Proliferation associated 2G4 is required for the ciliation of vertebrate motile cilia.

Motile cilia are critical structures that regulate early embryonic development and tissue homeostasis through synchronized ciliary motility. The formation of motile cilia is dependent on precisely controlled sequential processes including the generation, migration, and docking of centrioles/basal bodies as well as ciliary growth. Using the published proteomics data from various organisms, we identified proliferation-associated 2G4 as a novel regulator of ciliogenesis.

The role of Wnt signaling in the development of the epiblast and axial progenitors.

Understanding how the body plan is established during embryogenesis remains a fundamental biological question. The Wnt/β-catenin signaling pathway plays a crucial and highly conserved role in body plan formation, functioning to polarize the primary anterior-posterior (AP) or head-to-tail body axis in most metazoans. In this chapter, we focus on the roles that the mammalian Wnt/β-catenin pathway plays to prepare the pluripotent epiblast for gastrulation, and to elicit the emergence of multipotent axial progenitors from the caudal epiblast.

Development of opioid-induced hyperalgesia depends on reactive astrocytes controlled by Wnt5a signaling.

Opioids are the frontline analgesics for managing various types of pain. Paradoxically, repeated use of opioid analgesics may cause an exacerbated pain state known as opioid-induced hyperalgesia (OIH), which significantly contributes to dose escalation and consequently opioid overdose. Neuronal malplasticity in pain circuits has been the predominant proposed mechanism of OIH expression.

Autophagy in mesenchymal progenitors protects mice against bone marrow failure after severe intermittent stress.

The cellular mechanisms required to ensure homeostasis of the hematopoietic niche and the ability of this niche to support hematopoiesis upon stress remain elusive. We here identify Wnt5a in Osterix+ mesenchymal progenitor and stem cells (MSPCs) as a critical factor for niche-dependent hematopoiesis. Mice lacking Wnt5a in MSPCs suffer from stress-related bone marrow (BM) failure and increased mortality.

Placental defects lead to embryonic lethality in mice lacking the Formin and PCP proteins Daam1 and Daam2.

The actin cytoskeleton plays a central role in establishing cell polarity and shape during embryonic morphogenesis. Daam1, a member of the Formin family of actin cytoskeleton regulators, is a Dvl2-binding protein that functions in the Wnt/Planar Cell Polarity (PCP) pathway. To examine the role of the Daam proteins in mammalian development, we generated Daam-deficient mice by gene targeting and found that Daam1, but not Daam2, is necessary for fetal survival.

A dorsal-ventral gradient of Wnt3a/β-catenin signals controls mouse hindgut extension and colon formation.

Despite the importance of Wnt signaling for adult intestinal stem cell homeostasis and colorectal cancer, relatively little is known about its role in colon formation during embryogenesis. The development of the colon starts with the formation and extension of the hindgut. We show that is expressed in the caudal embryo in a dorsal-ventral (DV) gradient across all three germ layers, including the hindgut.

Wnt regulates amino acid transporter Slc7a5 and so constrains the integrated stress response in mouse embryos.

Amino acids are essential for cellular metabolism, and it is important to understand how nutrient supply is coordinated with changing energy requirements during embryogenesis. Here, we show that the amino acid transporter Slc7a5/Lat1 is highly expressed in tissues undergoing morphogenesis and that Slc7a5-null mouse embryos have profound neural and limb bud outgrowth defects. Slc7a5-null neural tissue exhibited aberrant mTORC1 activity and cell proliferation; transcriptomics, protein phosphorylation and apoptosis analyses further indicated induction of the integrated stress response as a potential cause of observed defects.

Coordinated directional outgrowth and pattern formation by integration of Wnt5a and Fgf signaling in planar cell polarity.

Embryonic morphogenesis of a complex organism requires proper regulation of patterning and directional growth. Planar cell polarity (PCP) signaling is emerging as a crucial evolutionarily conserved mechanism whereby directional information is conveyed. PCP is thought to be established by global cues, and recent studies have revealed an instructive role of a Wnt signaling gradient in epithelial tissues of both invertebrates and vertebrates.

