Endocrine Abstracts

Thyroid hormone transport into cells critically depends on plasma membrane transport proteins. One of these, monocarboxylate transporter 8 (MCT8), is mutated in patients suffering from a form of X-linked mental retardation, the Allan-Herndon-Dudley syndrome. These patients are characterized by abnormal thyroid hormone and TSH plasma levels indicating a role for MCT8 in the regulation of the thyroid hormone axis. Mice lacking the Mct8 gene replicate the thyroid hormone a...

Objective: Mutations in the gene encoding the thyroid hormone transport protein, monocarboxylate transporter 8 (MCT8), underlie severe mental retardation. In vitro expression of mutant transporters was performed to understand phenotypical differences.Methods: We established cell lines stably expressing 16 MCT8 variants in JEG1 and MDCK cells. Several of these mutants have never been analysed before. The cell lines were characterized according to M...

Thyroid hormones are essential for the proper development of a variety of tissues, especially the nervous system. Their transport into target cells is mediated by specific thyroid hormone transporters like the monocarboxylate transporter 8 (MCT8). Mutations in this X-chromosomal gene in humans lead to a severe phenotype characterized by psychomotor retardation, hypotonia, and a striking derangement of serum thyroid hormone levels: high T3 in the presence of low T4, and no sign...