Molecular Mechanisms of Endothelialitis in SARS-CoV-2 Infection: Evidence for VE-Cadherin Cleavage by ACE2.

Long COVID-19 syndrome appears after Severe Acute Respiratory Syndrome-Corona Virus (SARS-CoV-2) infection with acute damage to microcapillaries, microthrombi, and endothelialitis. However, the mechanisms involved in these processes remain to be elucidated. All blood vessels are lined with a monolayer of endothelial cells called vascular endothelium, which provides a the major function is to prevent coagulation. A component of endothelial cell junctions is VE-cadherin, which is responsible for maintaining the integrity of the vessels through homophilic interactions of its Ca++-dependent adhesive extracellular domain. Here we provide the first evidence that VE-cadherin is a target in vitro for ACE2 cleavage because its extracellular domain (hrVE-ED) contains two amino acid sequences for ACE2 substrate recognition at the positions 256P-F257 and 321PMKP-325L. Indeed, incubation of hrVE-ED with the active ectopeptidase hrACE2 for 16 hrs in the presence of 10 µM ZnCl2 showed a dose-dependent (from 0.2 ng/µL to 2 ng/µL) decrease of the VE-cadherin immunoreactive band. In vivo, in the blood from patients having severe COVID-19 we detected a circulating form of ACE2 with an apparent molecular mass of 70 kDa, which was barely detectable in patients with mild COVID-19. Of importance, in the patients with severe COVID-19 disease, the presence of three soluble fragments of VE-cadherin (70, 62, 54 kDa) were detected using the antiEC1 antibody while only the 54 kDa fragment was present in patients with mild disease. Altogether, these data clearly support a role for ACE2 to cleave VE-cadherin, which leads to potential biomarkers of SARS-CoV-2 infection related with the vascular disease in "Long COVID-19".

Safety profile of immune checkpoint inhibitors according to cancer type.

INTRODUCTION: Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment in recent years, but have led to the emergence of new so-called immune-related adverse events (irAE). The objective of this study was to determine whether cancer type is a potential predictive factor of irAEs. METHODS: This retrospective study included patients who had started an ICI treatment between 2019 and 2020 at the Grenoble Alpes University Hospital. A logistic regression model and a Fine and Gray survival model with death as a competing risk were used to identify variables associated with grade≥2 irAEs and grade≥2 irAEs-free survival. RESULTS: Of the 512 patients included, 160 (31.2%) had a grade≥2 irAE. Grade≥2 irAEs were less frequent in head and neck cancer compared to other cancers. Ipilimumab (odds ratio [OR]: 6.05; 95% confidence interval [CI]: 2.81-13.7), treatment duration (OR: 1.01; 95% CI: 1.01-1.02), and history of autoimmune disease (OR: 6.04; 95% CI: 2.45-16.5) were independently associated with grade≥2 irAEs. With death as a competing risk, grade≥2 irAEs-free survival was independently improved with treatment duration (subdistribution hazard ratio [sdHR]: 0.93; 95% CI: 0.92-0.94), ipilimumab (sdHR: 0.24; 95% CI: 0.1-0.59) and history of autoimmune disease (sdHR: 0.23; 95% CI: 0.08-0.69) whereas it was poorer for patients with performance status≥2 (sdHR: 2.04; 95% CI: 1.5-2.76) and an older age (sdHR: 1.02; 95% CI: 1.00-1.03). CONCLUSION: Ipilimumab and history of autoimmune disease were both associated with the presence of grade≥2 irAEs and grade≥2 irAEs-free survival. The different cancer groups were not.

Dataset on early growth of cover crops in growth chamber.

The data presented in this data paper describe the early growth of cover crop cultivated in growth chamber under non-limiting conditions. Seventeen species of four botanical groups were described after one month of growth. Traits related to plant growth and leaf area development were measured (five traits) and calculated (eight traits). This data set is made available to enable comparisons between dataset, extended analysis and meta-analysis on cover crop traits. The data presented in this article were used on the research article entitled "Leaf area development strategies of cover plants used in banana plantations identified from a set of plant traits' [1].

Palm seed and fruit lipid composition: phylogenetic and ecological perspectives.

