It is well known that the excessive production of reactive oxygen species (ROS) can lead to the peroxidation of membrane lipids, glycation/oxidation/nitration of proteins, inactivation of enzymes, ...DNA mutation and damage, and other alterations in the subcellular components ....
Metal bioaccumulation and metallothionein (MT) expression were investigated in the gills and liver of the red-blooded Antarctic teleost Trematomus hansoni to evaluate the possibility for this species ...to face, with adequate physiological responses, an increase of copper and cadmium concentrations in its tissues. Specimens of this Antarctic fish were collected from Terra Nova Bay (Ross Sea) and used for a metal exposure experiment in controlled laboratory conditions. The two treatments led to a significant accumulation of both metals and increased gene transcription only for the MT-1. The biosynthesis of MTs was verified especially in specimens exposed to Cd, but most of these proteins were soon oxidized, probably because they were involved in cell protection against oxidative stress risk by scavenging reactive oxygen species. The obtained data highlighted the phenotypic plasticity of T. hansoni, a species that evolved in an environment characterized by naturally high concentrations of Cu and Cd, and maybe the possibility for the Antarctic fish to face the challenges of a world that is becoming more toxic every day.
There is growing concern for the wide use ofperfluorooctanoic acid (PFOA) because of its toxic effects on the environment and on human health. A new compound – the so called C6O4 (perfluoro ...(5-methoxy-1,3-dioxolan-4-yloxy) acetic acid) - was recently introduced as one of the alternative to traditional PFOA, however this was done without any scientific evidence of the effects of C6O4 when dispersed into the environment. Recently, the Regional Agency for the Protection of the Environment of Veneto (Italy) detected high levels of C6O4 in groundwater and in the Po river, increasing the alarm for the potential effects of this chemical into the natural environment. The present study investigates for the first time the effects of C6O4 on the Manila clam Ruditapes philippinarum exposed to environmental realistic concentrations of C6O4 (0.1 µg/L and 1 µg/L) for 7 and 21 days. Furthermore, in order to better understand if C6O4 is a valid and less hazardous alternative to its substitute, microbial and transcriptomic alterations were also investigated in clams exposed to 1 µg/L ofPFOA. Results indicate that C6O4 may cause significant perturbations to the digestive gland microbiota, likely determining the impairment of host physiological homeostasis. Despite chemical analyses suggest a 5 times lower accumulation potential of C604 as compared to PFOA in clam soft tissues, transcriptional analyses reveal several alterations of gene expression profile. A large part of the altered pathways, including immune response, apoptosis regulation, nervous system development, lipid metabolism and cell membrane is the same in C6O4 and PFOA exposed clams. In addition, clams exposed to C6O4 showed dose-dependent responses as well as possible narcotic or neurotoxic effects and reduced activation of genes involved in xenobiotic metabolism. Overall, the present study suggests that the potential risks for marine organism following environmental contamination are not reduced by replacing PFOA with C6O4. In addition, the detection of both C6O4 and PFOA into tissues of clams inhabiting the Lagoon of Venice - where there are no point sources of either compounds - recommends a similar capacity to spread throughout the environment. These results prompt the urgent need to re-evaluate the use of C6O4 as it may represent not only an environmental hazard but also a potential risk for human health.
Fish exhibit complex social behaviours that can influence their stress levels and well-being. However, little is known about the link between social interactions and stress in wild fish, especially ...in running water environments. While many studies have explored the stress axis in fish, most have focused on specific social contexts, leaving gaps in understanding stress responses to social changes. Our study investigated collective behaviour and stress in wild Italian riffle dace (Telestes muticellus) in a controlled experimental setup simulating a natural river system. Results reveal that group-living fish have lower cortisol and oxidative stress levels in muscle tissue compared to solitary counterparts, suggesting a calming effect of conspecific presence. Additionally, we observed upregulated expression of antioxidant enzymes in group-living fish, indicating potential benefits to antioxidant defence systems. These insights shed light on the dynamic relationship between group behaviour and stress in wild fish within running water habitats and emphasise the use of multidisciplinary approaches.