Myeloid Wnt ligands are required for normal development of dermal lymphatic vasculature.

Resident tissue myeloid cells play a role in many aspects of physiology including development of the vascular systems. In the blood vasculature, myeloid cells use VEGFC to promote angiogenesis and can use Wnt ligands to control vascular branching and to promote vascular regression. Here we show that myeloid cells also regulate development of the dermal lymphatic vasculature using Wnt ligands.

A Wnt5 Activity Asymmetry and Intercellular Signaling via PCP Proteins Polarize Node Cells for Left-Right Symmetry Breaking.

Polarization of node cells along the anterior-posterior axis of mouse embryos is responsible for left-right symmetry breaking. How node cells become polarized has remained unknown, however. Wnt5a and Wnt5b are expressed posteriorly relative to the node, whereas genes for Sfrp inhibitors of Wnt signaling are expressed anteriorly.

Planar cell polarity signaling in the uterus directs appropriate positioning of the crypt for embryo implantation.

Blastocyst implantation is a complex process requiring coordination of a dynamic sequence of embryo-uterine interactions. Blood vessels enter the uterus from the mesometrium, demarcating the uterus into mesometrial (M) and antimesometrial (AM) domains. Implantation occurs along the uterine longitudinal axis within specialized implantation chambers (crypts) that originate within the evaginations directed from the primary lumen toward the AM domain.

A new gain-of-function mouse line to study the role of Wnt3a in development and disease.

Wnt/β-catenin signals are important regulators of embryonic and adult stem cell self-renewal and differentiation and play causative roles in tumorigenesis. Purified recombinant Wnt3a protein, or Wnt3a-conditioned culture medium, has been widely used to study canonical Wnt signaling in vitro or ex vivo. To study the role of Wnt3a in embryogenesis and cancer models, we developed a Cre recombinase activatable Rosa26(Wnt3a) allele, in which a Wnt3a cDNA was inserted into the Rosa26 locus to allow for conditional, spatiotemporally defined expression of Wnt3a ligand for gain-of-function (GOF) studies in mice.

Zfp703 Is a Wnt/β-Catenin Feedback Suppressor Targeting the β-Catenin/Tcf1 Complex.

The Wnt/β-catenin signaling pathway controls embryonic development and adult stem cell maintenance through the regulation of transcription. Failure to downregulate Wnt signaling can result in embryonic malformations and cancer, highlighting the important role of negative regulators of the pathway. The Wnt pathway activates several negative feedback targets, including axin2 and Dkk1, that function at different levels of the signaling cascade; however, none have been identified that directly target active β-catenin/Tcf1 transcriptional complexes.

Sp5 and Sp8 recruit β-catenin and Tcf1-Lef1 to select enhancers to activate Wnt target gene transcription.

The ancient, highly conserved, Wnt signaling pathway regulates cell fate in all metazoans. We have previously shown that combined null mutations of the specificity protein (Sp) 1/Klf-like zinc-finger transcription factors Sp5 and Sp8 (i.e.

Spatial regulation of cell cohesion by Wnt5a during second heart field progenitor deployment.

Wnt5a, a non-canonical Wnt ligand critical for outflow tract (OFT) morphogenesis, is expressed specifically in second heart field (SHF) progenitors in the caudal splanchnic mesoderm (SpM) near the inflow tract (IFT). Using a conditional Wnt5a gain of function (GOF) allele and Islet1-Cre, we broadly over-expressed Wnt5a throughout the SHF lineage, including the entire SpM between the IFT and OFT. Wnt5a over-expression in Wnt5a null mutants can rescue the cell polarity and actin polymerization defects as well as severe SpM shortening, but fails to rescue OFT shortening.

Non-canonical Wnt signalling modulates the endothelial shear stress flow sensor in vascular remodelling.

Endothelial cells respond to molecular and physical forces in development and vascular homeostasis. Deregulation of endothelial responses to flow-induced shear is believed to contribute to many aspects of cardiovascular diseases including atherosclerosis. However, how molecular signals and shear-mediated physical forces integrate to regulate vascular patterning is poorly understood.

