Endothelial-derived angiocrine factors as instructors of embryonic development.

Blood vessels are well-known to play roles in organ development and repair, primarily owing to their fundamental function in delivering oxygen and nutrients to tissues to promote their growth and homeostasis. Endothelial cells however are not merely passive conduits for carrying blood. There is now evidence that endothelial cells of the vasculature actively regulate tissue-specific development, morphogenesis and organ function, as well as playing roles in disease and cancer.

Global ubiquitinome profiling identifies NEDD4 as a regulator of Profilin 1 and actin remodelling in neural crest cells.

The ubiquitin ligase NEDD4 promotes neural crest cell (NCC) survival and stem-cell like properties to regulate craniofacial and peripheral nervous system development. However, how ubiquitination and NEDD4 control NCC development remains unknown. Here we combine quantitative analysis of the proteome, transcriptome and ubiquitinome to identify key developmental signalling pathways that are regulated by NEDD4.

Mandible Explant Assay for the Analysis of Meckel's Cartilage Development.

Ex vivo explant models are a valuable tool for analyzing organ and tissue morphogenesis, providing the opportunity to manipulate and interrogate specific cellular and/or molecular pathways that may not be possible using conventional methods in vivo. The mandible primordia is a remarkably self-organizing structure that has the ability to develop cartilage, bone, teeth, epithelial tissue, and the tongue when grown in culture ex vivo and closely mimics the development of these structures in vivo. Here we describe a robust protocol for the culture of mandibular explants using serum-free, chemically defined culture media.

Notch signaling is a critical initiator of roof plate formation as revealed by the use of RNA profiling of the dorsal neural tube.

Background: The dorsal domain of the neural tube is an excellent model to investigate the generation of complexity during embryonic development. It is a highly dynamic and multifaceted region being first transiently populated by prospective neural crest (NC) cells that sequentially emigrate to generate most of the peripheral nervous system. Subsequently, it becomes the definitive roof plate (RP) of the central nervous system.

Exploring the Intracrine Functions of VEGF-A.

Vascular endothelial growth factor A (VEGF-A or VEGF) is a highly conserved secreted signalling protein best known for its roles in vascular development and angiogenesis. Many non-endothelial roles for VEGF are now established, with the discovery that VEGF and its receptors VEGFR1 and VEGFR2 are expressed in many non-vascular cell-types, as well as various cancers. In addition to secreted VEGF binding to its receptors in the extracellular space at the cell membrane (i.

Vessel-derived angiocrine IGF1 promotes Meckel's cartilage proliferation to drive jaw growth during embryogenesis.

Craniofacial development is a complex morphogenic process that requires highly orchestrated interactions between multiple cell types. Blood vessel-derived angiocrine factors are known to promote proliferation of chondrocytes in Meckel's cartilage to drive jaw outgrowth, however the specific factors controlling this process remain unknown. Here, we use and cell and tissue culture, as well as genetic mouse models, to identify IGF1 as a novel angiocrine factor directing Meckel's cartilage growth during embryonic development.

Notch signalling defines dorsal root ganglia neuroglial fate choice during early neural crest cell migration.

Background: The dorsal root ganglia (DRG) are a critical component of the peripheral nervous system, and function to relay somatosensory information from the body's periphery to sensory perception centres within the brain. The DRG are primarily comprised of two cell types, sensory neurons and glia, both of which are neural crest-derived. Notch signalling is known to play an essential role in defining the neuronal or glial fate of bipotent neural crest progenitors that migrate from the dorsal ridge of the neural tube to the sites of the DRG.

Ex Vivo Culture and Manipulation of Mouse Neural Crest Cells from Primary Embryonic Tissue Explants.

In vitro culture of neural crest cells allows for the manipulation and study of neural crest cell function in a cell-autonomous manner. While several stable neural crest cell lines exist, the transformed nature of these cells may not closely reflect the in vivo properties of neural crest cells, hence making molecular and functional analyses using these cell lines difficult to interpret. Here we describe a robust method to culture primary mouse neural crest cells ex vivo for several days to weeks in culture.

