Vikman Petter, Xu Cang-Bao, Edvinsson Lars
Department of Clinical Sciences, Experimental Vascular Research, Lund, Sweden.
Vasc Health Risk Manag. 2009;5(1):333-41. doi: 10.2147/vhrm.s4866. Epub 2009 Apr 8.
Cigarette smoking is one of the strongest risk factors for stroke. However, the underlying molecular mechanisms that smoke leads to the pathogenesis of stroke are incompletely understood.
Dimethyl sulfoxide (DMSO)-soluble (lipid-soluble) cigarette smoking particles (DSP) were extracted from cigarette smoke (0.8 mg nicotine per cigarette; Marlboro). Rat cerebral arteries were isolated and organ cultured in the presence of DSP (0.2 microl/ml, equivalent to the plasma level in smokers) for 24 h. The expression of matrix metalloproteinase 9 and 13 (MMP9 and MMP13), angiotensin receptor 1 and 2 (AT(1) and AT(2)), interleukin 6 and inducible nitric oxide synthase (iNOS) were investigated at mRNA level by real-time PCR and/or at protein level by immunohistochemistry. In addition, the activity of three mitogen-activated protein kinases (p38, ERK 1/2 and SAPK/JNK) and their downstream transcription factors (ATF-2, Elk-1 and c-Jun) were examined.
We observed that compared with control (DMSO-treated cerebral arteries), the cerebral arteries treated by DSP exhibited enhanced expression of MMP13 and AT(1) receptors, but not of AT(2) receptors, at both mRNA and protein levels, suggesting that a transcriptional mechanism is most likely involved in the DSP effects. This is further supported by the findings that DSP induced phosphorylation of p38 mitogen-activated protein kinases inflammatory signal protein in parallel with activation of its downstream transcription factor ATF-2 and Elk-1. However, ERK 1/2 and SAPK/JNK activities were markedly expressed in the control (organ culture per se with DMSO), and DSP failed to further enhance the activation of ERK 1/2 and SAPK/JNK in the cerebral arteries.
DSP induces cerebral vessel inflammation with activation of p38 MAPK inflammatory signal and the downstream transcriptional factors (ATF-2 and Elk-1) in parallel with enhanced extracellular-matrix-related gene transcription and increased AT(1) receptor expression in the cerebral arteries, which are key events in stroke pathogenesis.
吸烟是中风最强的危险因素之一。然而，吸烟导致中风发病的潜在分子机制尚未完全明确。
从香烟烟雾（每支香烟含0.8毫克尼古丁；万宝路）中提取二甲基亚砜（DMSO）可溶性（脂溶性）吸烟颗粒（DSP）。分离大鼠脑动脉并在DSP（0.2微升/毫升，相当于吸烟者血浆水平）存在的情况下进行器官培养24小时。通过实时聚合酶链反应在mRNA水平和/或通过免疫组织化学在蛋白质水平研究基质金属蛋白酶9和13（MMP9和MMP13）、血管紧张素受体1和2（AT(1)和AT(2)）、白细胞介素6和诱导型一氧化氮合酶（iNOS）的表达。此外，检测三种丝裂原活化蛋白激酶（p38、ERK 1/2和SAPK/JNK）及其下游转录因子（ATF-2、Elk-1和c-Jun）的活性。
我们观察到，与对照组（DMSO处理的脑动脉）相比，DSP处理的脑动脉在mRNA和蛋白质水平上均表现出MMP13和AT(1)受体表达增强，但AT(2)受体未增强，这表明转录机制很可能参与了DSP的作用。DSP诱导p38丝裂原活化蛋白激酶炎性信号蛋白磷酸化，同时其下游转录因子ATF-2和Elk-1活化，这一发现进一步支持了上述观点。然而，ERK 1/2和SAPK/JNK活性在对照组（仅用DMSO进行器官培养）中明显表达，DSP未能进一步增强脑动脉中ERK 1/2和SAPK/JNK的活化。
DSP通过激活p38丝裂原活化蛋白激酶炎性信号及其下游转录因子（ATF-2和Elk-1），诱导脑血管炎症，同时增强细胞外基质相关基因转录并增加脑动脉中AT(1)受体表达，这些都是中风发病机制中的关键事件。
