Wnt5a: its signalling, functions and implication in diseases

Secreted frizzled-related protein 5 overexpression reverses oxLDL-induced lipid accumulation in human vascular smooth muscle cells

Atherosclerosis (AS) is the major cause of multiple cardiovascular diseases. In addition, the lipid accumulation of human vascular smooth muscle cells (HVSMCs) can cause the occurrence of AS. Secreted frizzled-related protein 5 (Sfrp5) was known to be downregulated in AS; however, the detailed function of Sfrp5 in HVSMCs remains unclear. Specifically, we found that Sfrp5 expression in oxLDL-treated HVSMCs was downregulated. Sfrp5 overexpression inhibited the viability of HVSMCs induced by oxLDL. In addition, oxLDL-induced proliferation and migration in HVSMCs were abolished by Sfrp5 overexpression. Sfrp5 overexpression reduced oxLDL-caused oxidative stress, lipid accumulation, and inflammation in HVSMCs. Meanwhile, oxLDL treatment increased the expressions of Wnt5a, c-Myc, and β-catenin in HVSMCs, while this phenomenon was rescued by Sfrp5 overexpression. Furthermore, the inhibitory effect of Sfrp5 upregulation on the viability and migration of HVSMCs was reversed by R-spondin 1. These results indicate that Sfrp5 overexpression could reverse oxLDL-induced lipid accumulation in HVSMCs through inactivating Wnt5a/β-catenin signaling pathway.

New insights in ubiquitin-dependent Wnt receptor regulation in tumorigenesis

Wnt signaling plays a crucial role in embryonic development and homeostasis maintenance. Delicate and sensitive fine-tuning of Wnt signaling based on the proper timings and positions is required to balance cell proliferation and differentiation and maintain individual health. Therefore, homeostasis is broken by tissue hypoplasia or tumor formation once Wnt signal dysregulation disturbs the balance of cell proliferation. The well-known regulatory mechanism of Wnt signaling is the molecular reaction associated with the cytoplasmic accumulation of effector β-catenin. In addition to β-catenin, most Wnt effector proteins are also regulated by ubiquitin-dependent modification, both qualitatively and quantitatively. This review will explain the regulation of the whole Wnt signal in four regulatory phases, as well as the different ubiquitin ligases and the function of deubiquitinating enzymes in each phase. Along with the recent results, the mechanism by which RNF43 negatively regulates the surface expression of Wnt receptors, which has recently been well understood, will be detailed. Many RNF43 mutations have been identified in pancreatic and gastrointestinal cancers and examined for their functional alteration in Wnt signaling. Several mutations facilitate or activate the Wnt signal, reversing the RNF43 tumor suppressor function into an oncogene. RNF43 may simultaneously play different roles in classical multistep tumorigenesis, as both wild-type and mutant RNF43 suppress the p53 pathway. We hope that the knowledge obtained from further research in RNF43 will be applied to cancer treatment in the future despite the fully unclear function of RNF43.

The role of Map1b in regulating osteoblast polarity, proliferation, differentiation and migration

Osteoblast polarity, proliferation, differentiation, and migration are essential for maintaining normal bone structure and function. While the microtubule-associated protein Map1b has been extensively studied in nerve cells, its role in bone cells is less known. We investigated the functional significance of Map1b in mouse bone marrow stromal cells (ST2) and elucidated its relationship and influence on cytoskeletal polarity and Golgi organization. Our results suggest that Map1b, as a microtubule regulatory protein, can also regulate the expression of cyclin PCNA, p-H3(S10) and migration-related protein integrin β1, thereby affecting the proliferation and migration of osteoblasts. The downstream target gene Rgc32 was screened by RNA sequencing. Furthermore, Map1b, as a downstream mediator, regulates the Wnt5a signaling pathway. This study expands our understanding of the involvement of Map1b in bone biology and highlights its crucial role in governing osteoblast polarity, proliferation, and migration, thereby providing a basis for developing novel therapeutic strategies targeting Map1b in orthopedic medicine and promoting precision treatment modalities. Further investigations on the precise mechanisms underlying Map1b's influence on bone cell function and disease progression are needed.

Neuromesodermal specification during head-to-tail body axis formation

The anterior-to-posterior (head-to-tail) body axis is extraordinarily diverse among vertebrates but conserved within species. Body axis development requires a population of axial progenitors that resides at the posterior of the embryo to sustain elongation and is then eliminated once axis extension is complete. These progenitors occupy distinct domains in the posterior (tail-end) of the embryo and contribute to various lineages along the body axis. The subset of axial progenitors with neuromesodermal competency will generate both the neural tube (the precursor of the spinal cord), and the trunk and tail somites (producing the musculoskeleton) during embryo development. These axial progenitors are called Neuromesodermal Competent cells (NMCs) and Neuromesodermal Progenitors (NMPs). NMCs/NMPs have recently attracted interest beyond the field of developmental biology due to their clinical potential. In the mouse, the maintenance of neuromesodermal competency relies on a fine balance between a trio of known signals: Wnt/β-catenin, FGF signalling activity and suppression of retinoic acid signalling. These signals regulate the relative expression levels of the mesodermal transcription factor Brachyury and the neural transcription factor Sox2, permitting the maintenance of progenitor identity when co-expressed, and either mesoderm or neural lineage commitment when the balance is tilted towards either Brachyury or Sox2, respectively. Despite important advances in understanding key genes and cellular behaviours involved in these fate decisions, how the balance between mesodermal and neural fates is achieved remains largely unknown. In this chapter, we provide an overview of signalling and gene regulatory networks in NMCs/NMPs. We discuss mutant phenotypes associated with axial defects, hinting at the potential significant role of lesser studied proteins in the maintenance and differentiation of the progenitors that fuel axial elongation.

TBXT dose sensitivity and the decoupling of nascent mesoderm specification from EMT progression in 2D human gastruloids

In the nascent mesoderm, TBXT expression must be precisely regulated to ensure that cells exit the primitive streak and pattern the anterior-posterior axis, but how varying dosage informs morphogenesis is not well understood. In this study, we define the transcriptional consequences of TBXT dosage reduction during early human gastrulation using human induced pluripotent stem cell models of gastrulation and mesoderm differentiation. Multi-omic single-nucleus RNA and single-nucleus ATAC sequencing of 2D gastruloids comprising wild-type, TBXT heterozygous or TBXT null human induced pluripotent stem cells reveal that varying TBXT dosage does not compromise the ability of a cell to differentiate into nascent mesoderm, but instead directly influences the temporal progression of the epithelial-to-mesenchymal transition with wild type transitioning first, followed by TBXT heterozygous and then TBXT null. By differentiating cells into nascent mesoderm in a monolayer format, we further illustrate that TBXT dosage directly impacts the persistence of junctional proteins and cell-cell adhesions. These results demonstrate that epithelial-to-mesenchymal transition progression can be decoupled from the acquisition of mesodermal identity in the early gastrula and shed light on the mechanisms underlying human embryogenesis.

WNT5A regulates the proliferation, apoptosis and stemness of human stem Leydig cells via the β-catenin signaling pathway

Stem Leydig cells (SLCs) are essential for maintaining normal spermatogenesis as the significant component of testis microenvironment and gonadal aging. Although progress has been achieved in the regulation of male germ cells in mammals and humans, it remains unknown about the genes and signaling pathways of human SLCs. Here we have demonstrated, for the first time, that WNT5A (Wnt family member 5a) mediates the proliferation, apoptosis, and stemness of human SLCs, namely NGFR+ Leydig cells. We revealed that NGFR+ Leydig cells expressed NGFR, PDGFRA, NES, NR2F2, and THY1, hallmarks for SLCs. RNA-sequencing showed that WNT5A was expressed at a higher level in human SLCs than non-SLCs, while immunohistochemistry and Western blots further illustrated that WNT5A was predominantly expressed in human SLCs. Notably, CCK-8, EdU and Western blots displayed that WNT5A enhanced the proliferation and DNA synthesis and retained stemness of human SLCs, whereas flow cytometry and TUNEL analyses demonstrated that WNT5A inhibited the apoptosis of these cells. WNT5A knockdown caused an increase in LC lineage differentiation of human SLCs and reversed the effect of WNT5A overexpression on fate decisions of human SLCs. In addition, WNT5A silencing  resulted in the decreases in nuclear translocation of β-catenin and expression levels of c-Myc, CD44, and Cyclin D1. Collectively, these results implicate that WNT5A regulates the proliferation, apoptosis and stemness of human SLCs through the activation of the β-catenin signaling pathway. This study thus provides a novel molecular mechanism underlying the fate determinations of human SLCs, and it offers a new insight into the niche regulation of human testis.

