Transforming growth factor-beta enhances and pro-inflammatory cytokines inhibit ob gene expression in 3T3-L1 adipocytes.
Leptin is a protein which is encoded by the obese (ob) gene. It is synthesized by adipocytes and binds to receptors in the hypothalamus, thereby suppressing appetite and increasing the metabolic rate. When mouse 3T3-L1 cells are induced to differentiate into adipocytes, they begin to constitutively express low levels of ob mRNA. Using reverse transcription and a semi-quantitative polymerase chain reaction, the experiments described herein demonstrate that the anti-inflammatory cytokine transforming growth factor-beta increases steady state ob mRNA. Conversely, treatment of 3T3-L1 adipocytes with the pro-inflammatory cytokines interleukin-1 beta, interleukin-6, interleukin-11, and tumor necrosis factor-alpha results in a decrease in ob transcripts. When considered in the context of animal studies showing that interleukin-1 and tumor necrosis factor-alpha induce leptin and ob mRNA, these results suggest that pro-inflammatory cytokines induce ob gene transcription in vivo via secondary mediators such as transforming growth factor-beta.
Granowitz
E V
EV
Department of Medicine, Baystate Medical Center, Springfield, Massachusetts, USA. granowitz@bmcsouth.bhs.org
D016475:3T3 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D016207:Cytokines / Q000494:pharmacology*; D017931:DNA Primers; D004357:Drug Synergism; D007249:Inflammation; D007375:Interleukin-1 / Q000494:pharmacology; D017370:Interleukin-11 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D020738:Leptin; D051379:Mice; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects* / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D016207:Cytokines; D017931:DNA Primers; D007375:Interleukin-1; D017370:Interleukin-11; D015850:Interleukin-6; D020738:Leptin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha