bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/363127

Hydrophobic organic contaminants are not linked to microplastic uptake in Baltic Sea herring

Ogonowski, M.·Wenman, V.·Danielsson, S.·Gorokhova, E.
View original source ↗Export metadata ↓

Abstract

It is commonly accepted that microplastic (MP) ingestion can lead to lower food intake and bioaccumulation of hydrophobic organic contaminants (HOCs) in aquatic organisms. However, causal links between MP and contaminant levels in biota are poorly understood and in situ data are very limited. Here, we investigated whether HOC concentrations in herring muscle tissue (Clupea harengus membras) are related to MP ingestion using fish caught along the West coast of the Baltic Sea. The MP occurrence exhibited a large geographic variability, with MP found in 22.3% of the fish examined. The population average was 1.0 MP ind-1; however, when only individuals containing MP were considered, the average MP burden was 4.4 MP ind-1. We also found that MP burden decreased with reproductive stage of the fish but increased with its body size. To predict MP abundance in fish guts, we constructed a mass-balance model using literature data on MP in the water column and physiological rates on ingestion and gut evacuation for clupeids of a similar size. The model output was in agreement with the observed values, thus supporting the validity of the results. Contaminant concentrations in the muscle tissue were unrelated to the MP levels in fish, suggesting a lack of direct links between the levels of HOCs and MP ingestion. Thus, despite their ubiquity, MP are unlikely to have a measurable impact on food intake or the total body burden of hydrophobic contaminants in Baltic herring. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/363127v3_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@4cb5b6org.highwire.dtl.DTLVardef@2de3c8org.highwire.dtl.DTLVardef@c58baborg.highwire.dtl.DTLVardef@154b828_HPS_FORMAT_FIGEXP M_FIG C_FIG

Explore related subjects

pharmacology and toxicologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ogonowski, M., Wenman, V., Danielsson, S., Gorokhova, E.. 2018-07-06. Hydrophobic organic contaminants are not linked to microplastic uptake in Baltic Sea herring. https://doi.org/10.1101/363127

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

PFOS and GenX Induce Mitochondrial Toxicity and Differentially Alter Respiratory Complex Activities in Liver and Brain

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants associated with adverse health effects, yet the mitochondrial consequences of exposure to individual PFAS and their mixtures remain incompletely understood. This study investigated the individual and combined effects of perfluorooctanesulfonic acid (PFOS) and hexafluoropropylene oxide dimer acid (GenX) on mitochondrial respiratory complex activities under acute, sub-chronic, and chronic exposure conditions. Acute effects were evaluated using isolated mouse liver and brain mitochondria, while repeated exposure was assessed in mice treated with PFOS, GenX, or their combination at 0.2, 2, and 10 mg/kg body weight for 1 month or 0.2 mg/kg for 5 months. PFAS distribution in plasma and brain tissues, mitochondrial oxidative phosphorylation (OXPHOS) protein expression, and predicted interactions with mitochondrial Complexes III and IV were also examined. Acute exposure inhibited Complex III and IV activities, with combined treatment generally producing greater inhibition than either compound alone. Following sub-chronic exposure, mitochondrial responses varied according to dose, treatment, and tissue, with more pronounced reductions in liver complex activities and comparatively limited changes in brain enzyme activities. Chronic low-dose exposure altered selected brain mitochondrial complex activities, while PFAS measurements revealed differences in plasma concentration and distribution across brain regions. OXPHOS protein expression also varied across brain regions and exposure conditions. Molecular docking indicated distinct predicted interaction patterns, with PFOS generally exhibiting more favorable scores at Complex III binding sites and GenX at selected Complex IV regions. Overall, these findings demonstrate exposure-dependent and tissue-specific mitochondrial responses to PFOS and GenX and highlight the importance of evaluating combined PFAS exposure across multiple exposure durations.

pharmacology and toxicology↗
bioRxiv2026

Target Specific Conformational Flexibility and Electrostatic Complementarity Modulate LTNF10 Peptide Binding to Phospholipase A2 Variants from Snake Venoms

Phospholipase A2 is one of the primary cytotoxins present in snake venoms, causing tissue damage through the hydrolysis of phospholipids in the cellular membrane. We prioritised and investigated in detail the binding and conformational dynamics of a ten-residue short peptide (LTNF10) from Lethal Toxin Neutralizing Factor from Opossum against snake venom Phospholipase A2 (svPLA2) variants. LTNF10 was prioritised from the curated list of peptide inhibitors. A charge-modulating mutation from aspartic acid to lysine at the fifth position in LTNF10 was observed to enhance the binding affinity to svPLA2 variants from Elapids. The mutant LTNF10 shows selectively enhanced binding affinity toward Group I svPLA2 from Elapidae. Free energy landscapes of LTNF10 and mutant LTNF10, and binding pocket-volume analysis of svPLA2 revealed that Lys5 substitution increases conformational flexibility of mutant LTNF10, allowing it to form favourable binding conformations, while svPLA2 shows a reduction in pocket volume. Conversely, the mutant LTNF10 shows reduced binding affinity in Group II svPLA2 from Viperidae while demonstrating reduced flexibility and a less significant decrease in binding pocket volume in svPLA2. These findings demonstrate that active-site charge microenvironments, binding pocket and structural differences in catalytically relevant loop regions influence LTNF10 binding to svPLA2. The differential binding affinity was primarily driven by improved non-covalent interactions, specifically reduced electrostatic repulsions and enhanced electrostatic interactions in Group I svPLA2 from Elapids. This was influenced by the enhanced flexibility of mutant LTNF10, suggesting the role of a complex scenario of enthalpy-entropy compensation. The understanding of dynamic and structural mechanisms of LTNF10 and svPLA2 interactions and binding offers key insights for designing target-specific peptide therapeutics against diverse svPLA2 toxins.

pharmacology and toxicology↗
bioRxiv2026

Long-PDE4D degradation attenuates left ventricular cardiomyocyte hypertrophic remodelling

Spatial compartmentalisation enables cyclic AMP (cAMP) to regulate distinct cellular functions, yet selectively targeting disease-associated signalling remains challenging. Phosphodiesterases constrain local cAMP responses, but conventional inhibitors offer limited isoform selectivity. Here we investigate whether targeted degradation of long phosphodiesterase-4D (PDE4D) isoforms can suppress pathological growth while preserving contractile function. Using adult rat and human ventricular cardiomyocytes and human myocardial slices, we show that the proteolysis-targeting chimera KTX-184 enhances compartmentalised cAMP signalling and attenuates hypertrophic remodelling. In rat cardiomyocytes, KTX-184 increases {beta}-adrenergic cAMP responses in the cytosol and at the plasma membrane, including T-tubule and crest regions, and enhances nuclear protein kinase A activity. In contrast, phospholamban- and ryanodine receptor-associated cAMP nanodomains, calcium transients and sarcomere shortening remain unchanged. KTX-184 prevents angiotensin II-induced hypertrophic remodelling, preserves T-tubule organisation and normalises hypertrophic marker expression. In human cardiomyocytes, it increases cytosolic cAMP responses and prevents overload-induced hypertrophy in myocardial slices. These findings identify long PDE4D isoforms as targets for spatially selective modulation of cAMP signalling and support targeted degradation as an approach to suppress cardiac hypertrophy without increasing contractility.

pharmacology and toxicology↗