A synthetic multifunctional mammalian pH sensor and CO2 transgene-control device

Area of Science:

• Biotechnology
• Synthetic Biology
• Physiology

Background:

• Metabolic processes require a narrow pH range, tightly regulated by the CO2-bicarbonate buffer system.
• Physiological pH fluctuations can indicate critical health states, but direct cellular monitoring is challenging.

Purpose of the Study:

• To engineer a synthetic signaling cascade for precise monitoring of extracellular pH within the physiological range.
• To develop a pH-responsive system controllable by organic acids and gaseous CO2.
• To demonstrate the therapeutic potential of pH-sensing cells in a disease model.

Main Methods:

• Rewiring the human proton-activated cell-surface receptor TDAG8 to chimeric promoters to create a synthetic pH sensor.
• Utilizing organic acids and gaseous CO2 to modulate the synthetic pH sensor's activity.
• Designing gas-programmable logic gates and remote control of cellular functions in microfluidic devices.
• Implanting engineered cells producing insulin into type 1 diabetic mice with ketoacidosis.

Main Results:

• Successfully created a synthetic pH sensor capable of monitoring extracellular pH in the physiological range.
• Demonstrated CO2-triggered biopharmaceutical production in bioreactors and remote control of cellular behavior.
• Engineered cells automatically detected acidic pH in diabetic mice and initiated insulin production.
• The prosthetic network corrected ketoacidosis in type 1 diabetic mice through automated insulin release.

Conclusions:

• A synthetic pH sensor can effectively monitor physiological pH and respond to changes.
• This technology enables controllable biopharmaceutical production and remote cellular function regulation.
• pH-sensing synthetic biology offers a promising therapeutic strategy for metabolic disorders like type 1 diabetes.