Abstract:

Objective To investigate the role and regulatory mechanism of lnc-NONHSAT074080 on the pathogenesis of rheumatoid arthritis (RA)-related common interstitial pneumonia (UIP). Methods According to whether combined with UIP, patients were divided into the RA pulmonary fibrosis group (n = 4) and the RA control group (n = 4). The long non coding RNA (lncRNA) related RA pulmonary fibrosis was analyzed by Affymetrix gene chip. The bioinformatics analysis was carried out, and lncRNAs with significantly up-regulated expression were verified by real-time auantitative polymerase chain reaction (qPCR). The lncRNA, which was verified by qPCR and showed significantly increased expression in RA pulmonary fibrosis, bioinformatics analysis showed the relationship with the process of pulmonary fibrosis, was selected as the target lncRNA. Then target lncRNA shRNA was constructed，as well as the relationship between the target lncRNA and the target gene was verified by luciferase gene report. Moreover, TGF-β1-induced human embryonic lung fibroblasts were transfected with target lncRNA shRNA. CCK8 was used to detect cell proliferation, and immunofluorescence was used to detect the expression of α smooth muscle actin (α-SMA). qPCR was used to detect the expression of target lncRNA and target genes, and enzyme-linked immunosorbent assay was used to detect the expression of ? collagen and fibronectin in cells. Results There were 192 significant upregulated lncRNA in the whole blood of RA pulmonary fibrosis group compared to the RA control group. qPCR showed that the expression of lnc-NONHSAT074080 in RA pulmonary fibrosis group was significantly increased (P<0.05). Bioinformatics analysis and luciferase gene report showed that lnc-NONHSAT074080 was related to fibrosis progression. The possible target gene including ARL6IP4 may play a role through fibrosis related pathway such as mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT) signal pathways. Compared with the blank control group, the proliferation level, α-SMA, lnc-NONHSAT074080, ARL6IP4, type I collagen and fibronectin expression levels were significantly increased in the TGF-β1 group (P<0.05). Compared with the TGF-β1 group, the TGF-β1+NONHSAT074080 shRNA group showed the opposite trend (P<0.05). Conclusion lnc-NONHSAT074080 is associated with the pathogenesis and fibrosis process of RA-UIP, and may participate in fibrosis in the fibrosis process by regulating the target gene ARL6IP4.

Key words: arthritis, rheumatoid, lung diseases, interstitial, RNA, long noncoding, collagen type I, fibronectins, lnc-NONHSAT074080