Wnt Signaling Cascade Research Articles

Deletion of Pr72 causes cardiac developmental defects in Zebrafish.

The alpha regulator subunit B'' of protein phosphatase 2 (PPP2R3A), a regulatory subunit of protein phosphatase 2A (PP2A), was reported to present a special subcellular localization in cardiomyocytes and elevate in non-ischemia failing hearts. PPP2R3A has two transcriptions PR72 and PR130. PR72 acts as a negative regulator of the Wnt signaling cascade, while the Wnt signaling cascade plays a pivotal role in cardiac development. And PR130 was found to be involved in cardiac development of zebrafish in our previous study. Thus, to investigate the function of PR72 in heart, two stable pr72 knockout (KO) zebrafish lines were generated using Transcription Activator-Like Effector Nuclease (TALEN) technology. Homozygous pr72 KO fish struggled to survive to adulthood and exhibited cardiac developmental defects, including enlarged ventricular chambers, reduced cardiomyocytes and decreased cardiac function. And the defective sarcomere ultrastructure that affected mitochondria, I bands, Z lines, and intercalated disks was also observed. Furthermore, the abnormal heart looping was detected in mutants which could be rescued by injection with wild type pr72 mRNA. Additionally, it was found that Wnt effectors were elevated in mutants. Those indicated that deletion of pr72 in zebrafish interrupted cardiac development, probably through activation of the Wnt pathway.

Oligodendrocytes Development and Wnt Signaling Pathway

Oligodendrocytes are specialized glial cell in central nervous system (CNS) responsible for the formation of myelin sheath around the axon. Oligodendrocyte proliferation and differentiation is regulated by Wnt signaling pathway, at various stages. However, different study groups have described controversial conclusions about the effect of Wnt on oligodendrocytes precursor cells (OPCs) development. Initially it has been proposed that Wnt pathway negatively regulates the OPCs proliferation and differentiation but recently some studies have described that Wnt promotes the differentiation of OPCs. After carefully reviewing the literature, we believe that Wnt play multiple roles in OPCs differentiation and its function is time (stage) and dose sensitive. Low to moderate activation of Wnt promotes OPC development, while too much or too low is inhibitory. Current evidences also suggested that in early developmental stages, Wnt inhibits the OPCs formation from neural progenitors and differentiation into immature oligodendrocytes. But in late stages Wnt plays promoting role in differentiation and maturation of oligodendrocytes. This review summarized the updated information regarding the critical role of Wnt signaling cascade in proliferation and differentiation of OPCs.

Interleukin-1 Signaling Mediates Obesity-Promoted Elevations in Inflammatory Cytokines, Wnt Activation, and Epithelial Proliferation in the Mouse Colon.

Obesity is a prominent risk factor for colorectal cancer (CRC). One mechanism by which obesity promotes the development of CRC is by generating a chronic, low-grade state of colonic inflammation. Interleukin-1β (IL-1β), a proinflammatory cytokine often elevated in obesity, is known to activate several procarcinogenic signaling pathways that are implicated in colonic carcinogenesis. We therefore sought to define the role of IL-1β in mediating some of the early biochemical and molecular events leading up to obesity-promoted CRC. Twenty-five wild-type (WT) C57BL/6J mice and 24 lacking a functional IL-1 receptor (IL1R-/-) were each randomized to either low-fat or high-fat diets, resulting in lean and obese mice. Compared to WT lean controls, WT obese mice displayed 30%-80% greater concentrations of IL-1β and tumor necrosis factor-α (TNF-α) in the colonic mucosa (IL-1β: P = 0.04; TNF-α: P < 0.05), activation of the Wnt signaling cascade [evidenced by a 2-fold increase in colonic crypt cells displaying intranuclear β-catenin (P < 0.03)], and a significant expansion of the proliferation zone of the colonic crypt (P < 0.04). These obesity-induced alterations in colonic cytokines, Wnt signaling, and proliferation were absent in the obese IL1R-/- mice. In the absence of IL-1 signaling, obesity-induced elevations of colonic IL-1β, TNF-α, Wnt activation, and enhanced epithelial proliferation no longer occur. These observations underscore the important mechanistic roles that IL-1 signaling appears to play in mediating the procancerous effects of obesity in the colon, thereby identifying a potential target for future strategies aimed at chemoprevention.

