Researchers in Switzerland at the Swiss Federal Institute for Technology engineered cells, have reached a method to control the insulin level in mice by light, using a protein from a human retina “melanopsin”. That may be a breakthrough in the production of biological drugs, like the drugs for cancer. The idea lies in enabling precise control over protein production. Cells engineered will be able to carry the light-sensitive switch that could be implanted into patients to produce a missing hormone, such as insulin, on demand.
The protein triggers a surge in calcium inside the cell when exposed to light. That calcium surge activates a second component, a protein that can be linked to any gene of interest. Shining light on the cells triggers the calcium, which activates the protein, thereby turning on the target gene. According to experiments in cultured cells, the timing and intensity of light controls both the amount and timing of the gene produced.
Researchers demonstrated the technology by implanting light-controlled cells into diabetic mice and using light to manipulate the animals’ insulin levels. When the cells were implanted just beneath the skin, exposure to blue light triggered insulin production. In a second experiment, researchers encapsulated the cells in a porous material and implanted them more deeply into the body, along with a fiber-optic cable to deliver light when needed. Both methods were able to control the animals’ blood sugar. The Swiss research is the latest effort to control increasingly complex biological functions with light. Most of the research has focused on brain cells, and activating and silencing them through light-sensitive channels—a rapidly growing field known as optogenetics. But a handful of researchers are fusing optogenetics techniques with synthetic biology, an offshoot of molecular biology that attempts to engineer cells to perform useful functions.