title: Circadian rhythms in adipose tissue:  an update.
abstract: OBJECTIVE
  Over the past decade, evidence has accumulated from basic science, clinical and epidemiological studies linking circadian mechanisms to adipose tissue biology and its related comorbidities, diabetes, metabolic syndrome and obesity. This review highlights recent in-vitro and in-vivo findings from murine, human and model organism studies.
  
  
  RESULTS
  High-fat diets attenuate circadian mechanisms in murine adipose depots and these effects appear to be due to obesity rather than hyperglycemia. Deletion of circadian regulatory genes such as AMPK1 and nocturnin alter the circadian biology of adipose tissue. Unlike the mouse, circadian gene oscillation in human adipose tissue appears to be independent of BMI and diabetes status, suggesting that circadian mechanistic variation occurs across species. Clues for future directions in this emerging field come from studies of the hibernation and torpor state in mammals and infection models involving the Drosophila metabolic organ or 'fat body'.
  
  
  CONCLUSIONS
  There is a growing consensus that circadian rhythms and metabolism are tightly regulated in adipose tissue and peripheral metabolic organs. Although central mechanisms are critical, autonomous clocks exist within the adipocytes themselves. Future circadian advances are likely to result from the studies of adipose tissue-specific gene deletions.
authors: Stem Cell Biology Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. gimblejm@pbrc.edu
authors: Jeffrey M
authors: JM
authors: Gimble
authors: Gregory M
authors: GM
authors: Sutton
authors: Andrey A
authors: AA
authors: Ptitsyn
authors: Z Elizabeth
authors: ZE
authors: Floyd
authors: Bruce A
authors: BA
authors: Bunnell
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D017667:Adipocytes; D000273:Adipose Tissue / Q000378:metabolism* / Q000503:physiopathology*; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D059305:Diet, High-Fat; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D006801:Humans; D051379:Mice; D023421:Models, Animal; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D009687:Nuclear Proteins; D014157:Transcription Factors; C102804:nocturnin; D055372:AMP-Activated Protein Kinases