Multifactorial Analysis of Environmental Metabolomic Data in Ecotoxicology: Wild Marine Mussel Exposed to WWTP Effluent as a Case Study

Abstract

<jats:p>Environmental metabolomics is a powerful approach to investigate the response of organisms to contaminant exposure at a molecular scale. However, metabolomic responses to realistic environmental conditions can be hindered by factors intrinsic to the environment and the organism. Hence, a well-designed experimental exposure associated with adequate statistical analysis could be helpful to better characterize and relate the observed variability to its different origins. In the current study, we applied a multifactorial experiment combined to Analysis of variance Multiblock Orthogonal Partial Least Squares (AMOPLS), to assess the metabolic response of wild marine mussels, Mytilus galloprovincialis, exposed to a wastewater treatment plant effluent, considering gender as an experimental factor. First, the total observed variability was decomposed to highlight the contribution of each effect related to the experimental factors. Both the exposure and the interaction gender × exposure had a statistically significant impact on the observed metabolic alteration. Then, these metabolic patterns were further characterized by analyzing the individual variable contributions to each effect. A main change in glycerophospholipid levels was highlighted in both males and females as a common response, possibly caused by oxidative stress, which could lead to reproductive disorders, whereas metabolic alterations in some polar lipids and kynurenine pathway were rather gender-specific. This may indicate a disturbance in the energy metabolism and immune system only in males. Finally, AMOPLS is a useful tool facilitating the interpretation of complex metabolomic data and is expected to have a broad application in the field of ecotoxicology.</jats:p>

Neurotoxicity in Marine Invertebrates: An Update

“…Moreover, a significant alteration of neurohormones was observed, in particular a down-modulation of dopamine (−36%) and a serotonin metabolite 5-methoxyindoleacetate (−57%) levels. Dopamine and serotonin are both neurotransmitters regulating neuromuscular functions (valves closing, siphon activity, and ciliary movement) and, therefore, this study confirmed the neuromuscular and feeding behavior alterations that were observed in molluscs following exposure of contaminants, especially as pesticides, as previously described [ 158 ].…”

“…A multifactorial analysis was applied to assess the metabolic response of mussel M. galloprovincialis exposed for seven days to a wastewater treatment plants (WWTP) effluent extract in laboratory conditions [ 158 ]. The WWTP was chemically characterized, identifying different organic contaminants, including drugs, chemotherapy drugs, stimulants (caffeine, nicotine), herbicides, and insecticides.…”

Early Biological Modulations Resulting from 1-Week Venlafaxine Exposure of Marine Mussels Mytilus galloprovincialis Determined by a Metabolomic Approach

“…Only a few metabolomic studies have explored sex-specific responses to a contaminant, although sex differences in response to contaminant exposure have been reported [ 38 , 47 , 48 ]. Such differences have already been highlighted in M. galloprovincialis when challenged by V. harveyi over a 24-h period [ 38 ].…”

Environmental Metabolomics Promises and Achievements in the Field of Aquatic Ecotoxicology: Viewed through the Pharmaceutical Lens

“…Indeed, prolonged exposure could trigger other MeOAs over time, or a contaminant might have several MeOAs [15]. Finally, regarding the organism under study, it is essential to inform the development stages (e.g., adult, larvae, and embryo) [42], as well as the sex [21,26,35,43], as the physiological and morphological differences could impact the MeOA (e.g., endocrine disruptors).…”