Effect of Adhesion and Substrate Elasticity on Neutrophil Extracellular Trap Formation
Effect of Adhesion and Substrate Elasticity on Neutrophil Extracellular Trap Formation
复制标题
粘附和基质弹性对神经细胞外陷阱形成的影响
DOI：
10.3389/fimmu.2019.02320
复制
发表时间：
2019-10-01
影响因子：
7.3
通讯作者：
Kruss, Sebastian
中科院分区：
文献类型：
--
作者：
Erpenbeck, Luise;Gruhn, Antonia Luise;Kruss, Sebastian
中性粒细胞是白细胞中数量最多的一种。在刺激下，它们能够去致密化并释放染色质作为中性粒细胞胞外陷阱（NETs）。这一过程（NETosis）是免疫防御机制的一部分，但在许多慢性和炎症性疾病（如动脉粥样硬化、类风湿性关节炎、糖尿病和癌症）中也起着重要作用。由于这个原因，很多努力已经投入到了解NETosis的生化信号通路。然而，机械微环境和粘附对NETosis的影响尚不清楚。在这里，我们研究了粘附性，特别是基质弹性如何影响NETosis。我们采用弹性明确的聚丙烯酰胺（PAA）凝胶（杨氏模量E）在1至128 kPa的生理相关范围内，并用整合素配体（胶原I，纤维蛋白原）包裹凝胶。在这些底物上培养中性粒细胞，并用有效的NETosis诱诱剂：phorbol 12-肉豆蔻酸13-乙酸酯（PMA）和脂多糖（LPS）刺激。有趣的是，pma诱导的NETosis既不受底物弹性的影响，也不受不同整合素配体的影响。相比之下，在LPS刺激下，NETosis率随着底物弹性的增加而增加（e> 20 kPa）。lps诱导的NETosis随着细胞接触面积的增加而增加，而pma诱导的NETosis完全不需要粘附。此外，抑制参与粘附信号传导的磷脂酰肌苷3激酶（PI3K）完全消除了lps诱导的NETosis，但仅轻微降低了pma诱导的NETosis。总之，我们表明lps诱导的NETosis依赖于粘附和底物弹性，而pma诱导的NETosis完全独立于粘附。
Neutrophils are the most abundant type of white blood cells. Upon stimulation, they are able to decondense and release their chromatin as neutrophil extracellular traps (NETs). This process (NETosis) is part of immune defense mechanisms but also plays an important role in many chronic and inflammatory diseases such as atherosclerosis, rheumatoid arthritis, diabetes, and cancer. For this reason,much effort has been invested into understanding biochemical signaling pathways in NETosis. However, the impact of the mechanical micro-environment and adhesion on NETosis is not well-understood. Here, we studied how adhesion and especially substrate elasticity affect NETosis. We employed polyacrylamide (PAA) gels with distinctly defined elasticities (Young's modulus E) within the physiologically relevant range from 1 to 128 kPa and coated the gels with integrin ligands (collagen I, fibrinogen). Neutrophils were cultured on these substrates and stimulated with potent inducers of NETosis: phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS). Interestingly, PMA-induced NETosis was neither affected by substrate elasticity nor by different integrin ligands. In contrast, for LPS stimulation, NETosis rates increased with increasing substrate elasticity (E > 20 kPa). LPS-induced NETosis increased with increasing cell contact area, while PMA-induced NETosis did not require adhesion at all. Furthermore, inhibition of phosphatidylinositide 3 kinase (PI3K), which is involved in adhesion signaling, completely abolished LPS-induced NETosis but only slightly decreased PMA-induced NETosis. In summary, we show that LPS-induced NETosis depends on adhesion and substrate elasticity while PMA-induced NETosis is completely independent of adhesion.