In this week's Science, a group led by University College London researchers report on a new gene therapy approach that combines optogenetics and embryonic stem cell-based regenerative medicine, and which was used to restore skeletal muscle function in injured and diseased mice. The scientists engineered ESC-derived motor neurons to express the light-sensitive ion channel known as channelrhodopsin-2 and grafted them onto the ligated sciatic nerves in the animals. Blue light was then used to stimulate the transplanted motor neurons, which survived, matured, and grew to help to restore nerve connectivity in the rodents’ lower limb muscles, which had been cut off from the nerves. Though early stage, the findings suggest that light may be a more precise and long-lasting means for controlling motor neurons than electrical stimulation.
In Science Translational Medicine, investigators describe a new computational tool called cell distance mapping, which can be used to track interactions between immune cells in a diseased tissue. The researchers used the approach to discover that, during inflammation, certain immune cells communicate and coordinate their actions in a way that makes inflammation worse. By measuring the distance between cells, the team could pinpoint which of them were in communication, which were activating each other, and which were not active.