The expression of native and oxidized LDL receptors in brain microvessels is specifically enhanced by astrocytes-derived soluble factor(s)

Ex vivo rat brain microvessels express receptors for native as well as for oxidized low-density lipoproteins. In brain microvessels-derived endothelial cells, the expression levels of both receptors were enhanced by co-cultivation with rat astrocytes, even in the absence of actual contact between the two cell types, suggesting a soluble factor(s)-based mechanism of induction. No modulation e¡ect could be evidenced in a heterologous cellular system. Since both receptors were found to be expressed also in astrocytes, these cells are likely to contribute substantially to the lipoprotein management at the blood^brain barrier and in the brain compartment.