Integrated transcriptomic and metabolomic analysis of rat serum to investigate potential target of puerarin in the treatment post-traumatic stress disorder

BACKGROUND: Puerarin is a root extract of Pueraria lobate that can alleviate the behavioral disorders and could be therapy for post-traumatic stress disorder (PTSD). However, the underlying mechanism of puerarin in PTSD is unclear, so, we hypothesized that integration of its metabolomic and transcriptomic profiles in rat serum could help to identify the mechanisms of the protective action of puerarin. METHODS: We used the single prolonged stress procedure to establish a model of PTSD in rats and then subjected them to treatment with or without puerarin. Serum metabolomics and transcriptomics were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry and mRNA sequencing. The differential metabolites were evaluated by multivariate analysis, and Bayes discriminant analysis and receiver operator characteristic (ROC) analysis were used to discover potential diagnostic or therapeutic biomarkers. Transcriptomic data were obtained from mRNA sequencing, and we identified the key target genes of puerarin in the treatment of PTSD by integrated analysis of bioinformatics, real-time reverse transcription-polymerase chain reaction (RT-PCR) and data mining. Finally, an integrative analysis of the different metabolites and differentially expressed genes was performed using MetaboAnalysis to investigate the possible molecular mechanisms. RESULTS: The metabolomics analysis showed that 17 dysregulated metabolites in PTSD were reversed by puerarin treatment, and daidzein, 3-succinoylpyridine, 5-(2,5-dihydroxyhexyl) oxolan-2-one and elaidic acid were identified as potential biomarkers for the treatment and diagnosis of PTSD. Transcriptomics analysis showed that dysregulation of 99 genes in PTSD was reversed by puerarin treatment, and further revealed that CD36 molecule (CD36), HBS1-like translational GTPase (HBS1L), CD59 molecule (CD59) and dynein cytoplasmic 1 heavy chain 1 (DYNC1H1) were not only key targets for puerarin’s action in the treatment of PTSD but also potential biomarkers for the diagnosis and treatment of PTSD. Finally, integrated analysis of the metabolomic and transcriptomic data revealed that puerarin treatment for PTSD was mainly regulated by the metabolic pathways of one carbon pool by folate, synthesis and degradation of ketone bodies, and antigen processing and presentation. CONCLUSIONS: Our results are a new genetic insight into the mechanism of action of puerarin in PTSD treatment. We identified four metabolites and four genes that might be considered as novel biomarkers for the diagnosis and treatment of patients with PTSD.