Enzyme may link inflammation to new cell fate

Gene silencing is the sine qua non of differentiation, and reversal of gene silencing paves the way for a cell to adopt a new fate. In a new study, Francesca De Santa, Giaocchino Natoli, and colleagues (European Institute of Oncology, Milan, Italy) identify a desilencing protein that might let cells find new fates during inflammation.

“Under conditions of chronic inflammation, tissues tend to show altered differentiation,” Natoli says. Chronic gastritis, for instance, can lead to the formation of intestinal cells within the stomach lining. And in a rejected kidney transplant, host macrophages turn into endothelial cells, creating new lymphatic vessels.

For macrophages to adopt new fates, a lysine in histone H3 must first be demethylated to relieve the silencing of cell fate determinants. One group of enzymes...