Sentinels of the brain

23 Apr 2014. Scientists in NUS have discovered the importance of microglia function in neuroinflammatory disease.

Microglia are resident cells in the brain that play a critical role in immune surveillance and maintenance of neural function. Though small in size and number, they respond dynamically to immune stimulus by releasing a cascade of signaling factors that protect the brain. CDr10 has been identified as a small molecule fluorescent probe that selectively labels live microglia over other neural cells and can be applied for live cell imaging of microglia activity. It labels microglia in both their resting and activated states, thus enabling real time monitoring of microglia activity.

This is important for the study of microglia function in neuroinflammatory disease, whereby unregulated microglial activity has been found to cause or exacerbate disease pathogenesis. CDr10 also shows brighter fluorescence in activated microglia, providing a useful indicator of cell activation status (see Figure). Its chloroacetyl motif as been identified to be crucial for its binding stability. The use of this small molecule fluorescent probe supersedes conventional methods of antibody labeling, setting the precedent for novel, live cell labeling approaches.

The discovery of CDr10 as a microglia selective probe makes the labeling of live microglia ultra fast and efficient by simple mixing, demonstrating the superiority of chemical tools in solving biological problems. Its stability makes it possible to carry out long duration time lapse imaging of microglia as well as enabling it to serve as a sensor of cell activation status, applications for which will be invaluable for a host of microglia-related studies.

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Microglia specific fluorescent probes for live cell imaging. [Image credit: Chemical Communications]

Leong C, L.S., Ock J, Li X, See P, Park SJ, Ginhoux F, Yun SW, Chang YT. "Microglia specific fluorescent probes for live cell imaging" Chemical Communications 50 (2013) 1089