Figure 1.

Lipid signaling interference generates insulin resistance. (a) Signaling through phosphatidylinositol 3-kinase (PI3-K) is crucial for insulin-mediated glucose transport in hepatocytes and skeletal muscle cells and for inflammatory protein and hormone secretion in adipocytes and pancreatic β cells. Free fatty acids (FFAs) induce a defective insulin-mediated signaling mainly through the activation of protein kinase C (PKC θ), inhibitor κB kinase (IKK) and c-Jun N-terminal kinase (JNK). (b) Main cell types involved in the development of insulin resistance. (c) Main inflammatory cell populations involved in hyperinsulinemia-induced inflammatory states.