Increased Expression of Visfatin in Macrophages of Human Unstable Carotid and Coronary Atherosclerosis

Abstract

Background-Although the participation of inflammation in atherogenesis is widely recognized, the identification of the different components has not been clarified. In particular, the role of inflammation in plaque destabilization is not fully understood. Methods and Results-Our main findings were as follows: (1) In a microarray experiment, we identified visfatin, one of the most recently identified adipokines, as a gene that was markedly enhanced in carotid plaques from symptomatic compared with plaques from asymptomatic individuals. This finding was confirmed when carotid plaques from 7 patients with asymptomatic and 14 patients with symptomatic lesions were examined with real-time reverse transcription polymerase chain reaction. (2) Immunohistochemistry showed that visfatin was localized in areas that were rich in lipid-loaded macrophages. (3) The relationship between visfatin and unstable lesions was also found in patients with coronary artery disease, demonstrating a strong visfatin immunostaining in lipid-rich regions within the material obtained at the site of plaque rupture in patients with acute myocardial infarction. (4) Both oxidized low-density lipoprotein and tumor necrosis factor-␣ increased visfatin expression in THP-1 monocytes, with a particularly enhancing effect when these stimuli were combined. (5) Visfatin increased matrix metalloproteinase-9 activity in THP-1 monocytes and tumor necrosis factor-␣ and interleukin-8 levels in peripheral blood mononuclear cells. Both of these effects were abolished when insulin receptor signaling was blocked. Conclusions-Our

Impact of metformin treatment and swimming exercise on visfatin levels in high-fat-induced obesity rats

“…The key findings of Arq Bras Endocrinol Metab. 2014;58/1 human unstable carotid and coronary atherosclerotic lesions, where the influence of insulin sensitizers seems to be limited (8,21). The mechanisms cited above indicate that insulin sensitizers may have little effect on visfatin.…”

Visfatin induces cholesterol accumulation in macrophages through up-regulation of scavenger receptor-A and CD36

“…With the discovery of pro-inflammatory role of visfatin, its potential effect in inflammation has gradually attracted much attention, especially in atherosclerosis, which is closely related with both lipid metabolism and inflammation (Yan et al 2010;Liu et al 2009). One of the most related studies has reported that visfatin should be considered as an inflammatory mediator, localized to foam cell macrophages within unstable atherosclerotic lesions, which potentially plays a role in plaque destabilization (Dahl et al 2007). Although it has been reported that visfatin is participated in the pathogenesis of atherosclerosis and may be involved in the early formation of foam cells, its exact effect is largely unknown.…”

Suppression of leukocyte infiltration and cartilage degradation by selective inhibition of pre-B cell colony-enhancing factor/visfatin/nicotinamide phosphoribosyltransferase: Apo866-mediated therapy in human fibroblasts and murine collagen-induced arthrit

“…Several groups have shown that PBEF interacts with the insulin receptor (8-10); however, this notion remains controversial (11,12), and it may be that PBEF signals through an alternative signaling route. It is also unlikely that this signaling effect is attributable to the endotoxin that may be present in PBEF preparations, since coincubation with polymixin B shows no abrogation of PBEF signaling (6,10,13).In vitro activation of signaling pathways by PBEF has been shown to regulate the expression of metalloproteinases, chemokines, and cytokines (6,7,(9)(10)(11)(12), but the in vivo contribution of this mediator of arthritis progression remains unclear. The recently developed small molecule inhibitor APO866 has been shown to act as a competitive inhibitor of PBEF/NAMPT activity by inhibiting binding of its natural substrate, nicotinamide (14,15).…”

“…Several groups have shown that PBEF interacts with the insulin receptor (8-10); however, this notion remains controversial (11,12), and it may be that PBEF signals through an alternative signaling route. It is also unlikely that this signaling effect is attributable to the endotoxin that may be present in PBEF preparations, since coincubation with polymixin B shows no abrogation of PBEF signaling (6,10,13).…”

“…In vitro activation of signaling pathways by PBEF has been shown to regulate the expression of metalloproteinases, chemokines, and cytokines (6,7,(9)(10)(11)(12), but the in vivo contribution of this mediator of arthritis progression remains unclear. The recently developed small molecule inhibitor APO866 has been shown to act as a competitive inhibitor of PBEF/NAMPT activity by inhibiting binding of its natural substrate, nicotinamide (14,15).…”