Fig. 2

Adipokines and LPA interactions with the blood brain barrier and the central nervous system. The BBB is composed of endothelial cells (displaying tight junctions), pericytes and astrocytes. a In physiological conditions, some adipokines such as leptin and TNFα can cross the BBB through different mechanisms and act on the central nervous system. b Adipokines can also activate endothelial cell receptors resulting in the modulation of the expression of tight junctions and in the modulation of the BBB permeability. In adiponectin case, one study reports its crossing through the BBB [191], while another indicates that it does not cross the BBB [138]. Both possibilities are shown. In inflammatory conditions, the BBB is leaking and could allow an increase passage of adipokines and LPA into the CNS, leading to an increase of oxidative stress and neurodegeneration (c)