TG2抑制剂在减轻大鼠肺动脉高压肺血管重构中的作用机制

发布时间：2019-01-12 11:24

【摘要】：目的:探讨TG2抑制剂在减轻大鼠肺动脉高压肺血管重构中的作用机制。方法:1、采用左肺切除加野百合碱注射建立大鼠肺动脉高压模型,利用TG2抑制剂─胱胺二盐酸,抑制肺动脉高压肺血管重构。2、将30只健康雄性SD大鼠随机分为3组(每组10只),即空白对照组:不做任何处理,同其他两组大鼠相同环境下饲养;模型组:左肺切除术7d后野百合碱(MCT,60mg/kg)项背部皮下注射;干预组:在模型组基础上,于左肺切除术5d后,每日腹腔注射胱胺二盐酸(112mg/kg)持续至实验35d。3、各组大鼠在实验35d后,测定平均肺动脉压力(mPAP),计算右心肥厚指数(RVHI),即右心室游离壁(RV)与左心室+室间隔(LV+S)之比,即RV/(LV+S)。4、将各组大鼠肺组织做HE染色、肺弹力纤维染色,观察肺血管及肺组织的病理改变,计算肺小动脉中膜厚度百分比(WT%)、肺小动脉管壁面积与血管总面积比值(WA%)、肺小动脉新生内膜增殖度等指标。5、采用RT-PCR测定各组大鼠肺组织中Akt mRNA相对表达水平。6、采用蛋白质免疫印迹法(Western blot)测定各组大鼠Akt和p-Akt蛋白表达水平。结果:1、与对照组比较,采用左肺切除加野百合碱注射的模型组大鼠形成了严重的肺动脉高压及右心室肥大,并有新生内膜形成,mPAP、右心肥厚指数百分比(RVHI%)、肺小动脉中膜厚度百分比(WT%)、肺小动脉管壁面积与血管总面积比值(WA%)及新生内膜增殖度百分比均明显高于对照组,差异均有统计学意义(p0.05)。2、采用胱胺二盐酸干预后,干预组mPAP、右心肥厚指数百分比(RVHI%)、肺小动脉中膜厚度百分比(WT%)、肺小动脉管壁面积与血管总面积比值(WA%)及新生内膜增殖度百分比较模型组均有不同程度的降低,差异均有统计学意义(p0.05)。3、RT-PCR结果显示模型组Akt mRNA的表达水平较对照组有增高,差异有统计学意义(p0.05),Western blot结果显示模型组肺组织Akt和p-Akt蛋白表达水平较对照组亦有增高,差异有统计学意义(p0.05)。采用胱胺二盐酸干预后,干预组Akt mRNA的表达水平、Akt和p-Akt蛋白表达量较模型组均有不同程度的下降,差异有统计学意义(p0.05)。结论:1、左肺切除+野百合碱注射成功建立大鼠肺动脉高压模型,并形成了新生内膜及典型病理学特征─肺血管重构。2、TG2抑制剂在一定程度上可以抑制肺动脉高压的形成及阻止肺血管重构;3、PI3K/Akt信号通路可能在TG2抑制剂抑制肺动脉高压大鼠肺血管重构中发挥重要作用。
[Abstract]:Objective: to investigate the mechanism of TG2 inhibitor on pulmonary vascular remodeling in rats with pulmonary hypertension. Methods: 1. Pulmonary hypertension model in rats was established by left pneumonectomy and monocrotaline injection. TG2 inhibitor-cysteamine dihydrochloric acid was used to inhibit pulmonary vascular remodeling. Thirty healthy male SD rats were randomly divided into 3 groups (10 rats in each group). The model group was treated with subcutaneous injection of monocrotaline (MCT,60mg/kg) on the back 7 days after left pneumonectomy. Intervention group: on the basis of the model group, 5 days after left pneumonectomy, daily intraperitoneal injection of cysteamine dihydrochloric acid (112mg/kg) continued until 35d.3.The mean pulmonary artery pressure (mPAP),) was measured after 35 days in each group. The ratio of right ventricular free wall (RV) to left ventricular septal (LV S) (RV/ (LV S). 4) was calculated by calculating the right ventricular hypertrophy index (RVHI),). The lung tissues in each group were stained with HE and the lung elastic fibers were stained. The pathological changes of pulmonary vessels and tissues were observed, the percentage of pulmonary arterioles medial thickness (WT%), the ratio of pulmonary arteriole wall area to total area (WA%), the proliferative degree of neointima of pulmonary arterioles were calculated. RT-PCR was used to detect the relative expression of Akt mRNA in the lung tissue of rats in each group. 6. The expression of Akt and p-Akt protein was detected by Western blot (Western blot). Results: 1. Compared with the control group, the rats in the model group treated with left lung resection and monocrotaline injection developed severe pulmonary hypertension and right ventricular hypertrophy, and formed neointima, mPAP, right cardiac hypertrophy index (RVHI%). The percentage of pulmonary arterioles media thickness (WT%), the ratio of pulmonary arteriole wall area to total area (WA%) and the percentage of neointimal proliferation were significantly higher than those of the control group (p0.05). After the intervention of cysteamine dihydrochloric acid, the right cardiac hypertrophy index (RVHI%) and pulmonary arteriole media thickness (WT%) were measured in the intervention group. The ratio of pulmonary arteriole wall area to total vascular area (WA%) and the percentage of neointimal proliferation in the model group were significantly lower than those in the model group (p0.05). The results of RT-PCR showed that the expression of Akt mRNA in the model group was higher than that in the control group, and the difference was statistically significant (p0.05), Western blot result showed that the expression of Akt and p-Akt protein in the lung tissue of the model group was also higher than that in the control group. The difference was statistically significant (p0.05). After the intervention of cysteamine dihydrochloric acid, the expression level of Akt mRNA, Akt and p-Akt protein in the intervention group were lower than those in the model group, and the difference was statistically significant (p0.05). Conclusion: 1. The pulmonary hypertension model was successfully established by injection of monocrotaline into the left lung, and the neointima and typical pathological features, pulmonary vascular remodeling, were formed. To some extent, TG2 inhibitor can inhibit the formation of pulmonary hypertension and prevent pulmonary vascular remodeling. The PI3K / Akt signaling pathway may play an important role in the inhibition of pulmonary vascular remodeling by TG2 inhibitors in rats with pulmonary hypertension.
【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R544.1

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