Nordic Bioscience A/S, DK-2730, Herlev, Denmark.
BMC Pulm Med. 2012 Jul 20;12:34. doi: 10.1186/1471-2466-12-34.
Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases.
Elastin fragments were identified by mass-spectrometry and one sequence, generated by MMP-9 and -12 (ELN-441), was selected for monoclonal antibody generation and used in the development of an ELISA. Soluble and insoluble elastin from lung was cleaved in vitro and the time-dependent release of fragments was assessed in the ELN-441 assay. The release of ELN-441 in human serum from patients with chronic obstructive pulmonary disease (COPD) (n = 10) and idiopathic pulmonary fibrosis (IPF) (n = 29) were compared to healthy matched controls (n = 11).
The sequence ELN-441 was exclusively generated by MMP-9 and -12 and was time-dependently released from soluble lung elastin. ELN-441 levels were 287% higher in patients diagnosed with COPD (p < 0.001) and 124% higher in IPF patients (p < 0.0001) compared with controls. ELN-441 had better diagnostic value in COPD patients (AUC 97%, p = 0.001) than in IPF patients (AUC 90%, p = 0.0001). The odds ratios for differentiating controls from COPD or IPF were 24 [2.06-280] for COPD and 50 [2.64-934] for IPF.
MMP-9 and -12 time-dependently released the ELN-441 epitope from elastin. This fragment was elevated in serum from patients with the lung diseases IPF and COPD, however these data needs to be validated in larger clinical settings.
弹性蛋白是某些结缔组织的重要组成部分，赋予组织独特的生理弹性。弹性蛋白可以被认为是肺部的标志性蛋白，其中基质金属蛋白酶（MMP）-9 和 -12 可以被认为是巨噬细胞的标志性蛋白酶，而巨噬细胞在疾病进展过程中部分负责组织损伤。因此，我们假设弹性蛋白的 MMP-9/-12 生成片段可能是肺部疾病的相关生化标志物。
通过质谱鉴定弹性蛋白片段，选择由 MMP-9 和 -12 生成的一个序列（ELN-441）用于单克隆抗体的生成，并用于 ELISA 的开发。体外切割肺中的可溶性和不溶性弹性蛋白，并在 ELN-441 测定中评估片段的时间依赖性释放。比较慢性阻塞性肺疾病（COPD）（n=10）和特发性肺纤维化（IPF）（n=29）患者与健康匹配对照（n=11）的人血清中 ELN-441 的释放。
序列 ELN-441 仅由 MMP-9 和 -12 生成，并随时间从可溶性肺弹性蛋白中释放。与对照组相比，COPD 患者的 ELN-441 水平高出 287%（p<0.001），IPF 患者的 ELN-441 水平高出 124%（p<0.0001）。与 IPF 患者相比，ELN-441 在 COPD 患者中具有更好的诊断价值（AUC 97%，p=0.001）。区分 COPD 或 IPF 患者与对照组的优势比为 24[2.06-280]和 50[2.64-934]。
MMP-9 和 -12 随时间从弹性蛋白中释放出 ELN-441 表位。该片段在 IPF 和 COPD 等肺部疾病患者的血清中升高，但这些数据需要在更大的临床环境中进行验证。
