Secreted and transmembrane wnt inhibitors and activators

MicroRNA-135b mainly functions as an oncogene during tumor progression

Late diagnosis is considered one of the main reasons of high mortality rate among cancer patients that results in therapeutic failure and tumor relapse. Therefore, it is needed to evaluate the molecular mechanisms associated with tumor progression to introduce efficient markers for the early tumor detection among cancer patients. The remarkable stability of microRNAs (miRNAs) in body fluids makes them potential candidates to use as the non-invasive tumor biomarkers in cancer screening programs. MiR-135b has key roles in prognosis and survival of cancer patients by either stimulating or inhibiting cell proliferation, invasion, and angiogenesis. Therefore, in the present review we assessed the molecular biology of miR-135b during tumor progression to introduce that as a novel tumor marker in cancer patients. It has been reported that miR-135b mainly acts as an oncogene by regulation of transcription factors, signaling pathways, drug response, cellular metabolism, and autophagy. This review paves the way to suggest miR-135b as a tumor marker and therapeutic target in cancer patients following the further clinical trials and animal studies.

Progress in the development of modulators targeting Frizzleds

The Frizzleds (FZDs) receptors on the cell surface belong to the class F of G protein-coupled receptors (GPCRs) which are the major receptors of WNT protein that mediates the classical WNT signaling pathway and other non-classical pathways. Besides, the FZDs also play a core role in tissue regeneration and tumor occurrence. With the structure and mechanism of FZDs activation becoming clearer, a series of FZDs modulators (inhibitors and agonists) have been developed, with the hope of bringing benefits to the treatment of cancer and degenerative diseases. Most of the FZDs inhibitors (small molecules, antibodies or designed protein inhibitors) block WNT signaling through binding to the cysteine-rich domain (CRD) of FZDs. Several small molecules impede FZDs activation by targeting to the third intracellular domain or the transmembrane domain of FZDs. However, three small molecules (FZM1.8, SAG1.3 and purmorphamine) activate the FZDs through direct interaction with the transmembrane domain. Another type of FZDs agonists are bivalent or tetravalent antibodies which activate the WNT signaling via inducing FZD-LRP5/6 heterodimerization. In this article, we reviewed the FZDs modulators reported in recent years, summarized the critical molecules' discovery processes and the elucidated relevant structural and pharmacological mechanisms. We believe the summaried molecular mechanisms of the relevant modulators could provide important guidance and reference for the future development of FZD modulators.

Lenvatinib in hepatocellular carcinoma: Resistance mechanisms and strategies for improved efficacy

Hepatocellular carcinoma (HCC), one of the most prevalent and destructive causes of cancer-related deaths worldwide, approximately 70% of patients with HCC exhibit advanced disease at diagnosis, limiting the potential for radical treatment. For such patients, lenvatinib, a long-awaited alternative to sorafenib for first-line targeted therapy, has become a key treatment. Unfortunately, despite some progress, the prognosis for advanced HCC remains poor because of drug resistance development. However, the molecular mechanisms underlying lenvatinib resistance and ways to relief drug resistance in HCC are largely unknown and lack of systematic summary; thus, this review not only aims to explore factors contributing to lenvatinib resistance in HCC, but more importantly, summary potential methods to conquer or mitigate the resistance. The results suggest that abnormal activation of pathways, drug transport, epigenetics, tumour microenvironment, cancer stem cells, regulated cell death, epithelial-mesenchymal transition, and other mechanisms are involved in the development of lenvatinib resistance in HCC and subsequent HCC progression. To improve the therapeutic outcomes of lenvatinib, inhibiting acquired resistance, combined therapies, and nano-delivery carriers may be possible approaches.

Advances in the role of resveratrol and its mechanism of action in common gynecological tumors

The incidence of common gynecological malignancies remains high, with current treatments facing multiple limitations and adverse effects. Thus, continuing the search for safe and effective oncologic treatment strategies continues. Resveratrol (RES), a natural non-flavonoid polyphenolic compound, is widely found in various plants and fruits, such as grapes, Reynoutria japonica Houtt., peanuts, and berries. RES possesses diverse biological properties, including neuroprotective, antitumor, anti-inflammatory, and osteoporosis inhibition effects. Notably, RES is broadly applicable in antitumor therapy, particularly for treating gynecological tumors (cervical, endometrial, and ovarian carcinomas). RES exerts antitumor effects by promoting tumor cell apoptosis, inhibiting cell proliferation, invasion, and metastasis, regulating tumor cell autophagy, and enhancing the efficacy of antitumor drugs while minimizing their toxic side effects. However, comprehensive reviews on the role of RES in combating gynecological tumors and its mechanisms of action are lacking. This review aims to fill this gap by examining the RES antitumor mechanisms of action in gynecological tumors, providing valuable insights for clinical treatment.

Wnt/β-catenin signaling components and mechanisms in bone formation, homeostasis, and disease

Wnts are secreted, lipid-modified proteins that bind to different receptors on the cell surface to activate canonical or non-canonical Wnt signaling pathways, which control various biological processes throughout embryonic development and adult life. Aberrant Wnt signaling pathway underlies a wide range of human disease pathogeneses. In this review, we provide an update of Wnt/β-catenin signaling components and mechanisms in bone formation, homeostasis, and diseases. The Wnt proteins, receptors, activators, inhibitors, and the crosstalk of Wnt signaling pathways with other signaling pathways are summarized and discussed. We mainly review Wnt signaling functions in bone formation, homeostasis, and related diseases, and summarize mouse models carrying genetic modifications of Wnt signaling components. Moreover, the therapeutic strategies for treating bone diseases by targeting Wnt signaling, including the extracellular molecules, cytosol components, and nuclear components of Wnt signaling are reviewed. In summary, this paper reviews our current understanding of the mechanisms by which Wnt signaling regulates bone formation, homeostasis, and the efforts targeting Wnt signaling for treating bone diseases. Finally, the paper evaluates the important questions in Wnt signaling to be further explored based on the progress of new biological analytical technologies.

Spatial Multi-omics Reveals the Role of the Wnt Modulator, Dkk2, in Palatogenesis'

Multiple genetic and environmental etiologies contribute to the pathogenesis of cleft palate, which is the most common of the inherited disorders of the craniofacial complex. Insights into the molecular mechanisms regulating osteogenic differentiation and patterning in the palate during embryogenesis are limited and needed for the development of innovative diagnostics and cures. This study used the Pax9-/- mouse model with a consistent phenotype of cleft secondary palate to investigate the role of Pax9 in the process of palatal osteogenesis. Although prior research has identified the upregulation of Wnt pathway modulators Dkk1 and Dkk2 in Pax9-/- palate mesenchyme, limitations of spatial resolution and technology restricted a more robust analysis. Here, data from single-nucleus transcriptomics and chromatin accessibility assays validated by in situ highly multiplex targeted single-cell spatial profiling technology suggest a distinct relationship between Pax9+ and osteogenic populations. Loss of Pax9 results in spatially restricted osteogenic domains bounded by Dkk2, which normally interfaces with Pax9 in the mesenchyme. Moreover, the loss of Pax9 leads to a disruption in the normal osteodifferentiaion of palatal osteogenic mesenchymal cells. These results suggest that Pax9-dependent Wnt signaling modulators influence osteogenic programming during palate formation, potentially contributing to the observed cleft palate phenotype.

Continuous tooth replacement: what can teleost fish teach us?

