Metabolome and transcriptome profiling reveal tRNA-derived small RNAs regulated glutathione metabolism in intrauterine growth-restricted pigs.

Intrauterine growth retardation (IUGR) has become a difficult problem in animal husbandry and is often accompanied by the occurrence of metabolic syndrome. tRNA-derived small RNAs (tsRNAs) are a novel class of regulatory small noncoding RNAs. However, the involvement of tsRNA in regulating the mechanism of IUGR remains unclear. Here, we first characterized the tsRNA expression profiles in the liver of normal pigs and IUGR pigs through high-throughput sequencing. IUGR pigs exhibit significantly increased 17 tsRNA levels including tRF-Ile-GAT, tRF-Pro-TGG, tRF-Leu-CAA and tRF-Ala-TGC etc. Transcriptome sequencing further revealed 1244 upregulated and 762 downregulated differentially expressed genes in IUGR pig liver. Functional enrichment analysis found that DEGs were mainly involved in insulin resistance, metabolic pathways, etc. Metabolomics was performed to determine the metabolic changes between the normal and IUGR pigs. Then, We constructed a potential tsRNA regulatory network involved in metabolic pathways in IUGR pig liver. Moreover, combined metabolome and transcriptome analysis showed a disorder of glutathione metabolism in the IUGR pigs liver. We identified tRF-Ile-GAT as the potential target of interest. NCTC1469 liver cells were used to validate the preliminary function of tRF-Ile-GAT in vitro. Bioinformatics analyses and luciferase reporter assays further revealed that microsomal glutathione S-transferase 1 (MGST1) was the target gene of tRF-Ile-GAT. In addition, tRF-Ile-GAT overexpression inhibited antioxidant gene expression, glutathione and glutathione glutathione S-transferase levels in NCTC1469 cells, while an MGST1 overexpression reversed the above phenomenon. These findings provide new insights into the understanding of the molecular mechanisms of IUGR pathogenesis.