Androgen Receptor Promotes Lung Cancer Metastasis by Modifying the miR23a-3p/EPHB2 Pathway.

OBJECTIVE: This study aimed to investigate the reasons behind the lower survival rates in male lung cancer patients than in female lung cancer patients. METHODS: Through various techniques, such as Argonaute immunoprecipitation, luciferase assays, and ChIP, this study confirmed the positive effects of androgen receptor (AR) on lung cancer cell invasion across different in vitro cell lines and in vivo mouse models. RESULTS: The findings suggest that AR enhanced the invasion of lung cancer cells by modifying EPHB2 signals at the protein expression level, which in turn required changes in miRNA-23a-3p. Restoring miRNA-23a-3p could counteract the intensified invasion of lung cancer cells mediated by AR. CONCLUSION: This study revealed that AR may facilitate the lung cancer matastasis by modulating miRNA-23a-3p/EPHB2 signaling and that targeting this signaling pathway could provide new approaches to inhibit lung cancer metastasis.

Second Report of the p.Leu874Pro Missense Variant in EPHB4 in a Family With Capillary Malformation-Arteriovenous Malformation Syndrome (CM-AVM) Syndrome.

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is characterized by the presence of multiple small (1-2 cm in diameter) capillary malformations of the skin. This disorder has been described as two distinct entities: CM-AVM1 and CM-AVM2. The diagnosis of these disorders has been associated with pathogenic variants in the RASA1 gene for RASA1-CM-AVM, formerly known as CM-AVM1, and, more recently, the EPHB4 genes for EPHB4-CM-AVM, formerly known as CM-AVM2. Affected patients with either type may also have arteriovenous malformations and fistulas, which can cause life-threatening bleeding, congestive heart failure, or neurologic consequences such as stroke. These syndromes are typically either sporadic or inherited in an autosomal dominant manner with variable expressivity. We report a case series of a father and three daughters who have clinically diagnosed EPHB4-CM-AVM syndrome who were found to have a variant of uncertain significance (VUS) in EPHB4 that has only been reported once prior.

EphB2, EphB4, and ephrin-B1 expression and localization in postnatal developing epididymis in mice.

BACKGROUND: Eph receptors and ephrin ligands, the transmembrane proteins, function as a mechanism of communication between cells. Therefore, we intended to explore the expression array of EphB2 and EphB4 receptors and ephrin-B1 ligand in postnatal developing mouse epididymis during 1 day to 8 weeks using RT-PCR amplification and immunofluorescence staining. RESULTS: RT-PCR analysis indicated that the expression levels of EphB2, EphB4, and ephrin-B1 in the epididymis declined with the advancement of age during the initial phases of postnatal development and stayed relatively near to adult levels until 4 weeks. We discovered that the predominant compartments expressing EphB2/B4 and ephrin-B1 emerged in the excurrent duct epithelia of postnatal developing epididymis until 3 weeks. Consequently, even before spermatozoa reach the excurrent duct in epididymis, at the age of 3 weeks, the epididymal excurrent duct system exhibits characteristics similar to those of an adult in terms of expression of EphB2/B4 and ephrin-B1. Moreover, ephrin-B1 was expressed in epididymal epithelial cells throughout the development and EphB4 was expressed only in early postnatal stages while basal cells expressed EphB4 throughout the postnatal development. CONCLUSION: The study represents the first expression analysis of ephrin-B1, EphB2, and EphB4 in the normal mouse epididymis during the postnatal development.

Corrigendum: Activation of EphrinB2/EphB2 signaling in the spine cord alters glia-neuron interactions in mice with visceral hyperalgesia following maternal separation.

[This corrects the article DOI: 10.3389/fphar.2024.1463339.].

Activation of EphrinB2/EphB2 signaling in the spine cord alters glia-neuron interactions in mice with visceral hyperalgesia following maternal separation.