Contribution of the Wnt Pathway to Defining Biology of Glioblastoma.

Glioblastoma (GBM), a highly lethal brain tumor, has been comprehensively characterized at the molecular level with the identification of several potential treatment targets. Data concerning the Wnt pathway are relatively sparse, but apparently very important in defining several aspects of tumor biology. The Wnt ligands are involved in numerous basic biological processes including regulation of embryogenic development, cell fate determination, and organogenesis, but growing amount of data also support the roles of Wnt pathways in the formation of many tumors, including gliomas. Two main Wnt pathways are distinguished: the canonical (β-catenin) and non-canonical (planar cell polarity, Wnt/Ca2+) routes. Wnt signaling regulates glioma stem cells (GSCs), thereby defining invasive potential, recurrence, and treatment resistance of GBM. Some observations suggest that the Wnt pathways are differentially active in molecular subtypes of this tumor, thereby may also guide prognostication and novel therapeutic decisions. In this review, we highlight main elements and biological relevance of the Wnt pathways, primarily focusing on the pathogenesis and subtypes of GBM. Finally, we briefly summarize newer therapeutic strategies targeting networks of the Wnt signaling cascades and their molecular associates that appear to be marked contributors to GBM aggressiveness.

A Notch in the joint that exacerbates osteoarthritis.

Tight regulation of signalling cascades is vital for the correct development and function of bones and joints. A new study suggests that Notch signalling might join the likes of the transforming growth factor superfamily and Wnt signalling cascades as having an important function in joint homeostasis and disease.

Clinically Relevant Doses of Sclerostin Antibody Do Not Induce Osteonecrosis of the Jaw (ONJ) in Rats with Experimental Periodontitis.

Antiresorptive agents, such as bisphosphonates and denosumab, are frequently used for the management of osteoporosis. Indeed, both medications decrease the risk of osteoporotic fractures; however, these medications are associated with rare but potentially severe side effects, such as osteonecrosis of the jaw (ONJ). ONJ, defined as an area of exposed bone in the maxillofacial region that lasts for 8 weeks, often presents with significant pain and infection and can lead to serious complications. Interestingly, other treatments for osteoporosis have been developed, such as antibodies against the osteocyte-secreted protein, sclerostin. Sclerostin functions to inhibit the Wnt signaling cascade, leading to inhibition of bone formation. In clinical trials, a sclerostin antibody (romosozumab, Amgen Inc., UCB Brussels) increases bone formation and lowers the risk of osteoporotic fractures. However, in conjunction with increased osteoblastic activity, a reduction in bone resorption markers is observed. This antiresorptive effect raises the concern of possible ONJ development in patients treated with sclerostin antibodies. Here, utilizing ligature-induced experimental periodontitis (EP), we evaluated the effects of sclerostin inhibition on the development of ONJ-like lesions in ovariectomized rats. Beginning 8 weeks post-ovariectomy, rats were treated for 22 weeks with weekly injections of vehicle (Veh), 200 μg/kg zoledronic acid (ZA), a potent bisphosphonate at 100-fold the osteoporosis dose, or 5 mg/kg sclerostin antibody (Scl-Ab) at the osteoporotic dose. EP was initiated at week 12 and maintained for the remainder of the study. Scl-Ab treatment transiently increased serum P1NP, a bone formation marker, increased BV/TV, and decreased eroded surfaces in lumbar vertebrae. ZA-treated rats developed histologic features of ONJ, whereas Veh-treated controls did not. Scl-Ab animals lost less periodontal bone in sites with EP. However, these animals presented with no histologic signs of ONJ. In conclusion, sclerostin inhibition enhanced structural bone parameters, without inducing ONJ-like lesions, in ovariectomized rats with EP. © 2018 American Society for Bone and Mineral Research.

