The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, QLD, 4102, Australia.
Gallipoli Medical Research Institute, Greenslopes Private Hospital, Brisbane, QLD, 4120, Australia.
Theranostics. 2020 May 18;10(15):6715-6727. doi: 10.7150/thno.44900. eCollection 2020.
Acetaminophen (APAP) is the foremost cause of drug-induced liver injury in the Western world. Most studies of APAP hepatotoxicity have focused on the hepatocellular injury, but current hepatocyte-related biomarkers have delayed presentation time and a lack of sensitivity. APAP overdose can induce hepatic microvascular congestion, which importantly precedes the injury of hepatocytes. However, the underlying molecular mechanisms remain unclear. It is imperative to discover and validate sensitive and specific translational biomarkers of APAP-induced liver injury. : In this study, we assessed APAP toxicity in sinusoidal endothelial cells and hepatocytes in mice treated with overdose APAP at different time points. The underlying mechanisms of APAP overdose induced sinusoidal endothelial cell injury were investigated by RT Profiler PCR arrays. The impact of APAP overdose on endothelial cell function was assessed by pseudovessel formation of endothelial cells in 2D Matrigel and hepatic vascular integrity using multiphoton microscopy. Finally, the effects of APAP overdose on oxygen levels in the liver and hepatic microcirculation were evaluated by contrast enhanced ultrasonography. Potential imaging-based vascular-related markers for early detection of APAP induced liver injury were assessed. : Our study confirmed that hepatic endothelial cells are an early and direct target for APAP hepatotoxicity. ICAM1-related cellular adhesion pathways played a prominent role in APAP-induced endothelial cell injury, which was further validated in primary human sinusoidal endothelial cells and human livers after APAP overdose. APAP overdose impacted pseudovessel formation of endothelial cells and hepatic vascular integrity. Use of ultrasound to detect APAP-induced liver injury demonstrated that mean transit time, an imaging-based vascular-related biomarker, was more sensitive and precise for early detection of APAP hepatotoxicity and monitoring the treatment response in comparison with a conventional blood-based biomarker. : Imaging-based vascular-related biomarkers can identify early and mild liver injury induced by APAP overdose. With further development, such biomarkers may improve the assessment of liver injury and the efficacy of clinical decision-making, which can be extended to other microvascular dysfunction of deep organs.
对乙酰氨基酚（APAP）是西方世界药物性肝损伤的首要原因。大多数对 APAP 肝毒性的研究都集中在肝细胞损伤上，但目前与肝细胞相关的生物标志物存在出现时间延迟和敏感性不足的问题。APAP 过量可诱导肝微血管充血，这一现象重要且发生在肝细胞损伤之前。然而，其潜在的分子机制尚不清楚。发现和验证 APAP 诱导的肝损伤的敏感和特异性转化生物标志物迫在眉睫。
在这项研究中，我们评估了过量 APAP 处理的不同时间点的小鼠肝窦内皮细胞和肝细胞中的 APAP 毒性。通过 RT Profiler PCR 阵列研究了 APAP 过量诱导肝窦内皮细胞损伤的潜在机制。通过 2D Matrigel 内皮细胞伪血管形成和多光子显微镜评估 APAP 过量对内皮细胞功能的影响。最后，通过对比增强超声评估 APAP 过量对肝脏氧水平和肝微循环的影响。评估了潜在的基于成像的血管相关标志物，用于早期检测 APAP 诱导的肝损伤。
我们的研究证实，肝内皮细胞是 APAP 肝毒性的早期和直接靶标。细胞间黏附分子 1（ICAM1）相关细胞黏附途径在 APAP 诱导的内皮细胞损伤中发挥了突出作用，这在过量 APAP 后原代人肝窦内皮细胞和人肝中得到了进一步验证。APAP 过量影响内皮细胞伪血管形成和肝血管完整性。使用超声检测 APAP 诱导的肝损伤表明，与传统的基于血液的生物标志物相比，基于成像的血管相关生物标志物平均通过时间（mean transit time）更敏感、更精确，可用于早期检测 APAP 肝毒性和监测治疗反应。
基于成像的血管相关生物标志物可识别 APAP 过量引起的早期和轻度肝损伤。随着进一步的发展，这些生物标志物可能会改善对肝损伤的评估和临床决策的疗效，并可扩展到其他深部器官的微血管功能障碍。