A therapeutical insight into the correlation between circRNAs and signaling pathways involved in cancer pathogenesis

Pre-messenger RNA molecules are back-spliced to create circular RNAs, which are non-coding RNA molecules. After a thorough investigation, it was discovered that these circRNAs have critical biological roles. CircRNAs have a variety of biological functions, including their ability to operate as microRNA sponges, interact with proteins to alter their stabilities and activities, and provide templates for the translation of proteins. Evidence supports a link between the emergence of numerous diseases, including various cancer types, and dysregulated circRNA expression. It is commonly known that a significant contributing element to cancer development is the disruption of numerous molecular pathways essential for preserving cellular and tissue homeostasis. The dysregulation of multiple biological processes is one of the hallmarks of cancer, and the molecular pathways linked to these processes are thought to be promising targets for therapeutic intervention. The biological and carcinogenic effects of circRNAs in the context of cancer are thoroughly reviewed in this article. Specifically, we highlight circRNAs' involvement in signal transduction pathways and their possible use as novel biomarkers for the early identification and prognosis of human cancer.

Helicobacter pylori and Epstein-Barr virus infection in cell polarity alterations

The asymmetrical distribution of the cellular organelles inside the cell is maintained by a group of cell polarity proteins. The maintenance of polarity is one of the vital host defense mechanisms against pathogens, and the loss of it contributes to infection facilitation and cancer progression. Studies have suggested that infection of viruses and bacteria alters cell polarity. Helicobacter pylori and Epstein-Barr virus are group I carcinogens involved in the progression of multiple clinical conditions besides gastric cancer (GC) and Burkitt's lymphoma, respectively. Moreover, the coinfection of both these pathogens contributes to a highly aggressive form of GC. H. pylori and EBV target the host cell polarity complexes for their pathogenesis. H. pylori-associated proteins like CagA, VacA OipA, and urease were shown to imbalance the cellular homeostasis by altering the cell polarity. Similarly, EBV-associated genes LMP1, LMP2A, LMP2B, EBNA3C, and EBNA1 also contribute to altered cell asymmetry. This review summarized all the possible mechanisms involved in cell polarity deformation in H. pylori and EBV-infected epithelial cells. We have also discussed deregulated molecular pathways like NF-κB, TGF-β/SMAD, and β-catenin in H. pylori, EBV, and their coinfection that further modulate PAR, SCRIB, or CRB polarity complexes in epithelial cells.

Risk of Sperm Disorders and Impaired Fertility in Frozen-Thawed Bull Semen: A Genome-Wide Association Study

Cryopreservation is a widely used method of semen conservation in animal breeding programs. This process, however, can have a detrimental effect on sperm quality, especially in terms of its morphology. The resultant sperm disorders raise the risk of reduced sperm fertilizing ability, which poses a serious threat to the long-term efficacy of livestock reproduction and breeding. Understanding the genetic factors underlying these effects is critical for maintaining sperm quality during cryopreservation, and for animal fertility in general. In this regard, we performed a genome-wide association study to identify genomic regions associated with various cryopreservation sperm abnormalities in Holstein cattle, using single nucleotide polymorphism (SNP) markers via a high-density genotyping assay. Our analysis revealed a significant association of specific SNPs and candidate genes with absence of acrosomes, damaged cell necks and tails, as well as wrinkled acrosomes and decreased motility of cryopreserved sperm. As a result, we identified candidate genes such as POU6F2, LPCAT4, DPYD, SLC39A12 and CACNB2, as well as microRNAs (bta-mir-137 and bta-mir-2420) that may play a critical role in sperm morphology and disorders. These findings provide crucial information on the molecular mechanisms underlying acrosome integrity, motility, head abnormalities and damaged cell necks and tails of sperm after cryopreservation. Further studies with larger sample sizes, genome-wide coverage and functional validation are needed to explore causal variants in more detail, thereby elucidating the mechanisms mediating these effects. Overall, our results contribute to the understanding of genetic architecture in cryopreserved semen quality and disorders in bulls, laying the foundation for improved animal reproduction and breeding.

Wnt5a: A promising therapeutic target for inflammation, especially rheumatoid arthritis

BACKGROUND

Wnt5a is a member of the Wnt protein family, which acts on classical or multiple non-classical Wnt signaling pathways by binding to different receptors. The expression regulation and signal transduction of Wnt5a is closely related to the inflammatory response. Abnormal activation of Wnt5a signaling is an important part of inflammation and rheumatoid arthritis (RA).

OBJECTIVES

This paper mainly focuses on Wnt5a protein and its mediated signaling pathway, summarizes the latest research progress of Wnt5a in the pathological process of inflammation and RA, and looks forward to the main directions of Wnt5a in RA research, aiming to provide a theoretical basis for the prevention and treatment of RA diseases by targeting Wnt5a.

RESULTS

Wnt5a is highly expressed in activated blood vessels, histocytes and synoviocytes in inflammatory diseases such as sepsis, sepsis, atherosclerosis and rheumatoid arthritis. It mediates the production of pro-inflammatory cytokines and chemokines, regulates the migration and recruitment of various immune effector cells, and thus participates in the inflammatory response. Wnt5a plays a pathological role in synovial inflammation and bone destruction of RA, and may be an important clinical therapeutic target for RA.

CONCLUSION

Wnt5a is involved in the pathological process of inflammation and interacts with inflammatory factors. Wnt5a may be a new target for regulating the progression of RA disease and intervening therapy because of its multi-modal effects on the etiology of RA, especially as a regulator of osteoclast activity and inflammation.

TBXT dose sensitivity and the decoupling of nascent mesoderm specification from EMT progression in 2D human gastruloids

In the nascent mesoderm, levels of Brachyury (TBXT) expression must be precisely regulated to ensure cells exit the primitive streak and pattern the anterior-posterior axis, but how this varying dosage informs morphogenesis is not well understood. In this study, we define the transcriptional consequences of TBXT dose reduction during early human gastrulation using human induced pluripotent stem cell (hiPSC)-based models of gastrulation and mesoderm differentiation. Multiomic single-nucleus RNA and single-nucleus ATAC sequencing of 2D gastruloids comprised of WT, TBXT heterozygous (TBXT-Het), or TBXT null (TBXT-KO) hiPSCs reveal that varying TBXT dosage does not compromise a cell's ability to differentiate into nascent mesoderm, but that the loss of TBXT significantly delays the temporal progression of the epithelial to mesenchymal transition (EMT). This delay is dependent on TBXT dose, as cells heterozygous for TBXT proceed with EMT at an intermediate pace relative to WT or TBXT-KO. By differentiating iPSCs of the allelic series into nascent mesoderm in a monolayer format, we further illustrate that TBXT dose directly impacts the persistence of junctional proteins and cell-cell adhesions. These results demonstrate that EMT progression can be decoupled from the acquisition of mesodermal identity in the early gastrula and shed light on the mechanisms underlying human embryogenesis.

YAP/WNT5A/FZD4 axis regulates osteogenic differentiation of human periodontal ligament cells under cyclic stretch

OBJECTIVE

To verify the role of YAP/WNT5A/FZD4 axis in stretch-induced osteogenic differentiation of hPDLCs.

BACKGROUND

During orthodontic tooth movement, differentiation of human periodontal ligament cells (hPDLCs) at the tension side of the periodontal ligament mediates new bone formation. WNT5A promotes osteogenesis and its regulator Yes-associated protein (YAP) is responsive to mechanical stimulation in hPDLCs. However, the mechanisms of YAP and WNT5A in alveolar bone remodeling remain unclear.

METHODS

Cyclic stretch was applied to hPDLCs to mimic the orthodontic stretching force. Osteogenic differentiation was determined by alkaline phosphatase (ALP) activity, Alizarin Red staining, qRT-PCR and western blotting. To detect activation of YAP and expression of WNT5A and its receptor Frizzled-4 (FZD4), western blotting, immunofluorescence, qRT-PCR and ELISA were performed. Verteporfin, Lats-IN-1, small interfering RNAs and recombinant protein were used to explore the relationship of YAP, WNT5A and FZD4, and the effect of their relationship on stretch-induced osteogenesis of hPDLCs.

RESULTS

WNT5A, FZD4 and nuclear localization of YAP were upregulated by cyclic stretch. YAP positively regulated WNT5A and FZD4 expression and osteogenic differentiation of hPDLCs under cyclic stretch by YAP inhibition or activation assay. Knockdown of WNT5A and FZD4 attenuated YAP-induced and stretch-induced osteogenic differentiation. Recombinant WNT5A rescued the suppressed osteogenic differentiation by YAP inhibitor in hPDLCs, whereas knockdown of FZD4 weakened the effect of WNT5A and amplified the suppression.

