Bacterial Lipopolysaccharide Stimulates the Thyrotropin-Dependent Thyroglobulin Gene Expression at the Transcriptional Level by Involving the Transcription Factors Thyroid Transcription Factor-1 and Paired Box Domain Transcription Factor 8

VÉLEZ MARIA LAURA; COSTAMAGNA MARIA EUGENIA; KIMURA ETNA; FOZZATTI LAURA; PELLIZAS CLAUDIA GABRIELA; MONTESINOS MARIA DEL MAR; LUCERO ARIEL MAXIMILIANO; COLEONI, ALDO HECTOR; SANTISTEBAN PILAR; MASINI-REPISO ANA MARIA

ENDOCRINE SOC

Año: 2006 p. 3260 - 3260

The bacterial lipopolysaccharide (LPS) is a biological activatorthat induces expression of multiple genes in several celltypes. LPS has been proposed as an etiopathogenic agent inautoimmune diseases. However, whether LPS affects the expressionof autoantigens has not been explored. Thyroglobulin(TG) is a key protein in thyroid hormonogenesis and oneof the major thyroid autoantigens. This study aimed to analyzethe action of LPS on TG gene expression in Fisher ratthyroid cell line FRTL-5 thyroid cells. We demonstrate thatLPS increases the TSH-induced TG protein and mRNA level.Evidence that the effect of LPS is exerted at the transcriptionallevel was obtained by transfecting the minimal TG promoter.The C element of the TG promoter, which containssequences for paired box domain transcription factor 8 (Pax8)and thyroid transcription factor (TTF)-1 binding, is essentialfor full TG promoter expres