Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
Respir Res. 2012 Sep 19;13(1):79. doi: 10.1186/1465-9921-13-79.
Prior studies have demonstrated that the distal 1.5 kb of the MMP-1 promoter is fundamental in directing the induction of the MMP-1 gene by cigarette smoke.
To characterize the genetic variants in the MMP-1 cigarette smoke-responsive element, deep re-sequencing of this element was performed on DNA samples from participants in the Lung Health Study. Furthermore, evidence of Sp1 binding to the MMP-1 promoter was assessed using chromatin immunoprecipitation assays and the influence of cigarette smoke exposure on this interaction was evaluated in cultured human small airway epithelial cells.
Ten polymorphisms (four novel) were detected in the cigarette smoke-responsive element. Chromatin immunoprecipitation assays to assess the protein-DNA interactions at Sp1 sites in the MMP-1 promoter showed increased binding to the Sp1 sites in the cigarette smoke-responsive element in small airway epithelial cells treated with cigarette smoke extract. In contrast, a Sp1 site outside of the element exhibited the opposite effect. None of the polymorphisms were more prevalent in the fast decliners versus the slow decliners (fast decliners = mean -4.14% decline in FEV1% predicted per year vs. decline in FEV1% predicted per year).
Sequencing analyses identified four novel polymorphisms within the cigarette smoke-responsive element of the MMP-1 promoter. This study identifies functional activity within the cigarette smoke-responsive element that is influenced by cigarette smoke and examines this region of the promoter within a small patient population.
先前的研究表明，MMP-1 启动子的远端 1.5kb 对于指导香烟烟雾诱导 MMP-1 基因的表达是至关重要的。
为了研究 MMP-1 香烟烟雾反应元件中的遗传变异，我们对来自 Lung Health Study 参与者的 DNA 样本进行了深度重测序。此外，我们还使用染色质免疫沉淀测定评估了 Sp1 与 MMP-1 启动子结合的证据，并在培养的人小气道上皮细胞中评估了香烟烟雾暴露对这种相互作用的影响。
在香烟烟雾反应元件中检测到了 10 个多态性（其中 4 个是新的）。染色质免疫沉淀测定评估了香烟烟雾提取物处理的小气道上皮细胞中 Sp1 位点与 MMP-1 启动子上的蛋白-DNA 相互作用，结果显示 Sp1 结合到香烟烟雾反应元件中的 Sp1 位点增加。相比之下，元件外的一个 Sp1 位点则表现出相反的效果。在快速下降者与缓慢下降者之间，没有一个多态性更为普遍（快速下降者=每年预测的 FEV1%下降平均值为-4.14%，而 FEV1%下降预测值为每年）。
测序分析确定了 MMP-1 启动子的香烟烟雾反应元件内的四个新的多态性。本研究鉴定了香烟烟雾反应元件内受香烟烟雾影响的功能活性，并在一个小患者群体中研究了启动子的这一区域。