CONCLUSIONS

WNT5A/FZD4 could be positively regulated by YAP and the YAP/WNT5A/FZD4 axis mediated osteogenic differentiation of hPDLCs under cyclic stretch. This study provided further insight into the biological mechanism of orthodontic tooth movement.

ZEB1-mediated biogenesis of circNIPBL sustains the metastasis of bladder cancer via Wnt/β-catenin pathway

BACKGROUND

Circular RNAs (circRNAs) circularized by back-splicing of pre-mRNA are widely expressed and affected the proliferation, invasion and metastasis of bladder cancer (BCa). However, the mechanism underlying circRNA biogenesis in mediating the distant metastasis of BCa still unexplored.

METHODS

RNA sequencing data between BCa and normal adjacent tissues was applied to identify the differentially expressed circRNAs. The functions of circNIPBL in BCa were investigated via a series of biochemical experiments. The Clinical significance of circNIPBL was examined in a cohort of larger BCa tissues.

RESULTS

In the present study, we identified a novel circRNA (hsa_circ_0001472), circNIPBL, which was significantly upregulated and had great influence on the poor prognosis of patients with BCa. Functionally, circNIPBL promotes BCa metastasis in vitro and in vivo. Mechanistically, circNIPBL upregulate the expression of Wnt5a and activated the Wnt/β-catenin signaling pathway via directly sponged miR-16-2-3p, leading to the upregulation of ZEB1, which triggers the EMT of BCa. Moreover, we revealed that ZEB1 interacted with the flanking introns of exons 2-9 on NIPBL pre-mRNA to trigger circNIPBL biogenesis, thus forming a positive feedback loop. Importantly, circNIPBL overexpression significantly facilitated the distant metastasis of BCa in the orthotopic bladder cancer model, while silencing ZEB1 remarkably blocked the effects of metastasis induced by circNIPBL overexpression.

CONCLUSIONS

Our study highlights that circNIPBL-induced Wnt signaling pathway activation triggers ZEB1-mediated circNIPBL biogenesis, which forms a positive feedback loop via the circNIPBL/miR-16-2-3p/Wnt5a/ZEB1 axis, supporting circNIPBL as a novel therapeutic target and potential biomarker for BCa patients.

Wnt5a-YAP signaling axis mediates mechanotransduction in cardiac myocytes and contributes to contractile dysfunction induced by pressure overload

Non-canonical Wnt signaling activated by Wnt5a/Wnt11 is required for the second heart field development in mice. However, the pathophysiological role of non-canonical Wnt signaling in the adult heart has not been fully elucidated. Here we show that cardiomyocyte-specific Wnt5a knockout mice exhibit improved systolic function and reduced expression of mechanosensitive genes including Nppb when subjected to pressure overload. In cultured cardiomyocytes, Wnt5a knockdown reduced Nppb upregulation induced by cyclic cell stretch. Upstream analysis revealed that TEAD1, a transcription factor that acts with Hippo pathway co-activator YAP, was downregulated both in vitro and in vivo by Wnt5a knockdown/knockout. YAP nuclear translocation was induced by cell stretch and attenuated by Wnt5a knockdown. Wnt5a knockdown-induced Nppb downregulation during cell stretch was rescued by Hippo inhibition, and the rescue effect was canceled by knockdown of YAP. These results collectively suggest that Wnt5a-YAP signaling axis mediates mechanotransduction in cardiomyocytes and contributes to heart failure progression.

Non-canonical Wnt signaling in the eye

Wnt signaling comprises a group of complex signal transduction pathways that play critical roles in cell proliferation, differentiation, and apoptosis during development, as well as in stem cell maintenance and adult tissue homeostasis. Wnt pathways are classified into two major groups, canonical (β-catenin-dependent) or non-canonical (β-catenin-independent). Most previous studies in the eye have focused on canonical Wnt signaling, and the role of non-canonical signaling remains poorly understood. Additionally, the crosstalk between canonical and non-canonical Wnt signaling in the eye has hardly been explored. In this review, we present an overview of available data on ocular non-canonical Wnt signaling, including developmental and functional aspects in different eye compartments. We also discuss important changes of this signaling in various ocular conditions, such as keratoconus, aniridia-related keratopathy, diabetes, age-related macular degeneration, optic nerve damage, pathological angiogenesis, and abnormalities in the trabecular meshwork and conjunctival cells, and limbal stem cell deficiency.

Noncanonical Wnt signaling promotes colon tumor growth, chemoresistance and tumor fibroblast activation

Colon tumors of the mesenchymal subtype have the lowest overall survival. Snail1 is essential for the acquisition of this phenotype, characterized by increased tumor stemness and invasion, and high resistance to chemotherapy. Here, we find that Snail1 expression in colon tumor cells is dependent on an autocrine noncanonical Wnt pathway. Accordingly, depletion of Ror2, the co-receptor for noncanonical Wnts such as Wnt5a, potently decreases Snail1 expression. Wnt5a, Ror2, and Snail1 participate in a self-stimulatory feedback loop since Wnt5a increases its own synthesis in a Ror2- and Snail1-dependent fashion. This Wnt5a/Ror2/Snail1 axis controls tumor invasion, chemoresistance, and formation of tumor spheres. It also stimulates TGFβ synthesis; consequently, tumor cells expressing Snail1 are more efficient in activating cancer-associated fibroblasts than the corresponding controls. Ror2 downmodulation or inhibition of the Wnt5a pathway decreases Snail1 expression in primary colon tumor cells and their ability to form tumors and liver metastases. Finally, the expression of SNAI1, ROR2, and WNT5A correlates in human colon and other tumors. These results identify inhibition of the noncanonical Wnt pathway as a putative colon tumor therapy.

Mechanotransduction in tumor dynamics modeling

Mechanotherapy is a groundbreaking approach to impact carcinogenesis. Cells sense and respond to mechanical stimuli, translating them into biochemical signals in a process known as mechanotransduction. The impact of stress on tumor growth has been studied in the last three decades, and many papers highlight the role of mechanics as a critical self-inducer of tumor fate at the in vitro and in vivo biological levels. Meanwhile, mathematical models attempt to determine laws to reproduce tumor dynamics. This review discusses biological mechanotransduction mechanisms and mathematical-biomechanical models together. The aim is to provide a common framework for the different approaches that have emerged in the literature from the perspective of tumor avascularity and to provide insight into emerging mechanotherapies that have attracted interest in recent years.

Wnt pathway inhibitors are upregulated in XLH dental pulp cells in response to odontogenic differentiation

X-linked hypophosphatemia (XLH) represents the most common form of familial hypophosphatemia. Although significant advances have been made in the treatment of bone pathology, patients undergoing therapy continue to experience significantly decreased oral health-related quality of life. The following study addresses this persistent oral disease by further investigating the effect of DMP1 expression on the differentiation of XLH dental pulp cells. Dental pulp cells were isolated from the third molars of XLH and healthy controls and stable transduction of full-length human DMP1 were achieved. RNA sequencing was performed to evaluate the genetic changes following the induction of odontogenic differentiation. RNAseq data shows the upregulation of inhibitors of the canonical Wnt pathway in XLH cells, while constitutive expression of full-length DMP1 in XLH cells reversed this effect during odontogenic differentiation. These results imply that inhibition of the canonical Wnt pathway may contribute to the pathophysiology of XLH and suggest a new therapeutic strategy for the management of oral disease.

Microglial WNT5A supports dendritic spines maturation and neuronal firing

There is increasing evidence showing that microglia play a critical role in mediating synapse formation and spine growth, although the molecular mechanism remains elusive. Here, we demonstrate that the secreted morphogen WNT family member 5A (WNT5A) is the most abundant WNT expressed in microglia and that it promotes neuronal maturation. Co-culture of microglia with Thy1-YFP+ differentiated neurons significantly increased neuronal spine density and reduced dendritic spine turnover rate, which was diminished by silencing microglial Wnt5a in vitro. Co-cultured microglia increased post-synaptic marker PSD95 and synaptic density as determined by the co-localization of PSD95 with pre-synaptic marker VGLUT2 in vitro. The silencing of Wnt5a expression in microglia partially reduced both PSD95 and synaptic densities. Co-culture of differentiated neurons with microglia significantly enhanced neuronal firing rate as measured by multiple electrode array, which was significantly reduced by silencing microglial Wnt5a at 23 days differentiation in vitro. These findings demonstrate that microglia can mediate spine maturation and regulate neuronal excitability via WNT5A secretion indicating possible pathological roles of dysfunctional microglia in developmental disorders.

