HIF2 Regulates Intestinal Wnt5a Expression

Radiation therapy for abdominal tumors is challenging because the small intestine is exquisitely radiosensitive. Unfortunately, there are no FDA-approved therapies to prevent or mitigate GI radiotoxicity. The EGLN protein family are oxygen sensors that regulate cell survival and metabolism through the degradation of hypoxia-inducible factors (HIFs). Our group has previously shown that stabilization of HIF2 through genetic deletion or pharmacologic inhibition of the EGLNs mitigates and protects against GI radiotoxicity in mice by improving intestinal crypt stem cell survival. Here we aimed to elucidate the molecular mechanisms by which HIF2 confers GI radioprotection. We developed duodenal organoids from mice, transiently overexpressed non-degradable HIF2, and performed bulk RNA sequencing. Interestingly, HIF2 upregulated known radiation modulators and genes involved in GI homeostasis, including Wnt5a. Non-canonical Wnt5a signaling has been shown by other groups to improve intestinal crypt regeneration in response to injury. Here we show that HIF2 drives Wnt5a expression in multiple duodenal organoid models. Luciferase reporter assays performed in human cells showed that HIF2 directly activates the WNT5A promoter via a hypoxia response element. We then evaluated crypt regeneration using spheroid formation assays. Duodenal organoids that were pre-treated with recombinant Wnt5a had a higher cryptogenic capacity after irradiation, compared to vehicle-treated organoids. Conversely, we found that Wnt5a knockout decreased the cryptogenic potential of intestinal stem cells following irradiation. Treatment with recombinant Wnt5a prior to irradiation rescued the cryptogenic capacity of Wnt5a knockout organoids, indicating that Wnt5a is necessary and sufficient for duodenal radioprotection. Taken together, our results suggest that HIF2 radioprotects the GI tract by inducing Wnt5a expression.

Noncanonical Wnt5a/JNK Signaling Contributes to the Development of D-Gal/LPS-Induced Acute Liver Failure

Acute liver failure (ALF) is a deadly clinical disorder with few effective treatments and unclear pathogenesis. In our previous study, we demonstrated that aberrant Wnt5a expression was involved in acute on chronic liver failure. However, the role of Wnt5a in ALF is unknown. We investigated the expression of Wnt5a and its downstream signaling of c-jun N-terminal kinase (JNK) in a mouse model of ALF established by co-injection of D-galactosamine (D-Gal) and lipopolysaccharide (LPS) in C57BL/6 mice. We also investigated the role of Box5, a Wnt5a antagonist in vivo. Moreover, the effect of Wnt5a/JNK signaling on downstream inflammatory cytokines expression, phagocytosis and migration in THP-1 macrophages was studied in vitro. Aberrant Wnt5a expression and JNK activation were detected in D-Gal/LPS-induced ALF mice. Box5 pretreatment reversed JNK activation, and eventually decreased the mortality rate of D-Gal/LPS-treated mice with reduced hepatic necrosis and apoptosis, serum ALT and AST levels, and liver inflammatory cytokines expression, although the last was not significant. We further demonstrated that recombined Wnt5a (rWnt5a) induced tumor necrosis α (TNF-α) and Interleukin-6 (IL-6) mRNA expression, and increased the phagocytosis ability of THP-1 macrophages in a JNK-dependent manner, which could be restored by Box5. In addition, rWnt5a-induced migration of THP-1 macrophages was also turned by Box5. Our findings suggested that Wnt5a/JNK signaling play important role in the development of ALF, and Box5 could have particular hepatoprotecive effects in ALF.

Clinical Importance of Wnt5a in the Pathogenesis of Colorectal Cancer

Wnt5a is one of the potent signaling molecules that initiates responses involved in cancer through activation of both canonical and noncanonical signaling cascades. Wnt5a both directly and indirectly triggers cancer-associated signaling pathways based on the cancer type. In colorectal cancer (CRC), altering Wnt5a expression can influence several cellular processes of tumor cells, including proliferation, differentiation, migration, invasion, and metastasis. This review summarizes the molecular mechanisms and clinical importance of Wnt5a in the pathogenesis of CRC for better understanding the pathogenesis and its potential role as a prognostic marker and as an appropriate therapeutic target in the treatment of this disease in the future.

