Background: Acute
myocardial infarction (AMI) is one of the main fatal diseases of
cardiovascular diseases.
Circular RNA (
circRNA) is a
non-coding RNA (ncRNA), which plays a role in
cardiovascular disease as a
competitive endogenous RNA (
ceRNA). However, their role in AMI has not been fully clarified. This study aims to explore the mechanism of
circRNA-related
ceRNA network in AMI, and to identify the corresponding immune infiltration characteristics. Materials and Methods: The
circRNA (GSE160717),
miRNA (GSE24548), and
mRNA (GSE60993) microarray datasets of AMI were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed
circRNAs (DEcircRNAs),
miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) were identified by the "limma" package. After integrating the
circRNA,
miRNA and
mRNA interaction, we constructed a
circRNA-
miRNA-
mRNA network. The "clusterProfiler" package and String database were used for functional enrichment analysis and
protein-
protein interaction (PPI) analysis, respectively. After that, we constructed a
circRNA-
miRNA-hub gene network and validated the
circRNAs and mRNAs using an independent dataset (GSE61144) as well as qRT-PCR. Finally, we used CIBERSORTx database to analyze the immune infiltration characteristics of AMI and the correlation between hub genes and immune cells. Results: Using the "limma" package of the R, 83 DEcircRNAs, 54 DEmiRNAs, and 754 DEmRNAs were identified in the microarray datasets of AMI. Among 83 DEcircRNAs, there are 55 exonic DEcircRNAs. Then, a
circRNA-
miRNA-
mRNA network consists of 21 DEcircRNAs, 11 DEmiRNAs, and 106 DEmRNAs were predicted by the database. After that, 10 hub genes from the PPI network were identified. Then, a new
circRNA-
miRNA-hub gene network consists of 14 DEcircRNAs, 7 DEmiRNAs, and 9 DEmRNAs was constructed. After that, three key
circRNAs (hsa_circ_0009018, hsa_circ_0030569 and hsa_circ_0031017) and three hub genes (BCL6,
PTGS2 and PTEN) were identified from the network by qRT-PCR. Finally, immune infiltration analysis showed that hub genes were significantly positively correlated with up-regulated immune cells (neutrophils, macrophages and plasma cells) in AMI. Conclusion: Our study constructed a
circRNA-related
ceRNA networks in AMI, consists of hsa_circ_0031017/hsa-miR-142-5p/PTEN axis, hsa_circ_0030569/hsa-miR-545/
PTGS2 axis and hsa_circ_0009018/hsa-miR-139-3p/BCL6 axis. These three hub genes were significantly positively correlated with up-regulated immune cells (neutrophils, macrophages and plasma cells) in AMI. It helps improve understanding of AMI mechanism and provides future potential therapeutic targets.