Background: Sress early in life has been linked to visceral hyperalgesia and associated functional gastrointestinal disorders. In a mouse model of visceral hyperalgesia, we investigated whether the EphB2 receptor and its EphrinB2 ligand in spinal cord contribute to dysregulation of glia-neuron interactions. Methods: An established mouse model of stress due to maternal separation (MS). Pups were separated from their mothers for 14 days during early development, then analyzed several weeks later in terms of visceral sensitivity based on the abdominal withdrawal reflex score and in terms of expression of c-fos, EphrinB2, EphB2, and phosphorylated MAP kinases (ERK, p38, JNK). Results: Visceral hyperalgesia due to MS upregulated EphB2, EphrinB2 and c-fos in the spinal cord, and c-fos levels positively correlated with those of EphB2 and EphrinB2. Spinal astrocytes, microglia, and neurons showed upregulation of EphB2, EphrinB2 and phosphorylated MAP kinases. Blocking EphrinB2/EphB2 signaling in MS mice reduced visceral sensitivity, activation of neurons and glia, and phosphorylation of NMDA receptor. Activating EphrinB2/EphB2 signaling in unstressed mice induced visceral hyperalgesia, upregulation of c-fos, and activation of NMDA receptor similar to maternal separation. Conclusion: The stress of MS during early development may lead to visceral hyperalgesia by upregulating EphrinB2/EphB2 in the spinal cord and thereby altering neuron-glia interactions.

Circadian system disorder induced by aberrantly activated EFNB2-EPHB2 axis leads to facilitated liver metastasis in gastric cancer.

BACKGROUND: Liver is one of the most preferred destinations for distant metastasis of gastric cancer (GC) and liver metastasis usually predicts poor prognosis. The achievement of liver metastasis requires continued cross-talk of complex members in tumor microenvironment (TME) including tumor associated macrophages (TAMs). METHODS: Results from 35 cases of ex vivo cultured living tissues of GC liver metastasis have elucidated that circadian rhythm disorder (CRD) of key molecules involved in circadian timing system (CTS) facilitates niche outgrowth. We next analyzed 69 cases of liver metastasis from patients bearing GC and designed co-culture or 3D cell culture, discovering that TAMs expressing EFNB2 could interact with tumor cell expressing EPHB2 for forward downstream signaling and lead to CRD of tumor cells. Moreover, we performed intrasplenic injection models assessed by CT combined 3D organ reconstruction bioluminescence imaging to study liver metastasis and utilized the clodronate treatment, bone marrow transplantation or EPH inhibitor for in vivo study followed by exploring the clinical therapeutic value of which in patient derived xenograft (PDX) mouse model. RESULTS: Ex vivo studies demonstrated that CRD of key CTS molecules facilitates niche outgrowth in liver metastases. In vitro studies revealed that TAMs expressing EFNB2 interact with tumor cells expressing EPHB2, leading to CRD and downstream signaling activation. The underlying mechanism is the enhancement of the Warburg effect in metastatic niches. CONCLUSION: Overall, we aim to uncover the mechanism in TAMs induced CRD which promotes liver metastasis of GC and provide novel ideas for therapeutic strategies.

Silencing EPHB2 diminished the malignant biological properties of esophagus cancer cells by blocking autophagy and Wnt/ß-catenin pathway.

Eph receptor B2 (EPHB2) is overexpressed in some tumors and relevant to unfavorable outcomes of tumor patients. By searching Gene Expression Profiling Interactive Analysis and KM Plot websites, we discovered that EPHB2 was highly expressed in patients with esophageal cancer, leading to poor prognosis. However, the role and molecular mechanism of EPHB2 in esophagus cancer is unknown. Our study aims to unveil the underlying mechanism by which EPHB2 modulates the biological properties of esophagus cancer cells. After si-EPHB2 transfection, the malignant biological properties of esophagus cancer cells were determined by several biological experiments. IWP-4 was applied to block Wnt/ß-catenin signaling pathway. The expressions of autophagy and Wnt/ß-catenin signaling pathway relevant molecules were tested by western blot assay. An increased expression of EPHB2 was happened in esophagus cancer samples and loss of EPHB2 diminished esophagus cancer cells proliferation, migration, and invasion. Moreover, our data showed that depletion of EPHB2 blocked the autophagy and in-activated Wnt/ß-catenin signaling pathway in esophagus cancer cells. While, IWP-4 treatment inhibited the autophagy and limited esophagus cancer cells proliferation, migration, and invasion. Moreover, EPHB2 knocked down strengthened the effect of IWP-4 treatment in regulating esophagus cancer cells proliferation, migration, and invasion. Finally, we illustrated that EPHB2 regulated the biological properties of esophagus cancer cells by modulating autophagy and Wnt/ß-catenin signaling pathway. Our study illustrated that EPHB2 might be a worthwhile target considering for the treatment of esophagus cancer.

