Biology subjects

Bernay, B.

Publications and source records attributed to Bernay, B..

6 recordsLinked to original sources

bioRxiv2026

Redirecting vacuolar nitrate transport improves nitrogen use efficiency and seed protein content

Improving seed protein content without compromising carbon allocation or yield is a major challenge for enhancing nitrogen use efficiency. Here, we show that redirecting vacuolar nitrate transport through concurrent manipulation of tonoplast proteins controlling nitrate storage or export provides an effective lever to reprogram nitrogen allocation from leaves toward the seeds. Using Arabidopsis thaliana Ws lines disrupted for the vacuolar CLC-a nitrate importer and/or overexpressing the NRT2.7 tonoplast nitrate exporter, we show that plants combining the two modifications (35S::NRT2.7(clc-a)) integrate reduced nitrogen retention in vegetative tissues with increased nitrogen allocation to seeds. As a result, 35S::NRT2.7(clc-a) plants exhibit the strongest increase in seed protein content among all genotypes (approximately +25%) without affecting seed yield, carbon concentration, or lipid composition. Altered vacuolar nitrate fluxes in 35S::NRT2.7(clc-a) stimulate nitrate assimilation, enhance nitrate reductase activity and amino acid biosynthetic pathways, and drive coordinated reprogramming of nitrogen and carbon metabolisms. Through 15N pulse chase experiments, we confirmed that 35S::NRT2.7(clc-a) shows the highest nitrogen remobilization efficiency toward seeds. Overexpression of the barley NRT2.7 homolog HvNRT2.10 in Arabidopsis wild type and clc-a backgrounds reproduces the key features of 35S::NRT2.7 phenotype, demonstrating the conservation of NRT2.7 regulatory effects on plant metabolism across species. Together, these findings identify vacuolar nitrate transport as a promising target to modulate grain protein content in cereals through genetic strategies acting on nitrogen storage and remobilization.

plant biology↗

bioRxiv2026

Lyophilized Cell-Secreted Matrix as a Bioactive Substrate for Chondrocyte Expansion and Redifferentiation

Articular cartilage repair is limited by the poor regenerative capacity of chondrocytes and their rapid dedifferentiation during in vitro expansion. This study investigated whether a decellularized and lyophilized cell-secreted matrix (CSM) could function as a bioactive material to regulate cell behavior, promote chondrogenic differentiation, and attenuate or reverse chondrocyte dedifferentiation without exogenous growth factor supplementation. CSM was generated from rabbit auricular perichondrial cells, decellularized, lyophilized, and characterized by histology, biochemical assays, and proteomic analysis. The resulting matrix was enriched in structurally and functionally relevant extracellular matrix proteins, including collagens, fibronectin, fibrillin, proteoglycans, and matricellular regulators, with minimal intracellular contamination and good batch-to-batch reproducibility. Functionally, CSM supported robust adhesion and proliferation of allogeneic and xenogeneic cells. Human articular chondrocytes cultured on CSM exhibited enhanced proliferation, sustained expression of cartilage-specific markers, and preserved type II collagen production over serial passages compared with standard plastic culture. CSM also promoted chondrogenic differentiation of human progenitor cells and partially reversed established chondrocyte dedifferentiation, as evidenced by increased expression of COL2A1, ACAN, SOX9, and COMP, with reduced COL1 expression and no induction of hypertrophic markers. These findings demonstrate that lyophilized CSM is a stable, off-the-shelf biomaterial capable of directing chondrocyte fate through intrinsic matrix-derived cues, highlighting its potential for cartilage tissue engineering and cell manufacturing applications.

bioengineering↗

bioRxiv2025

Inhibiting EZH2 Alleviates Osteoarthritis and Pain in an Experimental Murine Model Through Modulating Synovial and Macrophage Inflammation, Axon Guidance, and Osteoclastogenesis

Enhancer of zeste homolog 2 (EZH2), a histone methyltransferase responsible for H3K27 trimethylation, has emerged as a potential therapeutic target in osteoarthritis (OA). However, its contribution to the multicellular mechanisms driving joint degeneration and pain remains poorly understood. Here, we investigated the effects of pharmacological EZH2 inhibition in a pain-relevant murine OA model and explored its cellular and molecular consequences across OA-associated cell populations. OA was induced in mice by intra-articular monosodium iodoacetate (MIA) injection followed by local administration of the EZH2 inhibitor EPZ-6438. Joint pathology and pain-related behaviors were assessed by histological and functional analyses. Mechanistic studies were performed in primary human OA fibroblast-like synoviocytes and bone marrow-derived cells using targeted gene expression analyses, proteomics and ChIP-seq approaches. EZH2 inhibition reduced cartilage damage, synovial inflammation and pain-related behavioral alterations in vivo. In OA synoviocytes, EPZ-6438 decreased the expression of inflammatory, catabolic and pain-associated mediators while promoting autophagy-related responses. Proteomic and ChIP-seq analyses revealed EZH2-dependent regulation of inflammatory pathways, cellular homeostasis and neuronal-associated processes, including axon guidance-related pathways. ChIP-seq further identified inflammation-dependent EZH2 recruitment to promoters of neurodevelopmental regulators, including PAX6, suggesting a potential contribution of EZH2 to neuronal-associated mechanisms in OA. In addition, EZH2 inhibition reduced macrophage inflammatory activation and osteoclast differentiation. Together, these findings identify EZH2 as a candidate epigenetic regulator linking inflammatory, neuroimmune and osteoimmune pathways across the osteoarthritic joint. Targeting EZH2 may represent a therapeutic strategy to simultaneously modulate joint inflammation, remodeling and pain-associated pathways.

