Canonical and Non-Canonical Wnt Signaling in Immune Cells

Immune checkpoint blockade resistance in lung cancer: emerging mechanisms and therapeutic opportunities

Immune checkpoint blockade (ICB) therapy works by inhibiting suppressive checkpoints that become upregulated after T cell activation, like PD-1/PD-L1 and CTLA-4. While the initial FDA approvals of ICB have revolutionized cancer therapies and fueled a burgeoning immuno-oncology field, more recent clinical development of new agents has been slow. Here, focusing on lung cancer, we review the latest research uncovering tumor cell intrinsic and extrinsic ICB resistance mechanisms as major hurdles to treatment efficacy and clinical progress. These include genomic and non-genomic tumor cell alterations, along with host and microenvironmental factors like the microbiome, metabolite accumulation, and hypoxia. Together, these factors can cooperate to promote immunosuppression and ICB resistance. Opportunities to prevent resistance are constantly evolving in this rapidly expanding field, with the goal of moving toward personalized immunotherapeutic regimens.

Dishevelled2 activates WGEF via its interaction with a unique internal peptide motif of the GEF

The Wnt-planar cell polarity (Wnt-PCP) pathway is crucial in establishing cell polarity during development and tissue homoeostasis. This pathway is found to be dysregulated in many pathological conditions, including cancer and autoimmune disorders. The central event in Wnt-PCP pathway is the activation of Weak-similarity guanine nucleotide exchange factor (WGEF) by the adapter protein Dishevelled (Dvl). The PDZ domain of Dishevelled2 (Dvl2PDZ) binds and activates WGEF by releasing it from its autoinhibitory state. However, the actual Dvl2PDZ binding site of WGEF and the consequent activation mechanism of the GEF have remained elusive. Using biochemical and molecular dynamics studies, we show that a unique "internal-PDZ binding motif" (IPM) of WGEF mediates the WGEF-Dvl2PDZ interaction to activate the GEF. The residues at P2, P0, P-2 and P-3 positions of IPM play an important role in stabilizing the WGEFpep-Dvl2PDZ interaction. Furthermore, MD simulations of modelled Dvl2PDZ-WGEFIPM peptide complexes suggest that WGEF-Dvl2PDZ interaction may differ from the reported Dvl2PDZ-IPM interactions. Additionally, the apo structure of human Dvl2PDZ shows conformational dynamics different from its IPM peptide bound state, suggesting an induced fit mechanism for the Dvl2PDZ-peptide interaction. The current study provides a model for Dvl2 induced activation of WGEF.

The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities

The evolutionarily conserved Wnt signaling pathway plays a central role in development and adult tissue homeostasis across species. Wnt proteins are secreted, lipid-modified signaling molecules that activate the canonical (β-catenin dependent) and non-canonical (β-catenin independent) Wnt signaling pathways. Cellular behaviors such as proliferation, differentiation, maturation, and proper body-axis specification are carried out by the canonical pathway, which is the best characterized of the known Wnt signaling paths. Wnt signaling has emerged as an important factor in stem cell biology and is known to affect the self-renewal of stem cells in various tissues. This includes but is not limited to embryonic, hematopoietic, mesenchymal, gut, neural, and epidermal stem cells. Wnt signaling has also been implicated in tumor cells that exhibit stem cell-like properties. Wnt signaling is crucial for bone formation and presents a potential target for the development of therapeutics for bone disorders. Not surprisingly, aberrant Wnt signaling is also associated with a wide variety of diseases, including cancer. Mutations of Wnt pathway members in cancer can lead to unchecked cell proliferation, epithelial-mesenchymal transition, and metastasis. Altogether, advances in the understanding of dysregulated Wnt signaling in disease have paved the way for the development of novel therapeutics that target components of the Wnt pathway. Beginning with a brief overview of the mechanisms of canonical and non-canonical Wnt, this review aims to summarize the current knowledge of Wnt signaling in stem cells, aberrations to the Wnt pathway associated with diseases, and novel therapeutics targeting the Wnt pathway in preclinical and clinical studies.

Autophagy-related CMTM6 promotes glioblastoma progression by activating Wnt/β-catenin pathway and acts as an onco-immunological biomarker

BACKGROUND

Glioblastoma multiforme (GBM) is identified as one of the most prevalent and malignant brain tumors, characterized by poor treatment outcomes and a limited prognosis. CMTM6, a membrane protein, has been found to upregulate the expression of programmed cell death 1 ligand 1 protein (PD-L1) and acts as an immune checkpoint inhibitor by inhibiting the programmed death 1 protein/PD-L1 signaling pathway. Recent research has demonstrated a high expression of CMTM6 in GBM, suggesting its potential role in influencing the pathogenesis and progression of GBM, as well as its association with immune cell infiltration in the tumor microenvironment. However, the underlying mechanism of CMTM6 in GBM requires further investigation.

METHODS

Data from cancer patients in The Cancer Genome Atlas, Gene Expression Omnibus and Chinese Glioma Genome Atlas cohorts were consolidated for the current study. Through multi-omics analysis, the study systematically examined the expression profile of CMTM6, epigenetic modifications, prognostic significance, biological functions, potential mechanisms of action and alterations in the immune microenvironment. Additionally, the study investigated CMTM6 expression in GBM cell lines and normal cells using reverse transcription PCR and western blot analysis. The impact of CMTM6 on GBM cell proliferation, migration and invasion was evaluated using a combination of cell counting kit-8 assay, clone formation assay, 5-ethynyl-2'-deoxyuridine incorporation assay, wound healing assay and Transwell assay. In order to explore the mechanism of CMTM6, the Wnt/β-catenin signaling pathway and autophagy-related genes were further verified through western blot analysis.

RESULTS

CMTM6 is highly expressed in multiple tumors, particularly GBM. CMTM6 has been shown to be a valuable diagnostic and prognostic biomarker by various bioinformatics approaches. Additionally, CMTM6 plays a pivotal role in the pathogenesis of cancer, specifically GBM, by modulating various biological processes such as DNA methyltransferase expression, RNA modification, copy number variation, genomic heterogeneity, tumor stemness and DNA methylation. The findings of the experiment indicate a significant correlation between elevated CMTM6 expression and the proliferation, invasion, migration and autophagy of GBM cells, with potential key roles mediated through the Wnt/β-catenin signaling pathway. Furthermore, CMTM6 is implicated in modulating tumor immune cell infiltration and is closely linked to the expression of various immune checkpoint inhibitors and immune modulators, particularly within the context of GBM. High levels of CMTM6 expression also enhance the responsiveness of GBM patients to radiotherapy and chemotherapy, thereby offering valuable insights for guiding treatment strategies for GBM.

CONCLUSIONS

Autophagy-related CMTM6 is highly expressed in various types of cancer, especially GBM, and it can regulate GBM progression through the Wnt/β-catenin signaling pathway and is capable of being used as an underlying target for the diagnosis, treatment selection and prognosis of patients with GBM.

Novel biomarkers and interferon signature in secondary progressive multiple sclerosis

Multiple sclerosis (MS) exhibits poor immune regulation and subnormal interferon (IFN-β) signaling. Secondary Progressive MS displays waning exacerbations, relentless neurodegeneration, and diminished benefit of therapy. We find dysregulated serum protein balance (Th1/Th2) and excessive gene expression in Relapsing-Remitting MS vs. healthy controls (8700 differentially-expressed genes, DEG) and intermediate levels in SPMS (3900 DEG). Olfactory receptor genes (chemosensing), and WNT/ß-catenin (anti-inflammatory, repair) and metallothionein (anti-oxidant) gene pathways, have less expression in SPMS than RRMS. IFN-β treatment decreased pro-inflammatory and increased metallothionein gene expression in SPMS. These gene expression biomarkers suggest new targets for immune regulation and brain repair in this neurodegenerative disease.

Unraveling Dysregulated Cell Signaling Pathways, Genetic and Epigenetic Mysteries of Parkinson's Disease

Parkinson's disease (PD) is a prevalent and burdensome neurodegenerative disorder that has been extensively researched to understand its complex etiology, diagnosis, and treatment. The interplay between genetic and environmental factors in PD makes its pathophysiology difficult to comprehend, emphasizing the need for further investigation into genetic and epigenetic markers involved in the disease. Early diagnosis is crucial for optimal management of the disease, and the development of novel diagnostic biomarkers is ongoing. Although many efforts have been made in the field of recognition and interpretation of the mechanisms involved in the pathophysiology of the disease, the current knowledge about PD is just the tip of the iceberg. By scrutinizing genetic and epigenetic patterns underlying PD, new avenues can be opened for dissecting the pathology of the disorder, leading to more precise and efficient diagnostic and therapeutic approaches. This review emphasizes the importance of studying dysregulated cell signaling pathways and molecular processes associated with genes and epigenetic alterations in understanding PD, paving the way for the development of novel therapeutic strategies to combat this devastating disease.

Dihydrotanshinone I exhibits antitumor effects via β-catenin downregulation in papillary thyroid cancer cell lines

Thyroid cancer is the most common endocrine carcinoma and, among its different subtypes, the papillary subtype (PTC) is the most frequent. Generally, PTCs are well differentiated, but a minor percentage of PTCs are characterized by a worse prognosis and more aggressive behavior. Phytochemicals, naturally found in plant products, represent a heterogeneous group of bioactive compounds that can interfere with cell proliferation and the regulation of the cell cycle, taking part in multiple signaling pathways that are often disrupted in tumor initiation, proliferation, and progression. In this work, we focused on 15,16-dihydrotanshinone I (DHT), a tanshinone isolated from Salvia miltiorrhiza Bunge (Danshen). We first evaluated DHT biological effect on PTC cells regarding cell viability, colony formation ability, and migration capacity. All of these parameters were downregulated by DHT treatment. We then investigated gene expression changes after DHT treatment by performing RNA-seq. The analysis revealed that DHT significantly reduced the Wnt signaling pathway, which plays a role in various diseases, including cancer. Finally, we demonstrate that DHT treatment decreases protein levels of β-catenin, a final effector of canonical Wnt signaling pathway. Overall, our data suggest a possible use of this nutraceutical as an adjuvant in the treatment of aggressive papillary thyroid carcinoma.

Effects of sclerostin injection on soleus and extensor digitorum longus muscle tissue in male mice

Sclerostin, a potent inhibitor of the Wnt signaling pathway, plays a critical role in bone homeostasis. Evidence suggests that sclerostin may also be involved in crosstalk between other tissues, including muscle. This pilot study attempted to examine the effects of sclerostin on soleus and extensor digitorum longus (EDL) muscle tissue from male mice that were given continuous recombinant sclerostin injections for 4 weeks. A total of 48 10-week-old male C57BL/6J mice were assigned to be sedentary or perform 1 h treadmill running per day for 4 weeks and administered subcutaneous injections of either saline or recombinant sclerostin 5 days/week. Sclerostin injection led to a reduction in the soleus myosin heavy chain (MHC) I, MHC I/IIA, MHC IIA/X, and MHC IIB cross-sectional area (p < 0.05) with no exercise effects on these reductions. In contrast, there were no effects of sclerostin injections or exercise on the fast-twitch EDL muscle in terms of size, MHC protein, or markers of Wnt signaling. These findings provide preliminary evidence of sclerostin's endocrine role in muscle via decreases in myofiber cross-sectional area, which seems to be independent of fiber type but muscle type-specific. More studies, however, are needed to confirm these preliminary results.

Chemotherapy induces myeloid-driven spatial T-cell exhaustion in ovarian cancer

To uncover the intricate, chemotherapy-induced spatiotemporal remodeling of the tumor microenvironment, we conducted integrative spatial and molecular characterization of 97 high-grade serous ovarian cancer (HGSC) samples collected before and after chemotherapy. Using single-cell and spatial analyses, we identify increasingly versatile immune cell states, which form spatiotemporally dynamic microcommunities at the tumor-stroma interface. We demonstrate that chemotherapy triggers spatial redistribution and exhaustion of CD8+ T cells due to prolonged antigen presentation by macrophages, both within interconnected myeloid networks termed "Myelonets" and at the tumor stroma interface. Single-cell and spatial transcriptomics identifies prominent TIGIT-NECTIN2 ligand-receptor interactions induced by chemotherapy. Using a functional patient-derived immuno-oncology platform, we show that CD8+T-cell activity can be boosted by combining immune checkpoint blockade with chemotherapy. Our discovery of chemotherapy-induced myeloid-driven spatial T-cell exhaustion paves the way for novel immunotherapeutic strategies to unleash CD8+ T-cell-mediated anti-tumor immunity in HGSC.

Low-density lipoprotein receptor-related protein 6 ablation in macrophages differentially inhibits lung injury-mediated inflammation and metastasis

Low-density lipoprotein receptor-related protein 6 (LRP6) is a receptor protein for Wnt ligands. Yet, their role in immune cell regulation remains elusive. Here we demonstrated that genetic deletion of LRP6 in macrophages using LysM-cre Lrp6fl/fl (Lrp6MKO) mice showed differential inhibition of inflammation in the bleomycin (BLM)-induced lung injury model and B16F10 melanoma lung metastasis model. Lrp6MKO mice showed normal immune cell populations in the lung and circulating blood in homeostatic conditions. In the BLM-induced lung injury model, Lrp6MKO mice showed a decreased number of monocyte-derived alveolar macrophages, reduced collagen deposition and alpha-smooth muscle actin (αSMA) protein levels in the lung. In B16F10 lung metastasis model, Lrp6MKO mice reduced lung tumor foci. Monocytic and granulocytic-derived myeloid-derived suppressor cells (M-MDSCs and G-MDSCs) were increased in the lung. In G-MDSCs, hypoxia-inducible factor 1α (HIF1α)+ PDL1+ population was markedly decreased but not in M-MDSCs. Taken together, our results show that the role of LRP6 in macrophages is differential depending on the inflammation microenvironment in the lung.

Immunomodulation and immunopharmacology in heart failure

The immune system is intimately involved in the pathophysiology of heart failure. However, it is currently underused as a therapeutic target in the clinical setting. Moreover, the development of novel immunomodulatory therapies and their investigation for the treatment of patients with heart failure are hampered by the fact that currently used, evidence-based treatments for heart failure exert multiple immunomodulatory effects. In this Review, we discuss current knowledge on how evidence-based treatments for heart failure affect the immune system in addition to their primary mechanism of action, both to inform practising physicians about these pleiotropic actions and to create a framework for the development and application of future immunomodulatory therapies. We also delineate which subpopulations of patients with heart failure might benefit from immunomodulatory treatments. Furthermore, we summarize completed and ongoing clinical trials that assess immunomodulatory treatments in heart failure and present several therapeutic targets that could be investigated in the future. Lastly, we provide future directions to leverage the immunomodulatory potential of existing treatments and to foster the investigation of novel immunomodulatory therapeutics.

Death-associated protein 3 in cancer-discrepant roles of DAP3 in tumours and molecular mechanisms

Cancer, ranks as the secondary cause of death, is a group of diseases that are characterized by uncontrolled tumor growth and distant metastasis, leading to increased mortality year-on-year. To date, targeted therapy to intercept the aberrant proliferation and invasion is crucial for clinical anticancer treatment, however, mutant expression of target genes often leads to drug resistance. Therefore, it is essential to identify more molecules that can be targeted to facilitate combined therapy. Previous studies showed that death associated protein 3 (DAP3) exerts a pivotal role in regulating apoptosis signaling of tumors, meanwhile, aberrant DAP3 expression is associated with the tumorigenesis and disease progression of various cancers. This review provides an overview of the molecule structure of DAP3 and the discrepant roles played by DAP3 in various types of tumors. Considering the molecular mechanism of DAP3-regulated cancer development, new potential treatment strategies might be developed in the future.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

MALAT1/miR-7-5p/TCF4 Axis Regulating Menstrual Blood Mesenchymal Stem Cells Improve Thin Endometrium Fertility by the Wnt Signaling Pathway

Thin endometrium (TE) is a significant factor contributing to fertility challenges, and addressing this condition remains a central challenge in reproductive medicine. Menstrual blood-derived mesenchymal stem cells (MenSCs) play a crucial role in tissue repair and regeneration, including that of TE. The Wnt signaling pathway, which is highly conserved and prevalent in eukaryotes, is essential for cell proliferation, tissue development, and reproductive functions. MALAT1 is implicated in various transcriptional and molecular functions, including cell proliferation and metastasis. However, the combined effects of the Wnt signaling pathway and the long non-coding RNA (lncRNA) MALAT1 on the regulation of MenSCs' regenerative capabilities in tissue engineering have not yet been explored. To elucidate the regulatory mechanism of MALAT1 in TE, we analyzed its expression levels in normal endometrium and TE tissues, finding that low expression of MALAT1 was associated with poor clinical prognosis. In addition, we conducted both in vitro and in vivo functional assays to examine the role of the MALAT1/miR-7-5p/TCF4 axis in cell proliferation and migration. Techniques such as dual-luciferase reporter assay, fluorescent in situ hybridization, and immunoblot experiments were utilized to clarify the molecular mechanism. To corroborate these findings, we established a TE model and conducted pregnancy experiments, demonstrating a strong association between MALAT1 expression and endometrial fertility. In conclusion, our comprehensive study provides strong evidence supporting that lncRNA MALAT1 modulates TCF4 expression in the Wnt signaling pathway through interaction with miR-7-5p, thus enhancing MenSCs-mediated improvement of TE and improving fertility.

Wnt-3a improves functional recovery after spinal cord injury by regulating the inflammatory and apoptotic response in rats via wnt/β-catenin signaling pathway

The specific molecular mechanism of neuroprotective effects of wnt-3a on spinal cord injury (SCI) has not been elucidated. In our study, we evaluated the recovery of motor function after SCI by BBB, observed neuronal apoptosis by western blot and TUNEL, observed the changes of neuronal inflammation by western blot and immunofluorescence staining, and observed the changes of motoneurons and spinal cord area in the anterior horn of the spinal cord via Nissl and HE staining. We found that wnt-3a could significantly promote the recovery of motor function, reduce the loss of motor neurons in the anterior horn of the spinal cord, promote the recovery of injured spinal cord tissue, inhibit neuronal apoptosis and inflammatory response, and ultimately promote neuronal function after SCI. However, when XAV939 inhibits the wnt/β-catenin signaling pathway, the neuroprotective effects of wnt-3a are also significantly inhibited. The above results together indicated that wnt-3a exerts its neuroprotective effect on after SCI via activating the wnt/β-catenin signaling pathway.

Canonical and noncanonical Wnt signaling: Multilayered mediators, signaling mechanisms and major signaling crosstalk

Wnt signaling plays a major role in regulating cell proliferation and differentiation. The Wnt ligands are a family of 19 secreted glycoproteins that mediate their signaling effects via binding to Frizzled receptors and LRP5/6 coreceptors and transducing the signal either through β-catenin in the canonical pathway or through a series of other proteins in the noncanonical pathway. Many of the individual components of both canonical and noncanonical Wnt signaling have additional functions throughout the body, establishing the complex interplay between Wnt signaling and other signaling pathways. This crosstalk between Wnt signaling and other pathways gives Wnt signaling a vital role in many cellular and organ processes. Dysregulation of this system has been implicated in many diseases affecting a wide array of organ systems, including cancer and embryological defects, and can even cause embryonic lethality. The complexity of this system and its interacting proteins have made Wnt signaling a target for many therapeutic treatments. However, both stimulatory and inhibitory treatments come with potential risks that need to be addressed. This review synthesized much of the current knowledge on the Wnt signaling pathway, beginning with the history of Wnt signaling. It thoroughly described the different variants of Wnt signaling, including canonical, noncanonical Wnt/PCP, and the noncanonical Wnt/Ca2+ pathway. Further description involved each of its components and their involvement in other cellular processes. Finally, this review explained the various other pathways and processes that crosstalk with Wnt signaling.

Thrombocyte-derived Dickkopf1 promotes macrophage polarization in the Bleomycin-induced lung injury model

Immune responses are crucial to maintaining tissue homeostasis upon tissue injury. Upon various types of challenges, macrophages play a central role in regulating inflammation and tissue repair processes. While an immunomodulatory role of Wnt antagonist Dickkopf1 (DKK1) has been implicated, the role of Wnt antagonist DKK1 in regulating macrophage polarization in inflammation and the tissue repair process remains elusive. Here we found that DKK1 induces gene expression profiles to promote inflammation and tissue repair in macrophages. Importantly, DKK1 induced various genes, including inflammation and tissue repair, via JNK (c-jun N-terminal kinase) in macrophages. Furthermore, DKK1 potentiated IL-13-mediated macrophage polarization and activation. The co-inhibition of JNK and STAT6 markedly decreased gene expressions relevant to inflammation and fibrosis by DKK1 and IL-13. Interestingly, thrombocyte-specific deletion of DKK1 in mice reduced collagen deposition and decreased Arg1, CD206, HIF1α, and IL1β protein expressions in monocyte-derived alveolar macrophages in the acute sterile bleomycin (BLM)-induced lung injury model. These data suggested that thrombocytes communicate with macrophages via DKK1 to orchestrate inflammation and repair in this model. Taken together, our study demonstrates DKK1's role as an important regulatory ligand for macrophage polarization in the injury-induced inflammation and repair process in the lung.

NRF1 knockdown alleviates lipopolysaccharide-induced pulmonary inflammatory injury by upregulating DKK3 and inhibiting the GSK-3β/β-catenin pathway

Excessive inflammatory injury is the main cause of the incidence of severe neonatal pneumonia (NP) and associated deaths. Although dickkopf-3 (DKK3) exhibits anti-inflammatory activity in numerous pathological processes, its role in NP is still unknown. In this study, human embryonic lung WI-38 and MRC-5 cells were treated with lipopolysaccharide (LPS) to induce inflammatory injury of NP in vitro. The expression of DKK3 was downregulated in LPS-stimulated WI-38 and MRC-5 cells. DKK3 overexpression decreased LPS-induced inhibition of cell viability, and reduced LPS-induced apoptosis of WI-38 and MRC-5 cells. DKK3 overexpression also reduced LPS-induced production of pro-inflammatory factors such as ROS, IL-6, MCP-1, and TNF-α. Nuclear respiratory factors 1 (NRF1) knockdown was found to upregulate DKK3 and inactivate the GSK-3β/β-catenin pathway in LPS-injured WI-38 and MRC-5 cells. NRF1 knockdown also suppressed LPS-induced inhibition on cell viability, repressed LPS-induced apoptosis, and inhibited the accumulation of ROS, IL-6, MCP-1, and TNF-α in LPS-injured WI-38 and MRC-5 cells. DKK3 knockdown or re-activation of the GSK-3β/β-catenin pathway reversed the inhibitory effects of NRF1 knockdown on LPS-induced inflammatory injury. In conclusion, NRF1 knockdown can alleviate LPS-triggered inflammatory injury by regulating DKK3 and the GSK-3β/β-catenin pathway.

Single-cell RNA sequencing of intestinal crypts reveals vital events in damage repair and the double-edged sword effect of the Wnt3/β-catenin pathway in irradiated mice

In this study, we executed single-cell RNA sequencing of intestinal crypts. We analyzed the differentially expressed genes (DEGs) at different time points (the first, third, and fifth days) after 13 Gy and 15 Gy abdominal body radiation (ABR) exposure and then executed gene ontology (GO) enrichment analysis, RNA velocity analysis, cell communication analysis, and ligand‒receptor interaction analysis to explore the vital events in damage repair and the multiple effects of the Wnt3/β-catenin pathway on irradiated mice. Results from bioinformatics analysis were confirmed by a series of biological experiments. Results showed that the antibacterial response is a vital event during the damage response process after 13 Gy ABR exposure; ionizing radiation (IR) induced high heterogeneity in the transient amplification (TA) cluster, which may differentiate into mature cells and stem cells in irradiated small intestine (SI) crypts. Conducting an enrichment analysis of the DEGs between mice exposed to 13 Gy and 15 Gy ABR, we concluded that the Wnt3/β-catenin and MIF-CD74/CD44 signaling pathways may contribute to 15 Gy ABR-induced mouse death. Wnt3/β-catenin promotes the recovery of irradiated SI stem/progenitor cells, which may trigger macrophage migration inhibitory factor (MIF) release to further repair IR-induced SI injury; however, with the increase in radiation dose, activation of CD44 on macrophages provides the receptor for MIF signal transduction, initiating the inflammatory cascade response and ultimately causing a cytokine release syndrome. In contrast to previous research, we confirmed that inhibition of the Wnt3/β-catenin pathway or blockade of CD44 on the second day after 15 Gy ABR may significantly protect against ABR-induced death. This study indicates that the Wnt3/β-catenin pathway plays multiple roles in damage repair after IR exposure; we also propose a novel point that the interaction between intestinal crypt stem cells (ISCs) and macrophages through the MIF-CD74/CD44 axis may exacerbate SI damage in irradiated mice.

β-catenin inhibitors in cancer therapeutics: intricacies and way forward

β-catenin is an evolutionary conserved, quintessential, multifaceted protein that plays vital roles in cellular homeostasis, embryonic development, organogenesis, stem cell maintenance, cell proliferation, migration, differentiation, apoptosis, and pathogenesis of various human diseases including cancer. β-catenin manifests both signaling and adhesive features. It acts as a pivotal player in intracellular signaling as a component of versatile WNT signaling cascade involved in embryonic development, homeostasis as well as in carcinogenesis. It is also involved in Ca2+ dependent cell adhesion via interaction with E-cadherin at the adherens junctions. Aberrant β-catenin expression and its nuclear accumulation promote the transcription of various oncogenes including c-Myc and cyclinD1, thereby contributing to tumor initiation, development, and progression. β-catenin's expression is closely regulated at various levels including its stability, sub-cellular localization, as well as transcriptional activity. Understanding the molecular mechanisms of regulation of β-catenin and its atypical expression will provide researchers not only the novel insights into the pathogenesis and progression of cancer but also will help in deciphering new therapeutic avenues. In the present review, we have summarized the dual functions of β-catenin, its role in signaling, associated mutations as well as its role in carcinogenesis and tumor progression of various cancers. Additionally, we have discussed the challenges associated with targeting β-catenin molecule with the presently available drugs and suggested the possible way forward in designing new therapeutic alternatives against this oncogene.

The emerging role of the hedgehog signaling pathway in immunity response and autoimmune diseases

The Hedgehog (Hh) family is a prototypical morphogen involved in embryonic patterning, multi-lineage differentiation, self-renewal, morphogenesis, and regeneration. There are studies that have demonstrated that the Hh signaling pathway differentiates developing T cells into MHC-restricted self-antigen tolerant T cells in a concentration-dependent manner in the thymus. Whereas Hh signaling pathway is not required in the differentiation of B cells but is indispensable in maintaining the regeneration of hematopoietic stem cells (HSCs) and the viability of germinal centers (GCs) B cells. The Hh signaling pathway exerts both positive and negative effects on immune responses, which involves activating human peripheral CD4+ T cells, regulating the accumulation of natural killer T (NKT) cells, recruiting and activating macrophages, increasing CD4+Foxp3+ regulatory T cells in the inflammation sites to sustain homeostasis. Hedgehog signaling is involved in the patterning of the embryo, as well as homeostasis of adult tissues. Therefore, this review aims to highlight evidence for Hh signaling in the differentiation, function of immune cells and autoimmune disease. Targeting Hh signaling promises to be a novel, alternative or adjunct approach to treating tumors and autoimmune diseases.

RNF43 and ZNRF3 in Wnt Signaling - A Master Regulator at the Membrane

The Wnt β-catenin signaling pathway is a highly conserved mechanism that plays a critical role from embryonic development and adult stem cell homeostasis. However, dysregulation of the Wnt pathway has been implicated in various diseases, including cancer. Therefore, multiple layers of regulatory mechanisms tightly control the activation and suppression of the Wnt signal. The E3 ubiquitin ligases RNF43 and ZNRF3, which are known negative regulators of the Wnt pathway, are critical component of Wnt signaling regulation. These E3 ubiquitin ligases control Wnt signaling by targeting the Wnt receptor Frizzled to induce ubiquitination-mediated endo-lysosomal degradation, thus controlling the activation of the Wnt signaling pathway. We also discuss the regulatory mechanisms, interactors, and evolution of RNF43 and ZNRF3. This review article summarizes recent findings on RNF43 and ZNRF3 and their potential implications for the development of therapeutic strategies to target the Wnt signaling pathway in various diseases, including cancer.

Pterostilbene-Isothiocyanate Inhibits Proliferation of Human MG-63 Osteosarcoma Cells via Abrogating β-Catenin/TCF-4 Interaction-A Mechanistic Insight

Osteosarcoma, a highly metastasizing bone neoplasm, is a leading cause of death and disability in children and adolescents worldwide. Osteosarcoma is only suboptimally responsive to surgery and radio- and chemotherapy, that too with adverse side effects. Hence, there is a necessary need for safer alternative therapeutic approaches. This study evaluated the anticancer effects of the semi-synthetic compound, pterostilbene-isothiocyanate (PTER-ITC), on human osteosarcoma MG-63 cells through cytotoxicity, wound-healing, and transwell-migration assays. Results showed that PTER-ITC specifically inhibited the survival, proliferation, and migration of osteosarcoma cells. PTER-ITC induced apoptosis in MG-63 cells by disrupting mitochondrial membrane potential, as evident from the outcomes of different cytological staining. The antimetastatic potential of PTER-ITC was evaluated through immunostaining, RT-qPCR, and immunoblotting. In silico (molecular docking and dynamic simulation) and, subsequently, biochemical [co-immunoprecipitation (Co-IP) and luciferase reporter] assays deciphered the underlying mode-of-action of this compound. PTER-ITC increased E-cadherin and reduced N-cadherin levels, thereby facilitating the reversal of epithelial-mesenchymal transition (EMT). It also modulated the expressions of proliferative cell nuclear antigen (PCNA), caspase-3, poly [ADP-ribose] polymerase (PARP-1) and matrix metalloproteinase-2/9 (MMPs-2/9) at transcriptional and translational levels. PTER-ITC interfered with the β-catenin/transcription factor-4 (TCF-4) interaction in silico by occupying the β-catenin binding site on TCF-4, confirmed by their reduced physical interactions (Co-IP assay). This inhibited transcriptional activation of TCF-4 by β-catenin (as shown by luciferase reporter assay). In conclusion, PTER-ITC exhibited potent anticancer effects in vitro against human osteosarcoma cells by abrogating the β-catenin/TCF-4 interaction. Altogether, this study suggests that PTER-ITC may be regarded as a new approach for osteosarcoma treatment.

Regulation of the WNT-CTNNB1 signaling pathway by severe fever with thrombocytopenia syndrome virus in a cap-snatching manner

The segmented negative-strand RNA viruses (sNSVs) include highly pathogenic human and animal viruses such as Lassa virus (LASV), severe fever with thrombocytopenia syndrome virus (SFTSV), and influenza A virus (IAV). One of the conserved mechanisms at the stage of genome transcription of sNSVs is the cap-snatching process, providing druggable targets for the development of antivirals. SFTSV is an emerging tick-borne sNSV that causes severe hemorrhagic fever with a high fatality rate of 12%-50%. Here, we determined the correlation between death outcome and downregulation of the WNT-CTNNB1 signaling pathway through transcriptomic analysis of blood samples collected from SFTS patients. We further demonstrated that SFTSV affected this pathway by downregulating the mRNA levels of a series of pathway-related genes, including CTNNB1. Loss-of-function mutations or inhibitors targeting SFTSV cap-snatching activity effectively alleviated the inhibition of the WNT-CTNNB1 signaling pathway. Exogenous activation of the WNT-CTNNB1 signaling pathway enhanced SFTSV replication, while inhibition of this pathway reduced SFTSV replication. Treatment with a WNT-CTNNB1 signaling pathway inhibitor attenuated viral replication and decreased fatality in mice. Notably, downregulation of the WNT-CTNNB1 signaling pathway was also observed for other sNSVs, including LASV and IAV. These results suggested that RNAs related to the WNT-CTNNB1 signaling pathway might be utilized as a primer "pool" in a cap-snatching manner for viral transcription, which provides effective targets for the development of broad-spectrum antivirals against sNSVs.IMPORTANCEOne of the conserved mechanisms at the stage of genome transcription of segmented negative-strand RNA viruses (sNSVs) is the cap-snatching process, which is vital for sNSVs transcription and provides drugable targets for the development of antivirals. However, the specificity of RNAs snatched by sNSV is still unclear. By transcriptomics analysis of whole blood samples from SFTS patients, we found WNT-CTNNB1 signaling pathway was regulated according to the course of the disease. We then demonstrated that L protein of severe fever with thrombocytopenia syndrome virus (SFTSV) could interact with mRNAs of WNT-CTNNB1 signaling pathway-related gene, thus affecting WNT-CTNNB1 signaling pathway through its cap-snatching activity. Activation of WNT-CTNNB1 signaling pathway enhanced SFTSV replication, while inhibition of this pathway decreased SFTSV replication in vitro and in vivo. These findings suggest that WNT-associated genes may be the substrate for SFTSV "cap-snatching", and indicate a conserved sNSVs replication mechanism involving WNT-CTNNB1 signaling.

Reprogramming T cell differentiation and exhaustion in CAR-T cell therapy

T cell differentiation is a highly regulated, multi-step process necessary for the progressive establishment of effector functions, immunological memory, and long-term control of pathogens. In response to strong stimulation, as seen in severe or chronic infections or cancer, T cells acquire a state of hypo-responsiveness known as exhaustion, limiting their effector function. Recent advances in autologous chimeric antigen receptor (CAR)-T cell therapies have revolutionized the treatment of hematologic malignancies by taking advantage of the basic principles of T cell biology to engineer products that promote long-lasting T cell response. However, many patients' malignancies remain unresponsive to treatment or are prone to recur. Discoveries in T cell biology, including the identification of key regulators of differentiation and exhaustion, offer novel opportunities to have a durable impact on the fate of CAR-T cells after infusion. Such next-generation CAR-T cell therapies and their clinical implementation may result in the next leap forward in cancer treatment for selected patients. In this context, this review summarizes the foundational principles of T cell differentiation and exhaustion and describes how they can be utilized and targeted to further improve the design and efficacy of CAR-T cell therapies.

WNT16b promotes the proliferation and self-renewal of human limbal epithelial stem/progenitor cells via activating the calcium/calcineurin A/NFATC2 pathway

Our previous finding revealed that WNT16b promoted the proliferation of human limbal epithelial stem cells (hLESCs) through a β-catenin independent pathway. Here, we aimed to explore its underlying molecular mechanism and evaluate its potential in the treatment of limbal stem cell deficiency (LSCD). Based on the findings of mRNA-sequencing, the expression of key molecules in WNT/calcineurin A/NFATC2 signalling pathway was investigated in WNT16b-co-incubated hLESCs and control hLESCs. An epithelial wound healing model was established on Wnt16b-KO mice to confirm the regulatory effect of WNT16b in vivo. The therapeutic potential of WNT16b-co-incubated hLESCs was also evaluated in mice with LSCD. Our findings showed that WNT16b bound with Frizzled7, promoted the release of Ca2+ and activated calcineurin A and NFATC2. With the translocation of NFATC2 into cell nucleus and the activation of HDAC3, WDR5 and GCN5L2, the expression of H3K4me3, H3K14ac and H3K27ac in the promoter regions of FoxM1 and c-MYC increased, which led to hLESC proliferation. The effect of the WNT16b/calcium/calcineurin A/NFATC2 pathway on LESC homeostasis maintenance and corneal epithelial repair was confirmed in Wnt16b-KO mice. Moreover, WNT16b-coincubated hLESCs could reconstruct a stable ocular surface and inhibit corneal neovascularization in mice with LSCD. In conclusion, WNT16b enhances the proliferation and maintains the stemness of hLESCs by activating the non-canonical calcium/calcineurin A/NFATC2 pathway in vitro and in vivo, and accelerates corneal epithelial wound healing.

Melatonin Mitigates the Progression of Chemically Induced Hepatocellular Carcinoma in Rats via Targeting Wnt/Β-Catenin Pathway, and Small Noncoding miR-let-7b

Background

Melatonin, the controlling hormone of the sleep-wake cycle, has acquired attention due to its role in immunomodulation, anti-inflammation, as well as its proapoptotic effects. Wnt/β-catenin signaling can modulate cancer progression by promoting cell division and migration, while miR-let-7b may inhibit cell growth, migration, and invasion by affecting the function of adaptive immune cells. This work was designed to detect the effect of using melatonin as an immunomodulating therapeutic approach to control the progression of chemically induced hepatocellular carcinoma (HCC).

Methods

Thirty male rats were equally divided into control, HCC, and melatonin-HCC groups. Animals in the HCC and melatonin-HCC groups were injected with diethylnitrosamine (intraperitoneal single dose) followed by repeated carbon-tetrachloride subcutaneous injection once weekly for six weeks. Melatonin was given from the first week of the study and continued during the process of HCC induction.

Results

In the HCC group, the levels of tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), and Wnt/β-catenin expression significantly increased, while there was a downregulation of microRNA Let7b. Melatonin administration reversed these changes, along with an increase in hepatic content of interleukin-2 (IL-2) and caspase-3.

Conclusions

Melatonin exerted hepatic immunomodulating changes, in addition to proapoptotic and antiangiogenic effects, illustrated by increased IL-2, caspase-3, and decreased VEGF levels, respectively. Moreover, the use of melatonin during hepatocarcinogenesis positively modulated the disrupted expression of microRNA let7b and Wnt/β-catenin significantly.

Patient-specific iPSC-derived cardiomyocytes reveal aberrant activation of Wnt/β-catenin signaling in SCN5A-related Brugada syndrome

BACKGROUND

Mutations in the cardiac sodium channel gene SCN5A cause Brugada syndrome (BrS), an arrhythmic disorder that is a leading cause of sudden death and lacks effective treatment. An association between SCN5A and Wnt/β-catenin signaling has been recently established. However, the role of Wnt/β-catenin signaling in BrS and underlying mechanisms remains unknown.

METHODS

Three healthy control subjects and one BrS patient carrying a novel frameshift mutation (T1788fs) in the SCN5A gene were recruited in this study. Control and BrS patient-specific induced pluripotent stem cells (iPSCs) were generated from skin fibroblasts using nonintegrated Sendai virus. All iPSCs were differentiated into cardiomyocytes using monolayer-based differentiation protocol. Action potentials and sodium currents were recorded from control and BrS iPSC-derived cardiomyocytes (iPSC-CMs) by single-cell patch clamp.

RESULTS

BrS iPSC-CMs exhibited increased burden of arrhythmias and abnormal action potential profile featured by slower depolarization, decreased action potential amplitude, and increased beating interval variation. Moreover, BrS iPSC-CMs showed cardiac sodium channel (Nav1.5) loss-of-function as compared to control iPSC-CMs. Interestingly, the electrophysiological abnormalities and Nav1.5 loss-of-function observed in BrS iPSC-CMs were accompanied by aberrant activation of Wnt/β-catenin signaling. Notably, inhibition of Wnt/β-catenin significantly rescued Nav1.5 defects and arrhythmic phenotype in BrS iPSC-CMs. Mechanistically, SCN5A-encoded Nav1.5 interacts with β-catenin, and reduced expression of Nav1.5 leads to re-localization of β-catenin in BrS iPSC-CMs, which aberrantly activates Wnt/β-catenin signaling to suppress SCN5A transcription.

CONCLUSIONS

Our findings suggest that aberrant activation of Wnt/β-catenin signaling contributes to the pathogenesis of SCN5A-related BrS and point to Wnt/β-catenin as a potential therapeutic target.

Lead exposure suppresses the Wnt3a/β-catenin signaling to increase the quiescence of hematopoietic stem cells via reducing the expression of CD70 on bone marrow-resident macrophages

Lead (Pb) is a heavy metal highly toxic to human health in the environment. The aim of this study was to investigate the mechanism of Pb impact on the quiescence of hematopoietic stem cells (HSC). WT C57BL/6 (B6) mice treated with 1250 ppm Pb via drinking water for 8 weeks had increased the quiescence of HSC in the bone marrow (BM), which was caused by the suppressed activation of the Wnt3a/β-catenin signaling. Mechanically, a synergistic action of Pb and IFNγ on BM-resident macrophages (BM-Mφ) reduced their surface expression of CD70, which thereby dampened the Wnt3a/β-catenin signaling to suppress the proliferation of HSC in mice. In addition, a joint action of Pb and IFNγ also suppressed the expression of CD70 on human Mφ to impair the Wnt3a/β-catenin signaling and reduce the proliferation of human HSC purified from umbilical cord blood of healthy donors. Moreover, correlation analyses showed that the blood Pb concentration was or tended to be positively associated with the quiescence of HSC, and was or tended to be negatively associated with the activation of the Wnt3a/β-catenin signaling in HSC in human subjects occupationally exposed to Pb. Collectively, these data indicate that an occupationally relevant level of Pb exposure suppresses the Wnt3a/β-catenin signaling to increase the quiescence of HSC via reducing the expression of CD70 on BM-Mφ in both mice and humans.

Molecular Regulatory Mechanisms in Chicken Feather Follicle Morphogenesis

In China, the sale of freshly slaughtered chickens is becoming increasingly popular in comparison with that of live chickens, and due to this emerging trend, the skin and feather follicle traits of yellow-feathered broilers have attracted a great deal of research attention. The feather follicle originates from the interaction between the epidermis and dermis in the early embryonic stage. Feather follicle morphogenesis is regulated by the Wnt, ectodysplasin (Eda), epidermal growth factor (EGF), fibroblast growth factor (FGF), bone morphogenetic protein (BMP), sonic hedgehog (Shh), Notch, and other signaling pathways that exist in epithelial and mesenchymal cells. The Wnt pathway is essential for feather follicle and feather morphogenesis. Eda interacts with Wnt to induce FGF expression, which attracts mesenchymal cell movement and aggregates to form feather follicle primordia. BMP acts as an inhibitor of the above signaling pathways to limit the size of the feather tract and distance between neighboring feather primordia in a dose-dependent manner. The Notch/Delta pathway can interact with the FGF pathway to promote feather bud formation. While not a part of the early morphogenesis of feather follicles, Shh and BMP signaling are involved in late feather branching. This review summarizes the roles of miRNAs/lncRNA in the regulation of feather follicle and feather growth and development and suggests topics that need to be solved in a future study. This review focuses on the regulatory mechanisms involved in feather follicle morphogenesis and analyzes the impact of SNP sites on feather follicle traits in poultry. This work may help us to understand the molecular regulatory networks influencing feather follicle growth and provide basic data for poultry carcass quality.

Pathological role of long non-coding (lnc) RNA in the regulation of Wnt/β-catenin signaling pathway during epithelial-mesenchymal transition (EMT)

The term "epithelial-mesenchymal transition" (EMT) describes a biological process wherein epithelial cells acquire mesenchymal cell characteristics. This process enables the metastatic cells to migrate and invasion. Recent studies have established the connections between the EMT process and Wnt/β-catenin signaling in cancer. Key cellular functions such as differentiation, proliferation, migration, genetic stability, apoptosis, and stem cell renewal are modulated via Wnt/ β-catenin signaling pathway. Up-regulation of this evolutionarily conserved signal pathway leads to EMT. On the other hand, recent investigations have indicated that non-coding RNAs including microRNAs (miRNAs) and long non-coding RNA (lncRNAs) are involved in regulating of Wnt/β-catenin pathway. A high level of lncRNAs mainly has a positive correlation with EMT. However, lncRNA down-regulation has been observed in promoting EMT. It seems that depending on the specific targets, up-or down-regulation of lncRNAs can stimulate EMT by activating the Wnt/ β-catenin pathway. The evaluation of interactions between lncRNAs and the Wnt/ β-catenin signaling pathway in the regulation of EMT during metastasis can be fascinating. Herein, for the first time, the crucial role of lncRNAs-mediated regulation of the Wnt/ β-catenin signaling pathway in the EMT process of human tumors has been summarized.

Study on the protective effect of chondroitin sulfate from sturgeons on rat chondrocytes and its potential mechanisms

OBJECTIVE

To investigate the protective effect of Chondroitin Sulfate from Sturgeons on rat chondrocytes and its possible mechanism.

METHODS

The model of chondrocyte injury induced by hydrogen peroxide was established and chondrocytes were cultured and divided into the following groups: control group, sham group, model group, Sofast group, Low dose of Chondroitin Sulfate from Sturgeon B (CSSB-L) group, Moderate dose of Chondroitin Sulfate from Sturgeon B (CSSB-M) group and High dose of Chondroitin Sulfate from Sturgeon B (CSSB-H) group. The cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8) assay. The cell apoptosis was detected by flow cytometer. The expression levels of Interleukin-6 (IL-6), Interleukin-8 (IL-8) and Interferon gamma (IFN-γ) in cell supernatants were examined by Enzyme-linked immunosorbent assay (ELISA). Western blot analysis was used to detect the levels of proteins associated with Wnt signal pathway in chondrocytes.

RESULTS

Compared with the control group and sham group, the cell proliferation was decreased significantly, cell apoptosis was increased obviously, and the levels of IL-6, IL-8 and IFN-γ were remarkably increased in the model group. For Wnt signal pathway related proteins, the levels of Wnt3a, Frizzled5, Dsh, β-Catenin and C-myc proteins in the model group were significantly reduced, and p-GSK3β expression level was obviously increased (all P<0.05). Compared with the model group, CSSB could promote cell viability, and inhibit cell apoptosis and the levels of IL-6, IL-8 and IFN-γ (all P<0.05). The levels of Wnt signaling pathways related proteins in the CSSB-M group and CSSB-H group were obviously expressed.

CONCLUSIONS

Chondroitin sulfate from sturgeons protected rat chondrocytes from injuries induced by hydrogen peroxide, which may be associated with the Wnt signaling pathway.

Wnt/β-catenin signaling pathway inhibitors, glycyrrhizic acid, solanine, polyphyllin I, crocin, hypericin, tubeimoside-1, diosmin, and rutin in medicinal plants have better binding affinities and anticancer properties: Molecular docking and ADMET study

Wnt/β-catenin signaling pathway plays a role in cancer development, organogenesis, and embryogenesis. The abnormal activation promotes cancer stem cell renewal, proliferation, and differentiation. In the present study, molecular docking simulation and ADMET studies were carried out on selected bioactive compounds in search of β-catenin protein inhibitors for drug discovery against cancer. Blind docking simulation was performed using PyRx software on Autodock Vina. β-catenin protein (PDB ID: 1jdh) and 313 bioactive compounds (from PubChem database) with selected standard anticancer drugs were used for molecular docking. The ADMET properties of the best-performing compounds were calculated using SwissADME and pkCMS web servers. The results obtained from the molecular docking study showed that glycyrrhizic acid, solanine, polyphyllin I, crocin, hypericin, tubeimoside-1, diosmin, and rutin had the best binding interactions with β-catenin protein based on their binding affinities. Glycyrrhizic acid and solanine had the same and lowest binding energy of -8.5 kcal/mol. This was followed by polyphyllin I with -8.4 kcal/mol, and crocin, hypericin, and tubeimoside-1 which all had a binding energy of 8.1 kcal/mol. Other top-performing compounds include diosmin and rutin with binding energy of -8.0 kcal/mol. The ADMET study revealed that the following compounds glycyrrhizic acid, solanine, polyphyllin I, crocin, hypericin, tubeimoside-1, diosmin, rutin, and baicalin all violated Lipinski's rule of 5 which implies poor oral bioavailability. However, based on the binding energy score, it was suggested that these pharmacologically active compounds are potential molecules to be tested against cancer.

The recent progress of peptide regulators for the Wnt/β-catenin signaling pathway

Wnt signaling plays an important role in many biological processes such as stem cell self-renewal, cell proliferation, migration, and differentiation. The β-catenin-dependent signaling pathway mainly regulates cell proliferation, differentiation, and migration. In the Wnt/β-catenin signaling pathway, the Wnt family ligands transduce signals through LRP5/6 and Frizzled receptors to the Wnt/β-catenin signaling cascades. Wnt-targeted therapy has garnered extensive attention. The most commonly used approach in targeted therapy is small-molecule regulators. However, it is difficult for small-molecule regulators to make great progress due to their inherent defects. Therapeutic peptide regulators targeting the Wnt signaling pathway have become an alternative therapy, promising to fill the gaps in the clinical application of small-molecule regulators. In this review, we describe recent advances in peptide regulators for Wnt/β-catenin signaling.

Effects of HDAC inhibitors on neuroblastoma SH-SY5Y cell differentiation into mature neurons via the Wnt signaling pathway

Histone deacetylase (HDAC) inhibitors affect cell homeostasis, gene expression, and cell cycle progression and promote cell terminal differentiation or apoptosis. However, the effect of HDAC inhibition on SH-SY5Y cells, which are neuroblastoma cells capable of differentiating into neurons under specific conditions, such as in the presence of retinoic acid (RA), is unknown. In this study, we hypothesized that HDAC inhibitors induced the neuronal differentiation of SH-SY5Y cells. To test this hypothesis, we used phase contrast microscopy, immunocytochemistry (ICC), qPCR, and western blotting analysis. MS-275 and valproic acid (VPA), two HDAC inhibitors, were selected to evaluate neuronal differentiation. It was confirmed that cells treated with MS-275 or VPA differentiated into mature neurons, which were distinguished by bipolar or multipolar morphologies with elongated branches. In addition, the mRNA expression of neuronal markers (Tuj1 and NEFH) and the oligodendrocyte marker (CNP) was significantly increased with MS-275 or VPA treatment compared to that with RA treatment. In addition, the protein expression of the other neuronal markers, Tuj1 and NeuN, was highly increased with HDAC inhibitor treatments compared to that with RA treatment. Furthermore, we confirmed that noncanonical Wnt signaling was upregulated by HDAC inhibitors via MAPK signaling and the Wnt/JNK pathway. Therefore, both MS-275 and VPA promoted the differentiation of SH-SY5Y cells into mature neurons via the Wnt signaling pathway.

Hydrophilic surface-modified 3D printed flexible scaffolds with high ceramic particle concentrations for immunopolarization-regulation and bone regeneration

Bioceramic scaffolds used in bone tissue engineering suffer from a low concentration of ceramic particles (<50 wt%), because the high concentration of ceramic particles increases the brittleness of the composite. 3D printed flexible PCL/HA scaffolds with high ceramic particle concentrations (84 wt%) were successfully fabricated in this study. However, the hydrophobicity of PCL weakens the composite scaffold hydrophilicity, which may limit the osteogenic ability to some extent. Thus, as a less time-consuming, less labour intensive, and more cost-effective treatment method, alkali treatment (AT) was employed to modify the surface hydrophilicity of the PCL/HA scaffold, and its regulation of immune responses and bone regeneration were investigated in vivo and in vitro. Initially, several concentrations of NaOH (0.5, 1, 1.5, 2, 2.5, and 5 mol L^-1) were employed in tests to determine the appropriate concentration for AT. Based on the comprehensive consideration of the results of mechanical experiments and hydrophilicity, 2 mol L^-1 and 2.5 mol L^-1 of NaOH were selected for further investigation in this study. The PCL/HA-AT-2 scaffold dramatically reduced foreign body reactions as compared to the PCL/HA and PCL/HA-AT-2.5 scaffolds, promoted macrophage polarization towards the M2 phenotype and enhanced new bone formation. The Wnt/β-catenin pathway might participate in the signal transduction underlying hydrophilic surface-modified 3D printed scaffold-regulated osteogenesis, according to the results of immunohistochemical staining. In conclusion, hydrophilic surface-modified 3D printed flexible scaffolds with high ceramic particle concentrations can regulate the immune reactions and macrophage polarization to promote bone regeneration, and the PCL/HA-AT-2 scaffold is a potential candidate for bone tissue repair.

Cholesterol in the ciliary membrane as a therapeutic target against cancer

Primary cilium is a non-motile, antenna-like structure that develops in the quiescent G0 phase-cell surface. It is composed of an array of axonemal microtubules polymerized from the centrosome/basal body. The plasma membrane surrounding the primary cilium, which is called the ciliary membrane, contains a variety of receptors and ion channels, through which the cell receives extracellular chemical and physical stimuli to initiate signal transduction. In general, primary cilia disappear when cells receive the proliferative signals to re-enter the cell cycle. Primary cilia thus cannot be identified in many malignant and proliferative tumors. In contrast, some cancers, including basal cell carcinoma, medulloblastoma, gastrointestinal stromal tumor, and other malignancies, retain their primary cilia. Importantly, it has been reported that the primary cilia-mediated oncogenic signals of Hedgehog, Wnt, and Aurora kinase A are involved in the tumorigenesis and tumor progression of basal cell carcinoma and some types of medulloblastoma. It has also been demonstrated that cholesterol is significantly more enriched in the ciliary membrane than in the rest of the plasma membrane to ensure Sonic hedgehog signaling. A series of epidemiological studies on statin drugs (cholesterol-lowering medication) demonstrated that they prevent recurrence in a wide range of cancers. Taken together, ciliary cholesterol could be a potential therapeutic target in primary cilia-dependent progressive cancers.

Aberrant promoter methylation of Wnt inhibitory factor-1 gene is a potential target for treating psoriasis

Psoriasis is a chronic inflammatory skin disease mediated by immune and complex genetic factors. The wingless-related integration site (Wnt) signaling pathway plays a critical role in psoriasis, but how the Wnt pathway is regulated in psoriatic skin and whether it can be exploited for therapeutic benefits is unclear. By comparing biopsies from healthy and psoriatic skin, we found that Wnt inhibitory factor 1 (WIF1), an inhibitor of Wnt signaling, showed reduced expression at both mRNA and protein levels in psoriatic skin. We then quantified methylation of the WIF1 gene promoter by DNA methylation sequencing and found that the WIF1 promoter region was hypermethylated. We further showed that recombinant WIF1 injection ameliorates the imiquimod (IMQ) mouse model of psoriasis. We also revealed that treatment with the DNA methylation inhibitor, decitabine, inhibited proliferation of immortalized human keratinocytes (HaCaT) in a psoriasis-like inflammatory environment. Finally, we applied decitabine to the IMQ mouse model and demonstrated that treatment of mice with decitabine ameliorates the disease. Therefore, our study reveals that methylation of the WIF1 gene is associated with the pathogenesis of psoriasis, and suggests that pharmacological targeting of DNA methylation is a potential treatment strategy for psoriasis.

Genome-wide identification and expression profiling of Wnt gene family in Neocaridina denticulata sinensis

Wnt proteins are a class of hydrophobic secreted glycoproteins involved in diverse important biological processes, such as tissue formation and regeneration, embryonic development and innate immunity. The Wnt gene family has an early origin and is present in all deuterostomes. In the process of evolution, the phenomenon of gene expansion, contraction and adaptive evolution occurs in the Wnt gene family. In the current study, eleven Wnt genes (NdWnt1-2, NdWnt4-7, NdWnt9-11, NdWnt16, and NdWntA) belonging to different subfamilies were obtained based on the genomic and transcriptomic data of Neocaridina denticulata sinensis. Then the expression patterns of all NdWnts were analyzed in various tissues, at different developmental stages and under different stresses. The expression profiles of NdWnts at different developmental stages showed that most NdWnt genes were initially expressed at gastrula stage, and the expression of NdWnt5 and NdWnt16 throughout all developmental stages. The spatial expression of NdWnt genes presented tissue specificity. They were mainly expressed in four tissues, namely gill, intestines, ovary and eyestalk. After Vibrio parahemolyticus infection and under copper exposure, the expression levels of five NdWnts (NdWnt1, NdWnt5, NdWnt10, NdWnt16 and NdWntA) were variable. Our findings enrich the research on the Wnt gene family of N. denticulata sinensis and provide valuable insights into relationship between structure and function of Wnt genes in crustaceans.

Transcriptomic analysis of human cytomegalovirus to survey the indirect effects on renal transplant recipients

Post-transplant human cytomegalovirus (HCMV) viremia has been linked to adverse "indirect effects" among transplant patients. HCMV-created immunomodulatory mechanisms could be associated with the indirect effects.

OBJECTIVE

In the present study, the RNA-Seq whole transcriptome of renal transplant (RT) patients was analyzed to seek the underlying pathobiologic pathways associated with the long-term indirect effects of HCMV.

METHODS

To investigate the activated biological pathways in HCMV infection, total RNA was extracted from PBMCs of 2 RT patients with active HCMV and 2 RT patients without infection and then were sequenced using RNA-Seq. The resulted raw data were analyzed by conventional RNA-Seq software to determine the Differentially Expressed Genes (DEGs). Afterward, Gene Ontology (GO) and pathway enrichment analyses were conducted to determine the enriched pathways and biological processes by DEGs. Eventually, the relative expressions of some significant genes were validated in the twenty external RT patients.

RESULT

The analysis of RNA-Seq data related to RT patients with HCMV active viremia led to the identification of 140 up-regulated and 100 down-regulated DEGs. KEGG pathway analysis revealed the enrichment of DEGs in IL18 signaling, AGE-RAGE signaling pathway in diabetic complications, signaling by GPCR, Platelet activation, signaling and aggregation, Estrogen signaling pathway and signaling by Wnt due to HCMV infection. The expression levels of six genes involved in enriched pathways including F3, PTX3, ADRA2B, GNG11, GP9, HBEGF were then verified using RT-qPCR. The results were in consistent with RNA-Seq resultsoutcomes.

CONCLUSION

This study specifies some pathobiological pathways which are activated in HCMV active infection and could be linked to the adverse indirect effects caused by HCMV infection in transplant patients.

Pathogenesis and treatment of Sjogren's syndrome: Review and update

Sjogren's syndrome (SS) is a chronic autoimmune disease accompanied by multiple lesions. The main manifestations include dryness of the mouth and eyes, along with systemic complications (e.g., pulmonary disease, kidney injury, and lymphoma). In this review, we highlight that IFNs, Th17 cell-related cytokines (IL-17 and IL-23), and B cell-related cytokines (TNF and BAFF) are crucial for the pathogenesis of SS. We also summarize the advances in experimental treatment strategies, including targeting Treg/Th17, mesenchymal stem cell treatment, targeting BAFF, inhibiting JAK pathway, et al. Similar to that of SLE, RA, and MS, biotherapeutic strategies of SS consist of neutralizing antibodies and inflammation-related receptor blockers targeting proinflammatory signaling pathways. However, clinical research on SS therapy is comparatively rare. Moreover, the differences in the curative effects of immunotherapies among SS and other autoimmune diseases are not fully understood. We emphasize that targeted drugs, low-side-effect drugs, and combination therapies should be the focus of future research.

A DLG1-ARHGAP31-CDC42 axis is essential for the intestinal stem cell response to fluctuating niche Wnt signaling

A central factor in the maintenance of tissue integrity is the response of stem cells to variations in the levels of niche signals. In the gut, intestinal stem cells (ISCs) depend on Wnt ligands for self-renewal and proliferation. Transient increases in Wnt signaling promote regeneration after injury or in inflammatory bowel diseases, whereas constitutive activation of this pathway leads to colorectal cancer. Here, we report that Discs large 1 (Dlg1), although dispensable for polarity and cellular turnover during intestinal homeostasis, is required for ISC survival in the context of increased Wnt signaling. RNA sequencing (RNA-seq) and genetic mouse models demonstrated that DLG1 regulates the cellular response to increased canonical Wnt ligands. This occurs via the transcriptional regulation of Arhgap31, a GTPase-activating protein that deactivates CDC42, an effector of the non-canonical Wnt pathway. These findings reveal a DLG1-ARHGAP31-CDC42 axis that is essential for the ISC response to increased niche Wnt signaling.

An anoikis-based signature for predicting prognosis in hepatocellular carcinoma with machine learning

Background: Hepatocellular carcinoma (HCC) is a common malignancy with high mortality worldwide. Despite advancements in diagnosis and treatment in recent years, there is still an urgent unmet need to explore the underlying mechanisms and novel prognostic markers. Anoikis has received considerable attention because of its involvement in the progression of human malignancies. However, the potential mechanism of anoikis-related genes (ANRGs) involvement in HCC progression remains unclear. Methods: We use comprehensive bioinformatics analyses to determine the expression profile of ANRGs and their prognostic implications in HCC. Next, a risk score model was established by least absolute shrinkage and selection operator (Lasso) Cox regression analysis. Then, the prognostic value of the risk score in HCC and its correlation with clinical characteristics of HCC patients were further explored. Additionally, machine learning was utilized to identify the outstanding ANRGs to the risk score. Finally, the protein expression of DAP3 was examined on a tissue microarray (TMA), and the potential mechanisms of DAP3 in HCC was explored. Results: ANRGs were dysregulated in HCC, with a low frequency of somatic mutations and associated with prognosis of HCC patients. Then, nine ANRGs were selected to construct a risk score signature based on the LASSO model. The signature presented a strong ability of risk stratification and prediction for overall survival in HCC patients.Additionally, high risk scores were closely correlated with unfavorable clinical features such as advanced pathological stage, poor histological differentiation and vascular invasion. Moreover, The XGBoost algorithm verified that DAP3 was an important risk score contributor. Further immunohistochemistry determined the elevated expression of DAP3 in HCC tissues compared with nontumor tissues. Finally, functional analyses showed that DAP3 may promote HCC progression through multiple cancer-related pathways and suppress immune infiltration. Conclusion: In conclusion, the anoikis-based signature can be utilized as a novel prognostic biomarker for HCC, and DAP3 may play an important role in the development and progression of HCC.

Advances in the role of STAT3 in macrophage polarization

The physiological processes of cell growth, proliferation, differentiation, and apoptosis are closely related to STAT3, and it has been demonstrated that aberrant STAT3 expression has an impact on the onset and progression of a number of inflammatory immunological disorders, fibrotic diseases, and malignancies. In order to produce the necessary biological effects, macrophages (M0) can be polarized into pro-inflammatory (M1) and anti-inflammatory (M2) types in response to various microenvironmental stimuli. STAT3 signaling is involved in macrophage polarization, and the research of the effect of STAT3 on macrophage polarization has gained attention in recent years. In order to provide references for the treatment and investigation of disorders related to macrophage polarization, this review compiles the pertinent signaling pathways associated with STAT3 and macrophage polarization from many fundamental studies.

Dikkopf-1 promotes matrix mineralization of osteoblasts by regulating Ca+-CAMK2A- CREB1 pathway

Dickkopf-1 (DKK1) is a secreted protein that acts as an antagonist of the canonical WNT/β-catenin pathway, which regulates osteoblast differentiation. However, the role of DKK1 on osteoblast differentiation has not yet been fully clarified. Here, we investigate the functional role of DKK1 on osteoblast differentiation. Primary osteoprogenitor cells were isolated from human spinal bone tissues. To examine the role of DKK1 in osteoblast differentiation, we manipulated the expression of DKK1, and the cells were differentiated into mature osteoblasts. DKK1 overexpression in osteoprogenitor cells promoted matrix mineralization of osteoblast differentiation but did not promote matrix maturation. DKK1 increased Ca⁺ influx and activation of the Ca⁺/calmodulin-dependent protein kinase II Alpha (CAMK2A)-cAMP response element-binding protein 1 (CREB1) and increased translocation of p-CREB1 into the nucleus. In contrast, stable DKK1 knockdown in human osteosarcoma cell line SaOS2 exhibited reduced nuclear translocation of p-CREB1 and matrix mineralization. Overall, we suggest that manipulating DKK1 regulates the matrix mineralization of osteoblasts by Ca⁺-CAMK2A-CREB1, and DKK1 is a crucial gene for bone mineralization of osteoblasts. [BMB Reports 2022; 55(12): 627-632].

Blocking the Wnt/β‑catenin signaling pathway to treat colorectal cancer: Strategies to improve current therapies (Review)

Colorectal cancer (CRC) is one of the most common malignant tumor types occurring in the digestive system. The incidence of CRC has exhibits yearly increases and the mortality rate among patients with CRC is high. The Wnt/β‑catenin signaling pathway, which is associated with carcinogenesis, is abnormally activated in CRC. Most patients with CRC have adenomatous polyposis coli mutations, while half of the remaining patients have β‑catenin gene mutations. Therefore, targeting the Wnt/β‑catenin signaling pathway for the treatment of CRC is of clinical value. In recent years, with in‑depth research on the Wnt/β‑catenin signaling pathway, inhibitors have been developed that are able to suppress or hinder the development and progression of CRC. In the present review, the role of the Wnt/β‑catenin signaling pathway in CRC is summarized, the research status on Wnt/β‑catenin pathway inhibitors is outlined and potential targets for inhibition of this pathway are presented.

Gone with the Wnt(less): a mechanistic perspective on the journey of Wnt

Wnts are short-range signaling proteins, expressed in all metazoans from sponges to humans, critical for cell development and fate. There are 19 different Wnts in the human genome with varying expression levels and patterns, and post-translational modifications. Common to essentially all Wnts is the palmitoleation of a conserved serine by the O-acyltransferase PORCN in the endoplasmic reticulum (ER). All lipidated Wnts then bind a dedicated carrier Wntless (WLS), endowed with the task of transporting them from the ER to the plasma membrane, and ultimately facilitating their release to receptors on the Wnt-receiving cell to initiate signaling. Here, we will focus on the WLS-mediated transport step. There are currently two published structures, both obtained by single-particle cryo-electron microscopy of the Wnt/WLS complex: human Wnt8A-bound and human Wnt3A-bound WLS. We analyze the two Wnt/WLS structures - remarkably similar despite the sequence similarity between Wnt8A and Wnt3A being only ∼39% - to begin to understand the conserved nature of this binding mechanism, and ultimately how one carrier can accommodate a family of 19 different Wnts. By comparing how Wnt associates with WLS with how it binds to PORCN and FZD receptors, we can begin to speculate on mechanisms of Wnt transfer from PORCN to WLS, and from WLS to FZD, thus providing molecular-level insight into these essential steps of the Wnt signaling pathway.

Pasteurella multocida toxin - lessons learned from a mitogenic toxin

The gram-negative, zoonotic bacterium Pasteurella multocida was discovered in 1880 and found to be the causative pathogen of fowl cholera. Pasteurella-related diseases can be found in domestic and wild life animals such as buffalo, sheep, goat, deer and antelope, cats, dogs and tigers and cause hemorrhagic septicemia in cattle, rhinitis or pneumonia in rabbits or fowl cholera in poultry and birds. Pasteurella multocida does not play a major role in the immune-competent human host, but can be found after animal bites or in people with close contact to animals. Toxigenic strains are most commonly found in pigs and express a phage-encoded 146 kDa protein, the Pasteurella multocida toxin (PMT). Toxin-expressing strains cause atrophic rhinitis where nasal turbinate bones are destroyed through the inhibition of bone building osteoblasts and the activation of bone resorbing osteoclasts. After its uptake through receptor-mediated endocytosis, PMT specifically targets the alpha subunit of several heterotrimeric G proteins and constitutively activates them through deamidation of a glutamine residue to glutamate in the alpha subunit. This results in cytoskeletal rearrangement, proliferation, differentiation and survival of cells. Because of the toxin's mitogenic effects, it was suggested that it might have carcinogenic properties, however, no link between Pasteurella infections and cell transformation could be established, neither in tissue culture models nor through epidemiological data. In the recent years it was shown that the toxin not only affects bone, but also the heart as well as basically all cells of innate and adaptive immunity. During the last decade the focus of research shifted from signal transduction processes to understanding how the bacteria might benefit from a bone-destroying toxin. The primary function of PMT seems to be the modulation of immune cell activation which at the same time creates an environment permissive for osteoclast formation. While the disease is restricted to pigs, the implications of the findings from PMT research can be used to explore human diseases and have a high translational potential. In this review our current knowledge will be summarized and it will be discussed what can be learned from using PMT as a tool to understand human pathologies.

Dikkopf-1 promotes matrix mineralization of osteoblasts by regulating Ca+-CAMK2A- CREB1 pathway

Dickkopf-1 (DKK1) is a secreted protein that acts as an antagonist of the canonical WNT/β-catenin pathway, which regulates osteoblast differentiation. However, the role of DKK1 on osteoblast differentiation has not yet been fully clarified. Here, we investigate the functional role of DKK1 on osteoblast differentiation. Primary osteoprogenitor cells were isolated from human spinal bone tissues. To examine the role of DKK1 in osteoblast differentiation, we manipulated the expression of DKK1, and the cells were differentiated into mature osteoblasts. DKK1 overexpression in osteoprogenitor cells promoted matrix mineralization of osteoblast differentiation but did not promote matrix maturation. DKK1 increased Ca+ influx and activation of the Ca+/calmodulin-dependent protein kinase II Alpha (CAMK2A)-cAMP response element-binding protein 1 (CREB1) and increased translocation of p-CREB1 into the nucleus. In contrast, stable DKK1 knockdown in human osteosarcoma cell line SaOS2 exhibited reduced nuclear translocation of p-CREB1 and matrix mineralization. Overall, we suggest that manipulating DKK1 regulates the matrix mineralization of osteoblasts by Ca+-CAMK2A-CREB1, and DKK1 is a crucial gene for bone mineralization of osteoblasts. [BMB Reports 2022; 55(12): 627-632].

Preparation of Black pepper (Piper nigrum L.) essential oil nanoparticles and its antitumor activity on triple negative breast cancer in vitro

The active compounds isolated from Black pepper have anticancer effects, but the bioactivity of Black pepper essential oil (BP-EO) is rarely studied. BP-EO has poor stability and a suitable dose form should be prepared for in vivo delivery. Triple negative breast cancer (TNBC) has attracted more and more attention due to its high mitotic index, high metastasis rate and poor prognosis. In this study, the composition of BP-EO was analyzed by gas chromatography-mass spectrometry (GC-MS), and nanoparticles (NPs) loaded with BP-EO were prepared by nanoprecipitation method using Eudragit L100 as a carrier. We investigated the preparation, characterization, stability and in vitro release of nanoparticles. MTT assay, cell wound healing, Transwell invasion assay and Western blot were used to study the anti-tumor effect and mechanism of MDA-MB-231 cells. The GC-MS analysis identified a total of 33 compounds among which alkenes account for 63.55%. The prepared BP-EO NPs exhibited nanoscale morphology, good stability and pH-responsive and sustained release character which is suitable for in vivo delivery. BP-EO NPs significantly inhibited the proliferation, migration and invasion of MDA-MB-231 cells. Furthermore, BP-EO NPs significantly inhibited the expressions of Wnt and β-catenin and significantly activated the expression of GSK-3β in MDA-MB-231 cells. Therefore, BP-EO NPs prepared in this study provide a new effective strategy for the treatment of TNBC. PRACTICAL APPLICATIONS: Black pepper is rich in essential oil and has excellent antioxidant and antibacterial activities. However, the anti-tumor activity of BP-EO has not been studied. In this study, we found that BP-EO has excellent anticancer activity. To achieve effective encapsulation of black pepper essential oil and an excellent anti-triple negative breast cancer activity, nanoparticles loaded with BP-EO were prepared using Eudragit L100 as the carrier by the nanoprecipitation method. The in vitro study revealed that BP-EO NPs inhibited proliferation, migration and invasion of MDA-MB-231 cells via inhibiting the Wnt/β-Catenin signaling pathway. This study provides new ideas and innovations for the treatment of invasive triple negative breast cancer in the future. At the same time, we will further reveal the application potential, pharmacokinetic characteristics and precise mechanism of BP-EO NPs in vivo in subsequent studies.