Study on the Role of EPHB6 in Inhibiting the Malignant Progression of Cervical Cancer C33A Cells by Binding to CBX7.

Cervical cancer stands as the most frequently diagnosed malignancy affecting the female reproductive. The erythropoietin-producing hepatocyte (Eph) family tyrosine kinases play important roles in tumorigenesis and cancer aggression. However, the exact role of EPHB6 in cervical cancer remains unknown. The present study investigated the role of EPHB6 in the malignant process of cervical cancer. GEPIA, tnmplot and kmplot database was used to study the expression of EPHB6 in cervical cancer tissues. western blotting was used to detect the expression of EPHB6, CyclinD, CDK4, CDK6, CBX7, MMP2 and MMP9. CCK8 and EDU staining were used to detect cell proliferation. Wound healing and transwell were used to detect cell proliferation and migration. Flow cytometry was used to detect cell cycle level. The linkedomics database was used to predict the correlation of EPHB6 and CBX7 in cervical cancer. Subsequently, HDOCK server was used to predict the combination of EPHB6 and CBX7. Our current results suggested that the expression of EPHB6 is reduced in cervical cancer tissues and cell lines, and the lower the expression, the worse the prognosis. Moreover, overexpression of EPHB6 inhibits cell proliferation, invasion and migration and cycle acceleration of C33A cells. Furthermore, EPHB6 and CBX7 bind to each other in C33A cells, and EPHB6 inhibits cell proliferation, invasion, migration and cell cycle acceleration in cervical cancer by binding to CBX7. EPHB6 expression is reduced in cervical cancer tissues and cells. Its overexpression inhibits proliferation, invasion, migration, and cell cycle acceleration in C33A cells, exhibiting synergy when bound to CBX7.

Improved efficacy of pembrolizumab combined with soluble EphB4-albumin in HPV-negative EphrinB2 positive head neck squamous cell carcinoma.

OBJECTIVE: Patients with relapsed or metastatic head and neck squamous cell carcinoma (HNSCC) after primary local therapy have low response rates with cetuximab, systemic chemotherapy or check point inhibitor therapy. Novel combination therapies with the potential to improve outcomes for patients with HNSCC is an area of high unmet need. METHODS: This is a phase II single-arm clinical trial of locally advanced or metastatic HNSCC patients treated with a combination of soluble EphB4-human serum albumin (sEphB4-HSA) fusion protein and pembrolizumab after platinum-based chemotherapy with up to 2 prior lines of treatment. The primary endpoints were safety and tolerability and the primary efficacy endpoint was overall response rate (ORR). Secondary endpoints included progression free survival (PFS) and overall survival (OS). HPV status and EphrinB2 expression were evaluated for outcome. RESULTS: Twenty-five patients were enrolled. Median follow up was 40.4 months (range 9.8 - 40.4). There were 6 responders (ORR 24%). There were 5 responders in the 11 HPV-negative and EphrinB2 positive patients, (ORR 45%) with 2 of these patients achieving a complete response (CR). The median PFS in HPV-negative/EphrinB2 positive patients was 3.2 months (95% CI 1.1, 7.3). Median OS in HPV-negative/EphrinB2 positive patients was 10.9 months (95% CI 2.0, 13.7). Hypertension, transaminitis and fatigue were the most common toxicities. DISCUSSION: The combination of sEphB4-HSA and pembrolizumab has a favorable toxicity profile and favorable activity particularly among HPV-negative EphrinB2 positive patients with HNSCC.

Impact and Interrelationships of Striatal Proteins, EPHB2, OPRM1, and PER2 on Mild Cognitive Impairment.

