Biology subjects

Marques, L.

Publications and source records attributed to Marques, L..

8 recordsLinked to original sources

bioRxiv2025

Molecular Insights into ANPEP in Gastric Adenocarcinoma

Alanyl aminopeptidase (ANPEP) has been implicated in various cancers, but its specific role in gastric adenocarcinoma (GC) remains incompletely understood. This study analyzed ANPEP gene expression in gastric cancer (GC), peritumoral tissue (PTT), metaplasia (M), and normal tissue (N). Total RNA was extracted, libraries were prepared and sequenced on the Illumina NextSeq 500. Data was processed using the nf-core/rnaseq pipeline. Transcript quantifications were imported with tximport and normalized using DESeq2. Differential expression (|log2FC| >2; adj. p < 0.05) and Kruskal-Wallis tests identified key genes. ANPEP was significantly upregulated in GC, PTT, and M compared to normal tissue (p < 0.01), suggesting its involvement in early mucosal transformation and malignant progression. Heatmap analysis revealed upregulation of genes related to immune function and oxidative stress, indicating an immunosuppressive and apoptosis-resistant tumor microenvironment. Correlation analyses identified strong positive associations between ANPEP and genes involved in cytoskeletal remodeling, immune modulation, and metabolic regulation, suggesting that ANPEP supports both the invasive potential of tumor cells and the establishment of an immunosuppressive niche. These findings position ANPEP as a promising biomarker for early detection and a candidate for targeted therapies.

cancer biology↗

bioRxiv2024

Autoregulation of cluster root and nodule development by white lupin CCR1 receptor-like kinase

Root development is controlled by local and systemic regulatory mechanisms that optimize mineral nutrient uptake and carbon allocation. The Autoregulation of Nodulation (AoN) pathway defines a negative regulation of nodule development in Legumes as a way to regulate the costly production of nitrogen-fixing organs. This pathway is defined as a response to symbiotic interaction and has been shown to also control root formation to some extent. However, it remains unclear if root and nodule development are under coordinated genetic regulation. Here, we identified mutants with altered root development in white lupin, constitutively producing specialized lateral roots called cluster roots. We showed that the CCR1 receptor-kinase negatively regulates cluster root and nodule development and targets common molecular modules such as NIN/LBD16-NFYA, defining a novel pathway that we named Autoregulation of Development (AoDev). AoDev defines a negative systemic pathway controlling several types of root organ development, independently of symbiotic partners and nutrient availability.

plant biology↗

bioRxiv2022

Tree growth enhancement drives a persistent biomass gain in unmanaged temperate forests

While enhanced tree growth over the last decades has been reported in forests across the globe, it remains unclear whether it drives persistent biomass increases of the stands, particularly in mature forests. Enhanced tree growth and stand-level biomass are often linked with a simultaneous increase in density-driven mortality and a reduction in tree longevity. Identifying empirical evidence regarding the balance between these processes is challenging due to the confounding effects of stand history, management, and environmental changes. Here, we investigate the link between growth and biomass via the shift in the negative relationship between average tree size and stand density (tree number). We find increasing stand density for a given tree size in unmanaged closed-canopy forests in Switzerland over the past six decades and a positive relationship between growth and stand density - qualitatively consistent with simulations by a mechanistic, cohort-resolving ecosystem model (LM3-PPA). Model simulations show that, in the absence of other disturbances, enhanced growth persistently increases biomass stocks despite simultaneous decreases in carbon residence time and tree longevity, independent of assumptions about the drivers of tree mortality. However, the magnitude of simulated changes critically depends on the shape of the mortality parameterizations. Our analyses reconcile reports of growth-induced reductions of tree longevity with model predictions of persistent biomass increases, and with our finding of a trend towards denser forests in response to growth - also in mature stands.

ecology↗

bioRxiv2022

Acclimation of phenology relieves leaf longevity constraints in deciduous forests

Leaf phenology is key for regulating total growing season mass and energy fluxes. Long-term temporal trends towards earlier leaf unfolding are observed across Northern Hemisphere forests. Phenological dates also vary between years, whereby end-of-season (EOS) dates correlate positively with start-of-season (SOS) dates and negatively with growing season total net CO2 assimilation (Anet). These associations have been interpreted as the effect of a constrained leaf longevity or of premature carbon (C) sink saturation - with far-reaching consequences for long-term phenology projections under climate change and rising CO2. Here, we use multi-decadal ground and remote-sensing observations to show that the relationships between Anet and EOS are opposite at the interannual and the decadal time scales. A decadal trend towards later EOS persists in parallel with a trend towards increasing Anet - in spite of the negative Anet-EOS relationship at the interannual scale. This indicates that acclimation of phenology has enabled plants to transcend a constrained leaf longevity or premature C sink saturation over the course of several decades, leading to a more effective use of available light and a sustained extension of the vegetation CO2 uptake season over time.

ecology↗

bioRxiv2021

The fungicide Tebuconazole induces electromechanical cardiotoxicity in murine hearts

Tebuconazole (TEB) is an important fungicide that belongs to the triazole family. It is largely applied in agriculture and its use has increased in the last decade. Since TEB is stable in water and soil, long-term exposure of humans to this pesticide is a real threat. Acute toxicological studies to uncover the toxicity of TEB are limited, and there is evidence of an association between long-term exposure to TEB and damage of several biological systems, including hepatotoxicity and cardiotoxicity. In this paper, the effects of acute exposure of cardiomyocytes and murine hearts to TEB were addressed to elucidate its impact on electromechanical properties of the cardiac tissue. In whole-cell patch-clamp records, TEB inhibited both the total outward potassium current (IC50=5.7{+/-}1.5 mol.l-1) and the L-type calcium current (IC50=33.2{+/-}7.4 mol.l-1). Acute exposure to TEB at 30 mol.l-1 prolonged the action potential duration as well as an induced out-of-pace action potential, and increased the sodium/calcium exchanger current in its forward and reverse modes. Moreover, sarcomere shortening and calcium transient in isolated cardiomyocytes was enhanced when cells were exposed to TEB at 30 mol.l-1. In ex vivo experiments, TEB 30 mol.l-1 caused significant electrocardiogram remodeling with prolonged PR, QRS, and QT interval duration. Accordingly, TEB exposure was prone to the appearance of arrhythmias. Combined, our results demonstrate that acute TEB exposure affects the cardiomyocytes electro-contractile properties and triggers the appearance of ECG abnormalities, including conduction defects and arrhythmias.

pharmacology and toxicology↗

bioRxiv2021

Chemical phylogenetics of the staphylococcal quorum sensing landscape

Staphylococci utilize secreted autoinducing peptides (AIPs) to regulate group behaviour through a process called quorum sensing (QS). Here, we survey the QS interaction landscape within the Staphylococcus genus by assembling a unique compound collection, comprising all the currently known AIPs. These ribosomally synthesized and posttranslationally modified peptides (RiPPs) were obtained by chemical synthesis and mapping of their ability to modulate QS was evaluated using reporter strains of common human and animal colonizing pathogens (S. aureus, S. epidermidis, S. lugdunensis). The resulting map of >200 native QS interactions provides a holistic view of nodes that contribute to the complex signalling network within the Staphylococcus genus. This overview reveals surprising cross-species QS induction and identify the first pan-inhibitory AIP, which is then shown to attenuate MRSA induced skin infection in a mouse model. Our results expose a complex universe of possible staphylococcal interactions and provide further impetus for development of therapeutics based on QS modulators targeting antibiotic resistant pathogens.

microbiology↗

bioRxiv2020

Developmental atlas of white lupin cluster roots

During the course of evolution, plants have developed various strategies to improve micronutrient acquisition, such as cluster roots. These spectacular structures are dedicated to efficient phosphate remobilization and acquisition. When exposed to Pi-limitation, white lupin forms cluster roots made of dense clusters of short specialized roots, called rootlets. Although the physiological activity of rootlets has been well studied, their development remains poorly described. Here, we provide a developmental atlas of white lupin early rootlet development, using molecular markers derived from the model plant Arabidopsis. We first focused on cell division patterns to determine which cells contribute to the rootlet primordium. Then, we identified homologs of previously described tissue specific genes based on protein sequence analysis and also using detailed transcriptomic data covering rootlet development. This study provides a comprehensive description of the developmental phases of rootlet formation, highlighting that rootlet primordium arises from divisions in pericycle, endodermis and cortex. We describe that rootlet primordium patterning follows eight stages during which tissue differentiation is established progressively. HighlightWhite lupin cluster roots consist in the formation of numerous rootlets whose development can be divided in 8 stages and involves divisions in the pericycle, endodermis and cortex.

plant biology↗

bioRxiv2019

Genome sequence of the cluster root forming white lupin

White lupin (Lupinus albus L.) is a legume that produces seeds recognized for their high protein content and good nutritional value (lowest glycemic index of all grains, high dietary fiber content, and zero gluten or starch)1-5. White lupin can form nitrogen-fixing nodules but has lost the ability to form mycorrhizal symbiosis with fungi6. Nevertheless, its root system is well adapted to poor soils: it produces cluster roots, constituted of dozens of determinate lateral roots that improve soil exploration and phosphate remobilization7. As phosphate is a limited resource that comes from rock reserves8, the production of cluster roots is a trait of interest to improve fertilizers efficiency. Using long reads sequencing technologies, we provide a high-quality genome sequence of a modern variety of white lupin (2n=50, 451 Mb), as well as de novo assemblies of a landrace and a wild relative. We describe how domestication impacted soil exploration capacity through the early establishment of lateral and cluster roots. We identify the APETALA2 transcription factor LaPUCHI-1, homolog of the Arabidopsis morphogenesis coordinator9, as a potential regulator of this trait. Our high-quality genome and companion genomic and transcriptomic resources enable the development of modern breeding strategies to increase and stabilize yield and to develop new varieties with reduced allergenic properties (caused by conglutins10), which would favor the deployment of this promising culture.

genomics↗