Prenatal exposure to maternal low or high protein diets induces modest changes in the adipose tissue proteome of newborn piglets
Résumé
The possibility that maternal diets during gestation could affect growth and tissue development of offspring and program their later phenotype is an emerging challenge in pig production. The objective of the current study was to investigate the effects of contrasted protein levels in diets of pregnant sows on the proteomic features of subcutaneous adipose tissue (SCAT) of the offspring at birth and its possible persistence later in age. Sows were fed control (Con), low (LP), or high protein (HP) diets throughout gestation. A subset of piglets was killed at 1 d of age for SCAT sampling. The remaining piglets were cross-fostered to nonexperimental sows during lactation. They were fed standard diets during postweaning and fattening periods until 186 d of age. Modifications in SCAT protein abundance shortly after birth were investigated by 2-dimensional gel electrophoresis followed by mass spectrometry. A total of 65 spots were found differentially expressed (P <= 0.10) in SCAT of 1-d-old experimental piglets vs. Con piglets. Proteins with a greater abundance in LP piglets compared with Con piglets were involved in pathways related to glucose and fatty acid metabolisms, lipid transport, and regulation of apoptosis. Upregulation of 5 proteins representative of these biological pathways in LP group vs. Con group were further validated (P < 0.05) by Western blot analyses. Furthermore, the specific activity of the key lipogenic enzyme fatty acid synthase was found greater (P = 0.06) in SCAT of 1-d-old LP piglets than in Con piglets. The main changes evidenced in SCAT of HP piglets compared with Con animals at 1 d of age rather concerned proteins putatively involved in AA metabolism or in protein turnover. Adipose tissue contents in some proteins that had displayed a greater (P = 0.10) abundance in experimental pigs compared with Con at d 1 (e.g., transaldolase, annexin II, and apolipoprotein A4) were, however, similar (P > 0.10) in the 3 groups at d 186 of age. Enolase 1 has less abundance (P < 0.05) in LP pigs compared with Con pigs at this stage. In conclusion, the proteomics tool has allowed the identification of early changes in various molecular pathways of SCAT in response to the levels of maternal protein supply during gestation.