New therapy for Allan-Herdnon-Dudley Syndrome Tested in Mice
A recent study led by Dr Ana Guadaño from CIBERER proposes a new therapeutic strategy to alleviate the neurological disorders of Allan-Herndon-Dudley syndrome. This X-linked pathology produces severe intellectual disability with neuromuscular involvement characterized by infantile hypotonia and muscular hypoplasia among other symptoms.
Currently, there is no treatment to mitigate the neurological symptoms derived from the disease. The syndrome is caused by mutations in the thyroid hormone carrier protein called MCT8. These mutations produce the inactivation of the transporting protein, which generates peripheral hyperthyroidism (high levels of thyroid hormone T3 in the blood) and cerebral hypothyroidism (low T3 in the brain). This imbalance is due to the lack of MCT8 in the blood-brain barrier (that which regulates the passage of substances between the circulating blood and the brain) preventing thyroid hormones from being transported into the brain.
In the article, published in the journal PLOS One, the research team describes the use of a thyroid hormone analogue called TRIAC, which has a similar effect to the hormone itself and whose safety in patients is well known. This compound, unlike T3, does not require the MCT8 carrier to enter cells. The researchers injected the drug directly into the brain of a model mouse for Allan-Herndon-Dudley syndrome to test its effectiveness. The study results showed that levels of TRIAC in the mouse's cerebral cortex were increased and that the treatment did not worsen peripheral hyperthyroidism or cerebral hypothyroidism.
These results reveal that intracerebroventricular administration of TRIAC in mice facilitates its availability in the brain and sheds light on future therapeutic strategies for the disease.
Access to the original article: Intracerebroventricular administration of the thyroid hormone analog TRIAC increases its brain content in the absence of MCT8. PLOS One.