Rapamycin inhibits human adipocyte differentiation in primary culture

Obes Res. 2000 May;8(3):249-54. doi: 10.1038/oby.2000.29.


Objective: The immunosuppressant drug rapamycin, has been reported to inhibit 3T3-L1 adipocyte differentiation by interfering with critical postconfluent mitoses that are required early on for successful differentiation of this cell line (clonal expansion phase). In contrast to the murine 3T3-L1 preadipocyte cell line, human preadipocytes in primary culture do not undergo clonal expansion during differentiation. We investigated whether rapamycin could inhibit human adipocyte differentiation.

Research methods and procedures: The effect of rapamycin on the induction of differentiation of human preadipocytes in primary culture into adipocytes was measured using Oil Red O staining and glycerol phosphate dehydrogenase activity.

Results: We have observed that rapamycin severely curtails human adipocyte differentiation of both omental and abdominal subcutaneous preadipocytes (to 14% and 19% of standard differentiation, respectively). The rapamycin-mediated inhibition of human adipocyte differentiation could be reversed in the presence of excess amounts of FK-506, which displaces rapamycin from its intracellular receptor, FKPB12. Measurement of cytosolic protein and [3H]thymidine incorporation into DNA confirmed the absence of proliferation during differentiation of human preadipocytes in primary culture.

Discussion: Our data indicate that rapamycin exerts important negative regulatory effects on adipogenesis in human preadipocytes, through a mechanism that does not depend on interruption of clonal expansion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / cytology
  • Adipocytes / drug effects*
  • Adipose Tissue / cytology*
  • Azo Compounds / chemistry
  • Cell Culture Techniques
  • Cell Differentiation / drug effects*
  • Cell Differentiation / physiology
  • Cells, Cultured
  • Coloring Agents / chemistry
  • Female
  • Glycerolphosphate Dehydrogenase / analysis
  • Humans
  • Immunosuppressive Agents / pharmacology*
  • Male
  • Middle Aged
  • Scintillation Counting
  • Sirolimus / pharmacology*
  • Thymidine / chemistry


  • Azo Compounds
  • Coloring Agents
  • Immunosuppressive Agents
  • Glycerolphosphate Dehydrogenase
  • oil red O
  • Thymidine
  • Sirolimus