Objectives: Korean Medicine (KM) pattern identification comprehensively evaluates the constitution in a healthy state and symptoms in a diseased state. Multi-omics, which enables the integration of complex data, is an appropriate methodology for KM pa...
Objectives: Korean Medicine (KM) pattern identification comprehensively evaluates the constitution in a healthy state and symptoms in a diseased state. Multi-omics, which enables the integration of complex data, is an appropriate methodology for KM pattern analysis. Cold-heat pattern identification (CHPI) is fundamental in KM diagnosis, making it worthy of comparative analysis. However, no studies have explored the differences between cold pattern (CP) and heat pattern (HP) in healthy individuals, not diseased, using omics. This study aimed to identify genes and pathways differentially expressed according to the CHPI of healthy individuals, focusing on cell metabolism and exploring the various components of clinical phenotypes beyond the limits of single-component indicator analysis.
Methods: A study using a whole-genome transcriptome analysis of whole blood samples was conducted, including 25 healthy participants categorized into the CP (13) and HP (12) groups using a Cold-Heat Pattern Identification Questionnaire (CHPIQ) based on usual symptoms. After venous blood samples were collected from participants, total RNA extraction and sequencing were performed. RNA sequencing (RNA-seq) data were used to analyze the differentially expressed genes (DEGs) between CP and HP in males and females separately, and the results were applied to a volcano plot. Bioinformatic analysis [visualization method] was conducted, including gene set enrichment analysis (GSEA) with Gene Ontology (GO) biological process [network plot], transcriptome profiling on oxidative phosphorylation (OxPhos) [circular heatmap], energy-associated pathways using mitochondria-associated gene lists [heatmap], and pathway enrichment analysis. Pathway enrichment analysis included transcriptome profiling on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway [mapping] and GSEA with MitoCarta3.0 [lollipop plot].
Results: In the volcano plots for DEG analysis, gene expression levels between the CP and HP groups were significantly different in both males and females (cut-off values: | log2 (fold-change) (lfc) | > 0.3, p < 0.05). In the network plots for GSEA with GO biological process, most of the metabolic process-associated gene sets formed the largest cluster in both males and females (gene set registering values: p < 0.05, false discovery rate [FDR] q < 0.5). Females demonstrated pronounced up-regulation of gene expression in the CP and an apparent difference between the CP and HP, especially in the transcriptome profiling of the OxPhos pathway. Gene expression in the nucleotide synthesis pathway was up-regulated in transcriptome profiling of CP females. Additionally, the gene expression of more calcium-associated pathways was down-regulated in CP and up-regulated in HP of males in lollipop plots for GSEA with MitoCarta3.0.
Conclusion: According to the CHPI, there are differences in the transcriptome profiles associated with energy metabolism and mitochondria in healthy individuals. This study further specifies the diagnostic value of CHPI. These results enable future multi-omics studies on clinically available and objective diagnostic indicators, such as constitutional factors, through single-cell analysis and in-silico metabolic flux simulation.
Key words: Multi-omics; Transcriptome; Cold-heat pattern identification; Energy metabolism; Mitochondria; Oxidative phosphorylation.