Central players in inherited lipodystrophies.

Common obesity and inherited lipodystrophies, rare disorders characterized by a partial (familial partial lipodystrophy; FPLD) or complete (congenital generalized lipodystrophy; CGL) lack of adipose tissue, are both associated with metabolic complications such as insulin resistance and type 2 diabetes. Mutations in the transcription factor peroxisome proliferator activated receptor (PPAR)γ and a number of its downstream target genes result in lipodystrophy. We hypothesize that signalling by another transcription factor, sterol response element binding protein (SREBP)1c, also needs to be intact to prevent lipodystrophy. The future challenge is to understand how inactivation of such central players or of their upstream regulators or downstream effectors can affect adipose tissue in a depot-specific fashion.