Periostin: an emerging activator of multiple signaling pathways

Matricellular proteins are responsible for regulating the microenvironment, the behaviors of surrounding cells, and the homeostasis of tissues. Periostin (POSTN), a non-structural matricellular protein, can bind to many extracellular matrix proteins through its different domains. POSTN usually presents at low levels in most adult tissues but is highly expressed in pathological sites such as in tumors and inflamed organs. POSTN can bind to diverse integrins to interact with multiple signaling pathways within cells, which is one of its core biological functions. Increasing evidence shows that POSTN can activate the TGF-β, the PI3K/Akt, the Wnt, the RhoA/ROCK, the NF-κB, the MAPK and the JAK pathways to promote the occurrence and development of many diseases, especially cancer and inflammatory diseases. Furthermore, POSTN can interact with some pathways in an upstream and downstream relationship, forming complicated crosstalk. This article focuses on the interactions between POSTN and different signaling pathways in diverse diseases, attempting to explain the mechanisms of interaction and provide novel guidelines for the development of targeted therapies.

Deletion of RBP-Jkappa gene in mesenchymal cells causes rickets like symptoms in the mouse

Crosstalk between different signalling pathways provide deep insights for how molecules play synergistic roles in developmental and pathological conditions. RBP-Jkappa is the key effector of the canonical Notch pathway. Previously we have identified that Wnt5a, a conventional non-canonical Wnt pathway member, was under the direct transcriptional control of RBP-Jkappa in dermal papilla cells. In this study we further extended this regulation axis to the other two kind of skeletal cells: chondrocytes and osteoblasts. Mice with conditional mesenchymal deletion of RBP-Jkappa developed Rickets like symptoms. Molecular analysis suggested local defects of Wnt5a expression in chondrocytes and osteoblasts at both mRNA and protein levels, which impeded chondrocyte and osteoblast differentiation. The defects existing in the RBP-Jkappa deficient mutants could be rescued by recombinant Wnt5a treatment at both cellular level and tissue/organ level. Our results therefore provide a model of studying the connection of Notch and Wnt5a pathways with Rickets.

Macrophages and Wnts in Tissue Injury and Repair

Macrophages are important players in the immune system that sense various tissue challenges and trigger inflammation. Tissue injuries are followed by inflammation, which is tightly coordinated with tissue repair processes. Dysregulation of these processes leads to chronic inflammation or tissue fibrosis. Wnt ligands are present both in homeostatic and pathological conditions. However, their roles and mechanisms regulating inflammation and tissue repair are being investigated. Here we aim to provide an overview of overarching themes regarding Wnt and macrophages by reviewing the previous literature. We aim to gain future insights into how tissue inflammation, repair, regeneration, and fibrosis events are regulated by macrophages.

Modeling extracellular matrix through histo-molecular gradient in NSCLC for clinical decisions

Lung cancer still represents a global health problem, being the main type of tumor responsible for cancer deaths. In this context, the tumor microenvironment, and the extracellular matrix (ECM) pose as extremely relevant. Thus, this study aimed to explore the prognostic value of epithelial-to-mesenchymal transition (EMT), Wnt signaling, and ECM proteins expression in patients with non-small-cell lung carcinoma (NSCLC) with clinical stages I-IIIA. For that, we used 120 tissue sections from patients and evaluated the immunohistochemical, immunofluorescence, and transmission electron microscopy (TEM) to each of these markers. We also used in silico analysis to validate our data. We found a strong expression of E-cadherin and β-catenin, which reflects the differential ECM invasion process. Therefore, we also noticed a strong expression of chondroitin sulfate (CS) and collagens III and V. This suggests that, after EMT, the basal membrane (BM) enhanced the motility of invasive cells. EMT proteins were directly associated with WNT5A, and collagens III and V, which suggests that the WNT pathway drives them. On the other hand, heparan sulfate (HS) was associated with WNT3A and SPARC, while WNT1 was associated with CS. Interestingly, the association between WNT1 and Col IV suggested negative feedback of WNT1 along the BM. In our cohort, WNT3A, WNT5A, heparan sulfate and SPARC played an important role in the Cox regression model, influencing the overall survival (OS) of patients, be it directly or indirectly, with the SPARC expression stratifying the OS into two groups: 97 months for high expression; and 65 for low expression. In conclusion, the present study identified a set of proteins that may play a significant role in predicting the prognosis of NSCLC patients with clinical stages I-IIIA.

Wnt5a Promotes AT1 and Represses AT2 Lineage-Specific Gene Expression in a Cell-Context-Dependent Manner

Lung maturation is not limited to proper structural development but also includes differentiation and functionality of various highly specialized alveolar cell types. Alveolar type 1 (AT1s) cells occupy nearly 95% of the alveolar surface and are critical for establishing efficient gas exchange in the mature lung. AT1 cells arise from progenitors specified during the embryonic stage as well as alveolar epithelial progenitors expressing surfactant protein C (Sftpcpos cells) during postnatal and adult stages. Previously, we found that Wnt5a, a non-canonical Wnt ligand, is required for differentiation of AT1 cells during the saccular phase of lung development. To further investigate the role of Wnt5a in AT1 cell differentiation, we generated and characterized a conditional Wnt5a gain-of-function mouse model. Neonatal Wnt5a gain-of-function disrupted alveologenesis through inhibition of cell proliferation. In this setting Wnt5a downregulated β-catenin-dependent canonical Wnt signaling, repressed AT2 (anti-AT2) and promoted AT1 (pro-AT1) lineage-specific gene expression. In addition, we identified 2 subpopulations of Sftpchigh and Sftpclow alveolar epithelial cells. In Sftpclow cells, Wnt5a exhibits pro-AT1 and anti-AT2 effects, concurrent with inhibition of canonical Wnt signaling. Interestingly, in the Sftpchigh subpopulation, although increasing AT1 lineage-specific gene expression, Wnt5a gain-of-function did not change AT2 gene expression, nor inhibit canonical Wnt signaling. Using primary epithelial cells isolated from human fetal lungs, we demonstrate that this property of Wnt5a is evolutionarily conserved. Wnt5a therefore serves as a selective regulator that ensures proper AT1/AT2 balance in the developing lung.

Wnt5a-Ror2 signaling mediates root resorption

INTRODUCTION

This study aimed to investigate the role of wingless-type MMTV integration site family member 5a (Wnt5a)-receptor tyrosine kinase-like orphan receptor 2 (Ror2) signaling in root resorption.

METHODS

The messenger RNA (mRNA) expression of Wnt5a, Ror2, and RANKL in periodontal ligament cells (PDLCs) under compression force (CF) with or without Ror2 small interfering RNA (siRNA) were measured by quantitative reverse transcription-polymerase chain reaction, and these proteins released into culture supernatants were measured using enzyme-linked immunosorbent assay. Then these PDLC-conditioned media under CF with or without Ror2 siRNA were used to culture osteoclast precursors to detect osteoclastogenesis effects via tartrate-resistant acid phosphatase staining. In in vivo studies, the odontoclast number and the root resorption volume under excessive CF with or without Ror2 siRNA were investigated by tartrate-resistant acid phosphatase immunohistochemical staining and microcomputed tomography. The protein levels for Wnt5a, Ror2, and receptor activator of nuclear factor-kappa B ligand (RANKL) in the periodontal ligament tissues were also detected using immunohistochemical staining. Finally, the odontoclast number, root resorption volume, and the mRNA and protein expressions were compared between immature and mature teeth.

RESULTS

The mRNA production and protein release level of Wnt5a, Ror2, and RANKL increased after CF, whereas they were significantly downregulated with Ror2 siRNA. The osteoclast number increased treating with culture medium from PDLC applying CF, but the increase was inhibited after adding Ror2 siRNA. In the animal model, the odontoclast number and root resorption volume significantly increased in the CF group but decreased in the CF with the Ror2 siRNA group. The protein levels of Wnt5a, Ror2, and RANKL in periodontal ligament were upregulated under excessive CF, and the pathway was inhibited with Ror2 siRNA. In the immature tooth group, the odontoclast number, root resorption volume, and the mRNA and protein expressions of Wnt5a-Ror2 signaling were reduced.

CONCLUSIONS

Wnt5a-Ror2 signaling in PDLCs enhanced by excessive CF could promote RANKL release and induce precursor differentiation, partly leading to increased odontoclast activity and ultimate root resorption. The less resorption of the immature tooth may be due to odontoclastogenesis inhibition by decreased expression of Wnt5a-Ror2 signaling.

