Clinically compatible advances in blood-derived endothelial progenitor cell isolation and reprogramming for translational applications.

The promise of using induced pluripotent stem cells (iPSCs) for cellular therapies has been hampered by the lack of easily isolatable and well characterized source cells whose genomes have undergone minimal changes during their processing. Blood-derived late-outgrowth endothelial progenitor cells (EPCs) are used for disease modeling and have potential therapeutic uses including cell transplantation and the translation of induced pluripotent stem cell (iPSC) derivatives. However, the current isolation of EPCs has been inconsistent and requires at least 40-80 mL of blood, limiting their wider use.

An iPSC-Derived Myeloid Lineage Model of Herpes Virus Latency and Reactivation.

Herpesviruses undergo life-long latent infection which can be life-threatening in the immunocompromised. Models of latency and reactivation of human cytomegalovirus (HCMV) include primary myeloid cells, cells known to be important for HCMV latent carriage and reactivation . However, primary cells are limited in availability, and difficult to culture and to genetically modify; all of which have hampered our ability to fully understand virus/host interactions of this persistent human pathogen.

Autophagy contributes to BMP type 2 receptor degradation and development of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterised by an increase in mean pulmonary arterial pressure which almost invariably leads to right heart failure and premature death. More than 70% of familial PAH and 20% of idiopathic PAH patients carry heterozygous mutations in the bone morphogenetic protein (BMP) type 2 receptor (BMPR2). However, the incomplete penetrance of BMPR2 mutations suggests that other genetic and environmental factors contribute to the disease.

TNFα drives pulmonary arterial hypertension by suppressing the BMP type-II receptor and altering NOTCH signalling.

Heterozygous germ-line mutations in the bone morphogenetic protein type-II receptor (BMPR-II) gene underlie heritable pulmonary arterial hypertension (HPAH). Although inflammation promotes PAH, the mechanisms by which inflammation and BMPR-II dysfunction conspire to cause disease remain unknown. Here we identify that tumour necrosis factor-α (TNFα) selectively reduces BMPR-II transcription and mediates post-translational BMPR-II cleavage via the sheddases, ADAM10 and ADAM17 in pulmonary artery smooth muscle cells (PASMCs).

Generation and Culture of Blood Outgrowth Endothelial Cells from Human Peripheral Blood.

Historically, the limited availability of primary endothelial cells from patients with vascular disorders has hindered the study of the molecular mechanisms underlying endothelial dysfunction in these individuals. However, the recent identification of blood outgrowth endothelial cells (BOECs), generated from circulating endothelial progenitors in adult peripheral blood, may circumvent this limitation by offering an endothelial-like, primary cell surrogate for patient-derived endothelial cells. Beyond their value to understanding endothelial biology and disease modeling, BOECs have potential uses in endothelial cell transplantation therapies.

Applications of nuclear reprogramming and directed differentiation in vascular regenerative medicine.

As vertebrates proceed through embryonic development the growing organism cannot survive on diffusion of oxygen and nutrients alone and establishment of vascular system is fundamental for embryonic development to proceed. Dysfunction of the vascular system in adults is at the heart of many disease states such as hypertension and atherosclerosis. In this review we will focus on attempts to generate the key cells of the vascular system, the endothelial and smooth muscle cells, using human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs).

Transcript analysis reveals a specific HOX signature associated with positional identity of human endothelial cells.

The endothelial cell has a remarkable ability for sub-specialisation, adapted to the needs of a variety of vascular beds. The role of developmental programming versus the tissue contextual environment for this specialization is not well understood. Here we describe a hierarchy of expression of HOX genes associated with endothelial cell origin and location.

A practical and efficient cellular substrate for the generation of induced pluripotent stem cells from adults: blood-derived endothelial progenitor cells.

Induced pluripotent stem cells (iPSCs) have the potential to generate patient-specific tissues for disease modeling and regenerative medicine applications. However, before iPSC technology can progress to the translational phase, several obstacles must be overcome. These include uncertainty regarding the ideal somatic cell type for reprogramming, the low kinetics and efficiency of reprogramming, and karyotype discrepancies between iPSCs and their somatic precursors.

Therapeutic revascularisation of ischaemic tissue: the opportunities and challenges for therapy using vascular stem/progenitor cells.

