A group of researchers from the University of California at San Francisco has developed a new method for differentiation of stem cells that relies on beams of light.
Until now, many different molecular cues that signal stem cells to differentiate into their mature form have been discovered. However, directing stem cells to differentiate on demand on a population level has been difficult. Now, a completely new method that relies on light signals to direct populations of stem cells to differentiate has been described.
The work originates from Dr. Matt Thompson’s lab at the Department of Cellular and Molecular and colleagues at the Center for Systems and Synthetic Biology at UCSF. Dr. Thompson and colleagues engineered cultured mouse embryonic stem cells which responded to a pulse of blue light to switch on the Brn2 gene, a potent neural differentiation cue. By exposing cells to pulses of Brn2, they discovered that differentiation was “Switched on” when both a certain magnitude and duration of light threshold were met. The signal was completely ignored when it was not long or not intense enough.
By fluorescently labeling transcription factor Nanog with a GFP reporter, they discovered that Nanog is in fact the key to directing differentiation by responding to Brn2 triggers.
The paper, titled “Transcription Factor Competition Allows Embryonic Stem Cells to Distinguish Authentic Signals from Noise,” was published this week in the journal Cell Systems.
While these are merely preliminary results and more work on both the in vitro and, in particular, the in vivo efficacy yet have to take place, there is the hope that such mechanisms may be applicable to other cell types and tissues.