The Pathogenic Role of Smooth Muscle Cell-Derived Wnt5a in a Murine Model of Lung Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease characterized by extensive fibrosis of the lung tissue. Wnt5a expression was observed to be upregulated in IPF and suggested to be involved in the progression of the disease. Interestingly, smooth muscle cells (SMC) are a major source of Wnt5a in IPF patients. However, no study has been conducted until now to investigate the precise role of smooth muscle-derived Wnt5a in IPF. Here, we used the bleomycin-induced lung fibrosis model in a conditional gene-deficient mouse, where the Wnt5a gene was excised from SMC. We show here that the excision of the Wnt5a gene in SMC led to significantly improved health conditions with minimized weight loss and improved lung function. This improvement was based on a significantly lower deposition of collagen in the lung with a reduced number of fibrotic foci in lung parenchyma. Furthermore, the bleomycin-induced cellular infiltration into the airways was not altered in the gene-deficient mice compared with wild-type mice. Thus, we demonstrate that the Wnt5a expression of SMC of the airways leads to aggravated fibrosis of the lung with poor clinical conditions. This aggravation was not an influence in the bleomycin-induced inflammatory processes but on the development of fibrotic foci in lung parenchyma and the deposition of collagen.

LINGO-1 regulates Wnt5a signaling during neural stem and progenitor cell differentiation by modulating miR-15b-3p levels

Background Manipulation of neural stem and progenitor cells (NSPCs) is critical for the successful treatment of spinal cord injury (SCI) by NSPC transplantation, since their differentiation into neurons and oligodendrocytes can be inhibited by factors present in inflamed myelin. In this study, we examined the effects of LINGO-1 on spinal cord-derived NSPC (sp-NSPC) differentiation, the underlying mechanisms of action, and the functional recovery of mice after transplantation of manipulated cells. Methods sp-NSPCs were harvested from female adult C57/BL6 mice after SCI induced with an NYU impactor. These cells were infected with lentiviral vectors containing LINGO-1 shRNA sequence or a scrambled control and transplanted into SCI mice. Tuj-1- and GFAP-positive cells were assessed by immunofluorescence staining. Wnt5a, p-JNK, JNK, and β-catenin expression was determined by Western blot and RT-qPCR. miRNAs were sequenced to detect changes in miRNA expression. Motor function was evaluated 0–35 days post-surgery by means of the Basso Mouse Scale (BMS) and by the rotarod performance test. Results We discovered that LINGO-1 shRNA increased neuronal differentiation of sp-NSPCs while decreasing astrocyte differentiation. These effects were accompanied by elevated Wnt5a protein expression, but unexpectedly, no changes in Wnt5a mRNA levels. miRNA-sequence analysis demonstrated that miR-15b-3p was a downstream mediator of LINGO-1 which suppressed Wnt5a expression. Transplantation of LINGO-1 shRNA-treated sp-NSPCs into SCI mice promoted neural differentiation, wound compaction, and motor function recovery. Conclusions LINGO-1 shRNA promotes neural differentiation of sp-NSPCs and Wnt5a expression, probably by downregulating miR-15b-3p. Transplantation of LINGO-1 shRNA-treated NSPCs promotes recovery of motor function after SCI, highlighting its potential as a target for SCI treatment.

LncRNA HCP5 Induces Gastric Cancer Cell Proliferation, Invasion, and EMT Processes Through the miR-186-5p/WNT5A Axis Under Hypoxia

ObjectiveTo experimentally determine the involvement and mechanism of long non-coding RNA (lncRNA) HCP5 in the development of gastric cancer (GC).MethodsDetection of HCP5, miR-186-5p, and WNT5A expression in clinical GC tissues and adjacent healthy tissues was performed, followed by Pearson correlation analysis. BGC-823 and AGS cells, with interferences of HCP5, miR-186-5p, and WNT5A, were cultured under hypoxia. MTT, colony formation assay, Caspase-3 activity assay, and transwell assay were applied for the determination of cell proliferation, viability, apoptosis, and invasion, respectively. Expressions of WNT5A and protein markers of epithelial-mesenchymal transition (EMT) in cells were detected by western blotting. And the binding of HCP5 and WNT5A to miR-186-5p was validated using dual-luciferase reporter assay.ResultsIn GC tissues, an increase in HCP5 and WNT5A expressions and a reduction in miR-186-5p expression were found, and the negative correlation between miR-186-5p and HCP5/WNT5A was proven. Subsequently, under hypoxia, an increase in HCP5 and WNT5A expressions and a decrease in miR-186-5p expression in GC cells were confirmed. In addition, in GC cells under hypoxia, the inhibition of HCP5 suppressed cell biological activity and EMT, while the inhibition of miR-186-5p or the overexpression of WNT5A led to the opposite changes.ConclusionAn upregulation of WNT5A expression by HCP5 competitively binding to miR-186-5p promotes GC cell development.

