Plasma DNA fragmentomics is an emerging area in cell-free DNA diagnostics and research. In murine models, it has been shown that the extracellular DNase, DNASE1L3, plays a role in the fragmentation of plasma DNA. In humans, DNASE1L3 deficiency causes familial monogenic systemic lupus erythematosus with childhood onset and anti-dsDNA reactivity. In this study, we found that human patients with DNASE1L3 disease-associated gene variations showed aberrations in size and a reduction of a “CC” end motif of plasma DNA. Furthermore, we demonstrated that DNA from DNASE1L3-digested cell nuclei showed a median length of 153 bp with CC motif frequencies resembling plasma DNA from healthy individuals. Adeno-associated virus-based transduction of Dnase1l3 into Dnase1l3-deficient mice restored the end motif profiles to those seen in the plasma DNA of wild-type mice. Our findings demonstrate that DNASE1L3 is an important player in the fragmentation of plasma DNA, which appears to act in a cell-extrinsic manner to regulate plasma DNA size and motif frequency.

血浆 DNA 片段组学是游离 DNA 诊断和研究的一个新兴领域。在小鼠模型中，已表明细胞外 DNase DNASE1L3 在血浆 DNA 断裂中发挥作用。在人类中，DNASE1L3 缺陷会导致家族性单基因系统性红斑狼疮，儿童期发病并具有抗ds DNA 反应性。在这项研究中，我们发现携带DNASE1L3疾病相关基因变异的人类患者表现出大小异常以及血浆 DNA 的“CC”末端基序的减少。此外，我们证明来自 DNASE1L3 消化的细胞核的 DNA 的中位长度为 153 bp，CC 基序频率与健康个体的血浆 DNA 相似。基于腺相关病毒的Dnase1l3转导到Dnase1l3缺陷小鼠中，使末端基序图谱恢复到野生型小鼠血浆 DNA 中所见的特征。我们的研究结果表明，DNASE1L3 在血浆 DNA 片段化中发挥着重要作用，它似乎以细胞外源性方式发挥作用，调节血浆 DNA 大小和基序频率。