van Lith Robert, Yang Jian, Ameer Guillermo A
Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA.
Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA; Department of Surgery, Feinberg School of Medicine, Chicago, IL 60611, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Simpson Querrey Institute, Northwestern University, Evanston, IL 60208, USA.
Free Radic Biol Med. 2015 May;82:13-21. doi: 10.1016/j.freeradbiomed.2015.01.022. Epub 2015 Feb 2.
After vascular interventions, endothelial cells are typically injured or lacking, resulting in decreased NO synthesis to maintain vascular health. Moreover, inflammation as a result of the tissue injury and/or the presence of an implanted foreign polymer such as a vascular graft causes excessive generation of reactive oxygen species (ROS) (e.g., superoxide), which can react with NO. The combination of the above creates a general decline in NO bioavailability, as well as oxidative stress due to less available NO to scavenge ROS. Localized NO delivery is an attractive solution to alleviate these issues; however, NO donors typically exhibit unpredictable NO payload release when using nitrosothiols or the risk of nitrosamine formation for synthetic diazeniumdiolates. The objective of this study was therefore to synthesize an NO donor from a biological peptide that could revert to its native form upon NO release. To this effect, protamine sulfate (PS), an FDA-approved peptide with reported vasodilator and anticoagulant properties, was diazeniumdiolated to form PS/NO. PS/NO showed diazeniumdiolate-characteristic UV peaks and NO release in physiological solutions and was capable of scavenging radicals to decrease oxidative stress. Furthermore, PS/NO selectively inhibits the proliferation of smooth muscle cells and adventitial fibroblasts, thereby reversing reported mitogenic properties of PS. Endothelial cell growth, on the other hand, was promoted by PS/NO. Finally, PS retained its anticoagulant properties upon diazeniumdiolation at clinically relevant concentrations. In conclusion, we have synthesized an NO prodrug from a biological peptide, PS/NO, that selectively inhibits proliferation of smooth muscle cells and fibroblasts, retains anticoagulant properties, and reverts back to its native PS form upon NO payload release.
血管介入术后，内皮细胞通常会受损或缺失，导致一氧化氮（NO）合成减少，从而难以维持血管健康。此外，组织损伤和/或植入的外来聚合物（如血管移植物）引发的炎症会导致活性氧（ROS，如超氧化物）过度生成，而ROS会与NO发生反应。上述情况共同导致NO生物利用度普遍下降，同时由于用于清除ROS的NO减少，还会引发氧化应激。局部递送NO是缓解这些问题的一个有吸引力的解决方案；然而，使用亚硝基硫醇时，NO供体通常表现出不可预测的NO负载释放，而合成二氮烯二醇盐则存在形成亚硝胺的风险。因此，本研究的目的是从一种生物肽合成一种NO供体，该供体在释放NO后可恢复其天然形式。为此，将硫酸鱼精蛋白（PS，一种已获美国食品药品监督管理局批准、具有血管舒张和抗凝特性报道的肽）进行二氮烯二醇化反应，形成PS/NO。PS/NO在生理溶液中呈现二氮烯二醇盐特征的紫外峰并释放NO，且能够清除自由基以降低氧化应激。此外，PS/NO可选择性抑制平滑肌细胞和外膜成纤维细胞的增殖，从而逆转PS已报道的促有丝分裂特性。另一方面，PS/NO可促进内皮细胞生长。最后，在临床相关浓度下进行二氮烯二醇化反应后，PS仍保留其抗凝特性。总之，我们从一种生物肽合成了一种NO前药PS/NO，它可选择性抑制平滑肌细胞和成纤维细胞的增殖，保留抗凝特性，并在释放NO负载后恢复为其天然的PS形式。