BACKGROUND AND AIMS: Palms are vital to worldwide human nutrition, in particular as major sources of vegetable oils. However, our knowledge of seed and fruit lipid diversity in the family Arecaceae is limited. We therefore aimed to explore relationships between seed and fruit lipid content, fatty acid composition in the respective tissues, phylogenetic factors and biogeographical parameters. METHODS: Oil content and fatty acid composition were characterized in seeds and fruits of 174 and 144 palm species respectively. Distribution, linear regression and multivariate analyses allowed an evaluation of the chemotaxonomic value of these traits and their potential relationship with ecological factors. KEY RESULTS: A considerable intra-family diversity for lipid traits was revealed. Species with the most lipid-rich seeds belonged to the tribe Cocoseae, while species accumulating oil in the mesocarp occurred in all subfamilies and two-thirds of the tribes studied. Seed and fruit lipid contents were not correlated. Fatty acid composition of mesocarp oil was highly variable within tribes. By contrast, within-tribe diversity for seed lipid traits was low, whereas between-tribe variability was high. Consequently, multivariate analyses of seed lipid traits produced groupings of species belonging to the same tribe. Medium-chain fatty acids predominated in seeds of most palm species, but they were also accumulated in the mesocarp in some cases. Seed unsaturated fatty acid content correlated with temperature at the coldest latitude of natural occurrence. CONCLUSION: Several previously uncharacterized palms were identified as potential new sources of vegetable oils for comestible or non-food use. Seed lipid traits reflect genetic drift that occurred during the radiation of the family and therefore are highly relevant to palm chemotaxonomy. Our data also suggest that seed unsaturated fatty acids may provide an adaptive advantage in the coldest environments colonized by palms by maintaining storage lipids in liquid form for efficient mobilization during germination.

Gene coexpression network analysis of oil biosynthesis in an interspecific backcross of oil palm.

Global demand for vegetable oils is increasing at a dramatic rate, while our understanding of the regulation of oil biosynthesis in plants remains limited. To gain insights into the mechanisms that govern oil synthesis and fatty acid (FA) composition in the oil palm fruit, we used a multilevel approach combining gene coexpression analysis, quantification of allele-specific expression and joint multivariate analysis of transcriptomic and lipid data, in an interspecific backcross population between the African oil palm, Elaeis guineensis, and the American oil palm, Elaeis oleifera, which display contrasting oil contents and FA compositions. The gene coexpression network produced revealed tight transcriptional coordination of fatty acid synthesis (FAS) in the plastid with sugar sensing, plastidial glycolysis, transient starch storage and carbon recapture pathways. It also revealed a concerted regulation, along with FAS, of both the transfer of nascent FA to the endoplasmic reticulum, where triacylglycerol assembly occurs, and of the production of glycerol-3-phosphate, which provides the backbone of triacylglycerols. Plastid biogenesis and auxin transport were the two other biological processes most tightly connected to FAS in the network. In addition to WRINKLED1, a transcription factor (TF) known to activate FAS genes, two novel TFs, termed NF-YB-1 and ZFP-1, were found at the core of the FAS module. The saturated FA content of palm oil appeared to vary above all in relation to the level of transcripts of the gene coding for ß-ketoacyl-acyl carrier protein synthase II. Our findings should facilitate the development of breeding and engineering strategies in this and other oil crops.

Comparative transcriptome analysis of three oil palm fruit and seed tissues that differ in oil content and fatty acid composition.

Oil palm (Elaeis guineensis) produces two oils of major economic importance, commonly referred to as palm oil and palm kernel oil, extracted from the mesocarp and the endosperm, respectively. While lauric acid predominates in endosperm oil, the major fatty acids (FAs) of mesocarp oil are palmitic and oleic acids. The oil palm embryo also stores oil, which contains a significant proportion of linoleic acid. In addition, the three tissues display high variation for oil content at maturity. To gain insight into the mechanisms that govern such differences in oil content and FA composition, tissue transcriptome and lipid composition were compared during development. The contribution of the cytosolic and plastidial glycolytic routes differed markedly between the mesocarp and seed tissues, but transcriptional patterns of genes involved in the conversion of sucrose to pyruvate were not related to variations for oil content. Accumulation of lauric acid relied on the dramatic up-regulation of a specialized acyl-acyl carrier protein thioesterase paralog and the concerted recruitment of specific isoforms of triacylglycerol assembly enzymes. Three paralogs of the WRINKLED1 (WRI1) transcription factor were identified, of which EgWRI1-1 and EgWRI1-2 were massively transcribed during oil deposition in the mesocarp and the endosperm, respectively. None of the three WRI1 paralogs were detected in the embryo. The transcription level of FA synthesis genes correlated with the amount of WRI1 transcripts and oil content. Changes in triacylglycerol content and FA composition of Nicotiana benthamiana leaves infiltrated with various combinations of WRI1 and FatB paralogs from oil palm validated functions inferred from transcriptome analysis.