Hemmer Christoph J, Vogt Anna, Unverricht Marcus, Krause Robert, Lademann Matthias, Reisinger Emil C
Department of Tropical Medicine and Infectious Diseases, University of Rostock Medical School, Rostock, Germany.
Crit Care Med. 2008 Sep;36(9):2562-8. doi: 10.1097/CCM.0b013e31818441ee.
Apoptotic endothelial damage contributes to multiorgan failure in Plasmodium falciparum malaria and in sepsis. In malaria, endothelial apoptosis is amplified by neutrophils and their secretory products, and reduced by inhibitors of neutrophil-derived substances in vitro. We compared the mechanisms of endothelial apoptosis in malaria and in sepsis, using the human umbilical vein endothelial cell as a model.
Endothelial cells were incubated with patient sera (P. falciparum malaria, Escherichia coli sepsis, Staphylococcus aureus sepsis) or culture supernatants of the respective organisms, with or without neutrophils. Ascorbic acid or ulinastatin was used to neutralize reactive oxygen species or elastase secreted by neutrophils. Transwell sieve inserts or antibodies against leukocyte function antigen 1 or intercellular adhesion molecule 1 was used to study the effect of direct interaction between neutrophils and endothelial cells. The rate of apoptotic endothelial cells was determined by TUNEL and annexin staining.
Incubation of endothelial cells with patient sera or culture supernatants (P. falciparum, E. coli, S. aureus) lead to higher apoptosis rates, compared with incubation with control sera or control supernatants. Addition of neutrophils augmented the apoptosis rate further. Addition of ascorbic acid or ulinastatin reduced endothelial apoptosis in the presence of neutrophils. Separation of neutrophils from endothelial cells with Transwell sieve inserts, or addition of anti-leukocyte function antigen-1 antibodies also reduced endothelial cell apoptosis. However, addition of anti-intercellular adhesion molecule-1 antibodies restored high apoptosis rates that had been reduced by Transwell inserts.
These in vitro results show how neutrophils can contribute to endothelial damage in malaria and in sepsis, both by their secretory products and by binding to intercellular adhesion molecule-1 on endothelial cells. The presence of similar pathomechanisms suggests that similar antiapoptotic strategies may offer potential benefit in malaria and in sepsis.
凋亡性内皮损伤导致恶性疟原虫疟疾和脓毒症中的多器官功能衰竭。在疟疾中，中性粒细胞及其分泌产物会加剧内皮细胞凋亡，而在体外，中性粒细胞衍生物质的抑制剂可降低内皮细胞凋亡。我们以人脐静脉内皮细胞为模型，比较了疟疾和脓毒症中内皮细胞凋亡的机制。
将内皮细胞与患者血清（恶性疟原虫疟疾、大肠杆菌脓毒症、金黄色葡萄球菌脓毒症）或相应病原体的培养上清液共同孵育，同时或不加入中性粒细胞。使用抗坏血酸或乌司他丁来中和中性粒细胞分泌的活性氧或弹性蛋白酶。使用Transwell筛板插入物或抗白细胞功能抗原1或细胞间黏附分子1的抗体来研究中性粒细胞与内皮细胞直接相互作用的影响。通过TUNEL和膜联蛋白染色来测定凋亡内皮细胞的比例。
与对照血清或对照上清液孵育相比，内皮细胞与患者血清或培养上清液（恶性疟原虫、大肠杆菌、金黄色葡萄球菌）孵育会导致更高的凋亡率。加入中性粒细胞会进一步提高凋亡率。在有中性粒细胞存在的情况下，加入抗坏血酸或乌司他丁可降低内皮细胞凋亡。用Transwell筛板插入物将中性粒细胞与内皮细胞分离，或加入抗白细胞功能抗原-1抗体也可降低内皮细胞凋亡。然而加入抗细胞间黏附分子-1抗体可恢复因Transwell插入物而降低的高凋亡率。
这些体外实验结果表明，中性粒细胞可通过其分泌产物以及与内皮细胞上的细胞间黏附分子-1结合，导致疟疾和脓毒症中的内皮损伤。相似病理机制的存在表明，相似的抗凋亡策略可能对疟疾和脓毒症具有潜在益处。
