The role of PCD-related circRNA/miRNA/mRNA regulatory network in the HF with AF
Background: Atrial fibrillation (AF), a critical health and economic issue is common in patients with heart failure (HF). Meanwhile, HF is a leading complication of nonvalvular atrial fibrillation (NVAF), and the presence of both conditions is associated with worsen outcomes. Accumulating evidence has indicated that messenger RNA (mRNA), microRNA (miRNA) and circular RNA (circRNA) play vital roles in the occurrence and progression of HF and AF. However, the underlying molecular mechanism of HF with AF remains elusive. We aimed to investigate the role of circRNA/miRNA/mRNA regulatory network in HF with AF through High-throughput sequencing and bioinformatics analysis. Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from 4 patients who had heart failure with atrial fibrillation (HF /AF group) and 4 matched healthy subjects. RNA sequencing was performed to get circRNAs and mRNAs. miRNAs were obtained through miRanda and HMDD databases. qRT-PCR was used to verify our data. R software was employed for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The PPI network was completed using STRING. Immune infiltration analysis was performed using cibersort method. The ceRNA network of circRNA/miRNA/mRNA was constructed by Cytoscape.  Results: Differential expression analysis showed that circRNAs (137 upregulated and 31 downregulated) and mRNAs (534 upregulated and 255 downregulated) were considered as significantly different between HF with AF group and control group. Immune infiltration analysis demonstrated that macrophages were obviously upregulated and mast cells were significantly downregulated in PBMCs of the HF/AF group. GO and KEGG analyses showed that HF with AF-related mRNAs were abundant in the pathway of programmed cell death (PCD) and myocardial remodeling. So we confirm that hsa_circ_0047870/hsa-miR-34a-5p/SMPD1, hsa_circ_0127340/hsa-miR-192-3p/FBXW5, hsa_circ_0002484/hsa-miR-26b-3p/PYCARD, hsa_circ_0047870/hsa-miR-20b-3p/HTRA2 and hsa_circ_0004027/hsa-miR-26a-5p/HIF1A ceRNA axes could promote the development of HF with AF through the PCD-related pathway.  Conclusions: We suggested that the imbalance of immune cell composition in PBMCs may play an initial role in the progression of HF with AF. The PCD-related ceRNA regulatory network may be the potential therapeutic target in the occurrence and progression of HF with AF. The circRNAs could serve as novel diagnostic markers. Overall design: Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from 4 patients who had heart failure with atrial fibrillation (HF /AF group) and 4 matched healthy subjects. RNA sequencing was performed to get circRNAs and mRNAs. miRNAs were obtained through miRanda and HMDD databases. qRT-PCR was used to verify our data. R software was employed for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The PPI network was completed using STRING. Immune infiltration analysis was performed using cibersort method. The ceRNA network of circRNA/miRNA/mRNA was constructed by Cytoscape.