Wnt5a-mediated autophagy promotes radiation resistance of nasopharyngeal carcinoma

Wnt signaling pathways and autophagy play an essential role in tumor progression. Canonical Wnt signaling pathways in radiation resistance have been studied in the past, but it remains unclear whether the noncanonical Wnt signaling pathways can affect tumor radiation resistance through protective autophagy. Nasopharyngeal carcinoma, a particular subtype of head and neck squamous cell carcinoma, relies on radiation therapy. In this study, we found that radioactive rays could significantly promote the expression of Wnt noncanonical signaling pathways ligands in nasopharyngeal carcinoma, among which Wnt5A was the most markedly altered. We have demonstrated that Wnt5a can reduce the radiation sensitivity of nasopharyngeal carcinoma in vitro and in vitro experiments. Meanwhile, we found much more greater autophagosomes in overexpressed-Wnt5A nasopharyngeal carcinoma cells by electron microscopy. Further mechanism exploration revealed that Beclin1 is the main target of Wnt5A, and knocking down Beclin1 can partially reduce Wnt5a-induced radiation resistance. By studying Wnt5A-mediated protective autophagy in promoting radiation resistance in nasopharyngeal carcinoma cells, we hope that the Wnt5A and Beclin1 can become effective targets for overcoming radiation resistance in the future.

Berberine retarded the growth of gastric cancer xenograft tumors by targeting hepatocyte nuclear factor 4α

BACKGROUND

Gastric cancer is the third deadliest cancer in the world and ranks second in incidence and mortality of cancers in China. Despite advances in prevention, diagnosis, and therapy, the absolute number of cases is increasing every year due to aging and the growth of high-risk populations, and gastric cancer is still a leading cause of cancer-related death. Gastric cancer is a consequence of the complex interaction of microbial agents, with environmental and host factors, resulting in the dysregulation of multiple oncogenic and tumor-suppressing signaling pathways. Global efforts have been made to investigate in detail the genomic and epigenomic heterogeneity of this disease, resulting in the identification of new specific and sensitive predictive and prognostic biomarkers. Trastuzumab, a monoclonal antibody against the HER2 receptor, is approved in the first-line treatment of patients with HER2+ tumors, which accounts for 13%-23% of the gastric cancer population. Ramucirumab, a monoclonal antibody against VEGFR2, is currently recommended in patients progressing after first-line treatment. Several clinical trials have also tested novel agents for advanced gastric cancer but mostly with disappointing results, such as anti-EGFR and anti-MET monoclonal antibodies. Therefore, it is still of great significance to screen specific molecular targets for gastric cancer and drugs directed against the molecular targets.

AIM

To investigate the effect and mechanism of berberine against tumor growth in gastric cancer xenograft models and to explore the role of hepatocyte nuclear factor 4α (HNF4α)-WNT5a/β-catenin pathways played in the antitumor effects of berberine.

METHODS

MGC803 and SGC7901 subcutaneous xenograft models were established. The control group was intragastrically administrated with normal saline, and the berberine group was administrated intragastrically with 100 mg/kg/d berberine. The body weight of nude mice during the experiment was measured to assess whether berberine has any adverse reaction. The volume of subcutaneous tumors during this experiment was recorded to evaluate the inhibitory effect of berberine on the growth of MGC803 and SGC7901 subcutaneous transplantation tumors. Polymerase chain reaction assays were conducted to evaluate the alteration of transcriptional expression of HNF4α, WNT5a and β-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models. Western blotting and IHC were performed to assess the protein expression of HNF4α, WNT5a and β-catenin in tumor tissues and liver tissues from the MGC803 and SGC7901 xenograft models.

RESULTS

In the both MGC803 and SGC7901 xenograft tumor models, berberine significantly reduced tumor volume and weight and thus retarded the growth rate of tumors. In the SGC7901 and MGC803 subcutaneously transplanted tumor models, berberine down-regulated the expression of HNF4α, WNT5a and β-catenin in tumor tissues from both transcription and protein levels. Besides, berberine also suppressed the protein expression of HNF4α, WNT5a and β-catenin in liver tissues.

CONCLUSION

Berberine retarded the growth of MGC803 and SGC7901 xenograft model tumors, and the mechanism behind these anti-growth effects might be the downregulation of the expression of HNF4α-WNT5a/β-catenin signaling pathways both in tumor tissues and liver tissues of the xenograft models.

Human pancreatic microenvironment promotes β-cell differentiation via non-canonical WNT5A/JNK and BMP signaling

In vitro derivation of pancreatic β-cells from human pluripotent stem cells holds promise as diabetes treatment. Despite recent progress, efforts to generate physiologically competent β-cells are still hindered by incomplete understanding of the microenvironment's role in β-cell development and maturation. Here, we analyze the human mesenchymal and endothelial primary cells from weeks 9-20 fetal pancreas and identify a time point-specific microenvironment that permits β-cell differentiation. Further, we uncover unique factors that guide in vitro development of endocrine progenitors, with WNT5A markedly improving human β-cell differentiation. WNT5A initially acts through the non-canonical (JNK/c-JUN) WNT signaling and cooperates with Gremlin1 to inhibit the BMP pathway during β-cell maturation. Interestingly, we also identify the endothelial-derived Endocan as a SST+ cell promoting factor. Overall, our study shows that the pancreatic microenvironment-derived factors can mimic in vivo conditions in an in vitro system to generate bona fide β-cells for translational applications.

Identification of Circular RNA-Based Immunomodulatory Networks in Colorectal Cancer

BACKGROUND

Circular RNAs (circRNAs) have been recently proposed as hub molecules in various diseases, especially in tumours. We found that circRNAs derived from ribonuclease P RNA component H1 (RPPH1) were highly expressed in colorectal cancer (CRC) samples from Gene Expression Omnibus (GEO) datasets.

OBJECTIVE

We sought to identify new circRNAs derived from RPPH1 and investigate their regulation of the competing endogenous RNA (ceRNA) and RNA binding protein (RBP) networks of CRC immune infiltration.

METHODS

The circRNA expression profiles miRNA and mRNA data were extracted from the GEO and The Cancer Genome Atlas (TCGA) datasets, respectively. The differentially expressed (DE) RNAs were identified using R software and online server tools, and the circRNA-miRNA-mRNA and circRNA-protein networks were constructed using Cytoscape. The relationship between targeted genes and immune infiltration was identified using the GEPIA2 and TIMER2 online server tools.

RESULTS

A ceRNA network, including eight circRNAs, five miRNAs, and six mRNAs, was revealed. Moreover, a circRNA-protein network, including eight circRNAs and 49 proteins, was established. The targeted genes, ENOX1, NCAM1, SAMD4A, and ZC3H10, are closely related to CRC tumour-infiltrating macrophages.

CONCLUSIONS

We analysed the characteristics of circRNA from RPPH1 as competing for endogenous RNA binding miRNA or protein in CRC macrophage infiltration. The results point towards the development of a new diagnostic and therapeutic paradigm for CRC.

Noncanonical Wnt5a Signaling Suppresses Hippo/TAZ-Mediated Osteogenesis Partly Through the Canonical Wnt Pathway in SCAPs

Purpose

Stem cells from the apical papilla (SCAPs) are promising seed cells for tissue regeneration medicine and possess the osteogenic differentiation potential. Wnt5a, a typical ligand of the noncanonical Wnt pathway, exhibits diverse roles in the regulation of osteogenesis. The transcriptional co-activator with PDZ-binding motif (TAZ, WWTR1) is a core regulator in the Hippo pathway and regulates stem behavior including osteogenic differentiation. This study aims to examine how Wnt5a regulates SCAPs osteogenesis and explore the precise mechanistic relationship between Wnt5a and TAZ.

Methods

SCAPs were isolated from developing apical papilla tissue of extracted human immature third molars in vitro. ALP staining, ALP activity and Alizarin red staining were used to evaluate osteogenic capacity. Osteogenic-related factors were assessed by qRT-PCR or Western blotting. Additionally, the receptor tyrosine kinase-like orphan receptor 2 (ROR2) was detected by immunocytofluorescence staining and silenced by small interfering RNA to verify the function of Wnt5a/ROR2 in TAZ-mediated osteogenesis. And we constructed TAZ-overexpression and β-catenin-overexpression SCAPs generated by lentivirus to explore the precise mechanistic relationship between Wnt5a and TAZ.