Cell autonomous roles of Nedd4 in craniofacial bone formation.

Nedd4 is an E3 ubiquitin ligase that has an essential role in craniofacial development. However, how and when Nedd4 controls skull formation is ill defined. Here we have used a collection of complementary genetic mouse models to dissect the cell-autonomous roles of Nedd4 in the formation of neural crest cell derived cranial bone.

Neuropilin-2 genomic elements drive cre recombinase expression in primitive blood, vascular and neuronal lineages.

We have established a novel Cre mouse line, using genomic elements encompassing the Nrp2 locus, present within a bacterial artificial chromosome clone. By crossing this Cre driver line to R26R LacZ reporter mice, we have documented the temporal expression and lineage traced tissues in which Cre is expressed. Nrp2-Cre drives expression in primitive blood cells arising from the yolk sac, venous and lymphatic endothelial cells, peripheral sensory ganglia, and the lung bud.

Heterozygous expression of the oncogenic Pik3ca(H1047R) mutation during murine development results in fatal embryonic and extraembryonic defects.

The phosphoinositide 3-kinase (PI3K)/AKT signalling pathway regulates many cellular functions including proliferation, migration, survival and protein synthesis. Somatic mutations in PIK3CA, the gene encoding the p110α catalytic subunit of PI3K enzyme, are commonly associated with many human cancers as well as recently being implicated in human overgrowth syndromes. However, it is not clear if such mutations can be inherited through the germline.

Neural crest cell-derived VEGF promotes embryonic jaw extension.

Jaw morphogenesis depends on the growth of Meckel's cartilage during embryogenesis. However, the cell types and signals that promote chondrocyte proliferation for Meckel's cartilage growth are poorly defined. Here we show that neural crest cells (NCCs) and their derivatives provide an essential source of the vascular endothelial growth factor (VEGF) to enhance jaw vascularization and stabilize the major mandibular artery.

Neuropilins define distinct populations of neural crest cells.

Background: Neural crest cells (NCCs) are a transient embryonic cell type that give rise to a wide spectrum of derivatives, including neurons and glia of the sensory and autonomic nervous system, melanocytes and connective tissues in the head. Lineage-tracing and functional studies have shown that trunk NCCs migrate along two distinct paths that correlate with different developmental fates. Thus, NCCs migrating ventrally through the anterior somite form sympathetic and sensory ganglia, whereas NCCs migrating dorsolaterally form melanocytes.

The ubiquitin ligase Nedd4 regulates craniofacial development by promoting cranial neural crest cell survival and stem-cell like properties.

The integration of multiple morphogenic signalling pathways and transcription factor networks is essential to mediate neural crest (NC) cell induction, delamination, survival, stem-cell properties, fate choice and differentiation. Although the transcriptional control of NC development is well documented in mammals, the role of post-transcriptional modifications, and in particular ubiquitination, has not been explored. Here we report an essential role for the ubiquitin ligase Nedd4 in cranial NC cell development.

Li-gazing at the crest: modulation of the neural crest by the ubiquitin pathway.

Neural crest cells are a transient population of stem cells that give rise to a diverse range of cell types during embryonic development. Through gain-of-function and loss-of-function studies in several model organisms many key signalling pathways and cell-type specific transcription factors essential for neural crest cell development have been identified. However, the role of post-translational regulation remains largely unexplored.

HuB (elavl2) mRNA is restricted to the germ cells by post-transcriptional mechanisms including stabilisation of the message by DAZL.

The ability of germ cells to carry out a gene regulatory program distinct from the surrounding somatic tissue, and their capacity to specify an entire new organism has made them a focus of many studies that seek to understand how specific regulatory mechanisms, particularly post-transcriptional mechanisms, contribute to cell fate. In zebrafish, germ cells are specified through the inheritance of cytoplasmic determinants, termed the germ plasm, which contains a number of maternal mRNAs and proteins. Investigation of several of these messages has revealed that the restricted localisation of these mRNAs to the germ plasm and subsequent germ cells is due to cis-acting sequence elements present in their 3'UTRs.