Molecular and Cellular Effects Induced in Mytilus galloprovincialis Treated with Oxytetracycline at Different Temperatures

Abstract

The present study evaluatedthe interactive effects of temperature (16°C and 24°C) and a 4-day treatment with the antibiotic oxytetracycline (OTC) at 1 and 100μg/L on cellular and molecular parameters in the mussel Mytilus galloprovincialis. Lysosomal membrane stability (LMS), a sensitive biomarker of impaired health status in this organism, was assessed in the digestive glands. In addition, oxidative stress markers and the expression of mRNAs encoding proteins involved in antioxidant defense (catalase (cat) and glutathione-S-transferase (gst)) and the heat shock response (hsp90, hsp70, and hsp27) were evaluated in the gills, the target tissue of soluble chemicals. Finally, cAMP levels, which represent an important cell signaling pathway related to oxidative stress and the response to temperature challenges, were also determined in the gills. Exposure to heat stress as well as to OTC rendered a decrease in LMS and an increase in malonedialdehyde accumulation (MDA). CAT activity was not significantly modified, whereas GST activity decreased at 24°C. Cat and gst expression levels were reduced in animals kept at 24°C compared to 16°C in the presence or absence of OTC. At 16°C, treatment with OTC caused a significant increase in cat and gst transcript levels. Hsp27 mRNA was significantly up-regulated at all conditions compared to controls at 16°C. cAMP levels were increased at 24°C independent of the presence of OTC. PCA analysis showed that 37.21% and 25.89% of the total variance was explained by temperature and OTC treatment, respectively. Interestingly, a clear interaction was observed in animals exposed to both stressors increasing LMS and MDA accumulation and reducing hsp27 gene expression regulation. These interactions may suggest a risk for the organisms due to temperature increases in contaminated seawaters.

Dynamic changes in the sperm quality ofMytilus galloprovincialisunder continuous thermal stress

“…Indeed, our data confirm and support the use of this fluorochrome for efficiently evaluating lipid peroxidation, as we easily measured more lipid peroxidation at the beginning of the heat‐stress period, followed by a return to control‐group levels at a later time. This profile also implicates an active compensatory mechanism in the mussel, perhaps involving the production of antioxidants that are capable of recovering the oxidative status of lipids to within a physiological range (Frenzilli et al, ; Banni et al, ).…”

Human pharmaceuticals in the marine environment: Focus on exposure and biological effects in animal species

“…The relative importance of pharmaceuticals among other environmental pollutants cannot be stated at the moment; however, pharmaceuticals can induce profound biological effects and thus may act as additional stressors on marine ecosystems already impacted by other factors. Modifications of pH and temperature associated with climate change influence the chemical properties of most pharmaceuticals, which therefore may contribute differently to the global effect . Furthermore, the impact of pharmaceuticals on coastal environments is expected to increase with the increasing number of inhabitants in such areas and the increasing pressures attributable to human activities such as aquaculture , posing relevant implications for marine risk assessment and the determination of potential consequences for ecological and human health that cannot be neglected.…”

Toxic effects of antibiotic oxytetracycline in the fish, Cyprinus carpio using a multi-biomarker approach

“…Nakano et al (2018) found a reduction in HSP70 (stress protein) when fish Coho salmon was exposed to oxytetracycline. Furthermore, Banni et al (2015) found that oxytetracycline causes a drastic down-regulation of mRNA encoding hsp 27 protein. Similar studies by Franzellitti and Fabbri (2013) suggested that the impairment of regulatory pathways triggered by low concentrations of pharmaceuticals may affect the ability of animals to elaborate defense strategies or adapt to stress 2+ factors.…”

“…The other probable reason may be the formation of lipoproteins which are utilized to repair the damaged cell. Oxytetracycline decreased the lysosomal membrane stability in mussels (Banni et al, 2015) and enhance protein catabolism (Viarengo et al, 2007).…”