Ischaemia-related diseases such as peripheral artery disease and coronary heart disease constitute a major issue in medicine as they affect millions of individuals each year and represent a considerable economic burden to healthcare systems. If the underlying ischaemia is not sufficiently resolved it can lead to tissue damage, with subsequent cell death. Treating such diseases remains difficult and several strategies have been used to stimulate the growth of blood vessels and promote regeneration of ischaemic tissues, such as the use of recombinant proteins and gene therapy.

Loss of Xenopus tropicalis EMSY causes impairment of gastrulation and upregulation of p53.

EMSY interacts directly with BRCA2 and links the BRCA2 pathway to sporadic breast and ovarian cancer. It also interacts with BS69 and HP1b, both of which are involved in chromatin remodelling, and with NIF-1 and DBC-1 in the regulation of nuclear receptor-mediated transcription. Here we investigate the function of EMSY during amphibian development, and in doing so provide the first loss-of-function analysis of this protein.

Loss of REEP4 causes paralysis of the Xenopus embryo.

Members of the REEP (Receptor expression enhancing protein) family contain a TB2/DP1, HVA22 domain that is involved in intracellular trafficking and secretion. Consistent with the presence of this domain, REEP1 and REEP3 enhance the expression of odorant and taste receptors in mammals, while mutation of these genes causes defects in neural development. REEP4 was identified in the course of a functional antisense morpholino oligonucleotide screen searching for genes involved in the early development of Xenopus tropicalis: although over-expression of the gene causes no phenotype, embryos lacking REEP4 develop a slightly kinked body axis and are paralysed.

KazrinA is required for axial elongation and epidermal integrity in Xenopus tropicalis.

Kazrin is a recently described desmosomal protein that binds the cornified envelope precursor periplakin. In this study, we have examined kazrin isoform A expression during the development of Xenopus tropicalis and investigated the consequences of its depletion. Whole mount in situ hybridisation revealed that kazrinA mRNA is expressed throughout the embryo at least until tadpole stages.

CVAK104 is a novel regulator of clathrin-mediated SNARE sorting.

Clathrin-coated vesicles (CCVs) mediate transport between the plasma membrane, endosomes and the trans Golgi network. Using comparative proteomics, we have identified coated-vesicle-associated kinase of 104 kDa (CVAK104) as a candidate accessory protein for CCV-mediated trafficking. Here, we demonstrate that the protein colocalizes with clathrin and adaptor protein-1 (AP-1), and that it is associated with a transferrin-positive endosomal compartment.

Defining synphenotype groups in Xenopus tropicalis by use of antisense morpholino oligonucleotides.

To identify novel genes involved in early development, and as proof-of-principle of a large-scale reverse genetics approach in a vertebrate embryo, we have carried out an antisense morpholino oligonucleotide (MO) screen in Xenopus tropicalis, in the course of which we have targeted 202 genes expressed during gastrula stages. MOs were designed to complement sequence between -80 and +25 bases of the initiating AUG codons of the target mRNAs, and the specificities of many were tested by (i) designing different non-overlapping MOs directed against the same mRNA, (ii) injecting MOs differing in five bases, and (iii) performing "rescue" experiments. About 65% of the MOs caused X.

Targeted deletion of the novel cytoplasmic dynein mD2LIC disrupts the embryonic organiser, formation of the body axes and specification of ventral cell fates.

Dyneins have been implicated in left-right axis determination during embryonic development and in a variety of human genetic syndromes. In this paper, we study the recently discovered mouse dynein 2 light intermediate chain (mD2LIC), which is believed to be involved in retrograde intraflagella transport and which, like left-right dynein, is expressed in the node of the mouse embryo. Cells of the ventral node of mouse embryos lacking mD2LIC have an altered morphology and lack monocilia, and expression of Foxa2 and Shh in this structure is reduced or completely absent.

Characterizing embryonic gene expression patterns in the mouse using nonredundant sequence-based selection.

This article investigates the expression patterns of 160 genes that are expressed during early mouse development. The cDNAs were isolated from 7.5 d postcoitum (dpc) endoderm, a region that comprises visceral endoderm (VE), definitive endoderm, and the node-tissues that are required for the initial steps of axial specification and tissue patterning in the mouse.