Objective: To investigate the effect of histone deacetylase (HDAC) activity on connective tissue diseases (CTD) associated pulmonary fibrosis (PF) in mice. Methods: A single tracheal administration of bleomycin induced PF in C57BL/6J male mice was performed to establish a PF model. The experimental mice were divided into three groups: bleomycin group (group B, n = 16) which was given bleomycin A2 physiological saline solution 2.5 μl/g body weight, saline group (Group C, n = 16) which was given physiological saline solution 2.5 μl/g body weight and no operation group (group N, n = 16). At 7, 14 and 21 days after administration, the animals were randomly killed and their specimens were collected. The activity of HDAC2 and HDAC4 was detected by colorimetry. Hematoxylin-eosin staining was used to evaluate pulmonary alveolitis and Masson staining for pulmonary fibrosis. The variance, correlation and binary variable correlation were analyzed. Results: The HDAC2 activity in lung tissue of mice in the bleomycin group was significantly higher than that in the no operation group (2.00±0.40 vs 1.00±0.23, P<0.05) and the saline group (2.00±0.40 vs 1.48±0.33, P<0.05). The HDAC2 activity in the bleomycin group was significantly higher than that in the no operation group (2.40±0.28 vs 1.00±0.23, P<0.01, 2.23±0.41 vs 1.00±0.23, P<0.01) and the saline group (2.40±0.28 vs 1.39±0.23, P<0.05, 2.23±0.41 vs 1.35±0.42, P<0.05). The change trend of HDAC2 activity between the bleomycin group and the saline group was different. There was no significant difference in HDAC4 activity in lung tissue of mice between the bleomycin group, the no operation group and the saline group. 14 days after tracheal administration, HDAC4 activity in the bleomycin group and the saline group were significantly higher than that in the no operation group (1.18±0.36 vs 1.00±0.12, P<0.01, 1.09±0.33 vs 1.00±0.12, P<0.01). HDAC2 activity in lung tissue of mice was positively correlated with pathological scores of alveolitis (r=0.428, P<0.01) and pulmonary fibrosis (r=0.508, P<0.01). HDAC4 activity in lung tissue of mice was positively correlated with the pathological scores of alveolitis (r=0.355, P<0.05) and pulmonary fibrosis (r=0.457, P<0.01). Binary linear regression analysis showed that HDAC2 activity had a stronger effect on the process of PF lesions than HDAC4 activity in lung tissue of mice. Conclusions: When pulmonary fibrosis occurred in mice, the activities of HDAC2 and 4 in pulmonary fibrosis were significantly increased. The activity of HDAC2 increased rapidly and lastingly, and the activity of HDAC4 fluctuated significantly and increased briefly. Changes in HDAC2 activity have stronger effects on alveolitis and fibrosis than HDAC4.
目的： 探讨组蛋白脱乙酰基酶（HDAC）2和HDAC 4活性变化对小鼠肺纤维化（PF）的影响。 方法： 博来霉素单次气管给药诱导C57BL/6J雄性小鼠发生PF，建立PF模型。实验动物分3组：博来霉素组（B组，16只）予博来霉素A2生理盐水溶液2.5 μl/g、盐水组（C组，16只）给予生理盐水溶液2.5 μl/g体重和无手术组（N组，16只）。给药后7、14、21 d随机处死、取材。比色法检测肺组织细胞HDAC2、HDAC4活性。HE染色进行肺泡炎、Masson染色肺纤维化评分。对数据进行方差分析、相关性分析，用二元变量相关进行数据间相关性分析。 结果： 整体小鼠肺组织HDAC2活性，B组显著高于N组（2.00±0.40比1.00±0.23，P<0.05）、C组（2.00±0.40比1.48±0.33，P<0.05），给药后14、21 d B组均显著高于N组（2.40±0.28比1.00±0.23，P<0.01，2.23±0.41比1.00±0.23，P<0.01）、C组（2.40±0.28比1.39±0.23，P<0.05，2.23±0.41比1.35±0.42，P<0.05），B组与C组HDAC2活性变化趋势不同。整体小鼠肺组织HDAC4活性，B组与N组、C组差异无统计学意义。气管给药后14 d，B组、C组HDAC4活性均显著高于N组（1.18±0.36比1.00±0.12，P<0.01，1.09±0.33比1.00±0.12，P<0.01），B组与C组HDAC4活性变化趋势大致相同。相关性分析：小鼠肺组织HDAC2活性与肺泡炎（r=0.428，P<0.01）、肺纤维化（r=0.508，P<0.01）病理评分均呈正相关。小鼠肺组织HDAC4活性与肺泡炎（r=0.355，P<0.05）、肺纤维化（r=0.457，P<0.01）病理评分均呈正相关。二元线性回归：HDAC2活性对小鼠PF病变过程作用强于HDAC4活性。 结论： 小鼠发生肺纤维化时，HDAC2和4活性均显著升高，HDAC2活性升高迅速、持久，HDAC4活性波动显著、升高短暂，HDAC2活性变化对肺泡炎、纤维化作用均强于HDAC4。.