Dual suppression of adipogenesis by cigarette smoke through activation of the aryl hydrocarbon receptor and induction of endoplasmic reticulum stress.
Cigarette smoking decreases body weight, whereas molecular mechanisms underlying this phenomenon have not been elucidated. In this report, we investigated regulation of adipogenesis by cigarette smoke and involvement of aryl hydrocarbon receptor (AhR) and endoplasmic reticulum (ER) stress. We found that cigarette smoke extract (CSE) inhibited differentiation of preadipocytes into adipocytes dose dependently. It was associated with a decrease in lipid accumulation, blunted expression of adipocyte markers (adiponectin, PPAR-gamma, and C/EBPalpha), and sustained expression of a preadipocyte marker MCP-1. CSE markedly induced activation of AhR, and AhR agonists (2,3,7,8-tetrachlorodibenzo-p-dioxin, benzo[a]pyrene and 3-methylcholanthrene) reproduced the inhibitory effect of CSE on adipocyte differentiation. Furthermore, knockout of the AhR gene or blockade of AhR by a dominant-negative mutant attenuated the suppressive effects of CSE on adipocyte differentiation. We also found that CSE induced ER stress in preadipocytes, and ER stress inducers (thapsigargin, tunicamycin, and A23187) reproduced the suppressive effect of CSE on the differentiation of preadipocytes. Interestingly, AhR agonists did not cause ER stress, and ER stress inducers did not activate AhR. These results suggested that cigarette smoke has the potential to inhibit adipocyte differentiation via dual, independent mechanisms, i.e., through activation of the AhR pathway and induction of the unfolded protein response.
Shimada
Tsuyoshi
T
Department of Molecular Signaling, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Shimokato 1110, Chuo, Yamanashi 409-3898, Japan.
Hiramatsu
Nobuhiko
N
Hayakawa
Kunihiro
K
Takahashi
Shuhei
S
Kasai
Ayumi
A
Tagawa
Yasuhiro
Y
Mukai
Mai
M
Yao
Jian
J
Fujii-Kuriyama
Yoshiaki
Y
Kitamura
Masanori
M
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D050156:Adipogenesis / Q000187:drug effects* / Q000235:genetics; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D017510:Protein Folding / Q000187:drug effects; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D012906:Smoke / Q000009:adverse effects*; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D014026:Nicotiana / Q000009:adverse effects
D018336:Receptors, Aryl Hydrocarbon; D012906:Smoke