Roundabout signaling pathway involved in the pathogenesis of COPD by integrative bioinformatics analysis
Authors Lin YZ, Zhong XN, Chen X, Liang Y, Zhang H, Zhu DL
Received 17 May 2019
Accepted for publication 22 August 2019
Published 18 September 2019 Volume 2019:14 Pages 2145—2162
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Prof. Dr. Chunxue Bai
Yuan-Zhen Lin, Xiao-Ning Zhong, Xin Chen, Yi Liang, Hui Zhang, Dong-Lan Zhu
Department of Respiratory Medicine, The First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, People’s Republic of China
Correspondence: Xiao-Ning Zhong
Department of Respiratory Medicine, The First Affiliated Hospital, Guangxi Medical University, No. 6, Shuangyong Road, Nanning, Guangxi 530021 People’s Republic of China
Tel +86 771 535 1176
Fax +86 771 535 1176
Purpose: To explore the potential mechanism underpinning the development of chronic obstructive pulmonary disease (COPD) and to investigate the role of the Roundabout signaling pathway in COPD.
Methods: Three microarray datasets (GSE1650, GSE38974 and GSE76925) including 139 cases of severe COPD and 52 cases of normal smokers without carcinoma, were integrated to screen differentially expressed genes (DEGs) using bioinformatics methods. Gene ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of the DEGs were performed by a DAVID online tool. Finally, a cigarette smoke (CS)- induced emphysema mice model was established, the lung mRNA expression levels of genes associated with Slit guidance ligand 2 (SLIT2) -Roundabout (ROBO) signaling pathway were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and the protein level of SLIT2 was examined by immunohistochemistry staining.
Results: A total of 315 DEGs were identified in three databases. GO and KEGG pathway analyses suggested that the inflammatory response, extracellular matrix disassembly, immune response, the apoptotic signaling pathway, ubiquitination and the Roundabout signaling pathway all together were involved in the development of COPD. The genes SLIT2 and ROBO2 were decreased in patients with COPD and these decreases were significantly negatively correlated with the disease stages of COPD. Consistently, the mRNA expression levels of SLIT2, ROBO1 and ROBO2, and the protein level of SLIT2 were revealed to be lower in the lungs of CS-induced emphysema mice compared with the air-exposed control mice. In addition, the SLIT2 protein level was negatively associated with alveolar mean linear intercept.
Conclusion: Integrated bioinformatics analysis may provide novel insights into the complicated pathogenesis of COPD, and to the best of our knowledge, this study is the first to provide evidence to suggest that the Roundabout signaling pathway may be involved in the pathogenesis of COPD.
Keywords: chronic obstructive pulmonary disease, GEO database, roundabout signaling pathway, SLIT2, ROBO