Les facteurs modulant l’expression des adipokines en relation avec l’insulinorésistance associée à l’obésité

Abstract

L'obésité est fréquemment associée à une insulinorésistance. Celle-ci trouve son origine, à la fois, dans le dysfonctionnement de la voie de signalisation de l'insuline, mais également dans la modification du profil d'expression des adipokines, avec notamment une augmentation de la synthèse des adipokines pro-inflammatoires. Au niveau du tissu adipeux, de nombreux facteurs tels que l'hypoxie, l'augmentation des concentrations circulantes d'acides gras libres ou encore l'induction d'un stress oxydant, semblent être autant de facteurs causaux de cette dysrégulation des adipokines.Abstract: Obesity is frequently linked to insulin resistance. Insulin resistance results from dysfunctions in insulin signalling pathways and the modification of adipokine expression patterns, most notably the production of inflammatory adipokines. In adipose tissue, multiple factors, like hypoxia, increase the plasma concentration of free fatty acids and induce oxidative stress, both of which appear to be involved in adipokine dysregulation.

Lycopene inhibits proinflammatory cytokine and chemokine expression in adipose tissue

“…Thus, with these ex vivo cultures, we were able to evaluate the effect of a concentration of lycopene equivalent to that found in human plasma after tomato sauce consumption [24] on proinflammatory cytokine/chemokine expression. It is noteworthy that results obtained on the expression of proinflammatory cytokines such as IL-6, MCP-1 or IL-1β (at mRNA and protein levels) in adipose tissue, in response to HFD or TNFα incubation, are consistent with in vivo studies [5,9,11]. In addition, the two ex vivo approaches, i.e., HFD and TNFα incubation, revealed a similar range of induction of the different cytokine/chemokine measured.…”

“…This low-grade inflammatory state is notably characterized by the activation of inflammatory pathways (JNK and NF-κB) in adipose tissue [7,8] and increased production of cytokines and chemokines such as interleukin 6 (IL-6), interleukin 1 beta (IL-1 β), tumor necrosis factor alpha (TNFα) and monocyte chemotactic protein 1 (MCP-1), and of acute phase proteins such as C-reactive protein (CRP) [4,5,[9][10][11].…”