Results

Wnt5a (100ng/mL) significantly suppressed ALP activity, mineralization nodules formation, expression of osteogenic-related factors. Meanwhile, it decreased the expression of TAZ mRNA and protein. TAZ overexpression promoted osteogenesis of SCAPs while Wnt5a could block TAZ-mediated osteogenesis. Furthermore, ROR2 siRNA (siROR2) was found to upregulate TAZ and canonical Wnt pathway signaling related molecules such as β-catenin, GSK3β and p-GSK3β. The suppression of Wnt5a/ROR2 on osteogenesis was significantly reversed by β-catenin overexpression through Wnt5a/ROR2/β-catenin/TAZ pathway.

Conclusion

Taken together, the present study demonstrates that Wnt5a suppresses TAZ-mediated osteogenesis of SCAPs and there may be a Wnt5a/ROR2/β-catenin/TAZ pathway regulating osteogenesis of SCAPs. Moreover, Wnt5a could be a candidate for regulators in tissue regeneration.

MMP modulated differentiation of mouse embryonic stem cells on engineered cell derived matrices

Stem cell differentiation is dictated by the dynamic crosstalk between cells and their underlying extracellular matrix. While the importance of matrix degradation mediated by enzymes such as matrix metalloproteinases (MMPs) in the context of cancer invasion is well established, the role of MMPs in stem cell differentiation remains relatively unexplored. Here we address this question by assaying MMP expression and activity during differentiation of mouse embryonic stem cells (mESCs) on mouse embryonic fibroblast (MEF) derived matrices (MEFDMs) of varying stiffness and composition. We show that mESC differentiation into different germ layers is associated with expression of several MMPs including MMP-11, 2, 17, 25 and 9, with MMP-9 detected in cell secreted media. Different extents of softening of the different MEFDMs led to altered integrin expression, activated distinct mechanotransduction and metabolic pathways, and induced expression of germ layer-specific markers. Inhibition of MMP proteolytic activity by the broad spectrum MMP inhibitor GM6001 led to alterations in germ layer commitment of the differentiating mESCs. Together, our results illustrate the effect of MMPs in regulating mESC differentiation on engineered cell derived matrices and establish MEFDMs as suitable substrates for understanding molecular mechanisms regulating stem cell development and for regenerative medicine applications.

In situ slow-release recombinant growth differentiation factor 11 exhibits therapeutic efficacy in ischemic stroke

Systemic growth differentiation factor 11 (GDF11) treatment improves the vasculature in the hippocampus and cortex in mice in recent studies. However, systemic application of recombinant GDF11 (rGDF11) cannot cross the brain blood barrier (BBB). Thus, large doses and long-term administration are required, while systemically applied high-dose rGDF11 is associated with deleterious effects, such as severe cachexia. This study tested whether in situ low dosage rGDF11 (1 μg/kg) protects the brain against ischemic stroke and it investigated the underlying mechanisms. Fibrin glue mixed with rGDF11 was applied to the surgical cortex for the slow release of rGDF11 in mice after permanent middle cerebral artery occlusion (MCAO). In situ rGDF11 improved cerebral infarction and sensorimotor function by upregulating Smad2/3 and downregulating FOXO3 expression. In situ rGDF11 was associated with reductions in protein and lipid oxidation, Wnt5a, iNOS and COX2 expression, at 24 h after injury. In situ rGDF11 protected hippocampal neurons and subventricular neural progenitor cells against MCAO injury, and increased newborn neurogenesis in the peri-infarct cortex. Systematic profiling and qPCR analysis revealed that Pax5, Sox3, Th, and Cdk5rap2, genes associated with neurogenesis, were increased by in situ rGDF11 treatment. In addition, greater numbers of newborn neurons in the peri-infarct cortex were observed with in situ rGDF11 than with systemic application. Our evidence indicates that in situ rGDF11 effectively decreases the extent of damage after ischemic stroke via antioxidative, anti-inflammatory and proneurogenic activities. We suggest that in situ slow-release rGDF11 with fibrin glue is a potential therapeutic approach against ischemic stroke.

Wnt Signaling in Periodontal Disease

Periodontitis is a multifactorial and chronic condition associated with the formation of a dysbiotic biofilm, leading to a pro-inflammatory environment that can modulate cell signaling. The Wnt pathway plays fundamental roles during homeostasis and disease, and emerging evidence suggests its involvement in the maintenance of the periodontium and the development of periodontitis. Here, we summarize the role of the Wnt/β-catenin and non-canonical Wnt signaling pathways in periodontitis. The accumulated data suggests specific roles for each branch of the Wnt pathway. Wnt5a emerges as a critical player promoting periodontal ligament remodeling and impairing regenerative responses modulated by the Wnt/β-catenin pathway, such as alveolar bone formation. Collectively, the evidence suggests that achieving a proper balance between the Wnt/β-catenin and non-canonical pathways, rather than their independent modulation, might contribute to controlling the progression and severity of the periodontal disease.

An emergent Wnt5a/YAP/TAZ regulatory circuit and its possible role in cancer

Wnt5a is a ligand that plays several roles in development, homeostasis, and disease. A growing body of evidence indicates that Wnt5a is involved in cancer progression. Despite extensive research in this field, our knowledge about how Wnt5a is precisely involved in cancer is still incomplete. It is usually thought that certain combinations of Frizzled receptors and co-receptors might explain the observed effects of Wnt5a either as a tumor suppressor or by promoting migration and invasion. While accepting this 'receptor context' model, this review proposes that Wnt5a is integrated within a larger regulatory circuit involving β-catenin, YAP/TAZ, and LATS1/2. Remarkably, WNT5A and YAP1 are transcriptionally regulated by the Hippo and Wnt pathways, respectively, and might form a regulatory circuit acting through LATS kinases and secreted Wnt/β-catenin inhibitors, including Wnt5a itself. Therefore, understanding the precise role of Wnt5a and YAP in cancer requires a systems biology perspective.

Stage-dependent function of Wnt5a during male external genitalia development

External genitalia development in mice involves multiple developmental processes under the regulation of various signaling pathways. Wnt5a, one of the major Wnt ligands, is a crucial developmental regulator of outgrowing organs such as the limb, the mandible, and the external genitalia. Defects in Wnt5a signaling have been linked to Robinow syndrome, a genetic disorder in which male patients manifest a micropenis and defective urethral tube formation. Whereas Wnt5a is required for cell proliferation during embryonic external genitalia outgrowth, its role for urethral tube formation has yet to be understood. Here, we show that Wnt5a contributes to urethral tube formation as well as external genitalia outgrowth. Wnt5a is expressed in the embryonic external genitalia mesenchyme, and mesenchymal-specific conditional Wnt5a knockout mice resulted in hypospadias-like urethral defects. Early deletion of Wnt5a at E10.5 showed severe defects in both external genitalia outgrowth and urethral tube formation, along with reduced cell proliferation. The severe urethral tube defect persisted during later timing deletion of Wnt5a (E13.5). Further analyses revealed that loss of Wnt5a disrupted cell polarity and led to a reduction of the phosphorylated myosin light chain and the focal adhesion protein, vinculin. Altogether, these results suggest that Wnt5a coordinates cell proliferation and directed cell migration in a stage-dependent manner during male external genitalia development. Furthermore, Wnt5a may regulate cell polarity, focal adhesion formation, and cell contractility, leading to directed cell migration during male-type urethral formation in a manner that has not been reported in other organ fusion events.

WNT5B promotes vascular smooth muscle cell dedifferentiation via mitochondrial dynamics regulation in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by proliferative vascular remodeling. Abnormal vascular smooth muscle cell (VSMC) phenotype switching is crucial to this process, highlighting the need for VSMC metabolic changes to cover cellular energy demand in CTEPH. We report that elevated Wnt family member 5B (WNT5B) expression is associated with vascular remodeling and promotes VSMC phenotype switching via mitochondrial dynamics regulation in CTEPH. Using primary culture of pulmonary artery smooth muscle cells, we show that high WNT5B expression activates VSMC proliferation and migration and results in mitochondrial fission via noncanonical Wnt signaling in CTEPH. Abnormal VSMC proliferation and migration were abolished by mitochondrial division inhibitor 1, an inhibitor of mitochondrial fission. Secreted frizzled-related protein 2, a soluble scavenger of Wnt signaling, attenuates VSMC proliferation and migration by accelerating mitochondrial fusion. These findings indicate that WNT5B is an essential regulator of mitochondrial dynamics, contributing to VSMC phenotype switching in CTEPH.

GLIS1, a novel hypoxia-inducible transcription factor, promotes breast cancer cell motility via activation of WNT5A

We previously demonstrated that expression of a Krüppel-like zinc finger transcription factor, GLIS1, dramatically increases under hypoxic conditions via a transcriptional mechanism induced by HIF-2α cooperating with AP-1 members. In this study, we focused on the functional roles of GLIS1 in breast cancer. To uncover its biological function, the effects of altered levels of GLIS1 in breast cancer cell lines on cellular growth, wound-healing and invasion capacities were assessed. Knockdown of GLIS1 using siRNA in BT-474 cells resulted in significant growth stimulation under normoxia, while attenuation was found in the cell invasion assay under hypoxic conditions. In MDA-MB-231 cells expressing exogenous 3xFLAG-tagged GLIS1, GLIS1 attenuated cell proliferation and enhanced cell mobility and invasion capacities under normoxia. In addition, breast cancer cells expressing GLIS1 acquired resistance to irradiation. Whole transcriptome analysis clearly demonstrated that downstream signals of GLIS1 are related to various cellular functions. Among the genes with increased expression, we focused on WNT5A. Knockdown of WNT5A indicated that enhancement of acquired cell motility in the MDA-MB-231 cells expressing GLIS1 was mediated, at least in part, by WNT5A. In an analysis of publicly available data, patients with estrogen receptor-negative breast cancer showing high levels of GLIS1 expression showed much worse prognosis than those with low levels. In summary, hypoxia-induced GLIS1 plays significant roles in breast cancer cells via regulation of gene expression related to cell migration and invasion capacities, resulting in poorer prognosis in patients with advanced breast cancer.

Transcriptional Regulation of Drug Metabolizing CYP Enzymes by Proinflammatory Wnt5A Signaling in Human Coronary Artery Endothelial Cells

Downregulation of drug metabolizing enzymes and transporters by proinflammatory mediators in hepatocytes, enterocytes and renal tubular epithelium is an established mechanism affecting pharmacokinetics. Emerging evidences indicate that vascular endothelial cell expression of drug metabolizing enzymes and transporters may regulate pharmacokinetic pathways in heart to modulate local drug bioavailability and toxicity. However, whether inflammation regulates pharmacokinetic pathways in human cardiac vascular endothelial cells remains largely unknown. The lipid modified protein Wnt5A is emerging as a critical mediator of proinflammatory responses and disease severity in sepsis, hypertension and COVID-19. In the present study, we employed transcriptome profiling and gene ontology analyses to investigate the regulation of expression of drug metabolizing enzymes and transporters by Wnt5A in human coronary artery endothelial cells. Our study shows for the first time that Wnt5A induces the gene expression of CYP1A1 and CYP1B1 enzymes involved in phase I metabolism of a broad spectrum of drugs including chloroquine (the controversial drug for COVID-19) that is known to cause toxicity in myocardium. Further, the upregulation of CYP1A1 and CYP1B1 expression is preserved even during inflammatory crosstalk between Wnt5A and the prototypic proinflammatory IL-1β in human coronary artery endothelial cells. These findings stimulate further studies to test the critical roles of vascular endothelial cell CYP1A1 and CYP1B1, and the potential of vascular-targeted therapy with CYP1A1/CYP1B1 inhibitors in modulating myocardial pharmacokinetics in Wnt5A-associated inflammatory and cardiovascular diseases.

The human WNT5A isoforms display similar patterns of expression but distinct and overlapping activities in normal human osteoblasts

WNT5A activates noncanonical Wnt signaling pathways and has critical functions in early development, differentiation, and tissue homeostasis. Two major WNT5A protein isoforms, which in this study we term WNT5A-L(A) and WNT5A-S(B), have been identified that differ by 18 AA at their amino terminus. Functional differences between the isoforms have been indicated in studies utilizing cancer cell lines but the activities of the isoforms in normal cells and during differentiation have not been explored. We examined the WNT5A isoforms in the normal osteoblast cell line hFOB1.19. WNT5A-L(A) and WNT5A-S(B) transcripts increased from Days 3 to 21 of differentiation but WNT5A-S(B) showed a greater fold-change. In undifferentiated cells, there are 2-fold more WNT5A-L(A) than WNT5A-S(B) transcripts. Total intracellular WNT5A protein increased up to 3-fold during differentiation. siRNA knockdown of total WNT5A leads to a decrease in the expression of the differentiation markers, osteocalcin and RUNX2. Conditioned medium containing the isoform proteins [CM-L(A) and CM-S(B)] was used to analyze the effects of the isoforms on β-catenin and noncanonical signaling, proliferation, gene expression, and alkaline phosphatase (ALP) activity. Treatment with both CM-L(A) and CM-S(B) reduced β-catenin signaling. CM-L(A) but not CM-S(B) significantly increased the proliferation of nondifferentiated hFOB1.19 cells. CM-L(A) enhanced osteocalcin transcripts over 2-fold in differentiating cells, whereas CM-S(B) had no effect. Analysis of differentiating cells up to Day 21 revealed no significant effect of treatment with CM-L(A) or CM-S(B) on ALP activity or osteocalcin gene expression. pJNK levels were unaffected in proliferating cells by treatment with neither isoform. pPKC increased slightly in CM-L(A)-treated cells at 15 min but by 2 h pPKC levels were less than the control. CM-S(B) had a more robust effect on pPKC levels that continued up to 2 h. Together these results suggest that the WNT5A isoforms have distinct and overlapping functions in normal osteoblasts.

miR-493 by regulating of c-Jun targets Wnt5a/PD-L1-inducing esophageal cancer cell development

BACKGROUND

Esophageal cancer is one of the most common cancers across the globe; the 5-year survival of esophageal cancer patients is still low. MicroRNA (miRNA) dysregulation has been implicated in cancer development, and the miRNAs play a pivotal role in esophageal cancer pathogenesis. It is urgently needed to find out how miRNA dysregulation was involved in esophageal cancer (EC) development.

METHODS

Through experiments in vivo and in vitro, we explored potential signaling pathways, miR-493/Wnt5A/c-JUN loop, in EC. Their mechanistic roles in EC cell proliferation, migration, and invasion were investigated through multiple validation steps in EC9706 and TE13 cell lines and EC specimens.

RESULTS

Overexpression of miR-493 attenuates esophageal cancer cell proliferation, migration, and invasion in vivo and in vitro. Moreover, miR-493 downregulation is an unfavorable factor in EC and negatively correlated with Wnt5A. The existence of miR-493 is also an important attribute of metabolism. Based on mechanism analyses, we show that miR-493 inhibits the activity of c-JUN and p-PI3K/p-AKT with enhanced p21 and directly regulates Wnt5A expression and function, whereas c-JUN binds the promoter region of miR-493 and suppressed the expression of miR-493, forming a negative feedback loop.

CONCLUSIONS

The miR-493/Wnt5A/c-JUN loop is a molecular feedback loop that refers to the development of esophageal cancer cells and a potential target for the treatment of esophageal cancer.

Bone fracture healing: perspectives according to molecular basis

Fractures have a great impact on health all around the world and with fracture healing optimization; this problem could be resolved partially. To make a practical contribution to this issue, the knowledge of bone tissue, cellularity, and metabolism is essential, especially cytoskeletal architecture and its transformations according to external pressures. Special physical and chemical characteristics of the extracellular matrix (ECM) allow the transmission of mechanical stimuli from outside the cell to the plasmatic membrane. The osteocyte cytoskeleton is conformed by a complex network of actin and microtubules combined with crosslinker proteins like vinculin and fimbrin, connecting and transmitting outside stimuli through EMC to cytoplasm. Herein, critical signaling pathways like Cx43-depending ones, MAPK/ERK, Wnt, YAP/TAZ, Rho-ROCK, and others are activated due to mechanical stimuli, resulting in osteocyte cytoskeletal changes and ECM remodeling, altering the tissue and, therefore, the bone. In recent years, the osteocyte has gained more interest and value in relation to bone homeostasis as a great coordinator of other cell populations, thanks to its unique functions. By integrating the latest advances in relation to intracellular signaling pathways, mechanotransmission system of the osteocyte and bone tissue engineering, there are promising experimental strategies, while some are ready for clinical trials. This work aims to show clearly and precisely the integration between cytoskeleton and main molecular pathways in relation to mechanotransmission mechanism in osteocytes, and the use of this theoretical knowledge in therapeutic tools for bone fracture healing.

Current Status of MicroRNAs that Target the Wnt Signaling Pathway in Regulation of Osteogenesis and Bone Metabolism: A Review

The directional differentiation of bone mesenchymal stem cells (BMSCs) is regulated by a variety of transcription factors and intracellular signaling pathways. In the past, it was thought that the directional differentiation of BMSCs was related to transforming growth factors, such as bone morphogenetic protein (BMP) and MAPK pathway. However, in recent years, some scholars have pointed out that the Wnt signaling pathway, which is a necessary complex network of protein interactions for biological growth and development, takes a significant role in this process and plays a major part in regulating the development of osteoblasts by exerting signal transduction into cells. Also, they have proved the Wnt protein therapeutic truly have positive effects on the viability and osteogenic capacity of bone graft. Recent studies have shown that microRNAs (miRNAs) play an important regulatory role in this process. MiRNAs such as miRNA-218, miRNA-335, miRNA-29, microRNA-30 and other miRNAs exert negative or positive effects on some crucial molecules in the Wnt/β-catenin pathway, which in turn affect bone metabolism and osteopathy. Thus, miRNAs have been suggested as therapeutic targets for some metabolic bone diseases. This article aims to provide an update on the current status of microRNAs that target the Wnt signaling pathway in the regulation of osteogenesis and bone metabolism and includes a discussion of future areas of research, which can be a theoretical basis for bone metabolism-related diseases.

A Non-canonical Wnt Signature Correlates With Lower Survival in Gastric Cancer

Genetic evidence suggests a role for the Wnt/β-catenin pathway in gastric cancer. However, Wnt5a, regarded as a prototypical non-canonical Wnt ligand, has also been extensively associated with this disease. Therefore, the roles of the Wnt signaling pathway in gastric cancer initiation and progression, and particularly the precise mechanisms by which the non-canonical Wnt pathway might promote the development and progression of gastric cancer, are not entirely well understood. This article analyzes publicly available gene and protein expression data and reveals the existence of a WNT5A/FZD2/FZD7/ROR2 signature, which correlates with tumor-infiltrating and mesenchymal cell marker expression. High expression of FZD7 and ROR2 correlates with a shared gene and protein expression profile, which in turn correlates with poor prognosis. In summary, the findings presented in this article provide an updated view of the relative contributions of the Wnt/β-catenin and non-canonical Wnt pathways in gastric cancer.

Mist1+ gastric isthmus stem cells are regulated by Wnt5a and expand in response to injury and inflammation in mice

BACKGROUND AND AIMS

The gastric epithelium undergoes continuous turnover. Corpus epithelial stem cells located in the gastric isthmus serve as a source of tissue self-renewal. We recently identified the transcription factor Mist1 as a marker for this corpus stem cell population that can give rise to cancer. The aim here was to investigate the regulation of the Mist1+ stem cells in the response to gastric injury and inflammation.

METHODS

We used Mist1CreERT;R26-Tdtomato mice in two models of injury and inflammation: the acetic acid-induced ulcer and infection with Helicobacter felis. We analysed lineage tracing at both early (7 to 30 days) and late (30 to 90 days) time points. Mist1CreERT;R26-Tdtomato;Lgr5DTR-eGFP mice were used to ablate the corpus basal Lgr5+ cell population. Constitutional and conditional Wnt5a knockout mice were used to investigate the role of Wnt5a in wound repair and lineage tracing from the Mist1+ stem cells.

RESULTS

In both models of gastric injury, Mist1+ isthmus stem cells more rapidly proliferate and trace entire gastric glands compared with the normal state. In regenerating tissue, the number of traced gastric chief cells was significantly reduced, and ablation of Lgr5+ chief cells did not affect Mist1-derived lineage tracing and tissue regeneration. Genetic deletion of Wnt5a impaired proliferation in the gastric isthmus and lineage tracing from Mist1+ stem cells. Similarly, depletion of innate lymphoid cells, the main source of Wnt5a, also resulted in reduced proliferation and Mist1+ isthmus cell tracing.

CONCLUSION

Gastric Mist1+ isthmus cells are the main supplier of regenerated glands and are activated in part through Wnt5a pathway.

FOSL2 promotes VEGF-independent angiogenesis by transcriptionnally activating Wnt5a in breast cancer-associated fibroblasts

Cancer-associated fibroblasts (CAFs), a predominant component of the tumor microenvironment, contribute to aggressive angiogenesis progression. In clinical practice, traditional anti-angiogenic therapy, mainly anti-VEGF, provides extremely limited beneficial effects to breast cancer. Here, we reveal that FOS-like 2 (FOSL2), a transcription factor in breast CAFs, plays a critical role in VEGF-independent angiogenesis in stromal fibroblasts.

Methods: FOSL2 and Wnt5a expression was assessed by qRT-PCR, western blotting and immunohistochemistry in primary and immortalized CAFs and clinical samples. FOSL2- or Wnt5a-silenced CAFs and FOSL2-overexpressing NFs were established to explore their proangiogenic effects. Invasion, tubule formation, three-dimensional sprouting assays, and orthotopic xenografts were conducted as angiogenesis experiments. FZD5/NF-κB/ERK signaling activation was evaluated by western blotting after blocking VEGF/VEGFR with an anti-VEGF antibody and axitinib. Dual luciferase reporter assays and chromatin immunoprecipitation were performed to test the role of FOSL2 in regulating Wnt5a expression, and Wnt5a in the serum of the patients was measured to assess its clinical diagnostic value for breast cancer patients.

Results: Enhanced FOSL2 in breast CAFs was significantly associated with angiogenesis and clinical progression in patients. The supernatant from CAFs highly expressing FOSL2 strongly promoted tube formation and sprouting of human umbilical vein endothelial cells (HUVECs) in a VEGF-independent manner and angiogenesis as well as tumor growth in vivo. Mechanistically, the enhanced FOSL2 in CAFs was regulated by estrogen/cAMP/PKA signaling. Wnt5a, a direct target of FOSL2, specifically activated FZD5/NF-κB/ERK signaling in HUVECs to promote VEGF-independent angiogenesis. In addition, a high level of Wnt5a was commonly detected in the serum of breast cancer patients and closely correlated with microvessel density in breast tumor tissues, suggesting a promising clinical value of Wnt5a for breast cancer diagnostics.

Conclusion: FOSL2/Wnt5a signaling plays an essential role in breast cancer angiogenesis in a VEGF-independent manner, and targeting the FOSL2/Wnt5a signaling axis in CAFs may offer a potential option for antiangiogenesis therapy.

Analysis in silico of the functional interaction between WNT5A and YAP/TEAD signaling in cancer

To date, most data regarding the crosstalk between the Wnt signaling pathway and the YAP/TAZ transcriptional coactivators focuses on the Wnt/β-catenin branch of the pathway. In contrast, the relationship between the non-canonical Wnt pathway and YAP/TAZ remains significantly less explored. Wnt5a is usually regarded as a prototypical non-canonical Wnt ligand, and its expression has been related to cancer progression. On the other hand, YAP/TAZ transcriptional coactivators act in concert with TEAD transcription factors to control gene expression. Although one article has shown previously that WNT5A is a YAP/TEAD target gene, there is a need for further evidence supporting this regulatory relationship, because a possible YAP/Wnt5a regulatory circuit might have profound implications for cancer biology. This article analyzes publicly available ChIP-Seq, gene expression, and protein expression data to explore this relationship, and shows that WNT5A might be a YAP/TEAD target gene in several contexts. Moreover, Wnt5a and YAP expression are significantly correlated in specific cancer types, suggesting that the crosstalk between YAP/TAZ and the Wnt pathway is more intricate than previously thought.

Cholesterol activates the Wnt/PCP-YAP signaling in SOAT1-targeted treatment of colon cancer

Intracellular free cholesterol can be converted to cholesteryl ester and stored as lipid droplets through SOAT1-mediated esterification. Compelling evidence implicate targeting SOAT1 as a promising therapeutic strategy for cancer management. Herein, we demonstrate how targeting SOAT1 promotes YAP expression by elevating cellular cholesterol content in colon cancer cells. Results revealed that cholesterol alleviates the inhibitory effect of LRP6 on the Wnt/PCP pathway by impeding the interaction of LRP6 with FZD7. Subsequently, FZD7-mediated PCP signaling directly elevated YAP expression by activating RhoA. Nystatin-mediated cholesterol sequestration significantly inhibited YAP expression under SOAT1 inhibition. Moreover, nystatin synergized with the SOAT1 inhibitor avasimibe in suppressing the viability of colon cancer cells in vitro and in vivo. The present study provides new mechanistic insights into the functions of cholesterol metabolism on growth signaling pathways and implicates a novel strategy for cholesterol metabolic-targeted treatment of colon cancers.