The Endosomal Protein CEMIP Links WNT Signaling to MEK1–ERK1/2 Activation in Selumetinib-Resistant Intestinal Organoids

MAPK signaling pathways are constitutively active in colon cancer and also promote acquired resistance to MEK1 inhibition. Here, we demonstrate that BRAFV600E -mutated colorectal cancers acquire resistance to MEK1 inhibition by inducing expression of the scaffold protein CEMIP through a β-catenin- and FRA-1-dependent pathway. CEMIP was found in endosomes and bound MEK1 to sustain ERK1/2 activation in MEK1 inhibitor-resistant BRAFV600E-mutated colorectal cancers. The CEMIP-dependent pathway maintained c-Myc protein levels through ERK1/2 and provided metabolic advantage in resistant cells, potentially by sustaining amino acids synthesis. CEMIP silencing circumvented resistance to MEK1 inhibition, partly, through a decrease of both ERK1/2 signaling and c-Myc. Together, our data identify a cross-talk between Wnt and MAPK signaling cascades, which involves CEMIP. Activation of this pathway promotes survival by potentially regulating levels of specific amino acids via a Myc-associated cascade. Targeting this node may provide a promising avenue for treatment of colon cancers that have acquired resistance to targeted therapies.Significance: MEK1 inhibitor-resistant colorectal cancer relies on the scaffold and endosomal protein CEMIP to maintain ERK1/2 signaling and Myc-driven transcription. Cancer Res; 78(16); 4533-48. ©2018 AACR.

Nuclear receptor/Wnt beta-catenin interactions are regulated via differential CBP/p300 coactivator usage.

Over 400 million years ago, the evolution of vertebrates gave rise to a life cycle in which the organism began to live longer particularly as an adult. To accommodate such a longer lifespan, the organism underwent adaptation, developing a mechanism for long-lived cellular homeostasis. This adaptation required a population of long-lived relatively quiescent somatic stem cells (SSCs) along with a more proliferative differentiated daughter cell population, and was necessary to safeguard the genetic attributes with which SSCs were endowed. Intriguingly, cAMP response element binding protein (CREB)-binding protein (CBP) and E1A-binding protein, 300 kDa (p300), the highly homologous Kat3 coactivators had diverged, through duplication of ancestral Kat3, immediately preceding the evolution of vertebrates, given that both CBP and p300 have been detected in nearly all vertebrates versus non-vertebrates. We now demonstrate that a relatively small, highly evolutionarily conserved, amino terminal 9 amino acid deletion in CBP versus p300, plays a critical role in allowing for both robust maintenance of genomic integrity in stem cells and the initiation of a feed-forward differentiation mechanism by tightly controlling the interaction of the nuclear receptor family with the Wnt signaling cascade in either an antagonistic or synergistic manner.

THE CONTRIBUTION OF SEX-SPECIFIC ASSOCIATIONS IN GENETIC STUDIES OF ALZHEIMER’S DISEASE PATHOLOGY

Women are disproportionately affected by Alzheimer's disease (AD) and more likely to manifest clinical symptoms in the presence of AD neuropathology. Yet, sex differences are often ignored or modeled as a nuisance variable in genetic association studies of AD. We performed comprehensive sex-specific genetic analyses of AD biomarkers and autopsy measures of AD neuropathology to evaluate whether sex-specific genetic effects contribute to AD pathogenesis. First we performed a sex-stratified GWAS in 5,978 participants with autopsy measures of neurofibrillary tangles (Braak staging) and neuritic plaques (CERAD score). Then we used the innovative UTMOST (Unified Test for MOlecular SignaTures) method in 3,119 participants with CSF measures of Aβ42 and total tau to test for sex-specific associations with predicted gene expression. In these participants, gene expression profiles were jointly imputed in 44 tissues available in GTEx. Cross-tissue gene-level association results for 14,709 genes were then constructed using a generalized Berk-Jones test. Bonferroni-corrected significance thresholds for GWAS and UTMOST analyses were α=5.0x10−8 and α=3.4x10−6, respectively. In the GWAS, rs34331204 (intergenic; 7p21.1; MAF=0.07) was associated with presence of tangles in males (β=-0.74, p=9.1x10−9) but not females (β=-0.03, p=0.85). In the UTMOST analysis, we found a female-specific association between predicted expression of KLDR1 and CSF Aβ42 (pmales=0.13; pfemales=2.4x10−6). Male-specific associations were found for predicted expressions of PPP2R1B with CSF Aβ42 (pmales=1.5x10−7; pfemales=0.81) and NOTCH3 with CSF tau (pmales=5.6x10−7; pfemales=0.62). Results highlight how sex differences can enhance our understanding of the molecular basis and genetic architecture of AD. Among females, we identified KLDR1, an inhibitor of natural killer cells. This female-specific role of innate immunity is consistent with our previous findings. Among males, we identified rs34331204, a cis eQTL for BZW2 (BRAINEAC aveALL p=1.9x10−5), which has been implicated in neuronal differentiation. Additionally, we identified NOTCH3 and PPP2R1B, a regulatory subunit of PP2A, which are involved in Notch and Wnt signaling cascades. Combined with our past results, these findings suggest the innate immune pathway may be particularly relevant to AD pathogenesis in females, while the neurogenesis pathway may be particularly relevant in males. Future work will functionally assess these sex-specific candidate genes.

