鞘鞍醇激酶-1抑制剂PF-543改善1型糖尿病心肌纤维化的实验研究

Experimental Study of Amelioration of Cardiac Fibrosis by PF-543 in Type 1 Diabetic Mice

目的:研究鞘鞍醇激酶-1抑制剂PF-543对1型糖尿病心肌纤维化的影响及其机制。方法:取60只8周龄雄性C57BL6J小鼠,随机分为对照组、对照+PF-543组、1型糖尿病组及1型糖尿病+PF-543组。采用禁食后一次性腹腔注射链脲佐菌素(STZ,150 mg/kg)构建1型糖尿病模型。造模后每天通过腹腔注射给予溶媒或PF-543(1 mg/kg),持续至造模后第16周末。造模第16周末采用酶联免疫吸附试验(ELISA)检测心肌组织1-磷酸鞘鞍醇(S1P)浓度;采用心脏超声评估心脏收缩与舒张功能;Masson三色法染色以评估心肌纤维化情况;Western blot检测心脏转化生长因子-β1(TGF-β1)、I型胶原蛋白(Col I)、Ⅲ型胶原蛋白(Col Ⅲ)表达水平。结果:1型糖尿病+PF-543组小鼠血浆及心肌S1P水平显著低于1型糖尿病组(所有P<0.05)。超声结果显示,1型糖尿病+PF-543组小鼠心脏左心室射血分数(LVEF)显著高于1型糖尿病组(65.7±3.3%vs 54.4±3.4%,P<0.05),左心室舒张末期内径(LVEDD)显著小于1型糖尿病组(3.81±0.21mm vs 4.52±0.20mm,P<0.05)。Masson三色法染色显示1型糖尿病+PF-543组心肌纤维化程度显著低于1型糖尿病组(7.13±0.32%vs 10.21±0.41%,P<0.05)。1型糖尿病+PF-543组小鼠心脏TGF-β1、Col I与Col Ⅲ蛋白表达水平均低于1型糖尿病组(所有P<0.05)。结论:鞘鞍醇激酶-1抑制剂PF-543可显著降低1型糖尿病小鼠血浆与心脏S1P水平,降低心脏TGF-β1表达与胶原蛋白沉积,改善1型糖尿病小鼠心脏纤维化与心功能。

Objective: This study was aimed to explore the effects of PF-543, a specific inhibitor of sphingosine kinase-1(SphK1),on cardiac fibrosis in type 1 diabetes mice. Methods: Sixty eight-week-old C57 BL6 J mice were randomly divided into control group(n=15), control+PF-543 group(n=15), type 1 diabetes mellitus(T1DM)group(n=15), and T1 DM+PF-543 group(n=15). T1 DM were induced by intraperitoneally injected with streptozocin(STZ, 150 mg/kg). These control and diabetic mice were randomly received with vehicle or PF-543(10 mg/kg/d) treatment for 16 weeks. By the end of the study, cardiac sphingosine 1 phosphate(S1 P) levels were analyzed by enzyme linked immunosorbent assay(ELISA). Cardiac function was evaluated by echocardiography. Myocardial fibrosis was evaluated by masson trichrome staining. The cardiac expression levels of transforming growth factor-β1(TGF-β1), Collagen I(Col I)and Collagen III(Col III) were determined by Western blot. Results: Compared with T1 DM group, cardiac S1 P levels were significantly reduced in T1 DM+PF-543 group(P<0.05). PF-543 significantly increased the left ventricular ejection fractions(LVEF) in diabetic mice(65.7 ±3.3% vs 54.4 ±3.4%, P<0.05). PF-543 alsodecreased the left ventricular end-diastolic diameters(LVEDD) in diabetic mice(3.81±0.21 mm vs 4.52±0.20 mm P<0.05). Moreover, PF-543 treatment reduced interstitial fibrosis in diabetic mice(7.13±0.32% vs10.21±0.41%, P<0.05). the cardiac expression of TGF-β1, Col I and Col III were significantly reduced by PF-543 treatment in type 1 diabetic mice(all P<0.05). Conclusion: PF-543 treatment significantly reduces cardiac S1 P levels and ameliorates myocardial fibrosis by decreasing TGF-β1 and collagen expression in type 1 diabetic mice.