Toll-like receptor 4 confering lipopolysaccharide responsiveness is expressed in the thyroid cell

NICOLA JP; VELEZ ML; LUCERO AM; FOZZATTI L; PELLIZAS CG; MASINI-REPISO AM

The Endocrine Society

Lugar: Chevy Chase, MD, USA; Año: 2009 vol. 150 p. 500 - 500

font size="3" face="TimesNewRomanPSMT"> Lipopolysaccharide (LPS), a glycolipid found in the cell wall of Gram-negative bacteria, exerts pleiotropic biological effects in different cell types. LPS is mainly recognized by the TLR4/MD2/CD14 complex. We previously demonstrated that LPS produce a direct action on thyroid cells including up-regulation of thyroglobulin gene expression. This work aimed to further study the effect of LPS on thyroid function and to elucidate the mechanism by which LPS is recognized by the thyroid cell. We could detect the transcript and protein expression of TLR4, MD2 and CD14 in thyroid cells and that these proteins are localized at the plasma membrane. The sodium iodide symporter (NIS) is the transporter involved in the iodide uptake, the first step in thyroid hormonogenesis. We demonstrated that LPS increases the TSH-induced iodide uptake and NIS protein expression. The LPS agonist lipid A reproduced the LPS effect whereas the LPS an