DAAM1 and DAAM2 are co-required for myocardial maturation and sarcomere assembly.

Wnt ligands regulate heart morphogenesis but the underlying mechanisms remain unclear. Two Formin-related proteins, DAAM1 and 2, were previously found to bind the Wnt effector Disheveled. Here, since DAAM1 and 2 nucleate actin and mediate Wnt-induced cytoskeletal changes, a floxed-allele of Daam1 was used to disrupt its function specifically in the myocardium and investigate Wnt-associated pathways.

WNT5A inhibits hepatocyte proliferation and concludes β-catenin signaling in liver regeneration.

Activation of Wnt/β-catenin signaling during liver regeneration (LR) after partial hepatectomy (PH) is observed in several species. However, how this pathway is turned off when hepatocyte proliferation is no longer required is unknown. We assessed LR in liver-specific knockouts of Wntless (Wls-LKO), a protein required for Wnt secretion from a cell.

Lineage tracing of neuromesodermal progenitors reveals novel Wnt-dependent roles in trunk progenitor cell maintenance and differentiation.

In the development of the vertebrate body plan, Wnt3a is thought to promote the formation of paraxial mesodermal progenitors (PMPs) of the trunk region while suppressing neural specification. Recent lineage-tracing experiments have demonstrated that these trunk neural progenitors and PMPs derive from a common multipotent progenitor called the neuromesodermal progenitor (NMP). NMPs are known to reside in the anterior primitive streak (PS) region; however, the extent to which NMPs populate the PS and contribute to the vertebrate body plan, and the precise role that Wnt3a plays in regulating NMP self-renewal and differentiation are unclear.

Molecular Role of RNF43 in Canonical and Noncanonical Wnt Signaling.

Wnt signaling pathways are tightly regulated by ubiquitination, and dysregulation of these pathways promotes tumorigenesis. It has been reported that the ubiquitin ligase RNF43 plays an important role in frizzled-dependent regulation of the Wnt/β-catenin pathway. Here, we show that RNF43 suppresses both Wnt/β-catenin signaling and noncanonical Wnt signaling by distinct mechanisms.

Wnt8a and Wnt3a cooperate in the axial stem cell niche to promote mammalian body axis extension.

Background: Vertebrate body axis extension occurs in a head-to-tail direction from a caudal progenitor zone that responds to interacting signals. Wnt/β-catenin signaling is critical for generation of paraxial mesoderm, somite formation, and maintenance of the axial stem cell pool. Body axis extension requires Wnt8a in lower vertebrates, but in mammals Wnt3a is required, although the anterior trunk develops in the absence of Wnt3a.

Mesogenin 1 is a master regulator of paraxial presomitic mesoderm differentiation.

Neuromesodermal (NM) stem cells generate neural and paraxial presomitic mesoderm (PSM) cells, which are the respective progenitors of the spinal cord and musculoskeleton of the trunk and tail. The Wnt-regulated basic helix-loop-helix (bHLH) transcription factor mesogenin 1 (Msgn1) has been implicated as a cooperative regulator working in concert with T-box genes to control PSM formation in zebrafish, although the mechanism is unknown. We show here that, in mice, Msgn1 alone controls PSM differentiation by directly activating the transcriptional programs that define PSM identity, epithelial-mesenchymal transition, motility and segmentation.

An antiangiogenic isoform of VEGF-A contributes to impaired vascularization in peripheral artery disease.

Peripheral artery disease (PAD) generates tissue ischemia through arterial occlusions and insufficient collateral vessel formation. Vascular insufficiency in PAD occurs despite higher circulating levels of vascular endothelial growth factor A (VEGF-A), a key regulator of angiogenesis. Here we show that clinical PAD is associated with elevated levels of an antiangiogenic VEGF-A splice isoform (VEGF-A165b) and a corresponding reduction in levels of the proangiogenic VEGF-A165a splice isoform.