Differential protein expression profile in the liver of pikeperch (Sander lucioperca) larvae fed with increasing levels of phospholipids

Abstract

A comparative proteomic approach was used to assess the protein expression profile in the liver of 34days old pikeperch larvae fed from day 10 post hatching, with three isoproteic and isolipidic formulated diets varying by their phospholipid (PL) contents (% dry diet weight): 1.4% (PL1), 4.7% (PL5) and 9.5% (PL9). Using 2D-DIGE minimal labelling of liver extracts, we were able to show 56 protein spots with a differential intensity (p<0.05) depending on the dietary PL content. Among these spots, 11 proteins were unambiguously identified using nanoLC-MS/MS tandem mass spectrometry. In the PL9 larvae, our results indicate that the glycolytic pathway could be down-regulated due to the under-expression of the fructose biphosphate aldolase B and the phosphoglucomutase 1. Meanwhile, propionyl coenzyme A carboxylase (a gluconeogenic enzyme) was under-expressed. In addition, another gluconeogenic and lipogenic enzyme, pyruvate carboxylase, was identified in 3 different spots as being under-expressed in fish fed with the intermediate PL level (PL5). A high PL content increased the expression of sarcosine dehydrogenase, an enzyme involved in methionine metabolism, along with vinculin, a structural protein. Moreover, several stress proteins (glutathione S-transferase M, glucose regulated protein 75 and peroxiredoxin-1) were modulated in response to the dietary PL level and fatty acid composition. In the larvae fed with the lowest dietary PL content (PL1), over-expression of both GSTM and GRP75 might indicate a cellular stress in this experimental treatment, while the under-expression of Prx1 might indicate a lower defence against oxidative stress. In conclusion, this nutriproteomic approach showed significant modifications of protein expression in the liver of pikeperch larvae fed different PL contents, highlighting the importance of these nutrients and their influence on metabolism processes and on stress response.

Molecular characterization and expression analysis of six peroxiredoxin paralogous genes in gilthead sea bream (Sparus aurata): Insights from fish exposed to dietary, pathogen and confinement stressors

“…In Gadus morhua, substitution of fish meal by soybean meal produced no effect on the expression of PRDX-4 in the intestine [68]. In Sander lucioperca larvae, high levels of phospholipids increased the expression of hepatic PRDX1, whereas low levels decreased it [69]. In the present model, which induced a deficiency in EFAs, though dietary intervention did not alter the hepatic expression, it produced a marked down regulation in the head kidney.…”

Influence of dietary zinc on muscle composition, flesh quality and muscle antioxidant status of young grass carp (Ctenopharyngodon idellaVal.)

“…The culture of fish is highly dependent on artificial diets, which is formulated according to the nutritional requirements of this species (Hamza, Silvestre, Mhetli, Khemis, Dieu, Raes, Cahu & Kestemont 2010 . The dietary Zn requirement was also evaluated in juvenile grass carp (Liang et al 2012).…”

The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine

“…The culture of grass carp relies on artificial diets covering the requirements of this species [23]. The requirement of dietary valine has been determined in juvenile grass carp [24] but may vary with the growth stage of the fish [25,26].…”