceptibility.

Brugada syndrome (BrS) is a cardiac arrhythmia disorder associated with sudden death in young adults. With the exception of SCN5A, encoding the cardiac sodium channel Na1.5, susceptibility genes remain largely unknown. Here we performed a genome-wide association meta-analysis comprising 2,820 unrelated cases with BrS and 10,001 controls, and identified 21 association signals at 12 loci (10 new). Single nucleotide polymorphism (SNP)-heritability estimates indicate a strong polygenic influence. Polygenic risk score analyses based on the 21 susceptibility variants demonstrate varying cumulative contribution of common risk alleles among different patient subgroups, as well as genetic associations with cardiac electrical traits and disorders in the general population. The predominance of cardiac transcription factor loci indicates that transcriptional regulation is a key feature of BrS pathogenesis. Furthermore, functional studies conducted on MAPRE2, encoding the microtubule plus-end binding protein EB2, point to microtubule-related trafficking effects on Na1.5 expression as a new underlying molecular mechanism. Taken together, these findings broaden our understanding of the genetic architecture of BrS and provide new insights into its molecular underpinnings

AC Dielectrophoresis of Bacteria in Coaxial Mesoscopic Structure Potentially Applicable for rapid Detection and Easy Characterization at Low Cost.

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Maxwell-Wagner-based Detection of Bacteria through the Formation of a Dielectrophoretic Biofilm-like Layer in a Coaxial Mesoscopic Structure

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Spatially-resolved protein surface microsampling from tissue sections using liquid extraction surface analysis

International audienceTissue microenvironment characterization presents a challenge for a better understanding of the full complexity of a pathology. Unfortunately, making a precise "picture" of the disease needs an efficient microsampling method coupled to an accurate localization for performing region-dependent proteomics. Here, we present a method that enables rapid and reproducible extraction of proteins from a tissue section to analyze a specific region at a millimeter scale. The method used a liquid-microjunction extraction with conventional detergent solution for proteomics analysis. We successfully performed immunoblotting experiments and showed the possibility to retrieve and identify more than 1400 proteins from a 1-mm diameter spot size on tissue sections with a high degree of reproducibility both qualitatively and quantitatively. Moreover, the small size of the extracted region achieved by this sampling method allows the possibility to perform multiple extractions on different tissue section points. Ten points on a sagittal rat brain tissue section were analyzed and the measured proteins clearly distinguished the different parts of the brain, thus permitting precise functional mapping. We thus demonstrate that with this technology, it is possible to map the tissue microenvironment and gain an understanding of the molecular mechanisms at millimeter resolution

Persistence of Coxsackievirus B4 in Pancreatic β Cells Disturbs Insulin Maturation, Pattern of Cellular Proteins, and DNA Methylation

Coxsackievirus-B4 (CV-B4) can persist in pancreatic cell lines and impair the phenoytpe and/or gene expressions in these cells; however, the models used to study this phenomenon did not produce insulin. Therefore, we investigated CV-B4 persistence and its consequences in insulin-producing pancreatic β cells. The insulin-secreting rat β cell line, INS-1, was infected with CV-B4. After lysis of a large part of the cell layer, the culture was still maintained and no additional cytopathic effect was observed. The amount of insulin in supernatants of cell cultures persistently infected with CV-B4 was not affected by the infection; in fact, a larger quantity of proinsulin was found. The mRNA expression of pro-hormone convertase 2, an enzyme involved in the maturation of proinsulin into insulin and studied using real-time reverse transcription-polymerase chain reaction, was inhibited in infected cultures. Further, the pattern of 47 cell proteins analyzed using Shotgun mass spectrometry was significantly modified. The DNA of persistently infected cell cultures was hypermethylated unlike that of controls. The persistent infection of INS-1 cells with CV-B4 had a deep impact on these cells, especially on insulin metabolism. Cellular changes caused by persistent CV-B4 infection of β cells can play a role in type 1 diabetes pathogenesis

Proteomic and transcriptomic investigation of acne vulgaris microcystic and papular lesions: Insights in the understanding of its pathophysiology

International audienceBackground: The pathogenesis of acne vulgaris involves several phases including androgen-dependent hyper-seborrhea, colonization by Propionibacterium acnes, and inflammation. Recent investigations have shown that in fact P. acnes provokes the activation of the inflammasome present in macrophages and dendritic cells. This signaling pathway leads to excessive production of interleukin IL-1β, a proinflammatory cytokine. Nevertheless, these well-studied phenomena in acne fail to elucidate the mechanisms responsible for the appearance of different lesions.Methods: We investigate response pathways for specific acne lesions such as microcysts and papules using shot-gun proteomic followed by systemic biology and transcriptomic approaches.Results: Results show that most of the proteins identified as differentially expressed between the normal and acne tissue biopsies associated with the immune system response were identified as highly or exclusively expressed in the papule biopsies. They were also expressed in microcysts, but in lower amounts compared to those in papules. These results are supported by the identification of CAMP factor protein produced by P. acnes in microcysts, indicating its enhanced proliferation in this type of lesion CONCLUSIONS: As CAMP factor protein was not detected in papule biopsies, we can see a clear delineation in the stages of progression of acne pathogenesis, which begins with a hyphenated inflammatory response in the papule stage, followed by imbalance of lipid production, which in turn triggers the enhanced proliferation of P. acnes.General significance: We demonstrate that expression inflammation varies across the two types of lesions, suggesting different pathways enhanced as a function of the progression of P. acnes

Spatially-Resolved Top-down Proteomics Bridged to MALDI MS Imaging Reveals the Molecular Physiome of Brain Regions

International audienceTissue spatially-resolved proteomics was performed on 3 brain regions, leading to the characterization of 123 reference proteins. Moreover, 8 alternative proteins from alternative open reading frames (AltORF) were identified. Some proteins display specific post-translational modification profiles or truncation linked to the brain regions and their functions. Systems biology analysis performed on the proteome identified in each region allowed to associate sub-networks with the functional physiology of each brain region. Back correlation of the proteins identified by spatially-resolved proteomics at a given tissue localization with the MALDI MS imaging data, was then performed. As an example, mapping of the distribution of the matrix metallopeptidase 3-cleaved C-terminal fragment of α-synuclein (aa 95-140) identified its specific distribution along the hippocampal dentate gyrus. Taken together, we established the molecular physiome of 3 rat brain regions through reference and hidden proteome characterization

Unexpected proteomics and biochemical complexity of human salivary α\alpha-amylases in 2D gels

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