Effect of thiocyanate on microtubule assembly in rat brain during postnatal development

Abstract

The effects of feeding thiocyanate (a goitrogen derived from thioglucosides, which are naturally occurring in certain foods) to female rats throughout gestation and lactation on a microtubule assembly of pups during postnatal development were examined. Microtubules, which are important components of the neuronal cell cytoskeleton, may serve as markers of neurite growth. A progressive increase with age in the initial rate of microtubule assembly was apparent in both untreated control and thiocyanate-treated rat pups in the cerebrum, cerebellum and brainstem. Thiocyanate treatment did not alter the tubulin content at any of the developmental stages studied (7, 14 and 21 days postnatal). However, examination of the microtubule assembly revealed a markedly reduced polymerization of tubulin into microtubules in brain regions of thiocyanate-treated rats compared with untreated controls. The effect of thiocyanate on microtubule assembly was evident at all three ages (7, 14 and 21 days). Thiocyanate-induced hypothyroidism increased the lag period for initiation of assembly and also altered the initial rate of microtubule formation. This study suggests that a partial suppression of thyroid function by thiocyanate, as evidenced by a decrease in circulating concentrations of thyroxine, could bring about alterations in microtubule formation during brain development and suggests the possibility of an impairment in the process of microtubule metabolism.

Thyroid hormone increases fibroblast growth factor receptor expression and disrupts cell mechanics in the developing organ of corti

“…Previous studies found that hypothyroidism reduces the presence of tubulin in the developing central nervous system [41,42]. Furthermore, we observed a delay in the pattern of S100-A1 expression, which has been implicated in microtubule formation in vitro [8,43].…”

“…While disruption of the cytoskeleton in cases of hypothyroidism has long been known [3,7,42], the molecular basis for these effects is not yet fully understood. The results presented here suggest that Fgf signaling may act as an intermediary, with prolonged Fgf-signaling leading to disruptions in microtubule formation.…”

Developmental Iodine Deficiency and Hypothyroidism Impair Neural Development, Upregulate Caveolin-1, and Downregulate Synaptotagmin-1 in the Rat Cerebellum

“…Reduction in neurite growth can retard subsequent events in CNS development, such as synaptogenesis and myelination [52]. Furthermore, impairments of brain activity and structure induced by hypothyroidism are thought to be secondary to the effect of hypothyroidism on neurite growth [52]. Thus, the reduction of synaptotagmin-1 levels presented here, which can disturb neurite growth, may contribute to impairments of cerebellar development induced by iodine deficiency and hypothyroidism.…”

“…As a multifunction protein, synaptotagmin-1 is also involved in neurite outgrowth [26]. Reduction in neurite growth can retard subsequent events in CNS development, such as synaptogenesis and myelination [52]. Furthermore, impairments of brain activity and structure induced by hypothyroidism are thought to be secondary to the effect of hypothyroidism on neurite growth [52].…”