Discovery and validation of extracellular/circulating microRNAs during idiopathic pulmonary fibrosis disease progression.
BACKGROUND
Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial lung disease of unknown etiology that is currently untreatable. In this study we aim to characterize the potential of extracellular/circulating microRNAs (miRNAs) in serum as biomarkers for IPF.


METHODS
Total serum RNAs were isolated from serum from healthy control subjects (n=12), rapid progressive (n=12) and slowly progressive IPF patients (n=12). Serum RNA was analyzed by using TaqMan microRNA assays containing probes for 366 human miRNAs, and selected findings were validated with quantitative RT-PCR. Target prediction and pathway analysis on the significant differential miRNAs were performed using DIANA-mirPath.


RESULTS
We found 47 significantly differentially expressed serum miRNAs (p<0.05) in rapid progressive or slowly progressive IPF patients compared to healthy controls, including 21 up-regulated miRNAs and 26 down-regulated miRNAs. Bioinformatic analysis by DIANA-mirPath demonstrated that 53 KEGG biological processes were significantly enriched (p < 0.05, FDR corrected) among differentially expressed serum miRNAs, including TGF-beta signaling pathway (p < 0.0001), MAPK signaling pathway (p < 0.0001), PI3K-Akt signaling pathway (p < 0.0001), Wnt signaling pathway (p < 0.0001), HIF-1 signaling pathway (p < 0.0001), Regulation of actin cytoskeleton (p < 0.0001), Jak-STAT signaling pathway (p < 0.0001), Notch signaling pathway (p < 0.0001), and Cytokine-cytokine receptor interaction (p = 0.0062). We further validated six miRNAs (miR-21, miR-199a-5p, miR-200c, miR-31, let-7a, and let-7d) for further validation using an independent cohort of 20 rapid progressive IPF, 24 slowly progressive IPF patients and 20 healthy controls. In agreement with the preliminary data from miRNA assay, miR-21, miR-199a-5p, and miR-200c were significantly increased in serums of IPF patients while miR-31, let-7a, and let-7d were significantly under expressed in serums of IPF patients compared to healthy controls.


CONCLUSIONS
These studies demonstrated that extracellular/circulating miRNAs in serum could be potentially served as novel regulators influencing disease progression of IPF.
Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
Guanghai
G
Yang
Oncology Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China.
Lin
L
Yang
Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
Wendong
W
Wang
Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China.
Jiashun
J
Wang
Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province, China. Electronic address: bgjjw@163.com.
Jianjun
J
Wang
Department of Surgery, Washington University School of Medicine, St. Louis 63110, MO, USA. Electronic address: Xuzhonping@gmail.com.
Zhongping
Z
Xu
D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D053858:Metabolic Networks and Pathways / Q000235:genetics; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D012720:Severity of Illness Index; D015398:Signal Transduction
D015415:Biomarkers; C533896:MIRN200 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C531408:mirn199 microRNA, human
Idiopathic pulmonary fibrosis; MicroRNA; Serum