Perinatal Hypothyroidism and Cytoskeleton Dysfunction

Thyroid hormones (THs) are necessary for normal development particularly cytoskeletal system. Cytoskeletal system which consists of microtubules (Tubulin), microfilaments (Actin), and intermediate filaments, specific for neurons (Neurofilaments), glia (Glial Fibrillary Acidic Protein), or maturing cells (Vimentin, Nestin) can play important roles in neural cell shape and neuronal migration and outgrowth [1-40]. THs regulate and reorganize this system by nongenomic actions. Moreover, THs regulate the expression of extracellular matrix (ECM) and adhesion molecules that are important for neuronal migration and development, such as tenascin-C, neural cell adhesion molecule (N-CAM), reelin and dab1, laminin and fibronectin. Maternal THs controls the expression of neuronal migration and growth, branching of neurites, astrocytic cytoskeletal proteins, cell cycle regulators, neurotrophins and neurotrophin receptors and extracellular matrix proteins in the fetal brain [41-45].