Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland.
IUT Lyon 1, Département Génie Biologique, 74 Boulevard Niels Bohr, 69622 Villeurbanne Cedex, France.
Mol Cell. 2014 Aug 7;55(3):397-408. doi: 10.1016/j.molcel.2014.06.007. Epub 2014 Jul 10.
All metabolic activities operate within a narrow pH range that is controlled by the CO2-bicarbonate buffering system. We hypothesized that pH could serve as surrogate signal to monitor and respond to the physiological state. By functionally rewiring the human proton-activated cell-surface receptor TDAG8 to chimeric promoters, we created a synthetic signaling cascade that precisely monitors extracellular pH within the physiological range. The synthetic pH sensor could be adjusted by organic acids as well as gaseous CO2 that shifts the CO2-bicarbonate balance toward hydrogen ions. This enabled the design of gas-programmable logic gates, provided remote control of cellular behavior inside microfluidic devices, and allowed for CO2-triggered production of biopharmaceuticals in standard bioreactors. When implanting cells containing the synthetic pH sensor linked to production of insulin into type 1 diabetic mice developing diabetic ketoacidosis, the prosthetic network automatically scored acidic pH and coordinated an insulin expression response that corrected ketoacidosis.
所有代谢活动都在由二氧化碳-碳酸氢盐缓冲系统控制的狭窄 pH 范围内进行。我们假设 pH 值可以作为替代信号来监测和响应生理状态。通过将人质子激活细胞表面受体 TDAG8 功能重接到嵌合启动子上，我们创建了一个合成信号级联反应，可精确监测生理范围内的细胞外 pH 值。该合成 pH 传感器可被有机酸以及气态 CO2 调节，从而使 CO2-碳酸氢盐平衡向氢离子转移。这使得设计气体可编程逻辑门成为可能，为微流控设备内部的细胞行为提供了远程控制，并允许在标准生物反应器中 CO2 触发生物制药的生产。当将含有与胰岛素生产相关的合成 pH 传感器的细胞植入到发生糖尿病酮症酸中毒的 1 型糖尿病小鼠中时，该假体网络会自动记录酸性 pH 值，并协调胰岛素表达反应以纠正酮症酸中毒。
