PU.1 promotes miR-191 to inhibit adipogenesis in 3T3-L1 preadipocytes.

PU.1, an Ets family transcription factor, was previously demonstrated expressed in 3T3-L1 preadipocytes and had an negative effect on adiopogenesis. However, the underlying mechanism remains elusive. Here, miR-191 was identified as an inhibitor of adipocyte differentiation through targeting the 3' untranslated regions of C/EBPβ, the initial factor in the C/EBPα/β-PPARγ terminal pathway of adipogenic differentiation. MiR-191 suppressed the lipid accumulation by Oil Red O staining and downregulated the levels of adipogenic marker genes PPARγ (P<0.01), aP2 (P<0.01) and FAS (P<0.05). Then, we found that PU.1 overexpression resulted in upregulation of miR-191 and adipogenic inhibition. Likewise, PU.1 overexpression rescued the miR-191 decrease and resisted the adipogenic promotion caused by miR-191 oligonucleotide inhibitor. Collectively, these results revealed that PU.1 promoted miR-191 to suppress adipogenesis 3T3-L1 preadipocyte and indicated a new mechanism of PU.1 inhibiting adipogenesis.