CCAAT/enhancer-binding protein beta is not affected by tetrachlorodibenzo-p-dioxin (TCDD) inhibition of 3T3-L1 preadipocyte differentiation.
The differentiation of 3T3-L1 preadipocytes is induced by the coordinate activation of trans-acting factors in response to inducers. Depending on the time of treatment, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was effective in inhibiting 3T3-L1 preadipocyte differentiation and the expression of differentiation-dependent trans-acting factors. Based on glycerol-3-phosphate dehydrogenase activity, in the differentiation of 3T3-L1 cells was decreased by 70% in cells treated with TCDD before the induction of differentiation, 25% during induction, and not at all after induction. This time-dependent inhibition of cell differentiation by TCDD was correlated with the levels of aryl hydrocarbon receptor (AhR). TCDD treatment decreased the mRNA levels of C/EBP alpha and PPAR gamma 2 but did not affect the mRNA levels of RXR alpha and RAR alpha. Furthermore, TCDD did not change the mRNA or protein levels of C/EBP beta, which is thought to play a role in inducing C/EBP alpha and PPAR gamma 2 expression. These results suggest that TCDD inhibited 3T3-L1 preadipocyte differentiation through the AhR pathway, and the change of C/EBP beta mRNA and protein was not involved in reducing mRNA expression of C/EBP alpha and PPAR gamma 2.
Chen
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CL
Department of Animal Sciences, Oregon State University, Corvallis 97331, USA.
Brodie
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AE
Hu
C Y
CY
D016475:3T3 Cells; D017667:Adipocytes / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000032:analysis; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D013723:Teratogens / Q000494:pharmacology*; D013997:Time Factors; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D018160:Receptors, Cytoplasmic and Nuclear; D013723:Teratogens; D014157:Transcription Factors