This work aimed to evaluate the effects of zinc (Zn) relating to cadmium (Cd)-induced toxicity and the role played by MTF-1. This transcription factor regulates the expression of genes encoding ...metallothioneins (MTs), some Zn transporters and the heavy chain of γ-glutamylcysteine synthetase. For this reason, two cell lines of mouse fibroblasts were used: a wild-type strain and a knockout strain to study the effects. Cells were exposed to complete medium containing: (1) 50 μM ZnSO4 (Zn), (2) 1 μM CdCl2 (Cd 1), (3) 2 μM CdCl2 (Cd 2), (4) 50 μM ZnSO4 + 1 μM CdCl2 (ZnCd 1) and (5) 50 μM ZnSO4 + 2 μM CdCl2 (ZnCd 2) for 4, 18 and 24 h. Following exposure, cell viability, the intracellular content of metals, glutathione (GSH) and MT and the gene expression of the two isoforms of MT was evaluated. The results obtained suggest that a lower Cd content in the co-treatments is responsible for the protection offered by Zn due to the probable competition for a common transporter. Furthermore, Zn determines an increase in GSH in co-treatments compared to treatments with Cd alone. Finally, the MTF-1 factor is essential for the expression of MT-1 but not of MT-2 nor probably for the heavy chain of γ-glutamylcysteine synthetase.
Stress granules are non-membranous cytoplasmic foci, composed of non-translating messenger ribonucleoproteins, translational initiation factors and other additional proteins. They represent a primary ...mechanism to rapidly modulate gene expression when cells are subjected to adverse environmental conditions. Very few works have been devoted to study the presence of the molecular components of stress granules in invertebrates. In this work, we characterized the transcript sequences for two important protein components of stress granules, TIA-1-related nucleolysin (TIAR) and tristetraprolin (TTP), in the solitary ascidian Ciona robusta, an invertebrate chordate, and carried out the first studies on their gene expression under stress conditions induced by metals (Cu, Zn and Cd). Data on mRNA expression levels, provided by qRT-PCR analyses, show a generalized decrease at the second day of metal-exposure for both tiar and ttp, suggesting that metal accumulation induces acute stress and the inhibition of the transcription for the two studied proteins. In-situ hybridization analyses demonstrate that TIAR and TTP antisense riboprobes recognize circulating granular amoebocytes in the hemolymph, in both blood lacunae and tunic. The results obtained in this work increase our knowledge on the evolution of anti-stress proteins in metazoans and emphasize the importance of the transcription of tiar and ttp, which represents an efficient physiological response allowing organisms to survive in the environment under stress conditions.
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•tiar and ttp are actively transcribed in the intestine of metal-exposed Ciona robusta.•The transcription level reaches a minimum at 48 h metal exposure.•TIAR and TTP antisense riboprobes recognize circulating granular amoebocytes in the hemolymph.
The production of reactive oxygen species (ROS) is a normal consequence of the aerobic cell metabolism. Despite their high and potentially detrimental reactivity with various biomolecules, the ...endogenous production of ROS is a vital part of physiological, immunological, and molecular processes that contribute to fitness. The role of ROS in host-parasite interactions is frequently defined by their contribution to innate immunity as effectors, promoting parasite death during infections. In vertebrates, ROS and antioxidant system enzymes, such as superoxide dismutase (SOD) are also involved in acquired immune memory, where they are responsible for T-cell signalling, activation, proliferation, and viability. Based on recent findings, ROS are now also assumed to play a role in immune priming, i.e., a form of memory in invertebrates. In this study, the potential involvement of Cu,Zn SODs in immunity of the red flour beetle
is described for the first time, applying an approach that combines an
gene characterisation with an
immune priming experiment using the Gram-positive entomopathogen
. We identified an unusually high number of three different transcripts for extracellular SOD and found that priming leads to a fine-tuned modulation of SOD expression, highlighting the potential of physiological co-adaptations for immune phenotypes.