Downregulation of WNT11 is associated with bladder tissue fibrosis in patients with interstitial cystitis/bladder pain syndrome without Hunner lesion

This study assessed the functional role of WNT genes and the association between WNT signalling cascades and fibrosis in interstitial cystitis/bladder pain syndrome (IC/BPS) patients. Twenty-five patients (3 males, 22 females; mean age 59.7 ± 10.9 years), included 7 non-Hunner-type IC (NHIC), 18 Hunner-type IC (HIC), and 5 non-IC (control) groups. The expression of sonic hedgehog, WNT gene family, and genes previously reported as biomarkers for IC/BPS were examined using RT-PCR in biopsy specimens from the mucosa and submucosa layer of the bladder. WNT2B, WNT5A, WNT10A, and WNT11 functions in the urothelium were evaluated by silencing in an HBlEpC cell line. Pelvic Pain and Urgency/Frequency Patient Symptom Scale scores, O’Leary-Sant Symptom and Problem Index scores, and Visual Analogue Scores did not differ between the NHIC and HIC groups. However, HIC patients had significantly shorter symptom duration (30.9 vs 70.8 months, p = 0.046), higher daily urinary frequency (16.1 versus 8.5 times, p = 0.006), and smaller bladder capacity (208.6 versus 361.4 ml, p = 0.006) than NHIC patients. Overall WNT gene expression was lower in NHIC than HIC patients. Bladder epithelial tissues from HIC patients were characterised by the downregulation of WNT11. Silencing of WNT11, WNT2B, WNT5A, and WNT10A in HBlEpCs resulted in fibrotic changes, indicated by fibrotic morphology, increased fibrosis-related gene expression, and nuclear localisation of phosphorylated SMAD2, and increased vimentin and fibronectin levels. Downregulation of WNT11 results in fibrotic changes of bladder epithelial cells and is associated with the pathogenesis and differential diagnosis of NHIC. Decreased expression of WNT11 is a potential biomarker for predicting NHIC.

Hyperhomocysteinemia and hyperandrogenemia share PCSK9-LDLR pathway to disrupt lipid homeostasis in PCOS

Women with polycystic ovary syndrome (PCOS) are at increased risk of cardiovascular diseases (CVD); however, the independent role of PCOS in the incident CVD remains unknown. There are reports that hyperhomocysteinemia (HHcy), a potential cause of CVD, is frequently associated with PCOS. The present study investigates the independent attributes of hyperandrogenemia (HA), the integral associate of PCOS, and HHcy in causing atherogenic dyslipidemia. Twenty-five-day old rats were treated with homocysteine (Hcy) at 50 mg/kg/day dose level for 12 weeks. The HepG2 cell lines transfected with siRNA directed to PCSK9 were challenged with Hcy, homocysteine thiolactone (HTL), testosterone, 5α-dihydroxytestosterone (5α-DHT), or estradiol for 24 h. Rats administered with Hcy developed HHcy and displayed PCOS-like phenotypes with adversely altered lipid homeostasis and attenuated PI3K-AKT and Wnt signalling cascade. Overexpression of steroidogenic acute regulatory protein (StAR) and down-regulated expression of Aromatase together with elevated testosterone level marked the state of HA. In culture, the HepG2 cells responded independently to Hcy, HTL, testosterone, and 5α-DHT by an overt expression of PCSK9 and down-regulated expression of LDLR. The effect was magnified under the combined influence of Hcy and androgen(s). Estradiol, by contrast, exhibited the reverse effect. The findings suggest that HA may independently attribute to an increased cardiovascular risk in PCOS; however, the coexistence of HHcy catalyzes the risk further.

