The alteration of lipidomic profiles correlates with gene expression and physiological parameters of dairy cows during the periparturient period

Dairy cows undergo physiological adaptions during the periparturient period, including adipose tissue mobilization and the alteration of transcriptional factors in the liver and adipose tissue. During this period, overfeeding may alter lipidomic profiles in the peripheral tissues and subsequently influence the lipid and glucose metabolisms via the regulation of insulin action. Our aim was to study the interactions between the lipidomic and gene expression profiles and physiological parameters of dairy cows during the periparturient period. The experimental animals consisted of 16 multiparous cows in two groups. Controlled-energy feeding (100% of energy requirement of pregnant dairy cows) and high-energy feeding (142% of energy requirement of pregnant dairy cows) were applied to each group. The lipids in the subcutaneous adipose tissue and liver were identified and quantified using liquid chromatography-mass spectrometry based lipidomics from the samples collected at 8 days prepartum and 9 days postpartum. The identified lipid classes included ceramide (Cer), triglyceride (TG), diacylglycerol (DG), phosphatidylcholines (PC), phosphatidyl ethanolamine (PE), and sphingomyelin (SM). Spearman correlation analyses were conducted between lipids concentration, and the expression level of key factors in energy metabolism and physiological measurements.In the adipose tissue, the prepartal expression of insulin receptor 1 (IRS1) was negatively correlated with Cer (P<0.05) but positively correlated with TG (P<0.05). In the liver, prepartal glucose transporter type 4 (GLUT4) expression was negatively correlated with Cer (P<0.05) and SM (P<0.05). Moreover, prepartal liver Cer had a tendency to negatively correlate (P<0.10) with mitochondrial carnitine palmitoyltransferase 1 (CPT1) expression. However, Cer presented no positive correlation with plasma non-esterified fatty acid (NEFA) concentration neither in liver nor adipose tissue, suggesting that liver Cer relates to hepatic fatty acid oxidation but not to liver fatty acid uptake. Interestingly, there was a tendency of positive correlations (P<0.10) between prepartal dry matter intake, energy balance, or metabolic energy intake with Cer, PC, and PE, though these lipids displayed no relationship with body fatness in that time period.The alteration of lipidomic profiles caused by overfeeding prepartum shows interactions with changes of expression profile of proteins involved in lipid metabolism and insulin signalling in dairy cows during the periparturient period.