Fish Adam, Forster James, Malik Vaishali, Kulkarni Ashish
Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
Department of Biomedical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
ACS Appl Mater Interfaces. 2025 Feb 5;17(5):7363-7376. doi: 10.1021/acsami.4c18845. Epub 2025 Jan 21.
The innate immune system is tightly regulated by a complex network of chemical signals triggered by pathogens, cellular damage, and environmental stimuli. While it is well-established that changes in the extracellular environment can significantly influence the immune response to pathogens and damage-associated molecules, there remains a limited understanding of how changes in environmental stimuli specifically impact the activation of the NLRP3 inflammasome, a key component of innate immunity. Here, we demonstrated how shear stress can act as Signal 2 in the NLRP3 inflammasome activation pathway by treating LPS-primed immortalized bone marrow-derived macrophages (iBMDMs) with several physiologically relevant magnitudes of shear stress to induce inflammasome activation. We demonstrated that magnitudes of shear stress within 1.0 to 50 dyn/cm were able to induce ASC speck formation, while 50 dyn/cm was sufficient to induce significant calcium signaling, gasdermin-D cleavage, caspase-1 activity, and IL-1β secretion, all hallmarks of inflammasome activation. Utilizing NLRP3 and caspase-1 knockout iBMDMs, we demonstrated that the NLRP3 inflammasome was primarily activated as a result of shear stress exposure. Quantitative polymerase chain reaction (qPCR), ELISA, and a small molecule inhibitor study aided us in demonstrating that expression of Piezo1, NLRP3, gasdermin-D, IL-1β, and CCL2 secretion were all upregulated in iBMDMs treated with shear stress. This study provides a foundation for further understanding the interconnected pathogenesis of chronic inflammatory diseases and the ability of shear stress to play a role in their progression.
先天性免疫系统受到由病原体、细胞损伤和环境刺激引发的复杂化学信号网络的严格调控。虽然细胞外环境的变化会显著影响对病原体和损伤相关分子的免疫反应这一点已得到充分证实，但对于环境刺激的变化如何具体影响NLRP3炎性小体（先天性免疫的关键组成部分）的激活，人们的了解仍然有限。在此，我们通过用几种生理相关强度的剪切应力处理经脂多糖（LPS）预处理的永生化骨髓来源巨噬细胞（iBMDM）以诱导炎性小体激活，证明了剪切应力如何在NLRP3炎性小体激活途径中充当信号2。我们证明，1.0至50达因/平方厘米范围内的剪切应力强度能够诱导凋亡相关斑点样蛋白（ASC）斑点形成，而50达因/平方厘米足以诱导显著的钙信号传导、gasdermin-D裂解、半胱天冬酶-1活性和白细胞介素-1β分泌，这些都是炎性小体激活的标志。利用NLRP3和半胱天冬酶-1基因敲除的iBMDM，我们证明NLRP3炎性小体主要是由于暴露于剪切应力而被激活。定量聚合酶链反应（qPCR）、酶联免疫吸附测定（ELISA）和小分子抑制剂研究帮助我们证明，在用剪切应力处理的iBMDM中，Piezo1、NLRP3、gasdermin-D、白细胞介素-1β的表达以及CCL2分泌均上调。这项研究为进一步理解慢性炎症性疾病的相互关联发病机制以及剪切应力在其进展中发挥作用的能力提供了基础。