MicroRNA-671-3p inhibits the development of breast cancer: A study based on in vitro experiments, in-house quantitative polymerase chain reaction and bioinformatics analysis.

MicroRNAs (miRNAs or miRs) are highly conserved small noncoding RNA molecules involved in gene regulation. An increasing number of studies have demonstrated that miRNAs act as oncogenes or antioncogenes in various types of cancer, including breast cancer (BC). However, the exact role of miR-671-3p in BC has not yet been reported. In the present study, in vitro experiments were implemented to explore the effects of miR-671-3p on the proliferation and apoptosis of BC cells, and reverse transcription-quantitative polymerase chain reaction was conducted using in-house clinical BC samples to address the expression level and clinical value of miR-671-3p in BC. Simultaneously, miR-671-3p target genes were collected, and subsequent bioinformatics analyses were executed to probe the potential signaling pathway through which miR-671-3p influenced the occurrence and progression of BC. According to the results, the expression level of miR-671-3p was lower in BC tissues compared with that in adjacent non-tumorous tissues (P=0.048), and the area under the curve was 0.697 (95% confidence interval=0.538-0.856), with a sensitivity and specificity of 0.818 and 0.579, respectively. Forced miR-671-3p expression in the BC cell line MDA-MB-231 evidently arrested cell proliferation and induced cell apoptosis. Furthermore, in silico enrichment analyses suggested that miR-671-3p may be involved in the initiation and progression of BC through the targeting of genes associated with the Wnt signaling pathway. In conclusion, the present study findings suggested that miR-671-3p may function as a tumor suppressor in BC by influencing the Wnt signaling cascade, which provides a prospective molecular target for the therapy of BC.

Abstract P139: Association of a Potentially Functional Wnt Pathway Mutation With Carotid Artery Wall Traits in African Ancestry Men

The wingless (Wnt) pathway is known to regulate many human systems, including embryonic development, bone mineralization, and cancer. There is emerging basic research evidence that the Wnt pathway is also involved in angiogenesis, atherosclerosis, and vascular damage repair. However, there have been no studies of the Wnt pathway and cardiovascular disease (CVD) in human populations. In a cohort of Afro-Caribbean men (the Tobago Health Study (THS)), we previously identified a potentially functional coding mutation (Ala64Thr) in the Frizzled-1 ( FZD1 ) gene, which acts as a co-receptor with the low-density lipoprotein receptor protein (LRP) to initiate the Wnt signaling cascade. This mutation has a carrier frequency of ~4% in the THS and additional studies reported in the 1000 genomes project have found similar frequencies in other predominantly West African populations. In order to investigate the phenotypic consequences of this Wnt pathway mutation on subclinical CVD, we measured carotid artery wall traits using B-mode ultrasonography in 64 Ala64Thr mutation carriers and 395 controls from the THS. For this analysis, carotid artery measures of interest included carotid plaque prevalence, and common carotid mean intima-media thickness (IMT), inter-adventitial diameter (IAD), and lumen diameter (LD). We assessed differences in carotid traits by Ala64Thr status using multiple linear regression adjusting for CVD risk factors, including age, BMI, smoking, hypertension, diabetes, alcohol intake, physical activity, and sedentary behavior. Men were aged 64 years and were overweight (BMI: 27.5kg/m 2 ), on average. Prevalence of hypertension and type 2 diabetes is high in this sample (66% and 24%, respectively). Men with Ala64Thr tended to be older and had higher prevalence of hypertension than non-carriers (P&lt;0.05 for both). Carrying the Ala64Thr mutation was associated with significantly wider carotid diameters and, after adjustment for traditional CVD risk factors, mutation carriers had &gt;1/3 of a SD greater LD than non-carriers (P=0.01). The effect magnitude of this mutation was similar for IAD, though not statistically significant (P=0.08). There was no significant difference in carotid IMT or plaque prevalence. While this mutation is not expected to be severely deleterious using in silico prediction software, Ala64 is highly conserved and located in a putative signaling peptide sequence. Carriers of a low frequency FZD1 coding mutation show greater remodeling of the carotid artery compared to non-carriers, suggesting that the Wnt pathway may be involved in vascular changes that occur early in the atherosclerotic disease process.

