Identification and validation of potential diagnostic signature and immune cell infiltration for NAFLD based on cuproptosis-related genes by bioinformatics analysis and machine learning

Front Immunol. 2023 Sep 26:14:1251750. doi: 10.3389/fimmu.2023.1251750. eCollection 2023.

Abstract

Background and aims: Cuproptosis has been identified as a key player in the development of several diseases. In this study, we investigate the potential role of cuproptosis-related genes in the pathogenesis of nonalcoholic fatty liver disease (NAFLD).

Method: The gene expression profiles of NAFLD were obtained from the Gene Expression Omnibus database. Differential expression of cuproptosis-related genes (CRGs) were determined between NAFLD and normal tissues. Protein-protein interaction, correlation, and function enrichment analyses were performed. Machine learning was used to identify hub genes. Immune infiltration was analyzed in both NAFLD patients and controls. Quantitative real-time PCR was employed to validate the expression of hub genes.

Results: Four datasets containing 115 NAFLD and 106 control samples were included for bioinformatics analysis. Three hub CRGs (NFE2L2, DLD, and POLD1) were identified through the intersection of three machine learning algorithms. The receiver operating characteristic curve was plotted based on these three marker genes, and the area under the curve (AUC) value was 0.704. In the external GSE135251 dataset, the AUC value of the three key genes was as high as 0.970. Further nomogram, decision curve, calibration curve analyses also confirmed the diagnostic predictive efficacy. Gene set enrichment analysis and gene set variation analysis showed these three marker genes involved in multiple pathways that are related to the progression of NAFLD. CIBERSORT and single-sample gene set enrichment analysis indicated that their expression levels in macrophages, mast cells, NK cells, Treg cells, resting dendritic cells, and tumor-infiltrating lymphocytes were higher in NAFLD compared with control liver samples. The ceRNA network demonstrated a complex regulatory relationship between the three hub genes. The mRNA level of these hub genes were further confirmed in a mouse NAFLD liver samples.

Conclusion: Our study comprehensively demonstrated the relationship between NAFLD and cuproptosis, developed a promising diagnostic model, and provided potential targets for NAFLD treatment and new insights for exploring the mechanism for NAFLD.

Keywords: cuproptosis; immune infiltration; immune microenvironment; machine learning; nonalcoholic fatty liver disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Computational Biology
  • Copper
  • Humans
  • Machine Learning
  • Mast Cells
  • Mice
  • Non-alcoholic Fatty Liver Disease* / diagnosis
  • Non-alcoholic Fatty Liver Disease* / genetics

Substances

  • Copper

Grants and funding

This work was supported in part by National key research and development program (2022YFE0131600); National Natural Science Foundation of China (82160500); The 111 Project (D17011); Special project of central government guiding local science and technology development (ZY20198011); Guangxi science and technology base and talent project (GuikeAA21220002); Guangxi Key Research and Development Plan (2018AD03001); Natural Science Foundation of Guangxi (2022GXNSFAA035642); Liuzhou Science and Technology Project (2021CBC0101).