Abstract-The recent discovery of additional alternative spliced FLT1 transcripts encoding novel soluble (s)FLT1 protein isoforms complicates both the predictive value and functional implications of sFLT1 in preeclampsia. We investigated FLT1 expression levels and splicing patterns in placentas of normotensive and preeclamptic women, and established the tissue specificity of all FLT1 transcript variants. mRNA levels of sFLT1 splice variants were determined by real-time polymerase chain reaction in 21 normal human tissues and placental biopsies from 91 normotensive and 55 preeclamptic women. Cellular localization of placental FLT1 expression was established by RNA in situ hybridization. Of all tissues investigated, placenta has by far the highest FLT1 mRNA expression level, mainly localized in the syncytiotrophoblast layer. More than 80% of placental transcripts correspond to sFLT1_v2. Compared with normotensive placenta, preeclamptic placenta has Ϸ3-fold higher expression of all FLT1 transcript variants (PϽ0.001), with a slight shift in favor of sFLT1_v1. Although to a lesser degree, transcript levels are also increased in placenta from normotensive women that deliver a small for gestational age neonate. We conclude that sFLT isoform-specific assays could potentially improve the accuracy of current sFLT1 assays for the prediction of preeclampsia. However, placental FLT1 transcript levels are increased not only in preeclampsia but also in normotensive pregnancy with a small for gestational age fetus. This may indicate a common pathway involved in the development of both conditions but complicates the use of circulating sFLT1 protein levels for the prediction or diagnosis of preeclampsia alone. (Hypertension. 2011;58:70-76.) • Online Data SupplementKey Words: endothelial growth factors Ⅲ gene expression Ⅲ human Ⅲ preeclampsia Ⅲ pregnancy H ypertension-related disorders are a major cause of pregnancy complications. Preeclampsia in particular, defined as new-onset hypertension in combination with proteinuria after 20 weeks of gestation, is a leading cause of both maternal and fetal mortality and morbidity. 1 Because preeclampsia is a complex disease involving multiple organs, it has been difficult to clearly assign molecular pathways involved in the etiology. Consequently, proper targets for the development of early biomarkers and prophylaxis are scarce.Although the exact model how preeclampsia develops is still a matter of debate, preeclampsia is thought to originate from abnormal placentation followed by a release of placenta-produced factors into the maternal circulation. These in turn provoke dysfunction of the maternal endothelium, resulting in the preeclamptic clinical symptoms. 2,3 The vascular endothelial growth factor (VEGF) ligands/receptors play an essential role in both normal and pathological functioning of the endothelium 4 and have been implicated in the development of preeclampsia. In particular, the soluble truncated version of VEGF receptor 1 (sFLT1) has been shown to be markedly elevated in preecla...

Impaired thyroglobulin (Tg) synthesis is one of the putative causes for dyshormonogenesis of the thyroid gland. This type of hypothyroidism is characterized by intact iodide trapping, normal organification of iodide, and usually low serum Tg levels in relation to high TSH, and when untreated the patients develop goiter. In thyroid tissue from a 13-yr-old patient suspected of a thyroglobulin synthesis defect, the Tg mRNA was studied. The complete coding region of 8307 bp was directly sequenced and revealed a homozygous point mutation: a C886T transition in exon 7. Upon translation this mutation would result in a stopcodon at amino acid position 277, replacing the arginine residue. A Tg cDNA construct containing the mutation was expressed in rabbit reticulocyte lysate resulting in a truncated protein of 30 kDa. Expression in the presence of microsomal membranes resulted in a gel shift of this Tg molecule, indicating glycosylation ability. Two other siblings had a clinical presentation like the index patient, while their parents were unaffected. Additional restriction fragment length polymorphism analysis of the pedigree verified that the homozygous nonsense mutation cosegregated with the clinical phenotype. Clinically, hypothyroidism was not severe in the affected siblings because the truncated Tg glycoprotein was still capable of thyroid hormonogenesis.