AFF4 regulates cellular adipogenic differentiation via targeting autophagy

AFF4 was discovered as a scaffold protein of Super Elongation Complex (SEC) and exhibites an essential function on osteogenesis, tumorigenesis and odontogenesis. However, the adipogenic biological functions of AFF4 need further explorations. Here, we demonstrate that knockdown of AFF4 inhibits adipogenesis in both human mesenchymal stem cells (hMSCs) and lineage-committed 3T3-L1 preadipocytes. Conditional knocking down of Aff4 in transgenic mouse presents a thin body phenotype and impeded adipogenesis. Mechanistically, we define autophagy signaling as a crucial downstream of AFF4 through the combination of RNA-seq and ChIP-seq analyses. Depletion of AFF4 mediates the transcription of crutial autophagy genes ATG5 and ATG16L1. Simultaneous overexpression of ATG5 and ATG16L1 rescues the lineage commitment of AFF4-deficient cells. Our data elucidate that AFF4 is indispensable for adipogenic differentiation and reveal a novel mechanism for adipogenesis at transcriptional level. RNA profiles of AFF4 knockdown (siRNA) hMSCs versus the control cells