Ekaney Michael L, Bockmeyer Clemens L, Sossdorf Maik, Reuken Philipp A, Conradi Florian, Schuerholz Tobias, Blaess Markus F, Friedman Scott L, Lösche Wolfgang, Bauer Michael, Claus Ralf A
Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
Clinic for Anaesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany.
Mol Med. 2015 Apr 3;21(1):355-63. doi: 10.2119/molmed.2014.00202.
In sepsis, the severity-dependent decrease of von Willebrand factor (VWF)-inactivating protease, a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), results in platelet aggregation and consumption, leading to sepsis-associated thrombotic microangiopathy (TMA) and organ failure. Previous reports assessing its functional deficiency have pinpointed involvement of autoantibodies or mutations to propagate thrombotic thrombocytopenic purpura (TTP). However, mechanisms of acquired ADAMTS13 deficiency during host response remain unclear. To enhance understanding of ADAMTS13 deficiency in sepsis, we evaluated changes in expression of mRNA coding ADAMTS13 during septic conditions using primary cellular sources of the protease. We hypothesized that proinflammatory cytokines and constituents of serum from septic patients affect the transcriptional level of ADAMTS13 in vitro, and previously recommended therapeutic agents as adjunctive therapy for sepsis interact therewith. Cultured hepatic stellate cells (HSCs), endothelial cells (HMEC) and human precision-cut liver slices as an ex vivo model were stimulated with sepsis prototypic cytokines, bacterial endotoxin and pooled serum obtained from septic patients. Stimulation resulted in a significant decrease in ADAMTS13 mRNA between 10% and 80% of basal transcriptional rates. Costimulation of selenite or recombinant activated protein C (APC) with serum prevented ADAMTS13 decrease in HSCs and increased ADAMTS13 transcripts in HMEC. In archived clinical samples, the activity of ADAMTS13 in septic patients treated with APC (n = 5) increased with an accompanying decrease in VWF propeptide as surrogate for improved endothelial function. In conclusion, proinflammatory conditions of sepsis repress mRNA coding ADAMTS13 and the ameliorating effect by selenite and APC may support the concept for identification of beneficial mechanisms triggered by these drugs at a molecular level.
在脓毒症中，具有血小板反应蛋白基序的去整合素和金属蛋白酶13（ADAMTS13）这种血管性血友病因子（VWF）失活蛋白酶的严重程度依赖性降低，会导致血小板聚集和消耗，进而引发脓毒症相关的血栓性微血管病（TMA）和器官衰竭。以往评估其功能缺陷的报告指出，自身抗体或突变参与了血栓性血小板减少性紫癜（TTP）的发生。然而，宿主反应过程中获得性ADAMTS13缺乏的机制仍不清楚。为了增进对脓毒症中ADAMTS13缺乏的理解，我们使用该蛋白酶的原代细胞来源评估了脓毒症状态下编码ADAMTS13的mRNA表达变化。我们假设脓毒症患者的促炎细胞因子和血清成分在体外会影响ADAMTS13的转录水平，并且先前推荐的脓毒症辅助治疗药物会与其相互作用。用脓毒症原型细胞因子、细菌内毒素和从脓毒症患者获得的混合血清刺激培养的肝星状细胞（HSC）、内皮细胞（HMEC）以及作为离体模型的人精密肝切片。刺激导致ADAMTS13 mRNA显著降低，降至基础转录率的10%至80%之间。亚硒酸盐或重组活化蛋白C（APC）与血清共同刺激可防止HSC中ADAMTS13降低，并增加HMEC中ADAMTS13转录本。在存档的临床样本中，接受APC治疗的脓毒症患者（n = 5）的ADAMTS13活性增加，同时血管性血友病因子前体肽减少，这是内皮功能改善的替代指标。总之，脓毒症的促炎状态会抑制编码ADAMTS13的mRNA，亚硒酸盐和APC的改善作用可能支持在分子水平上识别这些药物触发的有益机制的概念。