With the global increase in life expectancy, there has been a rise in the incidence of cognitive impairments attributed to diverse etiologies. Notably, approximately 50% of individuals diagnosed with mild cognitive impairment (MCI) progress to dementia within 3 years. However, the precise mechanisms underlying MCI remain elusive. Therefore, this study aimed to elucidate potential mechanisms implicated in MCI utilizing Per2 knockout (KO) mice, which have previously been shown to have cognitive deficits. Behavioral (Y-maze, Barnes maze) and molecular (electrophysiology, RNA sequencing, western blot, and immunofluorescence) experiments were conducted in Per2 KO and wild-type (WT) mice. Per2 KO mice exhibited impaired spatial working memory in the Y-maze and Barnes maze. However, there were no significant group differences in hippocampal long-term potentiation (LTP) between Per2 KO and WT mice, whereas striatal LTP in Per2 KO mice was lower compared to WT mice. In RNA sequencing analysis, 58 genes were downregulated and 64 genes were upregulated in the striatum of Per2 KO mice compared to WT mice. Among the differentially expressed genes, four genes (Chrm2, EphB2, Htr1b, Oprm1) were identified. Optimal expression levels of EPHB2 and OPRM1 were found to significantly enhance cognitive performance in mice. Additionally, Per2 KO mice exhibited reduced EPHB2-NMDAR-LTP and OPRM-mTOR signaling, along with elevated amyloid beta (Aß) levels, when compared to WT mice. However, these alterations were reversed upon administration of morphine treatment. Striatal OPRM1-mTOR signaling, EPHB2-NMDAR-LTP signaling, and Aß expression levels may exert a combined effect on MCI under the control of Per2 expression.

EPHB2 Knockdown Mitigated Myocardial Infarction by Inhibiting MAPK Signaling.

Myocardial infarction (MI) is a common type of cardiovascular disease. The incidence of ventricular remodeling dysplasia and heart failure increases significantly after MI. The objective of this study is to investigate whether erythropoietin hepatocellular receptor B2 (EPHB2) can regulate myocardial injury after MI and explore its regulatory pathways. EPHB2 is significantly overexpressed in the heart tissues of MI mice. The downregulation of EPHB2 alleviates the cardiac function damage after MI. Knockdown EPHB2 alleviates MI-induced myocardial tissue inflammation and apoptosis, and myocardial fibrosis in mice. EPHB2 knockdown significantly inhibits the activation of mitogen activated kinase-like protein (MAPK) pathway in MI mice. Moreover, EPHB2 overexpression significantly promotes the phosphorylation of MAPK pathway-related protein, which can be reversed by MAPK-IN-1 (an MAPK inhibitor) treatment. In conclusion, silencing EPHB2 can mitigate MI-induced myocardial injury by inhibiting MAPK signaling in mice, suggesting that targeting EPHB2 can be a promising therapeutic target for MI-induced myocardial injury.

EphB2 activation in neural stem cells in the basolateral amygdala facilitates neurogenesis and enhances long-term memory.

Many brain diseases lead to a reduction in the number of functional neurons and it would be of value to be able to increase the number of neurons in the affected brain areas. In this study, we examined whether we can promote neural stem cells to produce mature neurons and whether an increase in the mature neurons can affect cognitive performance. We detected that the EphB2 receptor is localized in immature basolateral amygdala (BLA) neurons. We therefore aimed to increase the level of EphB2 activity in neural stem cells (NSCs) in the BLA and examine the effects on the production of mature neurons and cognition. Toward that end, we utilized a photoactivatable EphB2 construct (optoEphB2) to increase EphB2 forward signaling in NSCs in the BLA. We revealed that the activation of optoEphB2 in NSCs in the BLA increased the level of immature and mature neurons in the BLA. We further found that activation of optoEphB2 in BLA NSCs enhanced auditory, but not contextual, long-term fear memory formation. Impairing EphB2 forward signaling did not affect the level of immature and mature neurons in the BLA. This study provides evidence that NSCs can be promoted to produce mature neurons by activating EphB2 to enhance specific brain functions.

ephrin-B2 promotes nociceptive plasticity and hyperalgesic priming through EphB2-MNK-eIF4E signaling in both mice and humans.

