硫化氢经转化生长因子β/膜型基质金属蛋白酶通路改善糖尿病大鼠心肌纤维化

Hydrogen sulfide alleviates myocardial fibrosis by inhibiting transforming growth factor-β/membrane-type-3 matrix metalloproteinase signaling pathway in diabetic rats

目的观察气体信号分子硫化氢对糖尿病大鼠心肌纤维化以及转化生长因子β(TGF-β)/膜型基质金属蛋白酶(MT3-MMP)蛋白表达的影响。方法将52只成年雄性SD大鼠随机分成4组(每组13只):正常对照组、糖尿病组、糖尿病+硫化氢组、正常大鼠+硫化氢组(硫化氢组)。以链脲佐菌素(STZ)腹腔注射建立糖尿病大鼠模型,注射72h后尾静脉采血测血糖水平,血糖>16.7mmol/L提示造模成功。造模成功后,硫化氢组和糖尿病+硫化氢组大鼠腹腔注射NaHS溶液100μmol/(kg·d),正常对照组和糖尿病组腹腔注射等量生理盐水。8周后处死大鼠,取左心室心肌组织,Van Gieson(VG)染色观察大鼠心肌纤维化,Western blot检测大鼠心肌组织Ⅰ型、Ⅲ型胶原,基质金属蛋白酶(MMP)1,MMP-2,组织型基质金属蛋白酶抑制因子(TIMP)2蛋白的表达水平,以及TGF-β,MT3-MMP蛋白的表达水平。结果与正常对照组相比,糖尿病组存在明显心肌纤维化,心肌组织中Ⅰ型、Ⅲ型胶原,TIMP-2,TGF-β,MT3-MMP蛋白的表达升高(P<0.01),MMP-1和MMP-2蛋白的表达水平降低(P<0.01);与糖尿病组相比,糖尿病+硫化氢组大鼠心肌纤维化减轻,心肌组织Ⅰ型、Ⅲ型胶原,TIMP-2,TGF-β和MT3-MMP蛋白的表达降低,MMP-1和MMP-2蛋白的表达升高(P<0.01或P<0.05)。结论硫化氢可改善糖尿病大鼠心肌纤维化,其机制可能与下调TGF-β、MT3-MMP蛋白的表达水平有关。

Objective To explore the effects of hydrogen sulfide （H2S） on myocardial fibrosis and transforming growth factor-β （ TGF-β）/membrane-type-3 matrix metalloproteinase （MT3-MMP） signaling pathway in diabetic rats. Methods Fifty-two adult male SD rats were randomly divided into four groups （n= 13 ） ： control group, dia- betes group, H2S treatment group and normal H2S treatment group （H2S group）. Diabetic rats were induced by intraperitoneal injection of streptozotocin（STZ）. Blood glucose in tail venous blood was detected 72 h after injection. Rats with blood glucose ）16.7 mmol/L were considered diabetes. Then rats in H2S treatment group and H2S group were injected with sodium hydrosulfide [100 μmol/（ kg · d）] and rats in control group and diabetes group were injected with equal volume of normal saline by intraperitoneal administration every day. After 8 weeks, the patho logical morphology of myocardium was analyzed by Van Gieson（VG） staining. The expression levels of Collagen I, Collagen Ⅲ , matrix metalloproteinase （MMP） 1, MMP-2, tissue inhibitor of metalloproteinase 2 （TIMP-2） and TGF-β/MT3-MMP were analyzed by Western blotting. Results Compared with control group, collagen accumula- tion was markedly enhanced in diabetes group. The expression levels of Collagen I , Collagen Ⅲ , TIMP-2, TGF-β, and MT3-MMP were significantly increased, while MMP-1 and MMP-2 were significantly decreased in diabetes group （P〈0.01）. Compared with diabetes group, the expression levels of Collagen I , Collagen Ⅲ, TIMP-2, TGF-β and MT3-MMP were significantly decreased, while MMP-1 and MMP-2 were significantly increased in H2 S treatment group （P〈0.01 or P〈0. 05）. Conclusion H2S attenuates myocardial fibrosis in diabetic rats, and its mechanism may be related to down-regulation of TGF β/MT3-MMP.