Organ-Specific Metabolome Deciphering Cell Pathways to Cope with Mercury in Wild Fish (Golden Grey Mullet Chelon auratus)

Abstract

Metabolomics is a powerful approach in evaluating the health status of organisms in ecotoxicological studies. However, metabolomics data reflect metabolic variations that are attributable to factors intrinsic to the environment and organism, and it is thus crucial to accurately evaluate the metabolome of the tissue/organ examined when it is exposed to no stressor. The metabolomes of the liver and gills of wild golden grey mullet (Chelon auratus) from a reference area were analyzed and compared by proton nuclear magnetic resonance (1H NMR)-based metabolomics. Both organs were characterized by amino acids, carbohydrates, osmolytes, nucleosides and their derivatives, and miscellaneous metabolites. However, similarities and differences were revealed in their metabolite profile and related to organ-specific functions. Taurine was predominant in both organs due to its involvement in osmoregulation in gills, and detoxification and antioxidant protective processes in liver. Environmental exposure to mercury (Hg) triggered multiple and often differential metabolic alterations in fish organs. Disturbances in ion-osmoregulatory processes were highlighted in the gills, whereas differential impairments between fish organs were pointed out in energy-producing metabolic pathways, protein catabolism, membrane stabilization processes, and antioxidant defense system, reflecting the induction of organ-specific adaptive and defensive strategies. Overall, a strict correlation between metabolites and organ-specific functions of fish gills and liver were discerned in this study, as well as organ-specific cytotoxicity mechanisms of Hg in fish.

Metabolomic and transcriptomic analyses reveal response mechanisms of juvenile flounder (Paralichthys olivaceus) to sublethal methylmercury

“…Among which, amino acid and their derivatives, including pyroglutamic acid, oxidized glutathione, gly-phe, ile-glu and phe-thr, were identified as important secondary metabolites of flounder in response to MeHg stress. It is consistent with the results reported in other literatures (Liu et al, 2011;Brandão et al, 2015;Cosio and Renault, 2020;De Marco et al, 2022). For example, glutamic acid, cysteine and glycine are closely related to glutathione biosynthesis, which is essential in fish to avoid oxidative stress or toxic damages (Mohamed et al, 2020).…”

“…As a widely known neurotoxin and endocrine disruptor, MeHg could cause damages to cellular macromolecules, antioxidant systems, immune function, nervous or endocrine systems and many other biological processes, even important life processes of growth, development and reproduction, which have been elaborated in various literatures (Ceccatelli et al, 2010;Fretham et al, 2012;dos Santos et al, 2018;Wu et al, 2018) and our previous studies (Ren et al, 2019a;Ren et al, 2019b;Ren et al, 2020). Up to now, researchers have taken a lot of efforts to explore the response mechanisms of tested animinals especially freshwater fish to MeHg, which had not been quite mastered yet (Brandão et al, 2015;De Marco et al, 2022). Additionally, marine fish at early life stages (ELSs) are more sensitive to various pollutants (Ren et al, 2019b;Ren et al, 2020), which can pose great insights into the response mechanisms of marine fish to MeHg.…”

“…MeHg had adverse impacts on membrane stabilization/degradation/repair processes, osmoregulation, energy metabolism, gene expression and antioxidant protection of golden grey mullet (Liza aurata) in contaminated wild area (Brandão et al, 2015). Additionally, disturbances in ion osmoregulatory processes were highlighted in gills tissue, whereas differential impairments to energyproducing metabolic pathways, protein catabolism, membrane stabilization processes and alteration of antioxidant defense system were also found in Chelon auratus (De Marco et al, 2022). Moreover, multi-omic techniques had also been used for toxicological research to discuss the complex response mechanisms of tested organisms to different pollutants (Huang et al, 2017;Ortiz-Villanueva et al, 2017;Teng et al, 2018;Pang et al, 2021;Wang et al, 2022).…”

Ameliorative Hematological and Histomorphological Effects of Dietary Trigonella foenum-graecum Seeds in Common Carp (Cyprinus carpio) Exposed to Copper Oxide Nanoparticles

“…Furthermore, based on the histological observations, we also found a recovery tendency from CuO-NP-induced tissue damage in the gills, livers, and kidneys of common carp in a dose-dependent manner after treatment with the fenugreek extract. The liver is very important organ that performs vital functions including detoxification, synthesis of numerous components of blood plasma, storage of glycogen, and release of glucose to the blood [ 83 , 84 , 85 , 86 ]; gills are crucial for respiratory gas exchange activity, osmoregulation, active ion transport, acid–base balance and excretion of nitrogenous wastes [ 84 , 85 ]; whereas kidneys are the primary excretory and osmoregulatory organ in fish [ 87 ]. Therefore, the maintenance of the histological stability and integrity of these organs is critical for proper nutrition, defense, and fish growth.…”

Metabolomic Study on Tridacna maxima Giant Clams Reveals Metabolic Fingerprint of Environmental Pollutants

“…Thus metabolomics are increasingly utilized to examine the interactions between an organism and its environment (Emwas et al, 2021;Bayona et al, 2022). For example, different metabolomic approaches have been applied to investigate different areas in the environmental sciences, including the assessment of pollutants exposure and other risks (De Marco et al, 2022), such as oil-polluted wastewater (Caliani et al, 2022), pesticides (Vignet et al, 2019), pharmaceuticals (Cappello et al, 2017), and so on.…”