High-Temperature Stress Effect on the Red Cusk-Eel (Geypterus chilensis) Liver: Transcriptional Modulation and Oxidative Stress Damage

Abstract

Environmental stressors, such as temperature, are relevant factors that could generate a negative effect on several tissues in fish. A key fish species for Chilean aquaculture diversification is the red cusk-eel (Genypterus chilensis), a native fish for which knowledge on environmental stressors effects is limited. This study evaluated the effects of high-temperature stress on the liver of red cusk-eel in control (14 °C) and high-temperature (19 °C) groups using multiple approaches: determination of plasmatic hepatic enzymes (ALT, AST, and AP), oxidative damage evaluation (AP sites, lipid peroxidation, and carbonylated proteins), and RNA-seq analysis. High-temperature stress generated a significant increase in hepatic enzyme activity in plasma. In the liver, a transcriptional regulation was observed, with 1239 down-regulated and 1339 up-regulated transcripts. Additionally, high-temperature stress generated oxidative stress in the liver, with oxidative damage and transcriptional modulation of the antioxidant response. Furthermore, an unfolded protein response was observed, with several pathways enriched, as well as a heat shock response, with several heat shock proteins up regulated, suggesting candidate biomarkers (i.e., serpinh1) for thermal stress evaluation in this species. The present study shows that high-temperature stress generated a major effect on the liver of red cusk-eel, knowledge to consider for the aquaculture and fisheries of this species.

Effects on growth performance and immunity of Monopterus albus after high temperature stress

“…As the most vital organ in M. albus , the liver is directly communicates with the heart, intestine and gallbladder, related to growth and development, substance metabolism, detoxification, and hematopoiesis and can also reflect the physiological, pathological, and nutritional status of M. albus . Excessive temperature can also cause structural damage to fish, especially the liver, which has been confirmed in many species ( Dettleff et al, 2022 ; E. Liu et al, 2022 ; Zhao et al, 2022 ). Excessive temperature will also stimulate the production of endogenous reactive oxygen species (ROS) ( Wiens et al, 2017 ).…”

High-Temperature Stress Induces Autophagy in Rainbow Trout Skeletal Muscle

“…Autophagy is triggered by various stimuli, including lack of nutrients, reactive oxygen species (ROS), endoplasmic reticulum stress, and the presence of microorganisms [35]. Although various reports in teleosts have investigated autophagy in processes such as reproduction [36][37][38], hepatic metabolism [13,39,40], and immune response to infections [41,42], there is limited evidence of the role of autophagy in skeletal muscle catabolism. Studies of fine flounder (Paralichthys adspersus) have shown that stress induced by high-density farming can upregulate the expression of genes involved in the autophagy process, which is believed to be protective mechanism against apoptosis regulated by the ubiquitin-proteasome pathway [43].…”

“…In a recent study conducted on a marine teleost species, red cusk-eel (Genypterus chilensis), it was found that thermal stress leads to skeletal muscle oxidation and atrophy [12]. Additionally, RNA-Seq assays revealed that high-temperature stress induced the expression of various autophagyassociated genes in the liver of the species [13]. Autophagy is a fundamental cellular mechanism that plays an essential role in energetic catabolism and the lysosome-mediated degradation of cell components.…”

Transcriptome and Genome Analyses Applied to Aquaculture Research

“…The impact of different stressors was analyzed in different works included in this Special Issue. Dettleff et al [ 11 ] evaluated the effects of high-temperature stress on the liver of red cusk-eel ( Genypterus chilensis ) through different approaches, including RNA-Seq analysis. The results revealed that this stressor induced oxidative damage in the liver and affected the expression of a multitude of genes, which are mainly involved in the unfolded protein response, heat shock response, and oxidative stress, among others, providing a rich source of information to be considered for the aquaculture and fisheries industry of this species under a climate change scenario [ 11 ].…”

“…Dettleff et al [ 11 ] evaluated the effects of high-temperature stress on the liver of red cusk-eel ( Genypterus chilensis ) through different approaches, including RNA-Seq analysis. The results revealed that this stressor induced oxidative damage in the liver and affected the expression of a multitude of genes, which are mainly involved in the unfolded protein response, heat shock response, and oxidative stress, among others, providing a rich source of information to be considered for the aquaculture and fisheries industry of this species under a climate change scenario [ 11 ]. Interestingly, Naya-Catalá et al [ 12 ] found that gilthead sea bream ( Sparus aurata ) juveniles acclimated for 45 days to mild-hypoxia and then returned to normoxia showed an increased contribution of lipid metabolism to the whole energy supply to preserve the aerobic energy production, a better swimming performance regardless of changes in feed intake, as well as reduced protein turnover and improved anaerobic fitness with the restoration of normoxia.…”