The Influence Of Exogenous Hydrogen Sulfide On The Expression Of MMP-9 And TIMP-1 In Bleomycin-induced Pulmonary Fibrosis

Objectives:To discuss the expression of MMP-9 and TIMP-1 in bleomycin-induced pulmonary fibrosis and the effect of the Exogenous hydrogen sulfide on them.Methods:45 healthy male SD rats were randomly divided into three groups(15 in each group),they were control group, model group, bleomycin + sodium hydrosulfide(the H2 S donor) group. Model group, bleomycin + sodium hydrosulfide group rats intratracheal fed bleomycin(5mg/kg) to create the animal models of pulmonary fibrosis, control group intratracheal fed an equal volume of saline, the first day after eastablishing models, rats of the treated group simultaneously were adiministered intraperitoneal injections of Na HS(28?mol/kg) daily, control group and model group were adiministered intraperitoneal injections of equal volume of saline. Five rats in each group randomly sacrificed at 7th, 14 th and 28 th day after eastablishing models. The left lung tissue place in 4% formaldehyde fixed, then it was used to observe pulmonary alveolitis and pulmonary fibrosis by microscopein HE and Masson staining, also was used to observe the expression of Protein of MMP-9 and TIMP-1 analyzed by Immunohistochemistry. The right lung tissue was used to observe the expression of m RNA of MMP-9 and TIMP-1 analyzed by RT-PCR.Results:1. HE and Masson staining showed: the control group no inflammation and pulmonary fibrosis change all the time, BLM group 7d is given priority to with inflammation, 14 d started to appear fiber area, alveolar cavities began to appear mang lung fibroblasts;28d alveolar inflammation significantly reduce, alveolar cavities can see a large number of muscle fibroblasts and collagen deposition, the pulmonary fibrosis models had been built; BLM + Na HS group also had appeared the change of alveolar inflammation and fibrosis, but compare with the BLM group have significantly reduce.2. RT-PCR and Immunohistochemistry showed: In the control group, MMP-9 and TIMP-1 were lowly expressed at each time, while in the BLM group and the BLM + Na HS group the expression of MMP-9 and TIMP-1 increased significantly, the difference compare with the control group had statistical significance(P <0.05), the expression of MMP-9 in BLM + Na HS treatment group than BLM group has different rate reduce at each time, compared with BLM group,the expression of MMP-9 reduce had statistically significant differences at 7d(P <0.01), and had statistically differences at 14 d and 28d(P <0.05), the expression of TIMP-1 in BLM + Na HS treatment group than BLM group has different rate reduce at each time,the expression of TIMP-1 reduce had statistically differences at 7d(P <0.05), and had statistically significant differences at 14 d and 28d(P<0.01).3. MMP-9/TIMP-1 balance ratio results showed: compared with the control group, the MMP-9/TIMP-1 balance ratio of the BLM group increased significantly than the control group at 7d, which had significant difference statistically significant(P <0.01),and the ratio reduced than the control group at 14, 28 d, difference was statistically significant(P <0.05). The MMP-9/TIMP-1 balance ratio of the BLM + Na HS group reduced than the BLM group, and had statistically differences(P <0.05), the ratio increased than BLM group at 14, 28 d,difference was statistically significant(P <0.05). The MMP-9/TIMP-1 balance ratio of the BLM + Na HS group increasedthan the control group at 7d, difference was statistically significant(P <0.05), the ratio reduced than the control group at 14, 28 d, which has no statistically significant difference.Conclussions:1.Exogenous hydrogen sulfide can meliorate the extent of pulmonary alveolitis and fibrosis in lung tissues of the bleomycin-induced rats, and can prevent pulmonary fibrosis.2.Exogenous hydrogen sulfide can reducing the expression leves of MMP-9 and TIMP-1 in lung tissues, and reglating the ratio of MMP-9 and TIMP-1 at some extent, which might be one of the mechanisms that resist to pulmonary fibrosis.