Expression of intercellular adhesion molecule-1 in C6 glioma cells is up-regulated by thyroid hormone.

ICAM-1 is a cell surface adhesion glycoprotein playing an essential role in inflammatory responses. We have investigated the effects of the thyroid hormone T3 on the expression of the ICAM-1 gene in C6 glioma cells. In these cells, T3 stimulated the ICAM-1 protein expression significantly after 24 h of treatment. The induction of ICAM-1 by cytokines such as interleukin 1beta or tumour necrosis factor TNF as well as by lipopolysaccharide or T3 can be suppressed by the two anti-inflammatory compounds dexamethasone and parthenolide. The C6 glioma cell line could then be a useful model for studying the effect of T3 hormone on the expression of specific genes in glial cells, especially genes involved in lymphocyte-glial cell interactions.