烟雾暴露对大鼠肺血管细胞间黏附分子-1和基质金属蛋白酶-9表达的影响

目的 观察不同烟雾暴露量及断烟对大鼠肺血管形态、炎症和重塑的影响.方法 8周龄清洁级雄性Wistar大鼠32只,随机数字表法分为对照组、烟雾1组、烟雾2组和断烟组,每组8只.建立大鼠被动吸烟模型.分别测量各组大鼠肺血管管肇厚度占血管外径的百分率(WT%)及管壁面积占血管总面积的百分率(WA%);免疫组织化学染色检测细胞间黏附分子-1(ICAM-1)和基质金属蛋白酶9(MMP-9)在肺血管壁的表达,原位杂交法检测ICAM-1及MMP-9 mRNA在肺血管壁的表达,并分析各指标的相关性.结果 烟雾1组和烟雾2组肺血管的WT%[(15.3±2.1)%、(18.0 ±2.0)%]、WA%[(41±7)%、(50±7)%]均明显高于断烟组[(11.0±1.3)%、(35±5)%]和对照组[(10.4±2.0)%、(30±4)%],差异均有统计学意义(q值为4.93～11.16,P<0.05);烟雾1组和烟雾2组肺血管ICAM-1蛋白表达的阳性单位比值[(12.9±2.3)、(19.2±2.3)]及mRNA表达[(10.3±2.2)、(18.3±2.4)]均明显高于断烟组[(7.9±3.2)、(6.2±3.0)]和对照组[(4.7±2.3)、(2.7±1.7)],差异均有统计学意义(q值为3.28～15.76,P<0.05);烟雾1组和烟雾2组肺血管MMP-9蛋白表达的阳性单位比值[(16.1±2.8)、(22.5±3.5)]及mRNA表达[(12.5±1.8)、(20.0±3.1)]均明显高于断烟组[(12.0±2.8)、(7.0±3.4)]和对照组[(7.8±3.0)、(3.2±2.8)],差异均有统计学意义(q值为3.19～14.22,P<0.05);肺血管ICAM-1和MMP-9 mRNA表达与WT%和WA%均呈显著正相关(r值为0.619～0.703,P<0.05).结论 烟雾暴露可导致大鼠肺血管管壁增厚,上调肺血管细胞ICAM-1、MMP-9的表达,介导肺血管炎症及重塑,参与肺动脉高压的发生.戒烟后上述肺血管损害有所改善.

Effects of cigarette smoke exposure on pulmonary vascular intercellular adhesion molecule-1 and matrix metalloproteinase-9 in rats

Objective To understand the effects of cigarette smoke exposure and smoke cessation on the structure, inflammation and remodeling of pulmonary blood vessels in rats. Methods Thirty-two male Wistar rats were randomly divided into a control group, a smoke exposure group 1 (low dose smoke), a smoke exposure group 2 (high dose smoke) and a smoke cessation group, with 8 rats in each group. The ratio of pulmonary vascular wall thickness/vascular external diameter (WT%) and the ratio of pulmonary vascular wall area/total pulmonary vascular area (WA%) were measured by the image analysis system. The expressions of pulmonary vascular ICAM-1 and MMP-9 protein and mRNA were detected respectively by enzyme linked immunosorbent assay (ELISA) and in situ hybridization techniques. Results WT% and WA% increased significantly in the smoke exposure group 1 [(15.3±2.1)%, (41±7)% ]and smoke exposure group 2 [(18.0±2.0)%, (50±7)%] compared to those of the control group [(10.4± 2.0) %, (30±4) % ] (q = 4.93 - 11.16, P < 0.05, respectively). The WT% and WA% in the smoke cessation group [ (11.0±1.3) %, (35±5) % ] decreased significantly compared to those of the smoke exposure group 2 (q = 6.74-10.29, P < 0.05, respectively). The expression of pulmonary vascular ICAM-1 protein and mRNA increased significantly in the smoke cessation group, the smoke exposure group 1 and the smoke exposure group 2 [ (7.9±3.2 and 6.2±3.0), (12.9±2.3 and 10.3±2.2), (19.2±2.3 and 18.3±2.4) ] compared to those of the control group (4.7±2.3 and 2.7±1.7) (q=3.28-15. 76, P < 0.05, respectively). However, the expression of ICAM-1 protein and mRNA was lower in the smoke cessation group compared to those of the smoke exposure groups (q=3.85-12.46, P < 0.05, respectively). The expression of MMP-9 protein and mRNA increased significantly in the smoke cessation group, smoke exposure group 1 and smoke exposure group 2 [(12.0±2.8 and 7.0±3.4), (16.1±2.8 and 12.5±1.8), (22.5±3.5 and 20.0±3.1)] compared to those of the control group (7.8±3.0 and 3.2±2.8) (q=3.19-14.22, P <0.05, respectively). But the expression of MMP-9 protein and mRNA was lower in the smoke cessation group compared to those of the smoke exposure groups (q=3.68-11.03, P <0.05, respectively) . Both ICAM-1 and MMP-9 mRNA expression were positively correlated with WT% and WA% (r=0.619-0.703) (P<0.05, respectively). Conclusions Cigarette smoke exposure caused pulmonary vascular wall thickening. By up-regulating the expression of ICAM-1 and MMP-9 protein and mRNA in pulmonary vascular wall, cigarette smoke exposure mediated pulmonary vascular inflammation and remodeling, which were associated with pulmonary hypertension. Smoke cessation attenuated the smoke-induced pulmonary vascular impairment.