WNT receptor signalling in lung physiology and pathology.

The WNT signalling cascades have emerged as critical regulators of a wide variety of biological aspects involved in lung development as well as in physiological and pathophysiological processes in the adult lung. WNTs (secreted glycoproteins) interact with various transmembrane receptors and co-receptors to activate signalling pathways that regulate transcriptional as well as non-transcriptional responses within cells. In physiological conditions, the majority of WNT receptors and co-receptors can be detected in the adult lung. However, dysregulation of WNT signalling pathways contributes to the development and progression of chronic lung pathologies, including idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and lung cancer. The interaction between a WNT and the (co-)receptor(s) present at the cell surface is the initial step in transducing an extracellular signal into an intracellular response. This proximal event in WNT signal transduction with (cell-specific) ligand-receptor interactions is of great interest as a potential target for pharmacological intervention. In this review we highlight the diverse expression of various WNT receptors and co-receptors in the aforementioned chronic lung diseases and discuss the currently available biologicals and pharmacological tools to modify proximal WNT signalling.

Intermedin promotes hepatocellular carcinoma cell proliferation through the classical Wnt signaling pathway.

The proliferative activity of hepatic carcinoma cells is directly associated with tumorigenesis, tumor development, metastasis and invasion. A variety of cytokines and peptides serve important roles in the development of hepatic carcinoma. The aim of the present study was to examine the effect of intermedin (IMD) on hepatic carcinoma cell proliferation and its mechanism of action. HepG2 hepatic carcinoma cell lines were treated with human recombinant IMD1-53 and its receptor antagonist IMD17-47. Cell proliferation was detected using a Cell Counting kit-8. The activation of the classical Wnt signaling pathway was demonstrated by the ratio of TOPflash:FOPflash luciferase activity. The expression of c-Myc and cyclin D1 downstream of the Wnt signaling pathway were detected using reverse transcription-quantitative polymerase chain reaction analysis. It was demonstrated that IMD may promote the proliferation of HepG2 cells in a time-dependent manner, and that the IMD receptor antagonist IMD17-47 could eliminate this promotion. IMD may activate classical Wnt signaling pathway transcriptional activity and the mRNA levels of certain downstream target genes. Furthermore, blocking of the Wnt signaling pathway may inhibit IMD-induced HepG2 cell proliferation to a certain extent. IMD may promote hepatic carcinoma cell proliferation by binding with receptor antagonist IMD17-47 and activating the Wnt signaling cascade, thus providing a novel avenue for the treatment of hepatic carcinoma.

ERAD‐dependent control of the Wnt secretory factor Evi

Active regulation of protein abundance is an essential strategy to modulate cellular signaling pathways. Within the Wnt signaling cascade, regulated degradation of β‐catenin by the ubiquitin‐proteasome system (UPS) affects the outcome of canonical Wnt signaling. Here, we found that abundance of the Wnt cargo receptor Evi (Wls/GPR177), which is required for Wnt protein secretion, is also regulated by the UPS through endoplasmic reticulum (ER)‐associated degradation (ERAD). In the absence of Wnt ligands, Evi is ubiquitinated and targeted for ERAD in a VCP‐dependent manner. Ubiquitination of Evi involves the E2‐conjugating enzyme UBE2J2 and the E3‐ligase CGRRF1. Furthermore, we show that a triaging complex of Porcn and VCP determines whether Evi enters the secretory or the ERAD pathway. In this way, ERAD‐dependent control of Evi availability impacts the scale of Wnt protein secretion by adjusting the amount of Evi to meet the requirement of Wnt protein export. As Wnt and Evi protein levels are often dysregulated in cancer, targeting regulatory ERAD components might be a useful approach for therapeutic interventions.

