Vascular Biology Program, Department of Surgery, Boston Children's Hospital, Boston, MA, USA; Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
Haematologica. 2022 Feb 1;107(2):519-531. doi: 10.3324/haematol.2020.260059.
Antisense oligonucleotides (ASO) are DNA-based, disease-modifying drugs. Clinical trials with 2'-O-methoxyethyl (2'MOE) ASO have shown dose- and sequence-specific lowering of platelet counts according to two phenotypes. Phenotype 1 is a moderate (but not clinically severe) drop in platelet count. Phenotype 2 is rare, severe thrombocytopenia. This article focuses on the underlying cause of the more common phenotype 1, investigating the effects of ASO on platelet production and platelet function. Five phosphorothioate ASO were studied: three 2'MOE sequences; 487660 (no effects on platelet count), 104838 (associated with phenotype 1), and 501861 (effects unknown) and two CpG sequences; 120704 and ODN 2395 (known to activate platelets). Human cord bloodderived megakaryocytes were treated with these ASO to study their effects on proplatelet production. Platelet activation (determined by surface Pselectin) and platelet-leukocyte aggregates were analyzed in ASO-treated blood from healthy human volunteers. None of the ASO inhibited proplatelet production by human megakaryocytes. All the ASO were shown to bind to the platelet receptor glycoprotein VI (KD ~0.2-1.5 mM). CpG ASO had the highest affinity to glycoprotein VI, the most potent platelet-activating effects and led to the greatest formation of platelet-leukocyte aggregates. 2'MOE ASO 487660 had no detectable platelet effects, while 2'MOE ASOs 104838 and 501861 triggered moderate platelet activation and SYKdependent formation of platelet-leukocyte aggregates. Donors with higher platelet glycoprotein VI levels had greater ASO-induced platelet activation. Sequence-dependent ASO-induced platelet activation and platelet-leukocyte aggregates may explain phenotype 1 (moderate drops in platelet count). Platelet glycoprotein VI levels could be useful as a screening tool to identify patients at higher risk of ASO-induced platelet side effects.
反义寡核苷酸 (ASO) 是基于 DNA 的、可改变疾病进程的药物。用 2'-O-甲氧基乙基 (2' MOE) ASO 进行的临床试验表明，根据两种表型，血小板计数会出现剂量和序列特异性降低。表型 1 是血小板计数中度（但不严重）下降。表型 2 则罕见且严重的血小板减少症。本文重点研究了更为常见的表型 1 的根本原因，研究了 ASO 对血小板生成和血小板功能的影响。研究了五种硫代磷酸酯 ASO：三种 2' MOE 序列；487660（对血小板计数无影响）、104838（与表型 1 相关）和 501861（作用未知）以及两种 CpG 序列；120704 和 ODN 2395（已知能激活血小板）。用人脐带血来源的巨核细胞处理这些 ASO，以研究它们对前血小板生成的影响。分析了健康人类志愿者接受 ASO 治疗后的血液中的血小板激活（通过表面 P 选择素确定）和血小板-白细胞聚集体。没有一种 ASO 能抑制人巨核细胞的前血小板生成。所有 ASO 均被证明与血小板受体糖蛋白 VI 结合（KD~0.2-1.5 mM）。CpG ASO 与糖蛋白 VI 的亲和力最高，血小板激活作用最强，并导致最大的血小板-白细胞聚集体形成。2' MOE ASO 487660 对血小板没有可检测的作用，而 2' MOE ASOs 104838 和 501861 则触发中度血小板激活和 SYK 依赖性血小板-白细胞聚集体形成。血小板糖蛋白 VI 水平较高的供体具有更强的 ASO 诱导的血小板激活。序列依赖性 ASO 诱导的血小板激活和血小板-白细胞聚集体可能解释了表型 1（血小板计数中度下降）。血小板糖蛋白 VI 水平可用作筛选工具，以识别更易发生 ASO 诱导的血小板副作用的患者。
