Endocrine Abstracts

Action and metabolism of thyroid hormone are intracellular events which require the transport of iodothyronines across the plasma membrane through transporters. In recent years, several transporters have been identified which are capable of transporting thyroid hormone. They are members of different transporter families, including organic anion transporting polypeptides (OATPs) family, heterodimeric amino acid transporters (HATs), and monocarboxylate transporters (MCTs). In pa...

Background: The interest in the potential effect of thyromimetics in lowering serum cholesterol is growing. Thyroid hormone actions on lipid metabolism are exerted in the liver and mediated by the T3 receptor TRβ1. The creation of molecules transported into hepatocytes by liver-specific transporters can increase the liver selectivity of thyromimetics. Sodium taurocholate co-transporting polypeptide (NTCP), a solute carrier protein primarily expressed on the basolateral me...

Introduction: Type 1 iodothyronine deiodinase (DIO1) is one of the three enzymes regulating bioavailability of thyroid hormones. In contrast to DIO2 and DIO3, the specific cellular role of DIO1 remains controversial. Our previous studies showed that DIO1 expression in clear cell renal cell carcinoma (ccRCC) is decreased, followed by lowered intracellular T3 concentration. In this study we explored how re-introduction of DIO1 in ccRCC cells affects their mig...

Introduction: Maternal thyroid hormone during early pregnancy is important for proper fetal growth and development. Thyroid hormone receptors are widely expressed in placental tissue. Interestingly, thyroid dysfunction and suboptimal placental function have both been associated with pregnancy complications including preeclampsia, premature delivery and fetal growth restriction. First, we studied the association of the maternal thyroid and placental function and second, we inve...

Hypothyroidism causes delayed ossification and growth retardation. T3 stimulates hypertrophic chondrocyte differentiation whereas unliganded T3 receptors (TRs) repress gene expression and maintain cell proliferation in the absence of hormone. During development the type 3 deiodinase enzyme (D3) inactivates thyroid hormones and prevents T3-access to the fetus. At birth diminishing D3 activity and increasing T3 availability triggers the onset of cell differentiation and correlat...