Abstract: Objective　To investigate the effect of long non coding RNA (LncRNA) PVT1 on allergic rhinitis (AR) and its related mechanism. Methods　A total of 24 BALB/c mice were used in this study, of which 6 mice were in the normal group, and the remaining 18 mice were treated with ovalbumin (OVA) and Al (OH)3 to establish the AR model. Eighteen mice were randomly divided into the model group, the AR+NC group (empty vector lentivirus injected via tail vein) and the AR+shPVT1 group (shPVT1 lentivirus injected via tail vein). The behavioral score was used to investigate allergic symptoms of the mice in each group. HE staining was used to analyze the pathological changes of nasal mucosa in mice. qPCR was used to detect LncRNA PVT1, miR-149-5p and chitinase-3-like protein 1 (CHI3L1) relative mRNA expression. The protein expression of CHI3L1 was detected by Western blot assay. The serum levels of IgE, IL-5 and TNF-α were analyzed by ELISA. Luciferase reporter vector of LncRNA PVT1 and CHI3L1 of wild type (WT) and mutant type (MT) were constructed and transfected into 293T cells with miR-149-5p mimic. The relative luciferase activity was analyzed by double luciferase assay. Results　Compared with the model group, the behavior score was significantly decreased， serum levesls of IgE, IL-5 and TNF-α were reduced, the relative mRNA or protein expression of LncRNA PVT1 and CHI3L1 were significantly decreased, the relative mRNA of miR-149-5p was increased and the inflammatory response of the nasal mucosa was reduced in the AR+shPVT1 group. Dual luciferase assay confirmed that LncRNA PVT1 up-regulated the expression of miR-149-5p target gene CHI3L1 through competitive binding miR-149-5p. Conclusion　LncRNA PVT1, which is abnormally highly expressed in AR model mice, can inhibit the expression of miR-149-5p and enhance the expression of CHI3L1 by exerting its ceRNA function, thus promote inflammatory symptoms of nasal mucosa tissue and allergic reactions in mice.

Key words: rhinitis, allergic, RNA, long noncoding, mice, inbred BALB C, chitinase-3-like protein 1, LncRNA PVT1, miR-149-5p