RNA sequencing identifies gene regulatory networks controlling extracellular matrix synthesis in intervertebral disk tissues.

this investigation provides important data on extracellular matrix gene regulatory networks in disk tissues. This information can be used to optimize pharmacologic, stem cell, and tissue engineering strategies for regeneration of the intervertebral disk and the treatment of back pain. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1356-1369, 2018.

MicroRNA Expression Profiling in Psoriatic Arthritis.

Background Psoriatic arthritis (PsA) is an inflammatory arthritis, characterized by bone erosions and new bone formation. MicroRNAs (miRNAs) are key regulators of the immune responses. Differential expression of miRNAs has been reported in several inflammatory autoimmune diseases; however, their role in PsA is not fully elucidated. We aimed to identify miRNA expression signatures associated with PsA and to investigate their potential implication in the disease pathogenesis. Methods miRNA microarray was performed in blood cells of PsA patients and healthy controls. miRNA pathway analyses were performed and the global miRNA profiling was combined with transcriptome data in PsA. Deregulation of selected miRNAs was validated by real-time PCR. Results We identified specific miRNA signatures associated with PsA patients with active disease. These miRNAs target pathways relevant in PsA, such as TNF, MAPK, and WNT signaling cascades. Network analysis revealed several miRNAs regulating highly connected genes within the PsA transcriptome. miR-126-3p was the most downregulated miRNA in active patients. Noteworthy, miR-126 overexpression induced a decreased expression of genes implicated in PsA. Conclusions This study sheds light on some epigenetic aspects of PsA identifying specific miRNAs, which may represent promising candidates as biomarkers and/or for the design of novel therapeutic strategies in PsA.

CCAT1 stimulation of the symmetric division of NSCLC stem cells through activation of the Wnt signalling cascade.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortalities worldwide, yet this condition remains a poorly understood malignancy, and the subgroup of cancer stem cells (CSCs) leading to therapeutic resistance and adverse prognosis have not been well studied. CSCs frequently undergo symmetric division, which facilitates expansion of the stem cell pool, contributing to long-term relapse and therapy failure. CCAT1 could act as a miRNA sponge to influence downstream genes; however, its roles in NSCLC stem cell are unclear. We first identified activation of Wnt signalling in NSCLC. Analysis of the clinical data from a public database showed a significant decrease of the Wnt signalling repressor Let-7c. Using biological and informatics analyses, we hypothesized that CCAT1 stimulated the main factors of the Wnt signalling pathway, of which the three most deregulated genes were further confirmed by western blotting. Axitinib, a Wnt signalling inhibitor, effectively stimulated asymmetric division, similar to Let-7c. CCAT1 inhibition decreased the ratio of symmetric division of stem cells, and both Let-7c and Axitinib significantly abolished CCAT1 induction of symmetric division by inhibiting Wnt signalling. Restoration of Let-7c blocked the CCAT1 effects, forming the CCAT1/Let-7c/Wnt regulatory axis to control the division of lung cancer stem cells. Stimulation of stem cells to divide asymmetrically by delivering Let-7c or suppressive Axitinib could represent prospective strategies for curing lung cancer patients.

Wnt Signaling in Skeletal Muscle Development and Regeneration.

Wnt is a family of signaling molecules involved in embryogenesis, adult tissue repair, and cancer. They activate canonical and noncanonical Wnt signaling cascades in target cells. Several studies, within the last decades, showed that several Wnt ligands are involved in myogenesis and both canonical and noncanonical Wnt pathways regulate muscle formation and the maintenance of adult tissue homeostasis. In this review, we provide a comprehensive overview of the roles of Wnt signaling during muscle development and an updated description of Wnt functions during muscle repair. Lastly, we discuss the crosstalk between Wnt and TGFβ signaling pathways in skeletal muscle.