Inhibitory effect of IL-8 on insulin action in human adipocytes via MAP kinase pathway

Abstract

Background: Various cytokines and other compounds are produced in human adipose tissue and might have functions in the adipose tissue. They might be involved in complications associated with obesity and diabetes. Recently, interleukin-8 (IL-8) has been shown to be produced and released from human adipose tissue and/or adipocytes, suggesting IL-8 involvement in some obesity-related health complications. Therefore, we found it of interest to investigate whether IL-8 is involved in the insulin action in human adipocytes.

Biochemical markers of psoriasis as a metabolic disease

“…Significantly higher circulating levels of IL-8 have been found in patients with heart failure and metabolic syndrome compared to patients with heart failure without metabolic syndrome [123]. It has been proved that proinflammatory cytokines such as TNF-alpha, IL-1 and CRP induce synthesis of IL-8 in human adipocytes [124,125]. Kobashi et al [125] stated that IL-8 reduces phosphorylation of AKT by insulin in human adipocytes, which can induce resistance to insulin.…”

Impaired Glucose Tolerance, Obesity and Inflammatory Mediators

“…Through its multiple actions, IL-8 might promote intimal thickening and atherosclerosis. This cytokine is also able to increase the instability of atherosclerotic plaque [29][30][31]. Elevated circulating IL-8 levels were also reported in type 1 and type 2 diabetic patients.…”

“…Similarly interleukin 8 (IL-8) is a pro-inflammatory cytokine, overproduced in adipose tissue of several rodent models of obesity and has an important role in the pathogenesis of IR in these species [12,21,29,30]. However, IL-8 is basically evaluated as a cytokine with atherogenic properties and its actual involvement in glucose metabolism disorders remains controversial in humans [29][30][31].…”

“…However, IL-8 is basically evaluated as a cytokine with atherogenic properties and its actual involvement in glucose metabolism disorders remains controversial in humans [29][30][31]. Through its multiple actions, IL-8 might promote intimal thickening and atherosclerosis.…”

“…It now appears that obesity is associated with a lowgrade inflammation of adipose tissue, resulting from activation of innate immune system. Especially in obesity, adipose tissue is characterized by an increased production and secretion of a wide range of pro-inflammatory molecules including IL-1ß, IL-6, IL-8, TNF-, CRP, leptin, resistin and so on [23][24][25][26][27][28][29][30][31][32][33][34][35]. Recent data indicate that macrophages in obese adipose tissue are major source of most mediators.…”