Toxicity of Environmental and Polystyrene Plastic Particles on the Bivalve Corbicula Fluminea: Focus on the Molecular Responses
Microplastics (MPs) and nanoplastics (NPs) are major ecotoxicological concerns in aquatic environments. Among aquatic organisms, filter feeders are particularly exposed to the ingestion of MPs and NPs, filtering large quantities of water for food and having an unselective feeding strategy. The present study investigates the effect of environmental microplastics (ENV MPs) and nanoplastics (ENV NPs) generated from macro-sized plastic debris collected in the Garonne River (France), and polystyrene NPs (PS NPs) on the freshwater bivalve Corbicula fluminea (Müller 1774). The organisms were exposed to each type of plastic particle at three concentrations: 0.008, 10 and 100 μg L−1 for 21 days. Gene expression measurements were conducted in gills and visceral mass at 7 and 21 days to assess the effects of plastic particles on different functions (endocytosis, detoxication, respiratory chain, oxidative stress, immunity, apoptosis and neurotoxicity). Our results revealed that: i) an up-regulation of genes, mainly involved in endocytosis, oxidative stress, immunity, apoptosis and neurotoxicity, was observed at 7 days of exposure for almost all environmental plastic particles and at 21 days of exposure for PS NPs in the gills, ii) PS NPs at the three concentrations tested and ENV MPs at 0.008 μg L−1 induced strong down-regulation of genes involved in detoxication, oxidative stress, immunity, apoptosis and neurotoxicity at 7 days of exposure in the visceral mass whereas ENV MPs at 10 and 100 μg L−1 and all ENV NPs induced less pronounced effects, iii) overall, PS NPs and ENV MPs 0.008 μg L−1 did not trigger the same effects as ENV MPs 10 and 100 μg L−1 and all ENV NPs, either in the gills or the visceral mass at 7 and 21 days of exposure. This study highlighted the need to use MPs and NPs sampled in the environment for future ecotoxicological studies, compared to manufactured PS NPs as their properties (composition, size distribution, surface charge, additive and adsorbed contaminants) induce different effects at the molecular level to living organisms.
(SSRN : Social Science Research Network, n° 1556-5068, 01/01/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
How does the Southern Ocean palaeoenvironment during Marine Isotope Stage 5e compare to the modern?
(Marine Micropaleontology. vol. 170, n° 0377-8398, pp. 102066, 01/01/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Source-to-sink pathways of clay minerals in the cadiz contourite system over the last 25 kyrs: The segregational role of mediterranean outflow water
Despite major advances in our understanding of the interactions between bottom currents and sedimentary deposits over the last forty years, few studies have focused on the nature of fine particles in contourite depositional systems (CDS). XRD analyses of marine sediments can be used to improve our understanding of fine-grained sediment sources and settling processes. This work presents a detailed sedimentological study of sediment cores collected over the middle slope of the Gulf of Cadiz as part of Integrated Ocean Drilling Program Expedition 339 and the 2001 CADISAR cruise. We performed high-resolution clay mineral analyses to reconstruct the pathways of fine-grained particles from their sources to their deposition along the contourite depositional system of the Gulf of Cadiz (source-to-sink approach). The clay mineral associations reflect the major contribution of the Guadalquivir River and North African rivers/dusts to fine particles settling over the middle slope. Our
(Marine Geology. vol. 443, n° 0025-3227, pp. 106697, 01/01/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France]
MOW strengthening and contourite development over two analog climate cycles (MIS 12–11 and MIS 2–1) in the Gulf of Cadíz: An impact on North Atlantic climate during deglaciation V and MIS 11?
(Global and Planetary Change. vol. 208, n° 0921-8181, pp. 103721, 01/01/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Ideas and perspectives: Sea-level change, anaerobic methane oxidation, and the glacial-interglacial phosphorus cycle
The oceanic phosphorus cycle describes how phosphorus moves through the ocean, accumulates with the sediments on the seafloor, and participates in biogeochemical reactions. We propose a new two-reservoir scenario of the glacial-interglacial phosphorus cycle. It relies on diagenesis in methane hydrate-bearing sediments to mobilize sedimentary phosphorus and transfer it to the oceanic reservoir during times when falling sea level lowers the hydrostatic pressure on the seafloor and destabilizes methane hydrates. The stock of solid phase phosphorus mobilizable by this process is of the same order of magnitude as the dissolved phosphate inventory of the current oceanic reservoir. The potential additional flux of phosphate during the glacial period is of the same order of magnitude as pre-agricultural, riverine dissolved phosphate fluxes to the ocean. Throughout the cycle, primary production assimilates phosphorus and inorganic carbon into biomass, which, upon settling and burial, returns phosphorus to the sedimentary reservoir. Primary production also lowers the partial pressure of CO2 in the surface ocean, potentially drawing down CO2 from the atmosphere. Concurrent with this slow "biological pump", but operating in the opposite direction, a "physical pump" brings metabolic CO2-enriched waters from deep-ocean basins to the upper ocean. The two pumps compete, but the direction of the CO2 flux at the air-sea interface depends on the nutrient content of the deep waters. Because of the transfer of reactive phosphorus to the sedimentary reservoir throughout a glaciation cycle, low-phosphorus and high-CO2 deep waters reign at the beginning of a deglaciation, resulting in rapid transfer of CO2 to the atmosphere. The new scenario provides another element to the suite of processes that may have contributed to the rapid glacial-interglacial climate transitions documented in paleo-records.
