AsianScientist (May 3, 2019) – A research group in China has found a way to use light to guide stem cells towards sites of injury. They published their work in Nano Letters.
Complex signaling pathways coordinate cellular activities such as movement, proliferation and even death. For example, when signaling molecules bind to proteins called receptor tyrosine kinases on a cell’s surface, they trigger the receptors to form pairs and phosphorylate each other. This process can activate other proteins that ultimately lead to a cell moving or growing.
Seeking to take advantage of receptor tyrosine kinases to manipulate the behavior and properties of stem cells, scientists led by Professor Wang Hong-Hui and Nie Zhou at Hunan University, China, engineered receptor tyrosine kinases that responded to infrared light rather than signaling molecules. The researchers chose near-infrared light because it can go through living tissues, unlike ultraviolet or visible light, and decided to target a receptor tyrosine kinase called MET, which is essential for wound healing.
Importantly, they designed a DNA molecule that can bind to two MET receptors simultaneously, linking them together and activating them. To make the system responsive to light, the team attached multiple copies of the DNA sequence to gold nanorods.
When illuminated with near-infrared light, the nanorods heated up and released the DNA so that it could activate the receptors. The researchers injected the DNA-bound gold nanorods into mice at the site of an injury and shone a near-infrared light on the mice for a few minutes. After three days, more muscle stem cells had migrated to the wound in treated mice than in control mice. The treated mice also showed increased signs of muscle regeneration compared with untreated mice.
The article can be found at: Wang et al. (2019) Near-Infrared Light-Activated DNA-Agonist Nanodevice for Nongenetically and Remotely Controlled Cellular Signaling and Behaviors in Live Animals.
Source: American Chemical Society; Photo: Shutterstock.
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