Melatonin promotes circadian rhythm-induced proliferation through Clock/histone deacetylase 3/c-Myc interaction in mouse adipose tissue

J Pineal Res. 2017 May;62(4). doi: 10.1111/jpi.12383. Epub 2017 Mar 21.


Melatonin is synthesized in the pineal gland and controls circadian rhythm of peripheral adipose tissue, resulting in changes in body weight. Although core regulatory components of clock rhythmicity have been defined, insight into the mechanisms of circadian rhythm-mediated proliferation in adipose tissue is still limited. Here, we showed that melatonin (20 mg/kg/d) promoted circadian and proliferation processes in white adipose tissue. The circadian amplitudes of brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal1, P<.05) and circadian locomotor output cycles kaput (Clock, P<.05), period 2 (Per2, P<.05), cyclin E (P<.05), and c-Myc (P<.05) were directly increased by melatonin in adipose tissue. Melatonin also promoted cell cycle and increased cell numbers (P<.05), which was correlated with the Clock expression (P<.05). Further analysis demonstrated that Clock bound to the E-box elements in the promoter region of c-Myc and then directly stimulated c-Myc transcription. Moreover, Clock physically interacted with histone deacetylase 3 (HDAC3) and formed a complex with c-Myc to promote adipocyte proliferation. Melatonin also attenuated circadian disruption and promoted adipocyte proliferation in chronic jet-lagged mice and obese mice. Thus, our study found that melatonin promoted adipocyte proliferation by forming a Clock/HDAC3/c-Myc complex and subsequently driving the circadian amplitudes of proliferation genes. Our data reveal a novel mechanism that links circadian rhythm to cell proliferation in adipose tissue. These findings also identify a new potential means for melatonin to prevent and treat sleep deprivation-caused obesity.

Keywords: adipose; c-Myc; circadian clock; melatonin; proliferation.

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Adipose Tissue / cytology*
  • Adipose Tissue / metabolism*
  • Animals
  • Blotting, Western
  • CLOCK Proteins / genetics
  • CLOCK Proteins / metabolism*
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Central Nervous System Depressants / pharmacology
  • Circadian Rhythm / drug effects*
  • Circadian Rhythm / genetics
  • Histone Deacetylases / genetics
  • Histone Deacetylases / metabolism*
  • Immunoprecipitation
  • Male
  • Melatonin / pharmacology*
  • Mice
  • Mice, Inbred C57BL
  • Protein Binding / drug effects
  • Protein Binding / genetics
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Real-Time Polymerase Chain Reaction


  • Central Nervous System Depressants
  • Proto-Oncogene Proteins c-myc
  • CLOCK Proteins
  • Histone Deacetylases
  • histone deacetylase 3
  • Melatonin