Garnacho Carmen, Dhami Rajwinder, Solomon Melani, Schuchman Edward H, Muro Silvia
Department of Normal and Pathological Histology and Cytology, University of Seville School of Medicine, 41009 Seville, Spain.
Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Mol Ther. 2017 Jul 5;25(7):1686-1696. doi: 10.1016/j.ymthe.2017.05.014. Epub 2017 Jun 9.
Acid sphingomyelinase deficiency in type B Niemann-Pick disease leads to lysosomal sphingomyelin storage, principally affecting lungs, liver, and spleen. Infused recombinant enzyme is beneficial, yet its delivery to the lungs is limited and requires higher dosing than liver and spleen, leading to potentially adverse reactions. Previous studies showed increased enzyme pulmonary uptake by nanocarriers targeted to ICAM-1, a protein overexpressed during inflammation. Here, using polystyrene and poly(lactic-co-glycolic acid) nanocarriers, we optimized lung delivery by varying enzyme dose and nanocarrier concentration, verified endocytosis and lysosomal trafficking in vivo, and evaluated delivered activity and effects. Raising the enzyme load of nanocarriers progressively increased absolute enzyme delivery to all lung, liver, and spleen, over the naked enzyme. Varying nanocarrier concentration inversely impacted lung versus liver and spleen uptake. Mouse intravital and postmortem examination verified endocytosis, transcytosis, and lysosomal trafficking using nanocarriers. Compared to naked enzyme, nanocarriers increased enzyme activity in organs and reduced lung sphingomyelin storage and macrophage infiltration. Although old mice with advanced disease showed reactivity (pulmonary leukocyte infiltration) to injections, including buffer without carriers, antibody, or enzyme, younger mice with mild disease did not. We conclude that anti-ICAM nanocarriers may result in effective lung enzyme therapy using low enzyme doses.
B型尼曼-匹克病中的酸性鞘磷脂酶缺乏会导致溶酶体鞘磷脂蓄积，主要影响肺、肝和脾。注入的重组酶有益，但它向肺的递送受限，且与肝和脾相比需要更高剂量，从而导致潜在的不良反应。先前的研究表明，靶向细胞间黏附分子-1（ICAM-1，一种在炎症期间过度表达的蛋白质）的纳米载体可增加酶在肺中的摄取。在此，我们使用聚苯乙烯和聚乳酸-羟基乙酸纳米载体，通过改变酶剂量和纳米载体浓度来优化肺递送，在体内验证内吞作用和溶酶体运输，并评估递送的活性和效果。提高纳米载体的酶负载量可使向所有肺、肝和脾递送的绝对酶量比游离酶逐渐增加。改变纳米载体浓度对肺与肝和脾的摄取产生相反影响。小鼠活体和死后检查使用纳米载体验证了内吞作用、转胞吞作用和溶酶体运输。与游离酶相比，纳米载体增加了器官中的酶活性，减少了肺中鞘磷脂的蓄积和巨噬细胞浸润。尽管患有晚期疾病的老年小鼠对注射有反应（肺部白细胞浸润），包括注射不含载体、抗体或酶的缓冲液，但患有轻度疾病的年轻小鼠没有。我们得出结论，抗ICAM纳米载体可能使用低剂量酶实现有效的肺酶治疗。