Most tooth-bearing non-mammalian vertebrates have the capacity to replace their teeth throughout life. This capacity was lost in mammals, which replace their teeth only once at most. Not surprisingly, continuous tooth replacement has attracted much attention. Classical morphological studies (e.g. to analyse patterns of replacement) are now being complemented by molecular studies that investigate the expression of genes involved in tooth formation. This review focuses on ray-finned fish (actinopterygians), which have teeth often distributed throughout the mouth and pharynx, and more specifically on teleost fish, the largest group of extant vertebrates. First we highlight the diversity in tooth distribution and in tooth replacement patterns. Replacement tooth formation can start from a distinct (usually discontinuous and transient) dental lamina, but also in the absence of a successional lamina, e.g. from the surface epithelium of the oropharynx or from the outer dental epithelium of a predecessor tooth. The relationship of a replacement tooth to its predecessor is closely related to whether replacement is the result of a prepattern or occurs on demand. As replacement teeth do not necessarily have the same molecular signature as first-generation teeth, the question of the actual trigger for tooth replacement is discussed. Much emphasis has been laid in the past on the potential role of epithelial stem cells in initiating tooth replacement. The outcome of such studies has been equivocal, possibly related to the taxa investigated, and the permanent or transient nature of the dental lamina. Alternatively, replacement may result from local proliferation of undifferentiated progenitors, stimulated by hitherto unknown, perhaps mesenchymal, factors. So far, the role of the neurovascular link in continuous tooth replacement has been poorly investigated, despite the presence of a rich vascularisation surrounding actinopterygian (as well as chondrichthyan) teeth and despite a complete arrest of tooth replacement after nerve resection. Lastly, tooth replacement is possibly co-opted as a process to expand the number of teeth in a dentition ontogenetically whilst conserving features of the primary dentition. That neither a dental lamina, nor stem cells appear to be required for tooth replacement places teleosts in an advantageous position as models for tooth regeneration in humans, where the dental lamina regresses and epithelial stem cells are considered lost.

Sizzled (Frzb3) physically interacts with noncanonical Wnt ligands to inhibit gastrulation cell movement

The coordinated movement of germ layer progenitor cells reaches its peak at the dorsal side, where the Bmp signaling gradient is low, and minimum at the ventral side, where the Bmp gradient is high. This dynamic cell movement is regulated by the interplay of various signaling pathways. The noncanonical Wnt signaling cascade serves as a pivotal regulator of convergence and extension cell movement, facilitated by the activation of small GTPases such as Rho, Rab, and Rac. However, the underlying cause of limited cell movement at the ventral side remains elusive. To explore the functional role of a key regulator in constraining gastrulation cell movement at the ventral side, we investigated the Bmp4-direct target gene, sizzled (szl), to assess its potential role in inhibiting noncanonical Wnt signaling. In our current study, we demonstrated that ectopic expression of szl led to gastrulation defects in a dose-dependent manner without altering cell fate specification. Overexpression of szl resulted in decreased elongation of Activin-treated animal cap and Keller explants. Furthermore, our immunoprecipitation assay unveiled the physical interaction of Szl with noncanonical Wnt ligand proteins (Wnt5 and Wnt11). Additionally, the activation of small GTPases involved in Wnt signaling mediation (RhoA and Rac1) was diminished upon szl overexpression. In summary, our findings suggest that Bmp4 signaling negatively modulates cell movement from the ventral side of the embryo by inducing szl expression during early Xenopus gastrulation.

Therapeutic and pharmacological efficacy of plant-derived bioactive compounds in targeting breast cancer

Breast cancer (BC) ranks number one among cancers affecting women globally. Serious concerns include delayed diagnosis, poor prognosis, and adverse side effects of conventional treatment, leading to residual morbidity. Therefore, an alternative treatment approach that is safe and effective has become the need of the hour. In this regard, plant-based medicines via a combination of conventional drugs are gaining increasing acceptance worldwide, playing a pivotal role in cancer management as proven by their efficacy evaluation studies. This review aims to fill the knowledge gaps by providing the preclinical evidence of cellular and molecular mechanisms of Indian phytomedicines in targeting varied pathways of breast cancer progression. A comprehensive search was performed on different platforms, followed by screening of relevant studies for review. In this article, the in-depth of various botanical drugs covering their nomenclature, dosage, toxicity, and modus operandi in BC cells have been extensively discussed. Various signaling pathways like Notch signaling, MAPK signaling, apoptosis, Wnt signaling, etc. regulated by herbal medicine treatment in BC are also highlighted to understand the drug mechanism better. This will guide the researchers to plan future strategies and generate more robust integrated evidence of plant-based drugs or botanical formulations for their potential role in the management of BC.

The predictive value of serum Dickkopf-1, Dickkopf-3 level to coronary artery disease and acute coronary syndrome

BACKGROUND

Previous studies have already confirmed the association between Dickkopf (Dkk) protein and the occurrence and progression of atherosclerosis. However, there is limited clinical evidence regarding the serum levels of Dickkopf-1 (Dkk1) and Dickkopf-3 (Dkk3) in relation to atherosclerotic cardiovascular disease (ASCVD), particularly acute coronary syndrome (ACS).

MATERIALS AND METHODS

A total of 88 healthy volunteers and 280 patients with coronary artery disease (CAD) undergoing coronary angiography for angina between October 2021 and October 2022, including 96 cases of stable angina (SA), 96 of unstable angina (UA) and 88 of acute myocardial infarction (AMI) were included finally. The serum concentrations of Dkk1 and Dkk3 were measured using electrochemiluminescence of Meso Scale Discovery. The predictive value of single or combined application of serum Dkk1 and Dkk3 in CAD and ACS were evaluated.

RESULTS

The serum levels of Dkk1 were significantly higher in the SA group, UA group, and AMI group compared to the control group. Multivariable logistic regression analysis demonstrated that elevated serum Dkk1 levels were independent predictive factors for increased risk of CAD and ACS (OR = 1.027, 95%CI = 1.019-1.034, p < 0.001; OR = 1.045, 95%CI = 1.028-1.053, p < 0.001, respectively). Receiver operating characteristic curve (ROC) analysis showed that the optimal cutoff value of serum Dkk1 for predicting ACS was 205 ng/dl, with a sensitivity of 82.6% and specificity of 96.6%. The area under the curve (AUC) was 0.930 (95%CI: 0.899-0.961, p < 0.001). Regarding Dkk3, serum Dkk3 levels were elevated in CAD patients compared to the healthy control group, and significantly higher in ACS patients compared to SA patients. Serum Dkk3 was significantly associated with increased risk of CAD and ACS (OR = 1.131, 95%CI = 1.091-1.173, p < 0.001; OR = 1.201, 95%CI = 1.134-1.271, p < 0.001, respectively). ROC curve analysis showed that the optimal cutoff value of serum Dkk3 for predicting ACS was 50.82 ng/ml, with a sensitivity of 85.9% and specificity of 87.5%. The AUC was 0.925 (95%CI: 0.894-0.956, p < 0.001). When serum Dkk1 and Dkk3 are combined as predictive factors for ACS, the AUC was 0.975.

CONCLUSION

Serum levels of Dkk1 and Dkk3 are significantly associated with an increased risk of CAD and ACS, and they possess predictive value for CAD and ACS. The combination of serum Dkk1 and Dkk3 is a superior predictive factor for CAD and ACS.

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.

A spatiotemporal atlas of cholestatic injury and repair in mice

Cholestatic liver injuries, characterized by regional damage around the bile ductular region, lack curative therapies and cause considerable mortality. Here we generated a high-definition spatiotemporal atlas of gene expression during cholestatic injury and repair in mice by integrating spatial enhanced resolution omics sequencing and single-cell transcriptomics. Spatiotemporal analyses revealed a key role of cholangiocyte-driven signaling correlating with the periportal damage-repair response. Cholangiocytes express genes related to recruitment and differentiation of lipid-associated macrophages, which generate feedback signals enhancing ductular reaction. Moreover, cholangiocytes express high TGFβ in association with the conversion of liver progenitor-like cells into cholangiocytes during injury and the dampened proliferation of periportal hepatocytes during recovery. Notably, Atoh8 restricts hepatocyte proliferation during 3,5-diethoxycarbonyl-1,4-dihydro-collidin damage and is quickly downregulated after injury withdrawal, allowing hepatocytes to respond to growth signals. Our findings lay a keystone for in-depth studies of cellular dynamics and molecular mechanisms of cholestatic injuries, which may further develop into therapies for cholangiopathies.

Combination of 308-nm excimer laser and piperine promotes melanocyte proliferation, migration, and melanin content production via the miR-328/SFRP1 axis

OBJECTIVE

Both piperine and a 308-nm excimer laser have significant curative effects on vitiligo. This study mainly explored the molecular mechanism of a 308-nm excimer combined with piperine in regulating melanocyte proliferation.

METHODS

Epidermal melanocytes were cultured in piperine solution, and the cells were irradiated by an XTRAC excimer laser treatment system at 308-nm output monochromatic light. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were for detecting the expression levels of genes or proteins. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Transwell method was for assessing cell viability and migration capacity. The content of melanin was also detected.