(Biogeosciences. vol. 19, n° 1726-4170, pp. 1421-1434, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
NiONPs-induced alteration in calcium signaling and mitochondrial function in pulmonary artery endothelial cells involves oxidative stress and TRPV4 channels disruption
In New Caledonia, anthropic activities, such as mining, increase the natural erosion of soils in nickel mines, which in turn, releases nickel oxide nanoparticles (NiONPs) into the atmosphere. Pulmonary vascular endothelial cells represent one of the primary targets for inhaled nanoparticles. The objective of this in vitro study was to assess the cytotoxic effects of NiONPs on human pulmonary artery endothelial cells (HPAEC). Special attention will be given to the level of oxidative stress and calcium signaling, which are involved in the physiopathology of cardiovascular diseases. HPAEC were exposed to NiONPs (0.5–150 μg/cm2) for 4 or 24 h. The following different endpoints were studied: (i) ROS production using CM-H2DCF-DA probe, electron spin resonance, and MitoSOX probe; the SOD activity was also measured (ii) calcium signaling with Fluo4-AM, Rhod-2, and Fluo4-FF probes; (iii) inflammation by IL-6 production and secretion and, (iv) mitochondrial dysfunction and apoptosis with TMRM and MitoTracker probes, and AnnexinV/PI. Our results have evidenced that NiONPs induced oxidative stress in HPAEC. This was demonstrated by an increase in ROS production and a decrease in SOD activity, the two mechanisms seem to trigger a pro-inflammatory response with IL-6 secretion. In addition, NiONPs exposure altered calcium homeostasis inducing an increased cytosolic calcium concentration ([Ca2+]i) that was significantly reduced by the extracellular calcium chelator EGTA and the TRPV4 inhibitor HC-067047. Interestingly, exposure to NiONPs also altered TRPV4 activity. Finally, HPAEC exposure to NiONPs increased intracellular levels of both ROS and calcium ([Ca2+]m) in mitochondria, leading to mitochondrial dysfunction and HPAEC apoptosis.
(Nanotoxicology. vol. 16, n° 1743-5390, pp. 29-51, 02/09/2026)
CRCTB, UB, CHU Bordeaux, INSERM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CHU Bordeaux, BIC, UB, INSERM, CNRS, ICMCB, UB, INC-CNRS, CNRS
New cosmogenic nuclide constraints on Late Glacial and Holocene glacier fluctuations in the sub-Antarctic Indian Ocean (Kerguelen Islands, 49°S)
Cosmogenic nuclide dating of glacial landforms on the Kerguelen Archipelago (49°S, 69°E) gives the opportunity to study multi-millennial glacier fluctuations within the sub-Antarctic sector of the Indian Ocean. We here dated such geomorphic features to provide time constraints over the last 17,000 years using in situ-produced 36Cl in three glacial valleys: Val Travers valley, Ampere Glacier valley and Arago Glacier valley. For the first time, a combination of in situ-produced 36Cl and 10Be dating and 26Al/10Be ratios analysis was performed in the quartz-bearing syenite boulders of the Arago Glacier site. In addition, a Bayesian approach was computed to obtain a better constraint on moraine dating. Glacial advances occurred during the Late Glacial at 16.0 ± 1.9 ka and at 12.9 ± 1.7 ka in Val Travers, and at 13.6 ± 1.8 ka in Arago Glacier valley, probably linked to the Heinrich Stadial 1 and/or Antarctic Cold Reversal events, respectively. This suggests that all glaciers at this latitude were broadly sensitive to the large-scale climatic signal of the Antarctic Cold Reversal. So far, no Early nor Mid-Holocene moraines have been found in the glacial valleys on Kerguelen, indicating that the glaciers had probably receded significantly during these periods. This is in agreement with previously determined 14C ages from peat bogs, which suggest extensive deglaciation during several millennia of the Holocene period. Samples from glacially-polished bedrock surfaces (ranging from ~4.4 ka to ~14 ka) at Ampere Glacier site also suggest that this valley was ice free for several millennia during the Holocene. Finally, glaciers seem to have re-advanced only during the Late Holocene, especially within the last millennium, at ~1 ka, ~430 yr and ~300 yr. A comparison of this new dataset with the available 10Be ages from other southern mid latitude regions during the Holocene allows the identification of three different glacier evolution patterns. We suspect that variations of Kerguelen glaciers, which are located in the Southern Indian Ocean, were controlled by the combined effects of sea surface temperature related to the variations of the Antarctic Polar Front and fluctuations of precipitation related to long-term variations of the Southern Annular Mode.
