Biology subjects

Veron, V.

Publications and source records attributed to Veron, V..

3 recordsLinked to original sources

bioRxiv2024

Chaperone-Mediated Autophagy in Fish: A Key Function Amid a Changing Environment

Chaperone-Mediated Autophagy (CMA) is a major pathway of lysosomal proteolysis critical for cellular homeostasis and metabolism. While extensively studied in mammals, CMAs existence in fish has only been confirmed recently, offering exciting insights into its role in species facing environmental stress. Here, we shed light on the existence of 2 genes encoding the CMA-limiting factor Lamp2A (lysosomal associated membrane protein 2A) in rainbow trout (RT, Oncorhynchus mykiss), revealing distinct expression patterns across various tissues. Notably, RT lacking the most expressed Lamp2A exhibit profound hepatic proteome disturbances during acute nutritional stress, underscoring its pivotal role as a guardian of hepatic proteostasis. Building upon these findings, we introduce and validate the CMA activation score as a reliable indicator of CMA status, providing a valuable tool for detecting cellular stress in fish under environmental threats. Overall, our study offers new perspectives into understanding CMA from evolutionary and environmental contexts. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=70 SRC="FIGDIR/small/585855v1_ufig1.gif" ALT="Figure 1"> View larger version (10K): org.highwire.dtl.DTLVardef@de3c56org.highwire.dtl.DTLVardef@4b711forg.highwire.dtl.DTLVardef@efb4a1org.highwire.dtl.DTLVardef@13be9cc_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2023

High carbohydrate to protein ratio promotes changes in intestinal microbiota and host metabolism in rainbow trout (Oncorhynchus mykiss) fed plant-based diet.

To ensure the sustainability of aquaculture, it is necessary to change the "menu" of carnivorous fish such as rainbow trout from a fish-based diet to one with plant-based ingredients. However, there is a major problem with the growth performance decrease of fish fed with a 100% plant-based diet due to the reduction in feed intake and feed efficiency. For the first time, we incorporated high levels of digestible carbohydrates (high-starch diet) in a 100% plant-based diet during a 12-week feeding trial in order to improve protein utilization for growth (protein sparing effect) and reduce nitrogen waste. We measured the changes in the intestinal microbiota, Short-Chain Fatty Acid (SCFA) levels and metabolic responses in liver. Dietary carbohydrates had a strong effect on alpha and beta diversity and abundance of 12 genera, including Ralstonia and Bacillus in digesta associated microbiota whereas mucosa associated microbiota was less affected. The change in microbial diversity might be linked to the change observed in SCFA production. High levels of Mycoplasma were observed in the intestinal mucosa. Overall, hepatic gene expression was significantly altered by the CHO/protein ratio. Up-regulation of genes involved in glucose metabolism (gcka, gckb, g6pcb2a), down-regulation of genes involved in lipid metabolism (hadh, acox3, srebp2a, and cyp51a) were associated with higher enzymatic activities (such as glucokinase or pyruvate kinase) and higher glycogen levels in the liver, suggesting adequate adaptation to diet. Interestingly, strong correlations were observed between abundances of certain bacterial OTUs and gene expression in the liver. The inclusion of digestible carbohydrates in combination with a 100% plant-based diet, could be a promising way to improve and reduce the use of plant proteins in rainbow trout. In addition, the relationship between intestinal microbiota and host metabolism needs further investigation to better understand fish nutrition.

molecular biology↗

bioRxiv2023

Rainbow trout neomales broodstocks are able to eat and use a high carbohydrate diet during a complete reproductive cycle

The main challenge of the aquaculture relies on the shift from fishmeal to more sustainable ingredients. Interest on carbohydrates has growing rapidly as they are considered as promising resources, providing energy and preserving proteins for growth. However, rainbow trout is considered as a poor user of carbohydrates displaying postprandial hyperglycaemia and impaired growth performances when fed with diets containing more than 20% of carbohydrates. Nonetheless, recent evidence points that broodstocks could be better user of high carbohydrate diet compared to juveniles. However, no study investigates how sex-reversed females - neomales - eat, grow and reproduce under a high carbohydrate diet. Our objective was thus to assess growth and reproductive performances of neomales fed with a high carbohydrate diet during an entire reproductive cycle. Our results demonstrate that neomales display specific metabolic and physiological changes when fed with a high carbohydrate diet compared to both females and males broodstocks as well as compared to juveniles. Altogether, our data demonstrate the critical relevance to formulate specific diets in accordance with specificities of each type of broodstocks (i.e. females, males and neomales).

molecular biology↗