Antithrombin is a serine protease inhibitor that exerts a crucial role in hemostasis as the main inhibitor of the coagulation cascade. It plays also critical roles in other processes, such as inflammation and cancer. Here we show that exosomes released by Madin-Darby canine kidney (MDCK) cells cultured in the presence of heparin incorporate antithrombin from the serum. Exosomal antithrombin is found complexed with the serine protease high temperature requirement A1 (HTRA1), whose cellular levels are increased after serum deprival, the condition used to collect exosomes. Although the biological relevance of the presence of antithrombin in exosomes remains to be investigated, our results suggest a functional interplay between antithrombin and HTRA1.

中文翻译：

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将抗凝血酶掺入由抗凝血酶非表达细胞产生的外泌体中。

抗凝血酶是一种丝氨酸蛋白酶抑制剂，在止血中起着至关重要的作用，是凝血级联反应的主要抑制剂。它在炎症和癌症等其他过程中也起着至关重要的作用。在这里，我们显示由在肝素存在下培养的Madin-Darby犬肾（MDCK）细胞释放的外泌体结合了血清中的抗凝血酶。发现外泌体抗凝血酶与丝氨酸蛋白酶高温需求A1（HTRA1）形成复合物，后者在血清剥夺后即收集外泌体的条件下细胞水平升高。尽管抗凝血酶存在于外泌体中的生物学相关性尚待研究，但我们的结果表明抗凝血酶与HTRA1之间存在功能性相互作用。