Effect of Curcumin on Hepatic mRNA and lncRNA Co-Expression in Heat-Stressed Laying Hens

Abstract

Heat stress is an important factor affecting poultry production; birds have a range of inflammatory reactions under high-temperature environments. Curcumin has anti-inflammatory and antioxidant effects. The purpose of this experiment was to investigate the effect of dietary curcumin supplementation on the liver transcriptome of laying hens under heat stress conditions. In the animal experiment, a total of 240 Hy-Line brown hens aged 280 days were divided randomly into four different experimental diets with four replicates, and each replicate consisted of 15 hens during a 42-D experiment. The ambient temperature was adjusted to 34 ± 2 °C for 8 h per day, transiting to a range of 22 °C to 28 °C for the remaining 16 h. In the previous study of our lab, it was found that supplemental 150 mg/kg curcumin can improve production performance, antioxidant enzyme activity, and immune function in laying hens under heat stress. To further investigate the regulatory mechanism of curcumin on heat stress-related genes, in total, six samples of three liver tissues from each of 0 mg/kg and 150 mg/kg curcumin test groups were collected for RNA-seq analysis. In the transcriptome analysis, we reported for the first time that the genes related to heat stress of mRNA, such as HSPA8, HSPH1, HSPA2, and DNAJA4, were co-expressed with lncRNA such as XLOC010450, XLOC037987, XLOC053511, XLOC061207, and XLOC100318, and all of these genes are shown to be down-regulated. These findings provide a scientific basis for the possible benefits of dietary curcumin addition in heat-stressed laying hens.

Keywords: RNA-seq; curcumin; heat stress; laying hens; lncRNA; transcriptome analysis.

Figure 1

The typology and number of AS events. The x-axis stands for the typology of the AS event, SE is skipped exon, RI is retained intron, MXE is mutually exclusive exon, A5SS is alternative 5′ splice site, and A3SS is alternative 3′ splice site. The y-axis stands for the number of AS events.

Figure 2

Venn diagram of lncRNA filtration. CPC2 is a Coding Potential Calculator. PFAM is the Protein Families Database. phyloCSF is a Phylogenetic Codon Substitution Frequencies. CNCI is the Coding-Non-Coding Index.

Figure 3

(a) Comparison of gene expression levels under the same experimental conditions; (b) the heatmap of the Correlation coefficient between samples.

Figure 4

(a) Differentially expressed lncRNA volcano map; (b) Differentially expressed mRNA volcano map; (c) Differentially expressed lncRNA heat map; (d) Differentially expressed mRNA heat map.

Figure 5

(a) Histogram of GO enrichment of differential expression of lncRNA target genes; (b) Histogram of GO enrichment of differential expression of mRNA target genes. The y-axis presents the number of genes. The x-axis presents the enriched GO terms. BP is biological processes, CC is cellular components, and MF is molecular functions.

Figure 6

(a) KEGG enrichment of differentially expressed lncRNA target gene; (b) KEGG enrichment of differentially expressed mRNA target gene.

Figure 7

Validation of the differentially expressed genes by RT-PCR. IDH1, HSPA8, BAG3, and HSP90AA1 are the differentially expressed mRNAs. LNC_001282, LNC_001848, LNC_004633, and LNC_002246 are the differentially expressed lncRNAs.