(Quaternary Science Reviews. vol. 283, n° 0277-3791, pp. 107461, 02/09/2026)
CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, GEOPS, INSU - CNRS, CNRS, CRPG, INSU - CNRS, UL, CNRS, UL, ELI, UCLouvain, IGE, IRD, INSU - CNRS, CNRS, Fédération OSUG, UGA, Grenoble INP, UGA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ULaval, LGL-TPE, ENS de Lyon, UCBL, INSU - CNRS, UJM, UJM EPE, CNRS, UJM, UJM EPE, LGP, UP1, UPEC UP12, CNRS
Ammonium and sulfate assimilation is widespread in benthic foraminifera
(Frontiers in Marine Science, n° 2296-7745, 02/09/2026)
LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, Nantes Univ, EPFL, ENTROPIE [Réunion], IRD, UR, CNRS, WHOI, CAGE, UiT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNIL
NiONP-Induced Oxidative Stress and Mitochondrial Impairment in an In Vitro Pulmonary Vascular Cell Model Mimicking Endothelial Dysfunction
The development and use of nanomaterials, especially of nickel oxide nanoparticles (NiONPs), is expected to provide many benefits but also has raised concerns about the potential human health risks. Inhaled NPs are known to exert deleterious cardiovascular side effects, including pulmonary hypertension. Consequently, patients with pulmonary hypertension (PH) could be at increased risk for morbidity. The objective of this study was to compare the toxic effects of NiONPs on human pulmonary artery endothelial cells (HPAEC) under physiological and pathological conditions. The study was conducted with an in vitro model mimicking the endothelial dysfunction observed in PH. HPAEC were cultured under physiological (static and normoxic) or pathological (20% cycle stretch and hypoxia) conditions and exposed to NiONPs (0.5–5 μg/cm2) for 4 or 24 h. The following endpoints were studied: (i) ROS production using CM-H2DCF-DA and MitoSOX probes, (ii) nitrite production by the Griess reaction, (iii) IL-6 secretion by ELISA, (iv) calcium signaling with a Fluo-4 AM probe, and (v) mitochondrial dysfunction with TMRM and MitoTracker probes. Our results evidenced that under pathological conditions, ROS and nitrite production, IL-6 secretions, calcium signaling, and mitochondria alterations increased compared to physiological conditions. Human exposure to NiONPs may be associated with adverse effects in vulnerable populations with cardiovascular risks
(Antioxidants. vol. 11, n° 2076-3921, pp. 847, 02/09/2026)
CRCTB, UB, CHU Bordeaux, INSERM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, DER, ANSES, CHU Bordeaux
Wave Dissipation and Mean Circulation on a Shore Platform Under Storm Wave Conditions
While wave processes on shore platforms have been recently advanced by a number of field-based studies, few attention has been paid to the role of bed roughness on wave dissipation and wave setup dynamics in these environments. This study reports on a new field experiment conducted under storm wave conditions on a gently sloping shore platform which was instrumented from 10 m water depth up to the shoreline. Data analyses are complemented with numerical simulations performed with a 3D fully coupled modeling system using a vortex force formalism to represent the effects of short waves on the mean circulation. An accurate representation of wave dissipation by both depth-induced breaking and bottom friction is found essential to reproduce the transformation of short waves across the platform and the resulting wave setup. Wave energy dissipation by bottom friction is dominant in the subtidal part of the platform and contributes to about 40% of the total wave energy dissipation. The enhanced wave bottom friction on the platform decreases the wave height before breaking, which reduces the contribution of wave forces to the wave setup compared to a smooth bottom (mechanism 1). Conversely, an idealized analysis of the cross-shore momentum balance reveals that the wave-induced circulation increases the wave setup, this process being enhanced on a rough bottom (mechanism 2). The contribution of mechanism 2 increases with the bottom slope, accounting for up to 26% of the wave setup for a 1:20 sloping shore platform, and overcoming mechanism 1.
(Journal of Geophysical Research: Earth Surface. vol. 127, n° 2169-9003, pp. 105319, 02/09/2026)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS