Interleukin-6 is a negative regulator of visfatin gene expression in 3T3-L1 adipocytes.
Visfatin is a novel adipocytokine exerting insulin-mimetic effects in various insulin-sensitive tissues such as liver, muscle, and fat. In contrast, interleukin (IL)-6 is a proinflammatory adipose-secreted factor that induces insulin resistance and plasma concentrations that correlate with the development of type 2 diabetes mellitus. In the present study, the impact of IL-6 on visfatin gene expression in 3T3-L1 adipocytes was determined by quantitative real-time reverse transcription-polymerase chain reaction. Interestingly, 30 ng/ml IL-6 time-dependently downregulated visfatin synthesis with a significant 40% suppression seen after 4 h of treatment. Furthermore, the addition of IL-6 for 16 h dose-dependently suppressed visfatin mRNA with significant effects first observed at concentrations as low as 3 ng/ml and a maximal 43% reduction at 30 ng/ml effector. Moreover, inhibitor studies suggested that the negative effect of IL-6 on visfatin expression is, at least in part, mediated by p44/42 mitogen-activated protein kinase. In contrast, troglitazone did not reverse the negative effect of IL-6 on visfatin synthesis under these conditions. Taken together, our study suggests that IL-6 might influence glucose tolerance in part by regulation of the novel insulin-mimetic adipocytokine visfatin.
Kralisch
Susan
S
Department of Internal Medicine III, University of Leipzig, Germany.
Klein
Johannes
J
Lossner
Ulrike
U
Bluher
Matthias
M
Paschke
Ralf
R
Stumvoll
Michael
M
Fasshauer
Mathias
M
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D016207:Cytokines / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D015850:Interleukin-6 / Q000008:administration & dosage*; D051379:Mice; D054409:Nicotinamide Phosphoribosyltransferase
D016207:Cytokines; D015850:Interleukin-6; D054409:Nicotinamide Phosphoribosyltransferase; C495867:nicotinamide phosphoribosyltransferase, mouse