Analysis of tumor microenvironment composition in vestibular schwannomas: insights into NF2-associated and sporadic variations and their clinical correlations

ObjectiveVestibular schwannomas (VS), benign tumors stemming from the eighth cranial nerve’s Schwann cells, are associated with Merlin gene mutations, inflammation, and the tumor microenvironment (TME), influencing tumor initiation, maintenance, and potential neural dysfunction. Understanding TME composition holds promise for systemic therapeutic interventions, particularly for NF2-related schwannomatosis.MethodologyA retrospective analysis of paraffin-embedded tissue from 40 patients (2013-2020), evenly divided by neurofibromatosis type 2 status, with further stratification based on magnetic resonance imaging (MRI) progression and hearing function. Immunohistochemistry assessed TME components, including T-cell markers (CD4, CD8, CD25), NK cells (CD7), and macrophages (CD14, CD68, CD163, CCR2). Fiji software facilitated image analysis.ResultsT-cell markers (CD4, CD8, CD7) exhibited low expression in VS, with no significant NF2-associated vs. sporadic distinctions. Macrophage-related markers (CD14, CD68, CD163, CCR2) showed significantly higher expression (CD14: p = 0.0187, CD68: p < 0.0001, CD163: p = 0.0006, CCR2: p < 0.0001). CCR2 and CD163 significantly differed between NF2-associated and sporadic VS. iNOS, an M1-macrophage marker, was downregulated. CD25, a regulatory T-cell marker, correlated significantly with tumor growth dynamics (p = 0.016).DiscussionImmune cells, notably monocytes and macrophages, crucially contribute to VS pathogenesis in both NF2-associated and sporadic cases. Significant differences in CCR2 and CD163 expression suggest distinct immune responses. Regulatory T-cells may serve as growth dynamic markers. These findings highlight immune cells as potential biomarkers and therapeutic targets for managing VS

Mixing ratio and Nitrogen fertilization drive synergistic effects between biochar and compost

International audienceCompost and biochar mixtures used to replace mineral N fertilisers in agricultural systems showed contrasting results, especially when applied in combination. We hypothesised that their effect may depend on the mixing ratio between the two components. The aim of our study was to determine if varying ratios of biochar/compost mixtures in presence or absence of chemical nitrogen (N) fertilisation influence ryegrass growth and nutrient uptake. To this end, we set up a pot experiment with an agricultural soil amended with five compost and biochar mixtures differentiated by their mixing ratio. We followed soil fertility parameters and ryegrass growth over three harvests.Results showed that the addition of amendments improved nutrient availability. The highest nutrient availability was observed with pure compost. Despite their high C/N ratios, biochar and compost increased N availability while preventing its microbial immobilisation. Biomass and nutrient uptake by plants were improved by amendments, but were dependent on the biochar/compost ratio. Addition of a mixture containing less biochar than compost (30% biochar/70% compost, on a dry weight basis) showed highest plant growth response and nutrient uptake as compared to the chemical N fertilisation. In addition, the beneficial effects of biochar and compost on plant growth were strengthened by N fertiliser. All in all, we demonstrated the synergistic effects between biochar and compost, which were predominantly driven by the mixing ratio between those two materials, and highlighted their potential use as a sustainable alternative to chemical fertilisers

How does soil water status influence the fate of soil organic matter? A review of processes across scales

International audienc

Effect of Fresh and Aged Amendments on Alleviating Water-Stress Impacts on Plant Growth and Soil Microbial Functioning

International audienc

Promoting plant growth and carbon transfer to soil with organic amendments produced with mineral additives

