Integrated Transcriptomics and Proteomics Identified CMPK1 as a Potential Biomarker for Type 2 Diabetes Mellitus

Aim/Introduction: Type 2 diabetes mellitus (T2DM) is one of the most frequent and widespread disease in the world.Obesity is the most significant predictor of T2DM, but the exact mechanism how obesity promotes T2DM remains unknown. Finding specific biomarkers to assist in diagnosing and treating patients with obese and T2DM is critical. Materials and Methods: We collected liver tissues from obesity patients with and without T2DM for proteomic sequencing and immunohistochemistry assay. Analysis Gene Ontology(GO) enrichment, Kyoto Encyclopedia of Genes and Genomes(KEGG), and protein interaction network (PPI) were performed on the parameters and data derived from the Tandem Mass Tags(TMT)-based proteomics analysis of liver tissues. Transcriptome data were downloaded from the Gene Expression Omnibus(GEO)website and genes that are deferentially expressed in both transcriptome and proteome were selected. Results: We identified 140 deferentially expressed proteins from proteomic sequencing. Six biomarkers were deferentially expressed in both proteome and transcriptome with consistent changes in direction. The protein-protein interaction (PPI) analysis suggested CMPK1, the expression with greatest difference, was the core protein among the six biomarkers. Immunohistochemistry validated CMPK1 was upregulated significantly in the liver tissues of T2DM patients. The correlation analysis revealed that the expression of CMPK1 was significantly associated with key molecules in T2DM-related pathways at both protein and transcriptome levels. Conclusion and Novelty: Our study showed CMPK1 was upregulated in the liver of T2DM patients and provides a possible new target for screening and diagnosing T2DM in patients with obese and a novel theoretical basis for the pathophysiological mechanism of obesity-related metabolic diseases.