Objective: The aim of the study was to determine the expression profile of long noncoding RNAs (lncRNAs) in CD4⁺ T cells from COPD patients and explore the clinical value of the lncRNAs.
Methods: First, microarray analysis was performed. Differentially expressed lncRNAs were validated by quantitative real-time reverse transcription-PCR (qRT-PCR) in samples from 56 patients with acute exacerbations of COPD (AECOPD), 56 patients with stable COPD, and 35 healthy controls. Meanwhile, the clinical value was tested by receiver operating characteristic curve analysis. The functions of lncRNAs were analyzed by the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes database. The potential target genes that might be regulated by NR-026690 and ENST00000447867 were identified by the lncRNA-mRNA network and competing endogenous RNA network. The transcriptional expression level of rap guanine nucleotide exchange factor 3 (RAPGEF3) was tested by qRT-PCR. The correlation of the expression between NR-026690, ENST00000447867, and RAPGEF3 was analyzed by Spearman’s correlation test.
Results: We found that the relative expression levels of ENST00000447867 and NR-026690 in the CD4⁺ T cells of AECOPD patients were significantly higher than in the stable COPD patients and control subjects by microarray and qRT-PCR validation. The transcriptional expression level of RAPGEF3 in the CD4⁺ T cells was significantly higher in the AECOPD group compared to the control group (P <0.01) and the stable COPD group (P <0.05). RAPGEF3 expression was positively associated with NR-026690 (r =0.4925, P <0.01) and ENST00000447867 (r =0.4065, P <0.01).
Conclusion: NR-026690 and ENST00000447867 might be potential biomarkers for COPD. They might affect RAPGEF3 as miRNA sponges to regulate COPD development.
Keywords: long noncoding RNA, CD4⁺ T cell, chronic obstructive pulmonary disease, RAPGEF3