Objective To investigate the effects of histone modification on the expression of chemokines in alveolar epithelial typeⅡ cells ( AECⅡ) in a rat model of chronic obstructive pulmonary disease ( COPD) . Methods 20 SD rats were randomly assigned to a normal control group and a COPD group. The rat model of COPD was established by cigarette smoking. Lung histological changes were observed by HE staining. AECⅡ cells were isolated and identified by alkaline phosphatase staining and electron microscopic. The mRNA expressions of monocyte chemoattractant protein ( MCP) -1, IL-8, and macrophage inflammatory protein ( MIP) -2αwere detected by real-time quantitative PCR. The expression of histone deacetylase ( HDAC) 2 was measured by western blot. Chromatin immunoprecipitation ( ChIP) was used todetect H3 and H4 acetylation, and H4K9 methylation in the promoter region of chemokine gene. Results Compared with the control group, the mRNA expressions of MCP-1, IL-8, and MIP-2αin the COPD group increased 4. 48,3. 14, and 2. 83 times, respectively. The expression of HDAC2 protein in the COPD group wassignificantly lower than in the control group ( 0. 25 ±0. 15 vs. 0. 66 ±0. 15, P lt; 0. 05) . The expression of HDAC2 had a negative correlation with the gene expressions of IL-8, MCP-1, and MIP-2α( r = - 0. 960,- 0. 914, - 0. 928, respectively, all P lt;0. 05) . The levels of H3 and H4 acetylation were higher, and H4K9 methylation level was lower in the promoter region of chemokine gene in the COPD group compared with the control group ( all P lt; 0. 05) . Conclusions MCP-1, IL-8, and MIP-2α participate and promote the lung inflammatory response in COPD. HDAC2-mediated histone modification may play an important role in COPD inflammation.
Objective To investigate the expression of the histone deacetylases 1( HDAC1) and the level of whole histone acetylation and methylation in lung T cells of asthmatic rats, and investigate their role in the pathogenesis of asthma.Methods Sixteen wistar rats were randomly divided into a control group and an asthma group( n =8 in each group) . The rats was sensitized with ovalbumin( OVA) and challenged with aerosol OVA to establish asthma model. The asthmatic ratmodel was confirmed by measurement of pulmonary function, histochemical staining, HE staining, and the levels of interleukin-4 ( IL-4 ) , interferon-gamma ( IFN-γ) and immunoglobulin E( IgE) in serum and bronchoalveolar lavage fluid ( BALF) . T cells were isolated fromrat lungs and the purity was identified. The expression of the HDAC1, the level of whole histone H3 and H4 acetylation, and whole H3K9 dimethylation were analyzed by Western blot in lung T cells. Results Compared with the control group, the protein expression of HDAC1 was significantly lower( 0. 465±0. 087 vs 0. 790 ±0. 076, P lt;0. 05) in lung T cells of the asthma group. No significant differences werefound in regard to the level of whole histone H3 and H4 acetylation and whole H3K9 dimethylation betweenthe two groups. Conclusions HDAC1 in lung T cells may be involved in the pathogenesis of asthma.Histone modification by HDAC1 may be a specific eventwith gene transcription which may not be associated with asthma.