Ephrin-B-EphB signaling can promote pain through ligand-receptor interactions between peripheral cells, like immune cells expressing ephrin-Bs, and EphB receptors expressed by DRG neurons. Previous studies have shown increased ephrin-B2 expression in peripheral tissues like synovium of rheumatoid and osteoarthritis patients, indicating the clinical significance of this signaling. The primary goal of this study was to understand how ephrin-B2 acts on mouse and human DRG neurons, which express EphB receptors, to promote pain and nociceptor plasticity. We hypothesized that ephrin-B2 would promote nociceptor plasticity and hyperalgesic priming through MNK-eIF4E signaling, a critical mechanism for nociceptive plasticity induced by growth factors, cytokines and nerve injury. Both male and female mice developed dose-dependent mechanical hypersensitivity in response to ephrin-B2, and both sexes showed hyperalgesic priming when challenged with PGE2 injection either to the paw or the cranial dura. Acute nociceptive behaviors and hyperalgesic priming were blocked in mice lacking MNK1 (Mknk1 knockout mice) and by eFT508, a specific MNK inhibitor. Sensory neuron-specific knockout of EphB2 using Pirt-Cre demonstrated that ephrin-B2 actions require this receptor. In Ca2+-imaging experiments on cultured DRG neurons, ephrin-B2 treatment enhanced Ca2+ transients in response to PGE2 and these effects were absent in DRG neurons from MNK1-/- and EphB2-PirtCre mice. In experiments on human DRG neurons, ephrin-B2 increased eIF4E phosphorylation and enhanced Ca2+ responses to PGE2 treatment, both blocked by eFT508. We conclude that ephrin-B2 acts directly on mouse and human sensory neurons to induce nociceptor plasticity via MNK-eIF4E signaling, offering new insight into how ephrin-B signaling promotes pain.

3D bioprinting of DPSCs with GelMA hydrogel of various concentrations for bone regeneration.

Bioprinting technology promotes innovation of fabricating tissue engineered constructs. Dental pulp stem cells (DPSCs) have significant advantages over classical bone mesenchymal stem cells (BMSCs) and are a promising seed cell candidate for bone engineering bioprinting. However, current reports about bioprinted DPSCs for bone regeneration are incomprehensive. The objective of this study was to investigate the osteogenic potential of DPSCs in methacrylate gelatin (GelMA) hydrogels bioprinted scaffolds in vitro and in vivo. Firstly, we successfully bioprinted GelMA with different concentrations embedded with or without DPSCs. Printability, physical features and biological properties of the bioprinted constructs were evaluated. Then, osteogenic differentiation levels of DPSCs in bioprinted constructs with various concentrated GelMA were compared. Finally, effects of bioprinted constructs on cranial bone regeneration were evaluated in vivo. The results of our study demonstrated that 10% GelMA had higher compression modulus, smaller pores, lower swelling and degradation rate than 3% GelMA. Twenty-eight days after printing, DPSCs in three groups of bioprinted structures still maintained high cell activities (>90%). Moreover, DPSCs in 10% GelMA showed an upregulated expression of osteogenic markers and a highly activated ephrinB2/EphB4 signaling, a signaling involved in bone homeostasis. In vivo experiments showed that DPSCs survived at a higher rate in 10% GelMA, and more new bones were observed in DPSC-laden 10% GelMA group, compared with GelMA of other concentrations. In conclusion, bioprinted DPSC-laden 10% GelMA might be more appropriate for bone regeneration application, in contrast to GelMA with other concentrations.

ED-71 Improves Bone Mass in Ovariectomized Rats by Inhibiting Osteoclastogenesis Through EphrinB2-EphB4-RANKL/OPG Axis.

Purpose: Estrogen deficiency is the main reason of postmenopausal osteoporosis. Eldecalcitol (ED-71) is a new active vitamin D analogue clinically used in the treatment of postmenopausal osteoporosis. We aimed to investigate whether EphrinB2-EphB4 and RANKL/RANK/OPG signaling cooperate in mediating the process of osteoporosis by ED-71. Methods: In vivo, the ovariectomized (OVX) rats were administered orally with 30 ng/kg ED-71 once a day for 8 weeks. HE staining, Masson staining and Immunofluorescence staining were used to evaluate bone mass, bone formation, osteoclastogenesis associated factors and the expression of EphrinB2, EphB4, RANKL and OPG. In vitro, H2O2 stimulation was used to simulate the cell environment in osteoporosis. Immunofluorescence, quantitative real time PCR (qRT-PCR), enzyme-linked immunosorbent assay (ELISA) and Western Blot were applied to detect the expression of EphrinB2, EphB4, RANKL and OPG. In osteoblasts, EphB4 was knocked down by EphB4 small-interfering RNA (siRNA) transfection. LY294002 (PI3K inhibitor) or ARQ092 (AKT inhibitor) was used to block PI3K/AKT pathway. An indirect co-culture system of osteoblasts and osteoclasts was established. The mRNA and protein expression of osteoclastogenes is associated factors were tested by qRT-PCR and Western Blot. Results: ED-71 increased bone mass and decreased the number of osteoclasts in OVX rats. Moreover, ED-71 promoted the expression of EphrinB2, EphB4, and decreased the RANKL/OPG ratio in osteoblasts. Osteoclastogenesis was restrained when osteoclasts were indirectly co-cultured with ED-71-treated osteoblasts. After silencing of EphB4 expression in osteoblasts, ED-71 inhibited the expression of P-PI3K and P-AKT and increased the ratio of RANKL/OPG. This reversed the inhibitory effect of ED-71 on osteoclastogenes. Therefore, in ED-71-inhibited osteoclastogenes, EphB4 is a key factor affecting the secretion of RANKL and OPG by osteoblasts. EphB4 suppressed the RANKL/OPG ratio through activating PI3K/AKT signaling in osteoblasts. Conclusion: ED-71 inhibits osteoclastogenesis through EphrinB2-EphB4-RANKL/OPG axis, improving bone mass in ovariectomized rats. PI3K/AKT pathway is involved this process.

