Heparin is an essential anticoagulant used for treating and preventing thrombosis. However, the complexity of heparin has hindered the development of a recombinant source, making its supply dependent on a vulnerable animal population. In nature, heparin is produced exclusively in mast cells, which are not suitable for commercial production, but mastocytoma cells are readily grown in culture and make heparan sulfate, a closely related glycosaminoglycan that lacks anticoagulant activity. Using gene expression profiling of mast cells as a guide, a multiplex genome engineering strategy was devised to produce heparan sulfate with high anticoagulant potency and to eliminate contaminating chondroitin sulfate from mastocytoma cells. The heparan sulfate purified from engineered cells grown in chemically defined medium has anticoagulant potency that exceeds porcine-derived heparin and confers anticoagulant activity to the blood of healthy mice. This work demonstrates the feasibility of producing recombinant heparin from mammalian cell culture as an alternative to animal sources.

肝素是一种重要的抗凝剂，用于治疗和预防血栓形成。然而，肝素的复杂性阻碍了重组来源的开发，使其供应依赖于脆弱的动物种群。在自然界中，肝素仅在肥大细胞中产生，不适合商业化生产，但肥大细胞瘤细胞很容易在培养中生长并产生硫酸乙酰肝素，这是一种密切相关的糖胺聚糖，缺乏抗凝活性。以肥大细胞的基因表达谱为指导，设计了一种多重基因组工程策略，以生产具有高抗凝效力的硫酸乙酰肝素并消除肥大细胞瘤细胞中的污染硫酸软骨素。从在化学成分确定的培养基中生长的工程细胞中纯化的硫酸乙酰肝素具有超过猪源肝素的抗凝效力，并赋予健康小鼠血液抗凝活性。这项工作证明了从哺乳动物细胞培养物中生产重组肝素作为动物来源的替代品的可行性。