PDF(Pubmed)
Abstract：
Southeast Asian ovalocytosis (SAO) is characterized by the misfolding of band 3 protein in red blood cells (RBC). The abnormal structure of the band 3 protein results in dysmorphic RBC and related functions. Previous data showed that in vitro storage under hypothermic conditions alters band 3 protein structure and function. Microvesiculation includes shedding of RBC membranes, called RBC-derived microparticles/extracellular vesicles (RMP/EVs), and storage lesions. Unfortunately, there is no evidence of RBC microvesiculation under in vitro storage conditions in heterozygous SAO individuals. This study determined the generation of REVs and procoagulant activity during the storage of SAO blood samples in southern Thailand. Venous blood was collected from eight SAO and seven healthy individuals, preserved in citrate phosphate dextrose-adenine 1 (CPDA-1) at 4 °C for 35 days. The absolute numbers of REVs and PS-expressing RBCs were analyzed using flow cytometry. The procoagulant activity of the produced extracellular vesicles was determined by a clotting time assay. The results showed a significant increase in the number of REVs and PS-expressing RBCs in the SAO blood samples. Significantly correlated PS externalization and procoagulant activity were observed in the SAO blood samples. These lines of evidence indicate that the abnormality of the Band 3 protein is possibly involved in aberrant microvesiculation, exerting procoagulant activity in vitro. Increased pools of REV production and abnormal storage lesions in SAO blood samples should be a concern. Notably, the mechanisms underlying membrane vesiculation depend on the extent of blood cell storage under hypothermic conditions.
摘要：
东南亚卵细胞增多症（SAO）的特征是红细胞（RBC）中条带3蛋白的错误折叠。带3蛋白的结构异常导致异形红细胞和相关功能。先前的数据表明，低温条件下的体外储存会改变带3蛋白的结构和功能。微囊化包括红细胞膜脱落，称为红细胞衍生的微粒/细胞外囊泡（RMP/EV），和储存损伤。不幸的是,在杂合子SAO个体中,在体外储存条件下没有RBC微泡形成的证据。这项研究确定了泰国南部SAO血样储存过程中REV的产生和促凝血活性。收集了8名SAO和7名健康个体的静脉血，在4°C下在柠檬酸磷酸盐葡萄糖腺嘌呤1（CPDA-1）中保存35天。使用流式细胞术分析REV和表达PS的RBC的绝对数量。通过凝血时间测定确定所产生的细胞外囊泡的促凝血活性。结果显示SAO血液样品中REV和PS表达RBC的数量显著增加。在SAO血液样品中观察到显著相关的PS外化和促凝血活性。这些证据表明，Band3蛋白的异常可能与异常微泡有关，在体外发挥促凝血活性。应关注SAO血液样本中REV产生和异常存储病变的增加。值得注意的是,膜囊泡形成的机制取决于低温条件下血细胞的储存程度。