Imbalanced EphB4/EphrinB2 Signaling Modulates Bone Resorption in Periodontitis Induced by Porphyromonas gingivalis.

Periodontitis, a chronic infectious disease in periodontal tissues, is characterized by an imbalance of alveolar bone resorption and remodeling, which eventually results in tooth loosening and even tooth loss. The etiology of periodontitis is polymicrobial synergy and dysbiosis, in which Porphyromonas gingivalis (P. gingivalis) is one of the primary pathogens responsible for periodontitis progression. The interplay of EphrinB2/EphB4 is crucial for osteoblast-osteoclast communication during bone remodeling and healing. This study investigates the mechanism of EphB4/EphrinB2 transduction modulating osteogenesis inhibition and bone resorption in periodontitis induced by P. gingivalis. An in vivo model of chronic periodontitis provoked by P. gingivalis was constructed, the inflammation and bone resorption were evaluated. The expression of EphB4 and EphrinB2 proteins in periodontal tissues was detected, which was also evaluated, respectively, in osteoblasts and osteoclasts infected with P. gingivalis in vitro. Then, a simulated coculture model of osteoblasts and osteoclasts was established to activate the forward and reverse pathways of EphB4/EphrinB2 with P. gingivalis infection. This study showed that P. gingivalis infection promoted alveolar bone resorption in rats and enhanced EphB4 and EphrinB2 expression in periodontal tissues. EphB4 and molecules associated with osteogenesis in osteoblasts infected with P. gingivalis were inhibited, while EphrinB2 and osteoclast differentiation-related markers in osteoclasts were activated. In conclusion, this study suggested that EphB4/EphrinB2 proteins were involved in alveolar bone remodeling in the process of periodontitis induced by P. gingivalis infection. Moreover, attenuated EphB4/EphrinB2 with P. gingivalis infection weakened osteoblast activity and enhanced osteoclast activity.

Overexpression of EphB2 in the basolateral amygdala is crucial for inducing visceral pain sensitization in rats subjected to water avoidance stress.

AIMS: Basolateral amygdala (BLA), as a center for stress responses and emotional regulation, is involved in visceral hypersensitivity of irritable bowel syndrome (IBS) induced by stress. In the present study, we aimed to investigate the role of EphB2 receptor (EphB2) in BLA and explore the underlying mechanisms in this process. METHODS: Visceral hypersensitivity was induced by water avoidance stress (WAS). Elevated plus maze test, forced swimming test, and sucrose preference test were applied to assess anxiety- and depression-like behaviors. Ibotenic acid or lentivirus was used to inactivate BLA in either the induction or maintenance stage of visceral hypersensitivity. The expression of protein was determined by quantitative PCR, immunofluorescence, and western blot. RESULTS: EphB2 expression was increased in BLA in WAS rats. Inactivation of BLA or downregulation of EphB2 in BLA failed to induce visceral hypersensitivity as well as anxiety-like behaviors. However, during the maintenance stage of visceral pain, visceral hypersensitivity was only partially relieved but anxiety-like behaviors were abolished by inactivation of BLA or downregulation of EphB2 in BLA. Chronic WAS increased the expression of EphB2, N-methyl-D-aspartate receptors (NMDARs), and postsynaptic density protein (PSD95) in BLA. Downregulation of EphB2 in BLA reduced NMDARs and PSD95 expression in WAS rats. However, activation of NMDARs after the knockdown of EphB2 expression still triggered visceral hypersensitivity and anxiety-like behaviors. CONCLUSIONS: Taken together, the results suggest that EphB2 in BLA plays an essential role in inducing visceral hypersensitivity. In the maintenance stage, the involvement of EphB2 is crucial but not sufficient. The increase in EphB2 induced by WAS may enhance synaptic plasticity in BLA through upregulating NMDARs, which results in IBS-like symptoms. These findings may give insight into the treatment of IBS and related psychological distress.

