Circadian Rhythm and Neurotransmitters Are Potential Pathways through Which Ocean Acidification and Warming Affect the Metabolism of Thick-Shell Mussels

Abstract

Although the impacts of ocean acidification and warming on marine organisms have been increasingly documented, little is known about the affecting mechanism underpinning their interactive impacts on physiological processes such as metabolism. Therefore, the effects of these two stressors on metabolism were investigated in thick-shell mussel Mytilus coruscus in this study. In addition, because metabolism is primarily regulated by circadian rhythm and neurotransmitters, the impacts of acidification and warming on these two regulatory processes were also analyzed. The data obtained demonstrated that the metabolism of mussels (indicated by the clearance rate, oxygen consumption rate, ammonia excretion rate, O:N ratio, ATP content, activity of pyruvate kinase, and expression of metabolism-related genes) were significantly affected by acidification and warming, resulting in a shortage of energy supply (indicated by the in vivo content of ATP). In addition, exposure to acidification and warming led to evident disruption in circadian rhythm (indicated by the heartrate and the expression rhythm of Per2, Cry, and BMAL1) and neurotransmitters (indicated by the activity of acetyl cholinesterase and in vivo contents of ACh, GABA, and DA). These findings suggest that circadian rhythms and neurotransmitters might be potential routes through which acidification and warming interactively affect the metabolism of mussels.

Metabolic profiling of Mytilus coruscus mantle in response of shell repairing under acute acidification

“…and acute acidification and more ATP is required to fill the energy gap. The impact of OA on the energy metabolism of bivalves had been reported previously, and massive ATP consumption in the mantle of bivalves was observed, indicating that a large amount of energy was allocated to maintain the acid-base balance in a reduced-pH environment [70,74]. In addition, both shell damage and acute acidification decrease the content of propionylcarnitine (PLC), a molecule involved in both carbohydrate and lipid metabolism [75].…”

Spatial Variation of Soft Shell Clam Biochemical Health Status-Impacts on Age Pigments, Glucose and Melatonin Status

“…Hence, the increase of melatonin in tissues could indicate a stress response to protect against contaminants. In addition, circadian rhythms and neurotransmitters could also be negatively impacted by ocean acidification and global warming (Tang et al, 2022), making these endpoints critical physiological targets for ecotoxicological surveys in the future. Indeed, exposure of mussels to acidification and warming led to altered heart rate and the expression of clock gene Per2, Cry and BMALs in addition to neurotransmitters (acetylcholinesterase, acetylcholine, GABA and dopamine).…”

“…Serotonin promotes feeding activity, gonad maturation and spawning in invertebrates. These physiological systems (energy metabolism, neurotransmitters and rhythm regulation) are not only key targets from local sources of xenobiotics but to global stressors such as climate changes and ocean acidification as well (Tang et al, 2022). Previous studies revealed that municipal effluents display serotonergic properties in bivalves (Gagné et al, 2004).…”

MAPK/ERK-PK(Ser11) pathway regulates divergent thermal metabolism of two congeneric oyster species

“… 17 In marine organisms, extensive researches have used PK expression or enzyme activity as important indicators to measure stress tolerance and limits. 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 Furthermore, PK has been reported to be influenced by phosphorylation modifications in human cells. For example, phosphorylation of PKM2 at the Tyr105 site by FGFR1 26 or CDK6 27 disrupts the binding of PKM2 cofactor fructose-1,6-bisphosphate, inhibiting the formation of active tetrameric PKM2.…”