Prior work has established that transient Shh signals from the notochord and floor plate confer a competence in somitic tissue for subsequent BMP to induce chondrogenesis. We have therefore proposed induces factor(s) renders cells competent chondrify response signals. Recently, we shown forced expression of Nkx3.2, transcriptional repressor induced by Shh, is able chondrogenic somites. In this work, show administration or Nkx3.2 transcription factor Sox9 tissue. Forced can, turn, robust...

Recent studies have postulated that distinct regulatory cascades control myogenic differentiation in the head and trunk. However, although tissues signaling molecules induce skeletal myogenesis trunk been identified, source of signals trigger muscle formation remain obscure. Here we show paraxial mesoderm is induced by Wnt from dorsal neural tube, cranial blocked these same signals. In addition, BMP family members are expressed both tube surface ectoderm also potent inhibitors mesoderm. We...

Parathyroid hormone-related protein (PTHrP) is essential to maintain a pool of dividing, immature chondrocytes in the growth plate long bones. In chick and mouse, expression Nkx3.2/Bapx1 restricted proliferative zone downregulated as chondrocyte maturation begins. lost plates mice engineered lack PTHrP signaling and, conversely, maintained by ectopic developing Artificially preventing downregulation, forced either retroviral-encoded or Nkx3.2 inhibits maturation. Although wild-type blocks...

Abstract Vascular calcifications can occur in the elderly and patients suffering from various diseases. Interestingly, depending on pathology, different regions of arterial system be affected. Embryonic observations have clearly indicated that vascular smooth muscle cell (VSMC) origin is notably heterogeneous. For instance, aorta, VSMCs colonizing aortic arch region derive cardiac neural crest cells, whereas those populating descending aorta mesoderm. We examined here whether embryonic would...

ABSTRACT In the present study, we have applied an antagonist treatment to chick embryo in ovo order demonstrate and dissect essential roles of endothelin type A (ETA) receptor embryonic development. We cloned, sequenced expressed cDNA ETA shown that its affinity for antagonists is very similar by mammalian counterparts. studied spatio-temporal expression pattern this situ hybridization there a high level mRNA within mesenchyme branchial arches at E3-E5, keeping with direct effect...

The low efficiency in transfecting rat- and human-derived chondrocytes have been hampering developments the field of cartilage biology. Transforming growth factor (TGF)-β1 has shown positive effects on chondrocytes, but its applications remain limited due to short half-life, stability poor penetration into cartilage. Naturally derived liposomes be promising delivery nanosystems their similarities with biological membranes. Here, we used agro-based rapeseed liposomes, which contains a high...

EPAS1 is a hypoxia‐inducible transcription factor, highly expressed in vasculature and recently shown to be necessary for catecholamine production during embryogenesis. We report here the cloning detailed expression pattern of this factor chicken embryo. show that presents an overall identity 76% with human sequence it strongly blood vessel wall, mostly endothelial cells, but also vascular smooth muscle cells. Moreover, we non‐vascular sites: liver, kidney, and, quite interestingly, cells...

The relative timing of SHH and BMP signals controls whether presomitic mesoderm (PSM) cells will adopt either a chondrogenic or lateral plate fate. Here we document that SHH-mediated induction Nkx3.2 maintains the competence somitic to initiate chondrogenesis in response subsequent by repressing BMP-dependent GATA genes. Conversely, administration PSM forced expression family members chick explants blocks hedgehog-dependent gene expression. We demonstrate factors can interact with Gli...

Abstract Whereas Runx2 is necessary for bone formation and cartilage hypertrophy, it unclear why induces markers of chondrocyte hypertrophy only in chondrocytes. We document that chondrocytes either contain a cofactor, which can be induced somitic cells by prochondrogenic signals, to induce or, alternatively, lack repressor this maturation program. Sequential Shh morphogenetic protein (BMP) signals or forced expression Nkx3.2 Sox9 (plus BMP signals) chondrogenesis presomitic mesoderm...

Endothelial PAS protein 1 (EPAS1) is a bHLH-PAS transcription factor involved in cellular response to hypoxia. Its precise role angiogenesis unclear, but several genes essential vascular development, including those encoding endothelial growth (VEGF), its receptor VEGFR-2 and Tie2, are thought be targets of EPAS1. To investigate whether this putative were expressed concomitantly, we performed situ hybridization on serial adjacent sections human embryos at gestational ages 3 6 weeks. We...

We have previously shown that Nkx3.2, a member of the NK class homeoproteins, functions as transcriptional repressor to promote somitic chondrogenesis. However, it has not been addressed whether Nkx3.2 can bind DNA in sequence-specific manner and binding by is required for its biological activity. In this work, we employed site selection assay, which identified TAAGTG high affinity sequence. Sequence-specific motif vitro was confirmed electrophoretic mobility shift assays, mutagenesis...

Investigations in cartilage biology have been hampered by the limited capacity of chondrocytes, especially rats and humans, to be efficiently transfected. Liposomes are a promising delivery system due their lipid bilayer structure similar biological membrane. Here we used natural rapeseed lecithin, which contains high level mono- poly-unsaturated fatty acids, evaluate cytocompatibility these phospholipids as future potential carriers biomolecules joint regenerative medicine. Results show...

Islet vascularization, by controlling beta-cell mass expansion in response to increased insulin demand, is implicated the progression glucose intolerance and type 2 diabetes. We investigated how hyperglycaemia impairs differentiation of growing pancreas. have grafted xenogenic (avian) embryonic pancreas severe combined immuno-deficient (SCID) mouse analyzed endocrine endothelial development hyperglycaemic compared normoglycaemic conditions.14 dpi chicken pancreases were under kidney capsule...

A cDNA encoding a chicken angiotensin II receptor from adrenal gland was isolated to serve as molecular tool study the role of AngII in avian embryonic development. This cDNA, sharing high homology with another (turkey), encodes protein 359 amino acids 75% sequence identity mammalian type 1 receptor. Transient expression has revealed pharmacological properties distinct receptors and functional coupling leading increase inositol phosphate production. The mRNA is expressed classical target...

Fibroblast Growth Factor 23 (FGF23) is well documented as a crucial player in the systemic regulation of phosphate homeostasis. Moreover, loss-of-function experiments have revealed that FGF23 also has phosphate-independent and local impact on skeletogenesis. Here, we used ATDC5 cell line to investigate expression role it may play locally during differentiation these cells.ATDC5 cells were differentiated presence insulin, treated with recombinant (rFGF23), inorganic (Pi) and/or PD173074, an...