Hepatic lipid metabolomics in response to heat stress in local broiler chickens breed (Huaixiang chickens)

Abstract

High-temperature environment-induced heat stress (HS) is a hazard environmental element for animals, leading to dramatic changes in physiological and metabolic function. However, the metabolomic-level mechanisms underlying lipid metabolism in liver of slow-growing broilers are still obscure. The present study investigated the effects of HS on hepatic lipidomics in Chinese indigenous slow-growing broilers (Huaixiang chickens). The study includes two treatments, each treatment had 5 replicates with 4 broilers per cage, where a total of 40 eight-week-old female Huaixiang chickens (average initial body weight of 840.75 ± 20.79 g) were randomly divided into normal temperature (NT) and HS groups for 4 weeks, and the broilers of NT and HS groups were exposed to 21.3 ± 1.2℃ and 32.5 ± 1.4℃ respectively. The relative humidity of the two groups was maintained at 55%-70%. The liquid chromatography-mass spectrometry (LC-MS)-based metabolomics were conducted to evaluate the changes in hepatic lipidomics of broilers. The results showed that there were 12 differential metabolites between the two treatments. Compared with the NT group, HS group reduced the levers of hepatic phosphatidylcholine (PC) (16:0/16:0), PC (16:0/18:2), triglyceride (TG) (16:0/16:1/18:1), TG (18:0/18:1/20:4) (VIP > 1 and p < 0.05), while increased PC (18:1/20:3), PC (18:0/18:1), PC (18:1/18:1), PC (18:0/22:5), dimethyl-phosphatidyl ethanolamine (dMePE) (14:0/18:3), dMePE (18:0/18:1) and dMePE (16:0/20:3) levels (Variable Importance in the Projection; VIP > 1 and p < 0.05). In addition, according to the analysis of metabolic pathway, the pathways of linoleic acid, alpha-linolenic acid, glycerolipid and glycerophospholipid metabolism were involved in the effects of HS on hepatic lipid metabolism of broilers (p < 0.05). In conclusion, HS altered the hepatic lipid metabolism mainly through linoleic acid, alpha-linolenic acid, glycerolipid and glycerophospholipid metabolism pathway in indigenous broilers. These findings provided novel insights into the role of HS on hepatic lipidomics in Chinese indigenous broiler chickens.

Keywords: heat stress; indigenous broilers; lipid metabolomics; liver.

FIGURE 1

Score plot of projections to latent structures discriminant analyses (PLS‐DA) derived from the LC‐MS profiles of hepatic samples obtained from HS group and NT group. (a) Positive mode (pos) and (b) negative mode (neg). (Blue) NT group and (Green) HS group

FIGURE 2

Score plot of orthogonal projections to latent structures discriminant analyses (OPLS‐DA) derived from LC‐MS profiles of hepatic samples obtained from HS group and NT group. (a) Positive mode (pos) and (b) negative mode (neg). (Blue) NT group and (Green) HS group

FIGURE 3

Schematic overview of alpha‐Linolenic acid metabolic pathway and some related metabolites in heat‐stressed broilers. Red, metabolites in HS group versus NT group upregulation

FIGURE 4

Schematic overview of glycerolipid metabolic pathway and some related metabolites in heat‐stressed broilers. Blue, metabolites in HS group versus NT group downregulation

FIGURE 5

Schematic overview of glycerophospholipid metabolic pathway and some related metabolites in heat‐stressed broilers. Red, metabolites in HS group versus NT group upregulation

FIGURE 6

Schematic overview of linoleic acid metabolic pathway and some related metabolites in heat‐stressed broilers. Red, metabolites in HS group versus NT group upregulation