Advanced Drug Delivery & Biomaterials, Louvain Drug Research Institute (LDRI), Université catholique de Louvain, Brussels 1200, Belgium.
Department of Respiratory Diseases, University Hospitals Leuven, Leuven 3000, Belgium.
Clin Sci (Lond). 2018 Jul 18;132(13):1439-1452. doi: 10.1042/CS20180315.
Highly viscous mucus and its impaired clearance characterize the lungs of patients with cystic fibrosis (CF). Pulmonary secretions of patients with CF display increased concentrations of high molecular weight components such as DNA and actin. Recombinant human deoxyribonuclease I (rhDNase) delivered by inhalation cleaves DNA filaments contained in respiratory secretions and thins them. However, rapid clearance of rhDNase from the lungs implies a daily administration and thereby a high therapy burden and a reduced patient compliance. A PEGylated version of rhDNase could sustain the presence of the protein within the lungs and reduce its administration frequency. Here, we evaluated the enzymatic activity of rhDNase conjugated to a two-arm 40 kDa polyethylene glycol (PEG40) in CF sputa. Rheology data indicated that both rhDNase and PEG40-rhDNase presented similar mucolytic activity in CF sputa, independently of the purulence of the sputum samples as well as of their DNA, actin and ions contents. The macroscopic appearance of the samples correlated with the DNA content of the sputa: the more purulent the sample, the higher the DNA concentration. Finally, quantification of the enzymes in CF sputa following rheology measurement suggests that PEGylation largely increases the stability of rhDNase in CF respiratory secretions, since 24-fold more PEG40-rhDNase than rhDNase was recovered from the samples. The present results are considered positive and provide support to the continuation of the research on a long acting version of rhDNase to treat CF lung disease.
高度粘稠的黏液及其清除障碍是囊性纤维化（CF）患者肺部的特征。CF 患者的肺部分泌物显示出高分子量成分（如 DNA 和肌动蛋白）的浓度增加。吸入给予的重组人脱氧核糖核酸酶 I（rhDNase）可裂解呼吸道分泌物中的 DNA 丝，并使其变薄。然而，rhDNase 从肺部的快速清除意味着需要每天给药，从而增加了治疗负担并降低了患者的依从性。rhDNase 的聚乙二醇（PEG）化版本可以维持蛋白质在肺部中的存在并减少其给药频率。在这里，我们评估了与双臂 40 kDa 聚乙二醇（PEG40）缀合的 rhDNase 在 CF 痰液中的酶活性。流变学数据表明，rhDNase 和 PEG40-rhDNase 在 CF 痰液中均具有相似的粘液溶解活性，而与痰液的脓性程度以及其 DNA、肌动蛋白和离子含量无关。样品的宏观外观与痰液中的 DNA 含量相关：样品越脓性，DNA 浓度越高。最后，对流变学测量后 CF 痰液中的酶进行定量表明，PEG 化极大地增加了 rhDNase 在 CF 呼吸道分泌物中的稳定性，因为从样品中回收的 PEG40-rhDNase 比 rhDNase 多 24 倍。目前的结果被认为是积极的，并为继续研究长效 rhDNase 治疗 CF 肺部疾病提供了支持。