MEIS-WNT5A axis regulates development of 4th ventricle choroid plexus

The choroid plexus (ChP) produces cerebrospinal fluid and forms a critical brain barrier. ChP tissues form in each brain ventricle, each one adopting a distinct shape, but remarkably little is known about the mechanisms underlying ChP development. Here, we show that epithelial WNT5A is critical for determining fourth ventricle (4V) ChP morphogenesis and size. Systemic Wnt5a knockout, or forced Wnt5a overexpression beginning at E10.5, profoundly reduced ChP size and development. However, Wnt5a expression was enriched in Foxj1-positive epithelial cells of 4V ChP plexus, and its conditional deletion in these cells affected the branched, villous morphology of the 4V ChP. We found that WNT5A was enriched in epithelial cells localized to the distal tips of 4V ChP villi, where WNT5A acted locally to activate non-canonical Wnt signaling via Ror1/Ror2 receptors. During 4V ChP development, MEIS1 bound to the proximal Wnt5a promoter, and gain- and loss-of-function approaches demonstrated that MEIS1 regulated Wnt5a expression. Collectively, our findings demonstrate a dual function of WNT5A in ChP development and identify MEIS transcription factors as upstream regulators of Wnt5a in the 4V ChP epithelium.

Wnt5a Regulates Odontoblast Inflammation by Promoting CCL2 Expression

Objective Wnt5a is involved inflammation, including pulpitis, by upregulating cytokine/chemokine expression. Odontoblasts are the first layer cells in dental pulp and respond to inflammatory stimuli. However, whether Wnt5a is involved in odontoblast inflammation is unclear. This study aimed to investigate the role of Wnt5a in odontoblast inflammation. Methods We measured and compared Wnt5a- or TNF-α-induced cytokine/chemokine expression in mouse odontoblast-like (17IIA11) cells by real-time PCR and Western blotting. Transwell assays were used to examine the effect of Wnt5a on RAW264.7 macrophage migration. We examined whether the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways were involved in the molecular mechanism of TNF-α or Wnt5a in 17IIA11 cells by Western blotting. Results TNF-α upregulated Wnt5a in odontoblasts. Wnt5a upregulated CCL2 expression in odontoblasts and enhanced RAW264.7 cell migration. We also found that TNF-α-induced Wnt5a expression was abrogated by inhibiting the MAPK pathway or NF-κB activity and that inhibiting MAPK activity could lead to decreased NF-κB activity. Conclusions Wnt5a is involved in the TNF-α-induced inflammatory response in odontoblasts. TNF-α upregulates Wnt5a expression via MAPK-dependent NF-κB activation in odontoblasts. Wnt5a upregulates CCL2 expression in odontoblasts and enhances RAW264.7 macrophage migration.

XIST knockdown suppresses vascular smooth muscle cell proliferation and induces apoptosis by regulating miR-1264/WNT5A/β-catenin signaling in aneurysm

LncRNAs have been ascertained as vital modulators in abdominal aortic aneurysm (AAA) development. In this research, the function and molecular mechanisms of the lncRNA XIST in the evolution of vascular smooth muscle cells (VSMCs) were assessed. Results showed that XIST expression was increased but miR-1264 expression level was reduced in the serum of AAA patients. XIST depletion impeded HA-VSMCs’ ability to proliferate and stimulate apoptosis, while repressing miR-1264 expression through an unmediated interaction. Additionally, the influence of XIST knockdown on apoptosis and proliferation could be rescued by a miR-1264 inhibitor. Subsequent molecular investigations indicated that WNT5A was miR-1264's target, and XIST functioned as a ceRNA of miR-1264 to raise WNT5A expression. Further, a miR-1264 inhibitor stimulated the proliferation and suppressed the apoptosis of HA-VSMCs through the activation of WNT/β-catenin signaling. Taken together, XIST impeded the apoptosis and stimulated the proliferation of HA-VSMCs via the WNT/β-catenin signaling pathway through miR-1264, demonstrating XIST's underlying role in AAA.