International audienceThe quality of organic soil amendments such as composts and vermicomposts can be improved by using additives during their production. However, little is known about the impact of these materials on carbon flow in the plant-soil system. We investigated the impact of organic amendments produced through composting and vermicomposting in the presence of clay minerals (montmorillonite) and/or earthworms on plants (perennial ryegrass, Lolium perenne and common bean, Phaseolus vulgaris) and carbon flow in soil. We carried out a growth chamber experiment with continuous 13C labelling and analysed above-/below-ground biomass production, as well as biogeochemical parameters of plant and soil (rhizospheric and non-rhizospheric) compartments. Quantitative biogeochemical analyses were further merged with microscale elemental and isotopic information (NanoSIMS) to investigate carbon transfer in the rhizopheric soil. Our results showed lowest biomass production for treatments amended with organic amendments produced without minerals probably related to the release of harmful substances (excess of dissolved organic carbon, salts and inorganic nitrogen) due to the immature nature of these materials. The use of montmorillonite as additive during the preparation of the amendments alleviated these adverse effects and resulted in a significant increase of above-/below-ground plant biomass production. When the organic amendments were produced in the presence of eathworms and montmorillonite, the higher plant biomass promoted the release of root-derived carbon within the rhizospheric soil (compared with amendments without clay minerals), which was used as an energy-rich substrate by microorganisms. We conclude that the use of mineral additives during composting or vermicomposting favours plant biomass production and carbon transfer to the soil and its microorganisms, which could enhance soil carbon storage in the longer term

The older, the better: Ageing improves the efficiency of biochar-compost mixture to alleviate drought stress in plant and soil

International audienc

Comment le statut hydrique du sol influence le devenir des matières organiques du sol ? Une revue des processus à des échelles variées

National audienc

Positive or neutral effects of biochar-compost mixtures on earthworm communities in a temperate cropping system

International audienc

Biochar and compost addition increases soil organic carbon content and substitutes P and K fertilizer in three French cropping systems

International audienceAbstractBiochar and compost are increasingly considered sustainable amendments to improve soil fertility, while reducing agrochemical use. However, the efficiency of biochar, compost, and especially their mixtures under field conditions in temperate regions is still poorly studied. The objective of this study was to evaluate the effects of biochar/compost mixtures on crop yield and soil properties in French temperate cropping systems and to compare the amendment effects to soils receiving mineral potassium and phosphorus fertilization. To this end, green waste compost alone (8 t.ha−1) or in mixture with three contrasted biochars (8 t.ha−1 compost and 4 t.ha−1 biochar) were applied to maize-wheat cropping systems located in three major agricultural territories in France. Results showed that maize and wheat yields were predominantly site specific. Within each site, compost and biochar application led to similar yields and nutrient uptakes as compared to the mineral fertilization, suggesting that compost-biochar mixtures might be as efficient as mineral fertilizers to supply potassium and phosphorus, while biochar did not improve compost benefits to plant yield. Moreover, the effects of compost-biochar mixtures on soil organic carbon concentrations were site specific and led to no effect or increase by up to 53%. We conclude that compost-biochar mixtures may increase carbon content in soil and substitute phosphorus and potassium mineral fertilizers for crop production in temperate cropping systems, even though their effects are site specific

Diversity of soil biopores and their influence on soil water infiltration under various pedoclimatic conditions

International audienceDespite the large contribution of macropores made by soil engineers to the soil macroporosity and water infiltration, few studies have addressed the specific contribution of soil engineer groups, dynamics of biopores and their efficiency in conducting water. Thus, we aimed to investigate the link between soil macrofauna, soil biopores and water infiltration under different pedoclimatic conditions. To do so, we conducted an experimentation in twelve study sites with a large longitudinal gradient from France to Vietnam.  The experiment consisted in the field incubation of repacked soil in cores (15 cm in height and 15 cm in diameter) and controlling the activity of soil engineers in the manner of litter bag. For each site, soil columns were: (i) covered with a mesh (200µm) or not and (ii) with or without addition of organic residues to the soil surface. After 12 months, we measured (i) the 3D organization of biopores by X-ray computed tomography and (ii) the saturated hydraulic conductivity by Beerkan method. In addition, soil macrofauna communities and the 3D organization of biopores was measured in each study field. Addition of organic residues increased up to 2-fold the volume percentage of biopores which reached similar values than those observed for each study field. The co-inertia analysis between the data matrix characterizing the shape of biopores and the data matrix of the macrofauna communities showed no statistically significant correlation. Saturated hydraulic conductivity increased with the presence of biopores by 2 to 50-fold with the lowest increased in soils presenting largest saturated hydraulic conductivity. In conclusion, these results demonstrated that biopores are rapidly regenerated regardless the pedoclimatic conditions while the efficiency of biopores in conducting water is related to soil properties