Endocrine Abstracts

Background: Thyroid hormones (TH) are vital for fetal and placental development. TH transporters including monocarboxylate transporters 8 and 10 (MCT8, MCT10), organic anion transporters (OATP1A2, OATP4A1) and system-L amino acid transporters (LAT1, LAT2) are expressed in human placenta from 6 weeks of gestation. All of these TH transporters have been localized to the human syncytiotrophoblast layer of placental villi, which is in direct contact with maternal bl...

Background: Maternal severe iodine deficiency has been associated with pregnancy and neonatal loss but the impact of mild-moderate iodine deficiency on pregnancy is not well-documented. Mild-moderate iodine deficiency during pregnancy is common even in iodine replete countries. In the UK women of reproductive age have been found to be mildly-to-moderately iodine deficient. UI/C is an optimal indicator for iodine status in pregnancy.Aims: We...

Background: Maternal severe iodine deficiency has been associated with pregnancy and neonatal loss but the impact of mild-moderate iodine deficiency on pregnancy is not well-documented. Mild-moderate iodine deficiency during pregnancy is common even in iodine replete countries. In the UK women of reproductive age have been found to be mildly-to-moderately iodine deficient. UI/C is an optimal indicator for iodine status in pregnancy.Aims: We...

Background and aims: Thyroid peroxidase antibody (TPOAb) positivity is prevalent in women of reproductive age and pre-disposes to thyroid dysfunction, namely hypothyroidism, which has adverse effects on pregnancy. The aim of this study was to report the rate of development of abnormal thyroid function among initially euthyroid TPOAb positive women recruited into TABLET trial. To also identify factors associated with the development of hypothyroidism and to compare outcomes bet...

Thyroid dysfunction and autoimmunity are associated with adverse fertility and pregnancy outcomes. International bodies recommend routine thyroid function screening in women with history of subfertility or miscarriage. Knowledge about the frequency of, and risk factors for, thyroid disease is limited in the asymptomatic preconception population. A prospective multi-centre study of women with history of miscarriage or subfertility conducted at 49 hospitals across the United Kin...

Vitamin D-deficiency during pregnancy has been associated with increased complications of pregnancy including a high risk of pre-eclampsia (PET). Current analysis of vitamin D ‘status’ is based exclusively on analysis of maternal serum 25-hydroxyvitamin D3 (25(OH)D3), the circulating precursor form of vitamin D. We hypothesised that comprehensive profiling of vitamin D metabolites may provide a more accurate determination of vitamin D function i...

The plasma membrane thyroid hormone (TH) transporter, MCT8, is present in the human placenta from early gestation and is postulated to participate in transplacental transfer of TH. In vitro, MCT8 overexpression decreases the survival of human cytotrophoblast in a TH-independent manner.Objective: To examine the role of Mct8 in fetoplacental growth using the Mct8 knockout (ko) mouse model.Methods: Heterozygous females were mat...

Thyroid hormones (THs) are important for fetal and placental development. Monocarboxylate transporters 8 and 10 (MCT8 and MCT10) are effective plasma membrane TH transporters expressed in the human placenta from 6 weeks of gestation. Both have been localized to human villous trophoblasts and extravillous trophoblasts (EVTs).Aims: Using HTR-8/SVneo cells as a model of 1st trimester EVTs, we assessed 1) T3 effects on gene expression, cell prolif...

Thyroid hormones (TH) are important for the development of the fetus and placenta. We have previously reported increased placental expression of the potent TH transporter, MCT8, with advancing gestation. The amino acid plasma membrane transporters, MCT10, LAT1, LAT2, and the organic anion transporters, OATP1A2 and OATP4A1, are also known to transport TH.Objective: To describe the ontogeny of these TH transporters and the obligate heterodimer of the LATs,...

Thyroid hormones play vital roles in fetal brain development. Mutations in MCT8, recently recognised as a specific thyroid hormone transporter, define a novel syndrome of severe X-linked psychomotor retardation and thyroid hormone resistance.N-TERA-2 (NT2) cells (human embryonal cells with characteristics of CNS precursors) were transiently transfected with either WT MCT8 or its L471P, R271H or S448X mutations, described in males affected by severe psych...