RESULTS

The combination of the 308-nm excimer laser and piperine enhanced the cell proliferation, migration, and melanin production of melanocytes and upregulated the level of miR-328, and restraint of miR-328 reversed the influence of the 308-nm excimer laser and piperine. Secreted frizzled-related protein 1 (SFRP1) is a direct target gene of miR-328, and miR-328 can inhibit the expression of SFRP1 and elevate the protein level of the Wnt/β-catenin signaling pathway.

CONCLUSION

The 308-nm excimer laser combined with piperine may be more efficient than piperine alone in the remedy of vitiligo, and the miR-328/SFRP1 and Wnt/β-catenin pathways are participated in the proliferation, migration, and melanin synthesis of melanocytes.

The involvement of the Wnt/β-catenin signaling cascade in fibrosis progression and its therapeutic targeting by relaxin

Organ scarring, referred to as fibrosis, results from a failed wound-healing response to chronic tissue injury and is characterised by the aberrant accumulation of various extracellular matrix (ECM) components. Once established, fibrosis is recognised as a hallmark of stiffened and dysfunctional tissues, hence, various fibrosis-related diseases collectively contribute to high morbidity and mortality in developed countries. Despite this, these diseases are ineffectively treated by currently-available medications. The pro-fibrotic cytokine, transforming growth factor (TGF)-β1, has emerged as the master regulator of fibrosis progression, owing to its ability to promote various factors and processes that facilitate rapid ECM synthesis and deposition, whilst negating ECM degradation. TGF-β1 signal transduction is tightly controlled by canonical (Smad-dependent) and non-canonical (MAP kinase- and Rho-associated protein kinase-dependent) intracellular protein activity, whereas its pro-fibrotic actions can also be facilitated by the Wnt/β-catenin pathway. This review outlines the pathological sequence of events and contributing roles of TGF-β1 in the progression of fibrosis, and how the Wnt/β-catenin pathway contributes to tissue repair in acute disease settings, but to fibrosis and related tissue dysfunction in synergy with TGF-β1 in chronic diseases. It also outlines the anti-fibrotic and related signal transduction mechanisms of the hormone, relaxin, that are mediated via its negative modulation of TGF-β1 and Wnt/β-catenin signaling, but through the promotion of Wnt/β-catenin activity in acute disease settings. Collectively, this highlights that the crosstalk between TGF-β1 signal transduction and the Wnt/β-catenin cascade may provide a therapeutic target that can be exploited to broadly treat and reverse established fibrosis.

The Intricacies of Renal Phosphate Reabsorption-An Overview

To maintain an optimal body content of phosphorus throughout postnatal life, variable phosphate absorption from food must be finely matched with urinary excretion. This amazing feat is accomplished through synchronised phosphate transport by myriads of ciliated cells lining the renal proximal tubules. These respond in real time to changes in phosphate and composition of the renal filtrate and to hormonal instructions. How they do this has stimulated decades of research. New analytical techniques, coupled with incredible advances in computer technology, have opened new avenues for investigation at a sub-cellular level. There has been a surge of research into different aspects of the process. These have verified long-held beliefs and are also dramatically extending our vision of the intense, integrated, intracellular activity which mediates phosphate absorption. Already, some have indicated new approaches for pharmacological intervention to regulate phosphate in common conditions, including chronic renal failure and osteoporosis, as well as rare inherited biochemical disorders. It is a rapidly evolving field. The aim here is to provide an overview of our current knowledge, to show where it is leading, and where there are uncertainties. Hopefully, this will raise questions and stimulate new ideas for further research.

Study of the effect of sFRP1 protein on molecules involved in the regulation of DNA methylation in CML cell line

Wnt-signaling pathway plays a crucial role in the pathogenesis and progression of Chronic Myeloid Leukemia (CML). sFRP1 is involved in the suppression of the Wnt-signaling pathway and has been shown to be epigenetically silenced by promoter hypermethylation during CML progression. DNMT3A plays a crucial role in promoter hypermethylation and is responsible for establishing methylation patterns. We aimed to analyze the relationship between sFRP1 expression and DNMT3A, TET1, TET2 and TET3 proteins that are responsible for maintaining cellular methylation patterns; along with miRNAs miR144-3p and miR-767-5p that are known to be associated with these proteins. CML cell lines K562 and K562S which stably expresses sFRP1, were used to compare the changes in miR144-3p and miR-767-5p expression. DNMT3A, TET1, TET2 and TET3 protein levels were analyzed by Western blot. In K562S cells the expression of miR-144-3p and miR-767-5p were decreased along with DNMT3A and TET1 protein levels. On the contrary, TET2 protein was increased. Our results support other reports involving sFRP1 and methylation dynamics; as well as opening new avenues of exploration. Our data supports the conclusion that re-expression of sFRP1 protein alters the expression of factors that play important roles in the overall methylation patterns in the leukemic cell line K562.

Decoding spatiotemporal transcriptional dynamics and epithelial fibroblast crosstalk during gastroesophageal junction development through single cell analysis

The gastroesophageal squamocolumnar junction (GE-SCJ) is a critical tissue interface between the esophagus and stomach, with significant relevance in the pathophysiology of gastrointestinal diseases. Despite this, the molecular mechanisms underlying GE-SCJ development remain unclear. Using single-cell transcriptomics, organoids, and spatial analysis, we examine the cellular heterogeneity and spatiotemporal dynamics of GE-SCJ development from embryonic to adult mice. We identify distinct transcriptional states and signaling pathways in the epithelial and mesenchymal compartments of the esophagus and stomach during development. Fibroblast-epithelial interactions are mediated by various signaling pathways, including WNT, BMP, TGF-β, FGF, EGF, and PDGF. Our results suggest that fibroblasts predominantly send FGF and TGF-β signals to the epithelia, while epithelial cells mainly send PDGF and EGF signals to fibroblasts. We observe differences in the ligands and receptors involved in cell-cell communication between the esophagus and stomach. Our findings provide insights into the molecular mechanisms underlying GE-SCJ development and fibroblast-epithelial crosstalk involved, paving the way to elucidate mechanisms during adaptive metaplasia development and carcinogenesis.

Mapping functional to morphological variation reveals the basis of regional extracellular matrix subversion and nerve invasion in pancreatic cancer

Intratumor morphological heterogeneity of pancreatic ductal adenocarcinoma (PDAC) predicts clinical outcomes but is only partially understood at the molecular level. To elucidate the gene expression programs underpinning intratumor morphological variation in PDAC, we investigated and deconvoluted at single cell level the molecular profiles of histologically distinct clusters of PDAC cells. We identified three major morphological and functional variants that co-exist in varying proportions in all PDACs, display limited genetic diversity, and are associated with a distinct organization of the extracellular matrix: a glandular variant with classical ductal features; a transitional variant displaying abortive ductal structures and mixed endodermal and myofibroblast-like gene expression; and a poorly differentiated variant lacking ductal features and basement membrane, and showing neuronal lineage priming. Ex vivo and in vitro evidence supports the occurrence of dynamic transitions among these variants in part influenced by extracellular matrix composition and stiffness and associated with local, specifically neural, invasion.

Identification and validation of autophagy-related genes in SSc

Multiple organs are affected by the complex autoimmune illness known as systemic sclerosis (SSc), which has a high fatality rate. Genes linked to autophagy have been linked to the aetiology of SSc. It is yet unknown, though, whether autophagy-related genes play a role in the aetiology of SSc. After using bioinformatics techniques to examine two databases (the GSE76885 and GSE95065 datasets) and autophagy-related genes, we were able to identify 12 autophagy-related differentially expressed genes that are linked to the pathophysiology of SSc. Additional examination of the receiver operating characteristic curve revealed that SFRP4 (AUC = 0.944, P < 0.001) and CD93 (AUC = 0.904, P < 0.001) might be utilized as trustworthy biomarkers for the diagnosis of SSc. The SSc group's considerably greater CD93 and SFRP4 expression levels compared to the control group were further confirmed by qRT-PCR results. The autophagy-related genes SFRP4 and CD93 were found to be viable diagnostic indicators in this investigation. Our research sheds light on the processes by which genes linked to autophagy affect the pathophysiology of SSc.

Cyanidin Ameliorates Bisphenol A-Induced Alzheimer's Disease Pathology by Restoring Wnt/β-Catenin Signaling Cascade: an In Vitro Study

Alzheimer's disease (AD) is a progressive neurodegenerative disorder causing memory loss and cognitive decline, linked to amyloid-beta (Aβ) plaques and hyperphosphorylated tau protein accumulation in the brain. Environmental pollutant bisphenol A (BPA) has been implicated in AD pathology due to its neurotoxic effects. This study aims to evaluate cyanidin from flower bracts of Musa acuminata Colla (red variety; AAA group) for its neuroprotective properties against BPA-induced AD pathology. The extraction of cyanidin was optimized using 70% ethanol in acidified water, showing promising anti-acetylcholinesterase activity. Cyanidin was effectively purified from the resultant extract and characterized using spectroscopic techniques. Two gradient doses of cyanidin (90 and 10 µg/ml) were determined based on cell viability assay. The role of cyanidin in promoting nerve growth and differentiation was assessed in PC12 cells for up to 72 h. A discernible and statistically significant difference was assessed in neurite extension at both doses at 72 h, followed by pre-treatment with cyanidin. BPA stimulation significantly increased the p-tau expression compared to the control (p < 0.0001). Pre-treatment with cyanidin reduced the tau expression; however, a significant difference was observed compared to control cells (p = 0.0003). Cyanidin significantly enhanced the mRNA expression of Wnt3a (p < 0.0001), β-catenin (p = 0.0004), and NeuroD1 (p = 0.0289), and decreased the expression of WIF1(p = 0.0040) and DKK1 (p < 0.0001), which are Wnt antagonist when compared to cells stimulated with BPA. Conclusively, our finding suggests that cyanidin could agonize nerve growth factor and promote neuronal differentiation, reduce tau-hyperphosphorylation by restoring the Wnt/β-catenin signaling cascade, and thereby render its neuroprotective potential against BPA-induced AD pathology.

Kaempferol regulates apoptosis and migration of neural stem cells to attenuate cerebral infarction by O-GlcNAcylation of β-catenin

Ischemic stroke remains a major cause of disability and death. Kaempferol (Kae) is a neuroprotective flavonoid compound. Thus, this study aimed to explore the impact of Kae on cerebral infarction. We generated the middle cerebral artery occlusion (MCAO) mouse model to study the effects of Kae on infarction volume and neurological function. The oxygen and glucose deprivation (OGD)/reoxygenation (R) model of neural stem cells (NSCs) was established to study the effects of Kae on cell viability, migration, and apoptosis. Cell processes were assessed by cell counting kit-8, Transwell assay, flow cytometry, and TUNEL analysis. The molecular mechanism was assessed using the Western blot. The results indicated that Kae attenuated MCAO-induced cerebral infarction and neurological injury. Besides, Kae promoted cell viability and migration and inhibited apoptosis of OGD/R-treated NSCs. Moreover, OGD/R suppressed total O-GlcNAcylation level and O-GlcNAcylation of β-catenin, thereby suppressing the Wnt/β-catenin pathway, whereas Kae reversed the suppression. Inactivation of the Wnt/β-catenin pathway abrogated the biological functions of NSCs mediated by Kae. In conclusion, Kae suppressed cerebral infarction by facilitating NSC viability, migration, and inhibiting apoptosis. Mechanically, Kae promoted O-GlcNAcylation of β-catenin to activate the Wnt/β-catenin pathway. Kae may have a lessening effect on ischemic stroke.

El diálogo oculto entre el hueso y los tejidos a través del remodelado óseo

El hueso es mucho más que un reservorio de calcio y fósforo. Su disposición lacuno-canalicular ofrece una importante vía de intercambio con la circulación y actualmente, el esqueleto se considera un gran órgano endocrino, con acciones que van más allá del control del balance fosfocálcico mediado por el factor fibroblástico 23 (FGF23). Paralelamente al efecto modulador de las adipoquinas sobre el remodelado óseo, diversas proteínas óseas, como la osteocalcina y la esclerostina, ejercen cierta acción contra-reguladora sobre el metabolismo energético, posiblemente en un intento de asegurar los enormes requerimientos energéticos del remodelado. En esta interacción del hueso con otros tejidos, especialmente el adiposo, participa la señalización canónica Wnt/β-catenina y por ello la esclerostina, una proteína osteocítica que inhibe esta señalización, emerge como un potencial biomarcador. Es más, su participación en diversas patologías le posiciona como diana terapéutica, existiendo un anticuerpo anti-esclerostina, recientemente aprobado en nuestro país para el tratamiento de la osteoporosis. Esta revisión aborda el carácter endocrino del hueso, el papel de la osteocalcina y, especialmente, el papel regulador y modulador de la esclerostina sobre remodelado óseo y la homeóstasis energética a través de su interacción con la señalización canónica Wnt/β-catenina, así como su potencial utilidad como biomarcador.

The hidden cross talk between bone and tissues through bone turnover

Bone is more than a reservoir of calcium and phosphorus. Its lacuno-canalicular arrangement provides an important pathway for exchange with circulation and currently, the skeleton is considered a large endocrine organ with actions that go beyond the control of calcium-phosphorus balance mediated by fibroblastic growth factor 23 (FGF23). Parallel to the modulating effect of adipokines on bone turnover, certain bone proteins, such as osteocalcin and sclerostin, play a counter-regulatory role on energy metabolism, probably in an attempt to ensure its high energy requirement for bone turnover. In this crosstalk between bone and other tissues, especially with adipose tissue, canonical Wnt/β-catenin signaling is involved and therefore, sclerostin, an osteocyte derived protein that inhibits this signalling, emerges as a potential biomarker. Furthermore, its involvement in diverse pathologic conditions supports sclerostin as a therapeutic target, with an anti-sclerostin antibody recently approved in our country for the treatment of osteoporosis. This review addresses the endocrine nature of bone, the role of osteocalcin, and specially, the regulatory and modulatory role of sclerostin on bone turnover and energy homeostasis through its inhibitory effect on canonical Wnt/β-catenin signaling, as well as its potential utility as a biomarker.

Unravelling the Road to Recovery: Mechanisms of Wnt Signalling in Spinal Cord Injury

Spinal cord injury (SCI) is a complex neurodegenerative pathology that consistently harbours a poor prognostic outcome. At present, there are few therapeutic strategies that can halt neuronal cell death and facilitate functional motor recovery. However, recent studies have highlighted the Wnt pathway as a key promoter of axon regeneration following central nervous system (CNS) injuries. Emerging evidence also suggests that the temporal dysregulation of Wnt may drive cell death post-SCI. A major challenge in SCI treatment resides in developing therapeutics that can effectively target inflammation and facilitate glial scar repair. Before Wnt signalling is exploited for SCI therapy, further research is needed to clarify the implications of Wnt on neuroinflammation during chronic stages of injury. In this review, an attempt is made to dissect the impact of canonical and non-canonical Wnt pathways in relation to individual aspects of glial and fibrotic scar formation. Furthermore, it is also highlighted how modulating Wnt activity at chronic time points may aid in limiting lesion expansion and promoting axonal repair.

Spatial Multiomics Reveal the Role of Wnt Modulator, Dkk2, in Palatogenesis

Multiple genetic and environmental etiologies contribute to the pathogenesis of cleft palate, which constitutes the most common among the inherited disorders of the craniofacial complex. Insights into the molecular mechanisms regulating osteogenic differentiation and patterning in the palate during embryogenesis are limited and needed for the development of innovative diagnostics and cures. This study utilized the Pax9-/- mouse model with a consistent phenotype of cleft secondary palate to investigate the role of Pax9 in the process of palatal osteogenesis. While prior research had identified upregulation of Wnt pathway modulators Dkk1 and Dkk2 in Pax9-/- palate mesenchyme, limitations of spatial resolution and technology restricted a more robust analysis. Here, data from single-nucleus transcriptomics and chromatin accessibility assays validated by in situ highly multiplex targeted single-cell spatial profiling technology suggest a distinct relationship between Pax9+ and osteogenic populations. Loss of Pax9 results in spatially restricted osteogenic domains bounded by Dkk2, which normally interfaces with Pax9 in the mesenchyme. These results suggest that Pax9-dependent Wnt signaling modulators influence osteogenic programming during palate formation, potentially contributing to the observed cleft palate phenotype.

UCHL3 inhibits ferroptosis by stabilizing β-catenin and maintains stem-like properties of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic liver cancer. Dysregulated Wnt/β-catenin activation is closely related to the progression of cancer. Nevertheless, the mechanism that sustains the abnormal expression of β-catenin in HCC has yet to be identified. In this study, we find that UCHL3 is overexpressed in HCC tissues and correlated with β-catenin protein level. High expression of UCHL3 is associated with poor prognosis. UCHL3 knockdown markedly reduces the protein level of β-catenin in HCC cells. TOP-luciferase activity and β-catenin target genes expression are also decreased upon UCHL3 depletion. We find that the ARM domain of β-catenin is required for the interaction with UCHL3. UCHL3 increases β-catenin protein stability via removing K48-specific poly-ubiquitin chains from β-catenin protein. Furthermore, the depletion of UCHL3 induces ferroptosis and hinders the growth, invasion, and stem cell properties of HCC cells. These impacts could be restored by the overexpression of β-catenin. In addition, the UCHL3 inhibitor TCID inhibits the aggressive phenotype of HCC through the degradation of β-catenin. In general, our results indicates that UCHL3 increases the stability of β-catenin, which in turn facilitates tumorigenesis of HCC, suggesting that targeting UCHL3 may be a promising approach for the treatment of HCC.

Gut-liver axis calibrates intestinal stem cell fitness

The gut and liver are recognized to mutually communicate through the biliary tract, portal vein, and systemic circulation. However, it remains unclear how this gut-liver axis regulates intestinal physiology. Through hepatectomy and transcriptomic and proteomic profiling, we identified pigment epithelium-derived factor (PEDF), a liver-derived soluble Wnt inhibitor, which restrains intestinal stem cell (ISC) hyperproliferation to maintain gut homeostasis by suppressing the Wnt/β-catenin signaling pathway. Furthermore, we found that microbial danger signals resulting from intestinal inflammation can be sensed by the liver, leading to the repression of PEDF production through peroxisome proliferator-activated receptor-α (PPARα). This repression liberates ISC proliferation to accelerate tissue repair in the gut. Additionally, treating mice with fenofibrate, a clinical PPARα agonist used for hypolipidemia, enhances colitis susceptibility due to PEDF activity. Therefore, we have identified a distinct role for PEDF in calibrating ISC expansion for intestinal homeostasis through reciprocal interactions between the gut and liver.

The co-receptor Tspan12 directly captures Norrin to promote ligand-specific β-catenin signaling

Wnt/β-catenin signaling directs animal development and tissue renewal in a tightly controlled, cell- and tissue-specific manner. In the central nervous system, the atypical ligand Norrin controls angiogenesis and maintenance of the blood-brain barrier and blood-retina barrier through the Wnt/β-catenin pathway. Like Wnt, Norrin activates signaling by binding and heterodimerizing the receptors Frizzled (Fzd) and Low-density lipoprotein receptor-related protein 5 or 6 (LRP5/6), leading to membrane recruitment of the intracellular transducer Dishevelled (Dvl); this ultimately results in the stabilization of the transcriptional coactivator β-catenin. Unlike Wnt, the cysteine-knot ligand Norrin only signals through Fzd4 and additionally requires the co-receptor Tspan12; however, the mechanism underlying Tspan12-mediated signal enhancement is unclear. It has been proposed that Tspan12 integrates into the Norrin-Fzd4 complex to enhance Norrin-Fzd4 affinity or otherwise allosterically modulate Fzd4 signaling. Here, we measure direct, high-affinity binding between purified Norrin and Tspan12 in a lipid environment and use AlphaFold models to interrogate this interaction interface. We find that Tspan12 and Fzd4 can simultaneously bind Norrin and that a pre-formed Tspan12/Fzd4 heterodimer, as well as cells co-expressing Tspan12 and Fzd4, more efficiently capture low concentrations of Norrin than Fzd4 alone. We also show that Tspan12 competes with both heparan sulfate proteoglycans and LRP6 for Norrin binding and that Tspan12 does not impact Fzd4-Dvl affinity in the presence or absence of Norrin. Our findings suggest that Tspan12 does not allosterically enhance Fzd4 binding to Norrin or Dvl, but instead functions to directly capture Norrin upstream of signaling.

Exploring signaling pathway crosstalk in glioma by mapping miRNA and WNT pathways: A review

Glioma is a significant healthcare burden; nevertheless, the particular genetic regulatory mechanism underpinning its onset and progression is still unknown. Recent research has focused in large part on trying to determine the underlying molecular pathways that contribute to the malignancy of this disease because of the difficulties in treating it. Many tumors have been linked to changes in the expression of microRNAs (miRNAs). miRNAs play a critical role in cancer development by controlling a wide variety of targets and signaling cascades. A rising body of evidence emphasizes WNT pathway dysregulation in glioma, despite the fact that it is dysregulated in many malignancies. Here, we give a detailed analysis of the roles played by miRNAs in the WNT pathway by glioma. We also demonstrate how the WNT pathway cooperates with miRNAs to control a variety of functions, including cell proliferation, invasion, migration, and epithelial-mesenchymal transition.

Spatial gene expression profile of Wnt-signaling components in the murine enteric nervous system

Introduction

Wnt-signaling is a key regulator of stem cell homeostasis, extensively studied in the intestinal crypt and other metazoan tissues. Yet, there is hardly any data available on the presence of Wnt-signaling components in the adult enteric nervous system (ENS) in vivo.

Methods

Therefore, we employed RNAscope HiPlex-assay, a novel and more sensitive in situ hybridization technology. By amplifying target specific signals, this technique enables the detection of low abundance, tightly regulated RNA content as is the case for Wnt-signaling components. Additionally, we compared our data to previously published physiological single cell RNA and RiboTag-based RNA sequencing analyses of enteric gliosis using data-mining approaches.

Results

Our descriptive analysis shows that several components of the multidi-mensional regulatory network of the Wnt-signaling pathway are present in the murine ENS. The transport and secretion protein for Wnt-ligands Wntless as well as canonical (Wnt3a and Wnt2b) and non-canonical Wnt-ligands (Wnt5a, Wnt7a, Wnt8b and Wnt11) are detectable within submucosal and myenteric plexus. Further, corresponding Frizzled receptors (Fzd1, Fzd3, Fzd6, and Fzd7) and regulatory signaling mediators like R-Spondin/DKK ligands are present in the ENS of the small and large intestine. Further, data mining approaches revealed, that several Wnt-related molecules are expressed by enteric glial cell clusters and are dynamically regulated during the inflammatory manifestation of enteric gliosis.

Discussion

Our results suggest, that canonical and non-canonical Wnt-signaling has a much broader impact on the mature ENS and its cellular homeostasis in health and inflammation, than previously anticipated.

Transient suppression of Wnt signaling in poor-quality buffalo oocytes improves their developmental competence

Introduction

One of the most evolutionary conserved communication systems, the Wnt signaling pathway is a major gene regulatory pathway that affects the developmental competence of oocytes and regulates most embryonic developmental processes. The present study was undertaken to modulate the canonical Wnt (Wingless/integration) signaling pathway in the poor-quality (colorless cytoplasm after Brilliant Cresyl Blue staining, BCB-) buffalo cumulus-oocyte complexes (COCs) to improve their in vitro maturation (IVM) and embryo production (IVEP) rates.

Methods

The expression of key Wnt pathway genes was initially assessed in the good (blue cytoplasm after Brilliant Cresyl Blue staining, BCB+) and poor quality (BCB-) buffalo COCs to establish a differential activity of the Wnt pathway. The BCB- COCs were supplemented with the Wnt pathway inhibitor, Dickkopf-related protein 1 (DKK1) and later subjected to IVM and IVEP along with the BCB+ and BCB- controls. The cumulus expansion index (CEI), rate of nuclear maturation (mean percentage of oocytes in the MII stage) and embryo production, and the expression of developmentally important genes were evaluated to assess the effect of Wnt pathway inhibition on the development competence of these poor-quality oocytes.

Results

The Wnt pathway genes exhibited a significantly higher expression (p < 0.05) in the poor-quality BCB- oocytes compared to the good-quality BCB+ oocytes during the early maturation stages. The supplementation of BCB- COCs with 100 ng/mL DKK1 effectively inhibited the expression of the key mediators of the Wnt pathway (β-catenin and dishevelled homolog 1, DVL1). DKK1 supplemented BCB- COCs exhibited significantly improved cytoplasmic and nuclear maturation indices, development rates and significantly elevated expression (p < 0.05) of genes implicated in germinal vesicle breakdown (GVBD) and embryonic genome activation (EGA) vis-à-vis BCB- control COCs.

Conclusion

These data indicate that inhibition of the Wnt pathway during the initial course of oocyte maturation can improve the development competence of poor-quality buffalo oocytes.

Sex, hormones and cerebrovascular function: from development to disorder

Proper cerebrovascular development and neurogliovascular unit assembly are essential for brain growth and function throughout life, ensuring the continuous supply of nutrients and oxygen. This involves crucial events during pre- and postnatal stages through key pathways, including vascular endothelial growth factor (VEGF) and Wnt signaling. These pathways are pivotal for brain vascular growth, expansion, and blood-brain barrier (BBB) maturation. Interestingly, during fetal and neonatal life, cerebrovascular formation coincides with the early peak activity of the hypothalamic-pituitary-gonadal axis, supporting the idea of sex hormonal influence on cerebrovascular development and barriergenesis.Sex hormonal dysregulation in early development has been implicated in neurodevelopmental disorders with highly sexually dimorphic features, such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Both disorders show higher prevalence in men, with varying symptoms between sexes, with boys exhibiting more externalizing behaviors, such as aggressivity or hyperactivity, and girls displaying higher internalizing behaviors, including anxiety, depression, or attention disorders. Indeed, ASD and ADHD are linked to high prenatal testosterone exposure and reduced aromatase expression, potentially explaining sex differences in prevalence and symptomatology. In line with this, high estrogen levels seem to attenuate ADHD symptoms. At the cerebrovascular level, sex- and region-specific variations of cerebral blood flow perfusion have been reported in both conditions, indicating an impact of gonadal hormones on the brain vascular system, disrupting its ability to respond to neuronal demands.This review aims to provide an overview of the existing knowledge concerning the impact of sex hormones on cerebrovascular formation and maturation, as well as the onset of neurodevelopmental disorders. Here, we explore the concept of gonadal hormone interactions with brain vascular and BBB development to function, with a particular focus on the modulation of VEGF and Wnt signaling. We outline how these pathways may be involved in the underpinnings of ASD and ADHD. Outstanding questions and potential avenues for future research are highlighted, as uncovering sex-specific physiological and pathological aspects of brain vascular development might lead to innovative therapeutic approaches in the context of ASD, ADHD and beyond.

Acetylation and deacetylation of histone in adipocyte differentiation and the potential significance in cancer

Adipocytes are derived from pluripotent mesenchymal stem cells and can develop into several cell types including adipocytes, myocytes, chondrocytes, and osteocytes. Adipocyte differentiation is regulated by a variety of transcription factors and signaling pathways. Various epigenetic factors, particularly histone modifications, play key roles in adipocyte differentiation and have indispensable functions in altering chromatin conformation. Histone acetylases and deacetylases participate in the regulation of protein acetylation, mediate transcriptional and post-translational modifications, and directly acetylate or deacetylate various transcription factors and regulatory proteins. The adipocyte differentiation of stem cells plays a key role in various metabolic diseases. Cancer stem cells(CSCs) play an important function in cancer metastasis, recurrence, and drug resistance, and have the characteristics of stem cells. They are expressed in various cell lineages, including adipocytes. Recent studies have shown that cancer stem cells that undergo epithelial-mesenchymal transformation can undergo adipocytic differentiation, thereby reducing the degree of malignancy. This opens up new possibilities for cancer treatment. This review summarizes the regulation of acetylation during adipocyte differentiation, involving the functions of histone acetylating and deacetylating enzymes as well as non-histone acetylation modifications. Mechanistic studies on adipogenesis and acetylation during the differentiation of cancer cells into a benign cell phenotype may help identify new targets for cancer treatment.

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.

Genetic inactivation of β-catenin is salubrious, whereas its activation is deleterious in desmoplakin cardiomyopathy

AIMS

Mutations in the DSP gene encoding desmoplakin, a constituent of the desmosomes at the intercalated discs (IDs), cause a phenotype that spans arrhythmogenic cardiomyopathy (ACM) and dilated cardiomyopathy. It is typically characterized by biventricular enlargement and dysfunction, myocardial fibrosis, cell death, and arrhythmias. The canonical wingless-related integration (cWNT)/β-catenin pathway is implicated in the pathogenesis of ACM. The β-catenin is an indispensable co-transcriptional regulator of the cWNT pathway and a member of the IDs. We genetically inactivated or activated β-catenin to determine its role in the pathogenesis of desmoplakin cardiomyopathy.

METHODS AND RESULTS

The Dsp gene was conditionally deleted in the 2-week-old post-natal cardiac myocytes using tamoxifen-inducible MerCreMer mice (Myh6-McmTam:DspF/F). The cWNT/β-catenin pathway was markedly dysregulated in the Myh6-McmTam:DspF/F cardiac myocytes, as indicated by a concomitant increase in the expression of cWNT/β-catenin target genes, isoforms of its key co-effectors, and the inhibitors of the pathway. The β-catenin was inactivated or activated upon inducible deletion of its transcriptional or degron domain, respectively, in the Myh6-McmTam:DspF/F cardiac myocytes. Genetic inactivation of β-catenin in the Myh6-McmTam:DspF/F mice prolonged survival, improved cardiac function, reduced cardiac arrhythmias, and attenuated myocardial fibrosis, and cell death caused by apoptosis, necroptosis, and pyroptosis, i.e. PANoptosis. In contrast, activation of β-catenin had the opposite effects. The deleterious and the salubrious effects were independent of changes in the expression levels of the cWNT target genes and were associated with changes in several molecular and biological pathways, including cell death programmes.

CONCLUSION

The cWNT/β-catenin was markedly dysregulated in the cardiac myocytes in a mouse model of desmoplakin cardiomyopathy. Inactivation of β-catenin attenuated, whereas its activation aggravated the phenotype, through multiple molecular pathways, independent of the cWNT transcriptional activity. Thus, suppression but not activation of β-catenin might be beneficial in desmoplakin cardiomyopathy.

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.

Induced pluripotent stem cells modulate the Wnt pathway in the bleomycin-induced model of idiopathic pulmonary fibrosis

BACKGROUND

The Wnt signaling pathway has been implicated in the pathogenesis of fibrotic disorders and malignancies. Hence, we aimed to assess the potential of the induced pluripotent stem cells (IPS) in modulating the expression of the cardinal genes of the Wnt pathway in a mouse model of idiopathic pulmonary fibrosis (IPF).

METHODS

C57Bl/6 mice were randomly divided into three groups of Control, Bleomycin (BLM), and BLM + IPS; the BLM mice received intratracheal instillation of bleomycin, BLM + IPS mice received tail vein injection of IPS cells 48 h post instillation of the BLM; The Control group received Phosphate-buffered saline instead. After 3 weeks, the mice were sacrificed and Histologic assessments including hydroxy proline assay, Hematoxylin and Eosin, and Masson-trichrome staining were performed. The expression of the genes for Wnt, β-Catenin, Lef, Dkk1, and Bmp4 was assessed utilizing specific primers and SYBR green master mix.

RESULTS

Histologic assessments revealed that the fibrotic lesions and inflammation were significantly alleviated in the BLM + IPS group. Besides, the gene expression analyses demonstrated the upregulation of Wnt, β-Catenin, and LEF along with the significant downregulation of the Bmp4 and DKK1 in response to bleomycin treatment; subsequently, it was found that the treatment of the IPF mice with IPS cells results in the downregulation of the Wnt, β-Catenin, and Lef, as well as upregulation of the Dkk1, but not the Bmp4 gene (P values < 0.05).

CONCLUSION

The current study highlights the therapeutic potential of the IPS cells on the IPF mouse model in terms of regulating the aberrant expression of the factors contributing to the Wnt signaling pathway.

Sfrp4 is required to maintain Ctsk-lineage periosteal stem cell niche function

We have previously reported that the cortical bone thinning seen in mice lacking the Wnt signaling antagonist Sfrp4 is due in part to impaired periosteal apposition. The periosteum contains cells which function as a reservoir of stem cells and contribute to cortical bone expansion, homeostasis, and repair. However, the local or paracrine factors that govern stem cells within the periosteal niche remain elusive. Cathepsin K (Ctsk), together with additional stem cell surface markers, marks a subset of periosteal stem cells (PSCs) which possess self-renewal ability and inducible multipotency. Sfrp4 is expressed in periosteal Ctsk-lineage cells, and Sfrp4 global deletion decreases the pool of PSCs, impairs their clonal multipotency for differentiation into osteoblasts and chondrocytes and formation of bone organoids. Bulk RNA sequencing analysis of Ctsk-lineage PSCs demonstrated that Sfrp4 deletion down-regulates signaling pathways associated with skeletal development, positive regulation of bone mineralization, and wound healing. Supporting these findings, Sfrp4 deletion hampers the periosteal response to bone injury and impairs Ctsk-lineage periosteal cell recruitment. Ctsk-lineage PSCs express the PTH receptor and PTH treatment increases the % of PSCs, a response not seen in the absence of Sfrp4. Importantly, in the absence of Sfrp4, PTH-dependent increase in cortical thickness and periosteal bone formation is markedly impaired. Thus, this study provides insights into the regulation of a specific population of periosteal cells by a secreted local factor, and shows a central role for Sfrp4 in the regulation of Ctsk-lineage periosteal stem cell differentiation and function.

RNF2 regulates Wnt/ß-catenin signaling via TCF7L1 destabilization

The Wnt signaling pathway is a crucial regulator of various biological processes, such as development and cancer. The downstream transcription factors in this pathway play a vital role in determining the threshold for signaling induction and the length of the response, which vary depending on the biological context. Among the four transcription factors involved in canonical Wnt/ß-catenin signaling, TCF7L1 is known to possess an inhibitory function; however, the underlying regulatory mechanism remains unclear. In this study, we identified the E3 ligase, RNF2, as a novel positive regulator of the Wnt pathway. Here, we demonstrate that RNF2 promotes the degradation of TCF7L1 through its ubiquitination upon activation of Wnt signaling. Loss-of-function studies have shown that RNF2 consistently destabilizes nuclear TCF7L1 and is required for proper Wnt target gene transcription in response to Wnt activation. Furthermore, our results revealed that RNF2 controls the threshold, persistence, and termination of Wnt signaling by regulating TCF7L1. Overall, our study sheds light on the previously unknown degradation mechanism of TCF7L1 by a specific E3 ligase, RNF2, and provides new insights into the variability in cellular responses to Wnt activation.

The possible role of Wnt/β-catenin signalling in vitiligo treatment

Vitiligo is a common chronic skin disease which has an adverse impact on patients' life. Its pathogenesis is complex, involving autoimmunity and oxidative stress (OS). Autoimmunity leads to the loss of epidermal melanocytes and the formation of the depigmented patches of the disease. Treatment of vitiligo should control the exaggerated immune response to arrest the progress of active disease, and then promote melanocytes to repigmentation. Wnt/β-catenin signalling pathway has been of recent interest in vitiligo. Wnt/β-catenin signalling pathway is downregulated in vitiligo. Upregulation of Wnt/β-catenin signalling possibly control vitiligo autoimmune response by protecting melanocyte from OS damage, inhibiting CD8+ T cell effector cell differentiation and enhancing Treg. Wnt/β-catenin signalling plays a critical role in the melanocyte regeneration by driving the differentiation of melanocyte stem cells (McSCs) into melanocytes. Promoting Wnt/β-catenin signalling can not only arrest the progress of active disease of vitiligo but also promote repigmentation. Some of the main effective therapies for vitiligo are likely to work by activating Wnt/β-catenin signalling. Agents that can enhance the effect of Wnt/β-catenin signalling may become potential candidates for the development of new drugs for vitiligo treatment.

Differential gene expression profiling implicates altered network development in rat postnatal day 4 cortex following 4-Methylimidazole (4-MeI) induced maternal seizures

Compromised maternal health leading to maternal seizures can have adverse effects on the healthy development of offspring. This may be the result of inflammation, hypoxia-ischemia, and altered GABA signaling. The current study examined cortical tissue from F2b (2nd litter of the 2nd generation) postnatal day 4 (PND4) offspring of female Harlan SD rats chronically exposed to the seizuregenic compound, 4-Methylimidazole (0, 750, or 2500 ppm 4-MeI). Maternal seizures were evident only at 2500 ppm 4-MeI. GABA related gene expression as examined by qRT-PCR and whole genome microarray showed no indication of disrupted GABA or glutamatergic signaling. Canonical pathway hierarchical clustering and multi-omics combinatory genomic (CNet) plots of differentially expressed genes (DEG) showed alterations in genes associated with regulatory processes of cell development including neuronal differentiation and synaptogenesis. Functional enrichment analysis showed a similarity of cellular processes across the two exposure groups however, the genes comprising each cluster were primarily unique rather than shared and often showed different directionality. A dose-related induction of cytokine signaling was indicated however, pathways associated with individual cytokine signaling were not elevated, suggesting an alternative involvement of cytokine signaling. Pathways related to growth process and cell signaling showed a negative activation supporting an interpretation of disruption or delay in developmental processes at the 2500 ppm 4-MeI exposure level with maternal seizures. Thus, while GABA signaling was not altered as has been observed with maternal seizures, the pattern of DEG suggested a potential for alteration in neuronal network formation.

Dickkopf-Related Protein 1 (DKK-1) as a Possible Link between Bone Erosions and Increased Carotid Intima-Media Thickness in Psoriatic Arthritis: An Ultrasound Study

Psoriatic arthritis (PsA) is a heterogenous systemic inflammatory disorder that affects peripheral joints and skin, but also causes inflammation at entheseal sites, digits (dactylitis) and the axial skeleton. Despite considerable advances, our understanding of the pathogenesis and management of PsA is hampered by its complex clinical expression. We enrolled patients who met the ClASsification for Psoriatic Arthritis (CASPAR) criteria for PsA (n = 17), and healthy controls (n = 13). The lipid profile, C-reactive protein (CRP) and Dickkopf-related protein 1 (DKK-1) circulating levels were measured for all subjects. For the patients with PsA, (1) the erosive character of the articular disease was assessed by a musculoskeletal ultrasound and (2) the cardiovascular risk was evaluated using the Systematic Coronary Risk Evaluation (SCORE) chart and the ultrasound measurement of the carotid intima-media thickness. A higher titer of serum DKK-1 was associated with the presence of erosions (p < 0.005) and the cIMT correlated with DKK-1 levels in patients with PsA (r = 0.6356, p = 0.0061). Additionally, we observed a positive correlation between increased cIMT and CRP (r = 0.5186, p = 0.0329). Our results suggest that DKK-1 could be used as an early biomarker for the erosive character of the articular disease and for the assessment of the cardiovascular risk in PsA patients.

Ascorbic acid enhances chondrocyte differentiation of ATDC5 by accelerating insulin receptor signaling

Chondrogenesis is strictly regulated by several factors, including cytokines, hormones, and extracellular matrix proteins. Mouse teratocarcinoma-derived lineage cells, differentiate into chondrocytes in the presence of insulin. Although ascorbic acid promotes chondrogenic differentiation, the detailed regulative mechanisms underlying its role in chondrogenesis remain unclear. Therefore, in this study, we evaluated the effects of ascorbic acid on insulin-induced chondrogenic differentiation of ATDC5 cells and the underlying intracellular signaling. The results revealed that insulin-stimulated collagen deposition, matrix formation, calcification, and expression of chondrogenic differentiation marker genes in ATDC5 cells. This enhancement by insulin was amplified with the addition of ascorbic acid. Molecular analysis revealed that the activation of insulin-induced phosphoinositide 3-kinase (PI3K)/Akt signaling was enhanced in the presence of ascorbic acid. In contrast, Wnt/β-catenin signaling was suppressed during chondrocyte differentiation via upregulation of the Wnt agonist, secreted Frizzled-related protein 1 (sFRP-1) and 3 (sFRP-3). Notably, ascorbic acid upregulated the expression of insulin receptors and their substrates (IRS-1 and IRS-2). Furthermore, ascorbic acid reversed the suppression of IRS-1 and IRS-2 protein by insulin. These results indicate that ascorbic acid positively regulates the chondrogenic differentiation of ATDC5 cells via enhancement of insulin signaling. Our findings provide a substantial basis for further elucidation of the regulatory mechanisms of chondrocyte differentiation and the pathophysiology of OA, thus aiding in development of effective treatment strategies.

The WNT/β-catenin system in chronic kidney disease-mineral bone disorder syndrome

BACKGROUND

The WNT/β-catenin system is an evolutionarily conserved signaling pathway that plays a crucial role in morphogenesis and cell tissue formation during embryogenesis. Although usually suppressed in adulthood, it can be reactivated during organ damage and regeneration. Transient activation of the WNT/β-catenin pathway stimulates tissue regeneration after acute kidney injury, while persistent (uncontrolled) activation can promote the development of chronic kidney disease (CKD). CKD-MBD is a clinical syndrome that develops with systemic mineral and bone metabolism disorders caused by CKD, characterized by abnormal bone mineral metabolism and/or extraosseous calcification, as well as cardiovascular disease associated with CKD, including vascular stiffness and calcification.

OBJECTIVE

This paper aims to comprehensively review the WNT/β-catenin signaling pathway in relation to CKD-MBD, focusing on its components, regulatory molecules, and regulatory mechanisms. Additionally, this review highlights the challenges and opportunities for using small molecular compounds to target the WNT/β-catenin signaling pathway in CKD-MBD therapy.

METHODS

We conducted a comprehensive literature review using various scientific databases, including PubMed, Scopus, and Web of Science, to identify relevant articles. We searched for articles that discussed the WNT/β-catenin signaling pathway, CKD-MBD, and their relationship. We also reviewed articles that discussed the components of the WNT/β-catenin signaling pathway, its regulatory molecules, and regulatory mechanisms.

RESULTS

The WNT/β-catenin signaling pathway plays a crucial role in CKD-MBD by promoting vascular calcification and bone mineral metabolism disorders. The pathway's components include WNT ligands, Frizzled receptors, and LRP5/6 co-receptors, which initiate downstream signaling cascades leading to the activation of β-catenin. Several regulatory molecules, including GSK-3β, APC, and Axin, modulate β-catenin activation. The WNT/β-catenin signaling pathway also interacts with other signaling pathways, such as the BMP pathway, to regulate CKD-MBD.

CONCLUSIONS

The WNT/β-catenin signaling pathway is a potential therapeutic target for CKD-MBD. Small molecular compounds that target the components or regulatory molecules of the pathway may provide a promising approach to treat CKD-MBD. However, more research is needed to identify safe and effective compounds and to determine the optimal dosages and treatment regimens.

The odontoblastic differentiation of dental mesenchymal stem cells: molecular regulation mechanism and related genetic syndromes

Dental mesenchymal stem cells (DMSCs) are multipotent progenitor cells that can differentiate into multiple lineages including odontoblasts, osteoblasts, chondrocytes, neural cells, myocytes, cardiomyocytes, adipocytes, endothelial cells, melanocytes, and hepatocytes. Odontoblastic differentiation of DMSCs is pivotal in dentinogenesis, a delicate and dynamic process regulated at the molecular level by signaling pathways, transcription factors, and posttranscriptional and epigenetic regulation. Mutations or dysregulation of related genes may contribute to genetic diseases with dentin defects caused by impaired odontoblastic differentiation, including tricho-dento-osseous (TDO) syndrome, X-linked hypophosphatemic rickets (XLH), Raine syndrome (RS), hypophosphatasia (HPP), Schimke immuno-osseous dysplasia (SIOD), and Elsahy-Waters syndrome (EWS). Herein, recent progress in the molecular regulation of the odontoblastic differentiation of DMSCs is summarized. In addition, genetic syndromes associated with disorders of odontoblastic differentiation of DMSCs are discussed. An improved understanding of the molecular regulation and related genetic syndromes may help clinicians better understand the etiology and pathogenesis of dentin lesions in systematic diseases and identify novel treatment targets.

Xenopus cell-free extracts and their applications in cell biology study

Xenopus has proven to be a remarkably versatile model organism in the realm of biological research for numerous years, owing to its straightforward maintenance in laboratory settings and its abundant provision of ample-sized oocytes, eggs, and embryos. The cell cycle of these oocytes, eggs, and early embryos exhibits synchrony, and extracts derived from these cells serve various research purposes. Many fundamental concepts in biochemistry, cell biology, and development have been elucidated through the use of cell-free extracts derived from Xenopus cells. Over the past few decades, a wide array of cell-free extracts has been prepared from oocytes, eggs, and early embryos of different Xenopus species at varying cell cycle stages. Each of these extracts possesses distinct characteristics. This review provides a concise overview of the Xenopus species employed in laboratory research, the diverse types of cell-free extracts available, and their respective properties. Furthermore, this review delves into the extensive investigation of spindle assembly in Xenopus egg extracts, underscoring the versatility and potency of these cell-free systems in the realm of cell biology.

Transcription factor EB (TFEB) improves ventricular remodeling after myocardial infarction by inhibiting Wnt/β-catenin signaling pathway

Background

Adverse left ventricular remodeling after myocardial infarction (MI) compromises cardiac function and increases heart failure risk. Until now, comprehension of the role transcription factor EB (TFEB) plays after MI is limited.

Objectives

The purpose of this study was to describe the effects of TFEB on fibroblasts differentiation and extracellular matrix expression after MI.

Methods

AAV9 (adeno-associated virus) mediated up- and down-regulated TFEB expressions were generated in C57BL/6 mice two weeks before the MI modeling. Echocardiography, Masson, Sirius red staining immunofluorescence, and wheat germ agglutinin staining were performed at 3 days, and 1, 2, and 4 weeks after MI modeling. Fibroblasts collected from SD neonatal rats were transfected by adenovirus and siRNA, and cell counting kit-8 (CCK8), immunofluorescence, wound healing and Transwell assay were conducted. Myocardial fibrosis-related proteins were identified by Western blot. PNU-74654 (100 ng/mL) was used for 12 hours to inhibit β-catenin-TCF/LEF1 complex.

Results

The up-regulation of TFEB resulted in reduced fibroblasts proliferation and its differentiation into myofibroblasts in vitro studies. A significant up-regulation of EF and down-regulation of myocyte area was shown in the AAV9-TFEB group. Meanwhile, decreased protein level of α-SMA and collagen I were observed in vitro study. TFEB didn't affect the concentration of β-catenin. Inhibition of TFEB, which promoted cell migration, proliferation and collagen I expression, was counteracted by PNU-74654.

Conclusions

TFEB demonstrated potential in restraining fibrosis after MI by inhibiting the Wnt/β-catenin signaling pathway.

A WNT4- and DKK3-driven canonical to noncanonical Wnt signaling switch controls multiciliogenesis

Multiciliated cells contain hundreds of cilia whose directional movement powers the mucociliary clearance of the airways, a vital host defense mechanism. Multiciliated cell specification requires canonical Wnt signaling, which then must be turned off. Next, ciliogenesis and polarized ciliary orientation are regulated by noncanonical Wnt/planar cell polarity (Wnt/PCP) signaling. The mechanistic relationship between the Wnt pathways is unknown. We show that DKK3, a secreted canonical Wnt regulator and WNT4, a noncanonical Wnt ligand act together to facilitate a canonical to noncanonical Wnt signaling switch during multiciliated cell formation. In primary human airway epithelial cells, DKK3 and WNT4 CRISPR knockout blocks, whereas ectopic expression promotes, multiciliated cell formation by inhibiting canonical Wnt signaling. Wnt4 and Dkk3 single-knockout mice also display defective ciliated cells. DKK3 and WNT4 are co-secreted from basal stem cells and act directly on multiciliated cells via KREMEN1 and FZD6, respectively. We provide a novel mechanism that links specification to cilium biogenesis and polarization for proper multiciliated cell formation.

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.