Induction of the plasminogen activator system by mechanical stimulation of human bronchial epithelial cells
Induction of the plasminogen activator system by mechanical stimulation of human bronchial epithelial cells
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DOI：
10.1165/rcmb.2006-0040oc
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发表时间：
2006-12-01
影响因子：
6.4
通讯作者：
Drazen, Jeffrey M.
中科院分区：
文献类型：
--
作者：
Chu, Eric K.;Cheng, Jason;Drazen, Jeffrey M.
气道上皮的机械刺激，如支气管收缩时发生的，是一种强有力的刺激，可以激活促纤维化途径。我们使用DNA微阵列技术检测压缩正常人支气管上皮细胞（NHBE）的基因表达。连续施加在NHBE细胞上8小时的压缩应力导致几个基因家族的上调，包括一个纤溶酶原相关的基因家族，这些基因家族以前不知道在该系统中被调节。Real-time PCR结果显示，尿激酶纤溶酶原激活物（uPA）、尿激酶纤溶酶原激活物受体（uPAR）、纤溶酶原激活物抑制剂-1 （PAI-1）和组织纤溶酶原激活物（tPA）的基因表达峰值分别增加了8.0倍、16.2倍、4.2倍和3.9倍。压缩应力还增加了细胞裂解物中uPA蛋白水平（112.0对82.0 ng/ml, P = 0.0004），并增加了细胞培养基中uPA（4.7对3.3 ng/ml, P = 0.02）、uPAR（1.3对0.86 ng/ml, P = 0.007）和PAI-1（50对36 ng/ml， P = 0.006）蛋白水平。功能研究表明，受压刺激细胞中尿激酶依赖性纤溶酶生成增加（0.0090 OD/min vs 0.0033 OD/min, P = 0.03）。此外，压缩导致基质金属蛋白酶(MMP)-9和MMP-2以尿激酶依赖的方式激活增加。在死后的人肺组织中，我们观察到两名死于哮喘状态的患者气道中上皮uPA和uPAR免疫染色增加，而7名非哮喘肺供者气道中免疫反应性最低。综上所述，这些观察结果表明气道上皮细胞对机械刺激的综合反应，通过纤溶酶原激活系统来改变气道微环境。
Mechanical stimulation of the airway epithelium, as would occur during bronchoconstriction, is a potent stimulus and can activate profibrotic pathways. We used DNA microarray technology to examine gene expression in compressed normal human bronchial epithelial cells (NHBE). Compressive stress applied continuously over an 8-h period to NHBE cells led to the upregulation of several families of genes, including a family of plasminogen-related genes that were previously not known to be regulated in this system. Real-time PCR demonstrated a peak increase in gene expression of 8.0-fold for urokinase plasminogen activator (uPA), 16.2-fold for urokinase plasminogen activator receptor (uPAR), 4.2-fold for plasminogen activator inhibitor-1 (PAI-1), and 3.9-fold for tissue plasminogen activator (tPA). Compressive stress also increased uPA protein levels in the cell lysates (112.0 versus 82.0 ng/ml, P = 0.0004), and increased uPA (4.7 versus 3.3 ng/ml, P = 0.02), uPAR (1.3 versus 0.86 ng/ml, P = 0.007), and PAI-1 (50 versus 36 ng/ml, P = 0.006) protein levels in cell culture media. Functional studies demonstrated increased urokinase-dependent plasmin generation in compression-stimulated cells (0.0090 versus 0.0033 OD/min, P = 0.03). In addition, compression led to increased activation of matrix metalloproteinase (MMP)-9 and MMP-2 in a urokinase-dependent manner. In postmortem human lung tissue, we observed an increase in epithelial uPA and uPAR immunostaining in the airways of two patients who died in status asthmaticus compared with minimal immunoreactivity noted in airways from seven lung donors without asthma. Together these observations suggest an integrated response of airway epithelial cells to mechanical stimulation, acting through the plasminogen-activating system to modify the airway microenvironment.