EphB1 controls long-range cortical axon guidance through a cell non-autonomous role in GABAergic cells.

EphB1 is required for proper guidance of cortical axon projections during brain development, but how EphB1 regulates this process remains unclear. We show here that EphB1 conditional knockout (cKO) in GABAergic cells (Vgat-Cre), but not in cortical excitatory neurons (Emx1-Cre), reproduced the cortical axon guidance defects observed in global EphB1 KO mice. Interestingly, in EphB1 cKOVgat mice, the misguided axon bundles contained co-mingled striatal GABAergic and somatosensory cortical glutamatergic axons. In wild-type mice, somatosensory axons also co-fasciculated with striatal axons, notably in the globus pallidus, suggesting that a subset of glutamatergic cortical axons normally follows long-range GABAergic axons to reach their targets. Surprisingly, the ectopic axons in EphB1 KO mice were juxtaposed to major blood vessels. However, conditional loss of EphB1 in endothelial cells (Tie2-Cre) did not produce the axon guidance defects, suggesting that EphB1 in GABAergic neurons normally promotes avoidance of these ectopic axons from the developing brain vasculature. Together, our data reveal a new role for EphB1 in GABAergic neurons to influence proper cortical glutamatergic axon guidance during brain development.

EphB3 receptor suppressor invasion, migration and proliferation in glioma by inhibiting EGFR-PI3K/AKT signaling pathway.

Eph receptors are the largest subfamily of receptor tyrosine kinases, and they have been shown to play a crucial role in glioma. The EphB3 receptor is a member of this family, and its effect on the invasion, migration and proliferation of glioma cells was examined in this study. It was found that the expression of EphB3 was decreased in glioma specimens with increasing tumor grade. Additionally, the U87MG and U251 cell lines showed low levels of EphB3 expression. This finding was consistent with the negative correlation between EphB3 expression in glioma tissues and tumor grade. Depletion of EphB3 gene in U87MG and U251 cell lines resulted in a substantial enhancement of their invasion, migration, and proliferation capacities in vitro. Furthermore, the knockdown of EphB3 led to an upregulation of EGFR, p-PI3K, and p-AKT protein levels. On the other hand, EphB3 overexpression reduced the invasiveness, proliferative capacity and migration rate of U87MG and U251 cells, and downregulated EGFR, p-PI3K and p-AKT. These findings indicate that EphB3 functions as a tumor suppressor in glioma, and its downregulation enhances the malignant potential of glioma cells by activating the EGFR-PI3K/AKT pathway. Thus, EphB3 is a promising diagnostic marker for glioma, and the EphB3-EGFR-PI3K / AKT axis deserves further investigation as a potential therapeutic target.

Erythropoietin-producing hepatocellular receptor B6 is highly expressed in non-functioning pituitary neuroendocrine tumors and its expression correlates with tumor size.

BACKGROUND: Erythropoietin-producing hepatocellular (EPH) receptors are the largest known family of receptor tyrosine kinases characterized in humans. These proteins are involved in tissue organization, synaptic plasticity, vascular development and the progression of various diseases including cancer. The Erythropoietin-producing hepatocellular receptor tyrosine kinase member EphB6 is a pseudokinase which has not attracted an equivalent amount of interest as its enzymatically-active counterparts. The aim of this study was to assess the expression of EphB6 in pituitary tumors. METHODS AND RESULTS: Human normal pituitaries and pituitary tumors were examined for EphB6 mRNA expression using real-time PCR and for EphB6 protein by immunohistochemistry and Western blotting. EphB6 was highly expressed in non-functioning pituitary neuroendocrine tumors (NF-PitNETs) versus the normal pituitary and GH-secreting PitNETs. EphB6 mRNA expression was correlated with tumor size. CONCLUSIONS: Our results suggest EphB6 aberrant expression in NF-PitNETs. Future studies are warranted to determine the role and significance of EphB6 in NF-PitNETs tumorigenesis.