Abstract Introduction Rotaviruses are non-enveloped viruses that each consist of 11 double-stranded RNA molecules. These viruses are able to persist in the environment, and therefore play a ...fundamental role in the epidemiology of gastroenteritis and severe diarrhoea in children worldwide. While mussels have been primarily used as indicators of chemical pollution, they can also be used to monitor viral contamination. The purpose of this study was to demonstrate that the Mytilus galloprovincialis mussel can also be used to detect microbial contamination, owing to its tendency to naturally concentrate viruses and other pathogens. Material and Methods A total of 102 Mytilus galloprovincialis mussel samples from Albania were collected over a three-year period: 37 samples off the Cape of Stillo in 2015, 39 samples from Butrinti Lake in 2019 and 26 samples from Butrinti Lake in 2021. Results The presence of rotavirus in the Cape of Stillo samples in 2015 was noted in 47% of samples from site 1, 33% from site 2, and 52% from site 3. In Butrinti Lake the percentage of infected individuals in 2019 was 33% from site 1, 41% from site 2, and 33% from site 3, whereas in 2021, it was 50% from site 1, 19% from site 2, and 0% from site 3. In total the percentage of infected individuals off the Cape of Stillo in 2015 was 44%, in Butrinti Lake in 2019 it was 36%, and in Butrinti Lake in 2021 it was 23 %. Conclusion These results indicate the presence of rotavirus in the shellfish specimens tested, and further analysis is needed to assess the potential health risks associated with consuming these shellfish. This study also indicates that mussels can be used in marine virological surveillance programmes.
Typical 2-Cys peroxiredoxins (2-Cys Prdxs) are proteins with antioxidant properties belonging to the thioredoxin peroxidase family. With their peroxidase activity, they contribute to the homeostatic ...control of reactive oxygen species (ROS) and, therefore, participate in various physiological functions, such as cell proliferation, differentiation, and apoptosis. Although Prdxs have been shown to be potential biomarkers for monitoring aquatic environments, minimal scientific attention has been devoted to describing their molecular architecture and function in marine invertebrates. Our study aims to clarify the protective role against stress induced by exposure to metals (Cu, Zn, and Cd) of three Prdxs (Prdx2, Prdx3, and Prdx4) in the solitary ascidian
, an invertebrate chordate. Here, we report a detailed pre- and post-translational regulation of the three Prdx isoforms. Data on intestinal mRNA expression, provided by qRT-PCR analyses, show a generalized increase for Prdx2, -3, and -4, which is correlated to metal accumulation. Furthermore, the increase in tissue enzyme activity observed after Zn exposure is slower than that observed with Cu and Cd. The obtained results increase our knowledge of the evolution of anti-stress proteins in invertebrates and emphasize the importance of the synthesis of Prdxs as an efficient way to face adverse environmental conditions.
The Frank-Starling response is an intrinsic heart property that is particularly evident in the fish heart because piscine cardiomyocytes are extremely sensitive to stretch. Several mechanisms and ...compounds influence the Frank-Starling response, including the free radical nitric oxide produced by nitric oxide synthases in the vascular endothelium and cardiomyocytes of all vertebrates. Besides its role in scavenging nitric oxide, hemoglobin may act as a source and transporter. In this context, the hemoglobin-less Antarctic teleost Chionodraco hamatus (icefish) represents a unique opportunity to investigate the involvement of nitric oxide in the Frank-Starling response. Using an isolated perfused heart preparation, weverified a basal nitrergic tone that is not implicated in the Frank-Starling response. In addition, by comparing nitric oxide synthases expression and activation in C. hamatus and the red-blooded Antarctic teleost Trematomus bernacchii, we found the endothelial isoform of nitric oxide synthase (the primary generator of nitric oxide during shear stress) to be less expressed and activated in the former.
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