Ganglioside GM1 contributes to extracellular/intracellular regulation of insulin resistance, impairment of insulin signaling and down-stream eNOS activation, in human aortic endothelial cells after short- or long-term exposure to TNFa.

Authors:
Sasaki N1, Itakura Y1, Toyoda M1
In:
Source: OncoTarget
Publication Date: ()
Issue: 5: 5562-5577
Cells used in publication:
Endothelial, aortic, human (HAEC)
Species: human
Tissue Origin: aortic
Experiment


Abstract

Vascular insulin resistance induced by inflammatory cytokines leads to the initiation and development of vascular diseases. In humans, circulating TNFa levels are increased during aging, suggesting a correlation between vascular insulin resistance and plasma TNFa levels. Currently, the precise molecular mechanisms of vascular insulin resistance mediated by TNFa are not well characterized. We aimed at clarifying whether glycosphingolipids contribute to vascular insulin resistance after inflammatory stimulation. In this study, we examined vascular insulin resistance using human aortic endothelial cells after treatment with different concentrations of TNFa for different time intervals for mimicking in vivo acute or chronic inflammatory situations. We show that ganglioside GM1 levels on cell membranes change depending on time of exposure to TNFa and its concentration and that the GM1 expression is associated with specific extracellular/intracellular regulation of the insulin signaling cascade. Furthermore, we provide evidence that factors such as aging and senescence affect the regulation of insulin resistance. Our data suggest that GM1 is a key player in the induction of vascular insulin resistance after short- or long-term exposure to TNFa and is a good extracellular target for prevention and cure of vascular diseases