Expression Of PRMT6and Its Meaning In Lung Tissues Of COPD Mice

Objective:To investigate the expression of Protein arginine methyltransferases6(PRMT6) and the changes in histone H3R2asymmetric dimethylation (H3R2me2a) and histone H3K4trimethylation (H3K4me3) signal in lung tissue of chronic obstructive pulmonary disease (COPD) mice. To test whether the changes in PRMT6and histone H3K4me3and H3R2me2a signal affect the expression of inflammatory genes including IL-6、IL-13、COX-2、MMP-2.Methods:We use the method of intraperitoneal injection of cigarette smoke extract (CSE) to set a mice model of COPD, pulmonary function, pathology of lung tissue (Mean linear intercept, Destructive index, Mean alveolar septal thickness), antioxidant activity of bronchoalveolar lavage fluid, pulmonary parenchymal apoptosis index, were measured, and identify the model. Collect lung tissues in control group mice and COPD mice. PRMT6protein and signal in histone H3R2me2a and H3K4me3expression were detected by Western-blotting. PRMT6and inflammatory genes expression were detected by qRT-PCR.Results:(1) Compared with the control group, airway resistance (Raw) in COPD group were higher (P<0.05), airway dynamic compliance (Cdyn)、peak expiratory flow (PEF) in COPD group were lower (P<0.05), and inspiratory time than expiratory time (Ti/Te) were lower (P<0.05). Pathological changes in COPD group comply with COPD, compared with control group, mean linear intercept (MLI) and destructive index (DI) were higher in COPD group (P<0.05), mean alveolar septum thickness (MAST) were lower in CSE group (P<0.05). Compared with control group, antioxidant activity of alveolar lavage fluid in COPD group were lower (P<0.05). Compared to control group, apoptosis index (AI) of COPD group were higher (P<0.05).(2) Compared with the control group, PRMT6protein expression decreased in COPD group (P<0.05), and histone H3K4me3and H3R2me2a signal decreased in COPD (P<0.05).(3) Compared with the control group, PRMT6mRNA expression decreased (P<0.05), but inflammatory (IL、IL-13、COX-2、MMP-2) genes mRNA expression increased significantly in COPD group (P<0.05).Conclusions:PRMT6mRNA and protein expression decreased in lung tissue of COPD mice, that can cause histone H3R2me2a signal decreased to activate inflammatory gene transcriptional expression to participate in COPD.