OBJECTIVE Hyperphosphatemia and inorganic phosphate (Pi) transport by vascular smooth muscle cells (VSMCs) have been implicated in the pathogenesis of vascular calcification. The aim of this work has been to characterize Pi transport in VSMCs. METHODS AND RESULTS Primary cultures of VSMCs express both high affinity Na-dependent and Na-independent components of Pi transport. Under physiologica...

The complex pathogenesis of mineralization defects seen in inherited and/or acquired hypophosphatemic disorders suggests that local inorganic phosphate (P(i)) regulation by osteoblasts may be a rate-limiting step in physiological bone mineralization. To test whether an osteoblast autonomous phosphate regulatory system regulates mineralization, we manipulated well-established in vivo and in vitr...

Analysis of an allelic series in mice revealed that the Pitx2 homeobox gene is required at multiple stages of pituitary development. It is necessary for initiating expansion of Rathke's pouch and maintaining expression of the fetal-specific transcription factors Hesx1 and Prop1. At later stages Pitx2 is necessary for specification and expansion of the gonadotropes and Pit1 lineage within the ve...

Matrix vesicle-mediated mineralization is orchestrated by ultrastructural and biochemical events that lead to crystal nucleation and growth. Osteoblasts secrete extracellular matrix vesicles equipped with a variety of membrane transporters and enzymes, which are necessary for the initial nucleation and subsequent growth of calcium phosphate crystals. The influx of phosphate ions into the matrix...

Vascular calcification is frequently found already in early stages of chronic kidney disease (CKD) patients and is associated with high cardiovascular risk. The process of vascular calcification is not considered a passive phenomenon but involves, at least in part, phenotypical transformation of vascular smooth muscle cells (VSMCs). Following exposure to excessive extracellular phosphate concen...

1. Abstract 2. Introduction 3. Function and Development of the Pituitary Gland 3.1. Murine pituitary development 3.2. Pituitary development in humans 4. Induction and morphogenesis of Rathke’s Pouch 4.1. Origin of the pituitary primordium 4.2. BMP4 is essential for induction of RP 4.3. Opposing BMP and FGF gradients specify pituitary progenitors and pattern RP. 4.4. Sonic hedgehog signalling pr...

We examined the polymorphisms in the PIT1 gene of 103 pigs and compared their frequencies in the maternal and paternal lineages of the Pietrain and Large White breeds, which have undergone divergent selection for over 30 years. DNA samples extracted from the blood of these animals were amplified by PCR and genotyped by RFLP, using the restriction enzyme RsaI. The data were analyzed with the chi...

The adenohypophysis consists of at least six different cell types, somatotropes, lactotropes, thyrotropes, melanotropes, corticotropes, and gonadotropes. In mouse, cloning of spontaneous mutations and gene targeting has revealed multiple genes required for different steps of adenohypophysis development. Here, we report the results of a systematic search for genes required for adenohypophysis fo...