Bogguri Chandrakumar, George Vivek Kurien, Amiri Beheshta, Ladd Alexander, Hum Nicholas R, Sebastian Aimy, Enright Heather A, Valdez Carlos A, Mundhenk T Nathan, Cadena Jose, Lam Doris
Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States.
Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States.
Front Cell Neurosci. 2024 Sep 5;18:1378579. doi: 10.3389/fncel.2024.1378579. eCollection 2024.
Organophosphorus nerve agents (OPNA) are hazardous environmental exposures to the civilian population and have been historically weaponized as chemical warfare agents (CWA). OPNA exposure can lead to several neurological, sensory, and motor symptoms that can manifest into chronic neurological illnesses later in life. There is still a large need for technological advancement to better understand changes in brain function following OPNA exposure. The human-relevant multi-electrode array (MEA) system, which combines the MEA technology with human stem cell technology, has the potential to monitor the acute, sub-chronic, and chronic consequences of OPNA exposure on brain activity. However, the application of this system to assess OPNA hazards and risks to human brain function remains to be investigated. In a concentration-response study, we have employed a human-relevant MEA system to monitor and detect changes in the electrical activity of engineered neural networks to increasing concentrations of the sarin surrogate 4-nitrophenyl isopropyl methylphosphonate (NIMP). We report a biphasic response in the spiking (but not bursting) activity of neurons exposed to low (i.e., 0.4 and 4 μM) versus high concentrations (i.e., 40 and 100 μM) of NIMP, which was monitored during the exposure period and up to 6 days post-exposure. Regardless of the NIMP concentration, at a network level, communication or coordination of neuronal activity decreased as early as 60 min and persisted at 24 h of NIMP exposure. Once NIMP was removed, coordinated activity was no different than control (0 μM of NIMP). Interestingly, only in the high concentration of NIMP did coordination of activity at a network level begin to decrease again at 2 days post-exposure and persisted on day 6 post-exposure. Notably, cell viability was not affected during or after NIMP exposure. Also, while the catalytic activity of AChE decreased during NIMP exposure, its activity recovered once NIMP was removed. Gene expression analysis suggests that human iPSC-derived neurons and primary human astrocytes resulted in altered genes related to the cell's interaction with the extracellular environment, its intracellular calcium signaling pathways, and inflammation, which could have contributed to how neurons communicated at a network level.
有机磷神经毒剂（OPNA）是平民面临的有害环境暴露物，在历史上曾被用作化学战剂（CWA）。接触OPNA会导致多种神经、感觉和运动症状，这些症状可能在以后的生活中发展为慢性神经疾病。目前仍迫切需要技术进步，以更好地了解OPNA暴露后大脑功能的变化。与人类相关的多电极阵列（MEA）系统将MEA技术与人类干细胞技术相结合，有潜力监测OPNA暴露对大脑活动的急性、亚慢性和慢性影响。然而，该系统在评估OPNA对人类脑功能的危害和风险方面的应用仍有待研究。在一项浓度-反应研究中，我们使用了与人类相关的MEA系统，来监测和检测工程神经网络的电活动随沙林替代物4-硝基苯基异丙基甲基膦酸酯（NIMP）浓度增加而发生的变化。我们报告了暴露于低浓度（即0.4和4 μM）与高浓度（即40和100 μM）NIMP的神经元的尖峰（而非爆发）活动出现双相反应，该反应在暴露期间及暴露后长达6天进行监测。无论NIMP浓度如何，在网络水平上，神经元活动的通信或协调早在60分钟时就开始下降，并在NIMP暴露24小时时持续存在。一旦去除NIMP，协调活动与对照（0 μM NIMP）无异。有趣的是，仅在高浓度NIMP情况下，网络水平的活动协调在暴露后2天再次开始下降，并在暴露后第6天持续存在。值得注意的是，NIMP暴露期间及之后细胞活力未受影响。此外，虽然NIMP暴露期间乙酰胆碱酯酶（AChE）的催化活性降低，但去除NIMP后其活性恢复。基因表达分析表明，人诱导多能干细胞衍生的神经元和原代人星形胶质细胞导致与细胞与细胞外环境相互作用、细胞内钙信号通路和炎症相关的基因发生改变，这可能影响了神经元在网络水平上的通信方式。