physiology↗

bioRxiv2024

Exploring Adenosine Analogues for Chondrosarcoma Therapy: In Vitro and In Vivo Insights

Chondrosarcoma (CS) is described as resistant to conventional chemotherapy and radiotherapy. The development of new therapeutic approaches is necessary. The aim of the present study is to validate the use of adenosine analogues as a new therapeutic strategy in the treatment of CS. Five adenosine analogues (aristeromycin, cladribine, clofarabine, formycin, and pentostatin) were evaluated in vitro on several chondrosarcoma cell lines using both 2D cultures and 3D alginate bead models. Cell viability was assessed using Acridine Orange and DAPI staining, or ATP assay. Apoptosis was measured via Annexin V and Propidium Iodide staining, while cell cycle progression was analyzed with DAPI staining. The most promising compounds were further tested in vivo using a xenograft chondrosarcoma model in nude mice. Results showed that four analogues (aristeromycin, formycin, cladribine, and clofarabine) significantly reduced cell viability in 2D cell cultures. Of these, cladribine and clofarabine demonstrated potent efficacy in both 2D and 3D models by inducing apoptosis. Cladribine was further found to induce cell cycle arrest, leading to apoptosis-mediated cell death. In vivo, both cladribine and clofarabine exhibited substantial antitumor effects in a xenograft model. In conclusion, cladribine and clofarabine, which are already approved for clinical use in leukemia and multiple sclerosis, show promise as potential candidates for chondrosarcoma treatment. Their efficacy in preclinical models suggests these molecules could be repurposed for Phase II clinical trials in CS patients.

cancer biology↗

bioRxiv2024

Multi-omic analyses unveil temporal and spatial distribution of specialized metabolites in seeds of Camelina sativa

Seeds of Brassicaceae produce a large diversity of beneficial and antinutritional specialized metabolites (SMs) that influence their quality and provide resistance to stresses. While the distribution of these compounds has been described in leaves and roots tissues, limited information is available about their spatio-temporal accumulation in seeds. Camelina sativa (camelina) is an oilseed Brassicaceae cultivated for human and animal nutrition, and for industrial uses. While we previously explored SM diversity and plasticity, no information is available about SM distribution and expression of related proteins and genes in camelina seeds. In this study, we used a multi-omic approach, integrating untargeted metabolomics, data-independent acquisition proteomics, and transcriptomics to investigate the synthesis, modifications and degradations of SMs accumulated in the different seed tissues (i.e. seed coat, endosperm, and embryo) at 6 developmental and 2 germination stages. Our results showed distinct patterns of SMs and their related pathways, highlighting significant contrasts in seed composition and spatial distribution for the defence-related and antinutritional glucosinolate (GSL) compounds among camelina, Arabidopsis thaliana, and Brassica napus, three closely-related Brassicaceae species. Notably, the variation in GSL spatial distributions was primarily driven by differences in their structure and transport mechanisms. Long chain C8-C11 methylsulfinylalkyl GSLs were predominantly accumulated in the seed coat and endosperm, while mid- and short-chain C3-C7 methylsulfinylalkyl GSLs were accumulated in the embryo. Characterizing the spatial dynamics of seed SMs provides valuable insights that can guide the development of crops with optimized distribution of beneficial and toxic metabolites, improving seed nutritional profiles for feed and food.

plant biology↗

bioRxiv2022

Impacts of ocean acidification and warming on post-larval growth and metabolism in two populations of the great scallop (Pecten maximus L.)

Ocean acidification and warming are key stressors for many marine organisms. Some organisms display physiological acclimatisation or plasticity, but this may vary across species ranges, especially if populations are adapted to local climatic conditions. Understanding how acclimatisation potential varies among populations is therefore important in predicting species responses to climate change. We carried out a common garden experiment to investigate how different populations of the economically important great scallop (Pecten maximus) from France and Norway responded to variation in temperature and pCO2 concentration. After acclimation, post-larval scallops (spat) were reared for 31 days at one of two temperatures (13{degrees}C and 19{degrees}C) under either ambient or elevated pCO2 (pH 8.0 and pH 7.7). We combined measures of proteomic, metabolic, and phenotypic traits to produce an integrative picture of how physiological plasticity varies between the populations. The proteome of French spat showed significant sensitivity to environmental variation, with 12 metabolic, structural and stress-response proteins responding to temperature and/or pCO2. Principal component analysis revealed seven energy metabolism proteins in French spat that were consistent with countering ROS stress under elevated temperature. Oxygen uptake in French spat did not change under elevated temperature, but increased under elevated pCO2. In contrast, Norwegian spat reduced oxygen uptake under both elevated temperature and pCO2. Metabolic plasticity seemingly allowed French scallops to maintain greater energy availability for growth than Norwegian spat. However, increased physiological plasticity and growth in French spat may come at a cost, as French (but not Norwegian) spat showed reduced survival under elevated temperature. Summary StatementJuvenile scallops from France and Norway differ in their response to warming and acidification. French scallops show more physiological plasticity, adjusting their proteome and metabolism in order to maintain growth.

evolutionary biology↗