Dowey Rebecca, Cole Joby, Thompson A A Roger, Hull Rebecca C, Huang Chenghao, Whatmore Jacob, Iqbal Ahmed, Bradley Kirsty L, McKenzie Joanne, Lawrie Allan, Condliffe Alison M, Kiss-Toth Endre, Sabroe Ian, Prince Lynne R
Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK.
Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
ERJ Open Res. 2022 Apr 4;8(2). doi: 10.1183/23120541.00596-2021. eCollection 2022 Apr.
Neutrophil extracellular traps (NETs) are web-like DNA and protein lattices which are expelled by neutrophils to trap and kill pathogens, but which cause significant damage to the host tissue. NETs have emerged as critical mediators of lung damage, inflammation and thrombosis in coronavirus disease 2019 (COVID-19) and other diseases, but there are no therapeutics to prevent or reduce NETs that are available to patients.
Neutrophils were isolated from healthy volunteers (n=9) and hospitalised patients with COVID-19 at the acute stage (n=39) and again at 3-4 months post-acute sampling (n=7). NETosis was measured by SYTOX green assays.
Here, we show that neutrophils isolated from hospitalised patients with COVID-19 produce significantly more NETs in response to lipopolysaccharide (LPS) compared to cells from healthy control subjects. A subset of patients was captured at follow-up clinics (3-4 months post-acute sampling), and while LPS-induced NET formation is significantly lower at this time point, it remains elevated compared to healthy controls. LPS- and phorbol myristate acetate (PMA)-induced NETs were significantly inhibited by the protein kinase C (PKC) inhibitor ruboxistaurin. Ruboxistaurin-mediated inhibition of NETs in healthy neutrophils reduces NET-induced epithelial cell death.
Our findings suggest ruboxistaurin could reduce proinflammatory and tissue-damaging consequences of neutrophils during disease, and since it has completed phase III trials for other indications without safety concerns, it is a promising and novel therapeutic strategy for COVID-19.
中性粒细胞胞外陷阱（NETs）是一种由中性粒细胞排出的、类似网状的DNA和蛋白质晶格结构，用于捕获和杀死病原体，但会对宿主组织造成严重损害。NETs已成为2019冠状病毒病（COVID-19）和其他疾病中肺损伤、炎症和血栓形成的关键介质，但目前尚无可供患者使用的预防或减少NETs的治疗方法。
从9名健康志愿者、39名急性期COVID-19住院患者以及急性期采样后3 - 4个月的7名患者中分离中性粒细胞。通过SYTOX green检测法测定NETosis。
我们发现，与健康对照受试者的细胞相比，从COVID-19住院患者中分离的中性粒细胞对脂多糖（LPS）刺激产生的NETs显著更多。一部分患者在随访门诊（急性期采样后3 - 4个月）被纳入研究，此时LPS诱导的NET形成虽显著降低，但仍高于健康对照组。蛋白激酶C（PKC）抑制剂鲁比前列酮可显著抑制LPS和佛波酯（PMA）诱导的NETs形成。鲁比前列酮介导的对健康中性粒细胞NETs的抑制作用可减少NET诱导的上皮细胞死亡。
我们的研究结果表明，鲁比前列酮可减轻疾病期间中性粒细胞的促炎和组织损伤后果，且由于其已完成针对其他适应症的III期试验且无安全性问题，因此它是一种有前景的新型COVID-19治疗策略。
