LSD1-a pivotal epigenetic regulator of brown and beige fat differentiation and homeostasis.

In this issue of Genes & Development, Zeng and colleagues (pp. 1822-1836) identify lysine-specific demethylase 1 (LSD1) as a pivotal regulator of whole-body energy expenditure by controlling the oxidative and thermogenic activity of brown adipose tissue (BAT). They show that LSD1 interacts with PRDM16 to repress select white adipose tissue (WAT) genes but also represses hydroxysteroid 11-β-dehydrogenase 1 (HSD11B1) independently of PRDM16 to prevent production of glucocorticoids that impair BAT functions. Their study provides important insight into epigenetic mechanisms regulating the function of BAT.