High incidence of EDNRB gene mutation in seven southern Chinese familial cases with Hirschsprung's disease

PURPOSE

Hirschsprung's disease (HSCR) is the leading cause of neonatal functional intestinal obstruction, which has been identified in many familial cases. HSCR, a multifactorial disorder of enteric nervous system (ENS) development, is associated with at least 24 genes and seven chromosomal loci, with RET and EDNRB as its major genes. We present a genetic investigation of familial HSCR to clarify the genotype-phenotype relationship.

METHODS

We performed whole exome sequencing (WES) on Illumina HiSeq X Ten platform to investigate genetic backgrounds of core family members, and identified the possibly harmful mutation genes. Mutation carriers and pedigree relatives were validated by Sanger sequencing for evaluating the gene penetrance.

RESULTS

Four familial cases showed potential disease-relative variants in EDNRB and RET gene, accounting for all detection rate of 57.1%. Three familial cases exhibited strong pathogenic variants as frameshift or missense mutations in EDNRB gene. A novel c.367delinsTT mutation of EDNRB was identified in one family member. The other two EDNRB mutations, c.553G>A in family 2 and c.877delinsTT in family 5, have been reported in previous literatures. The penetrance of EDNRB variants was 33-50% according mutation carries. In family 6, the RET c.1858T>C (C620R) point mutation has previously been reported to cause HSCR, with 28.5% penetrance.

CONCLUSION

We identified a novel EDNRB (deleted C and inserted TT) mutation in this study using WES. Heterozygote variations in EDNRB gene were significantly enriched in three families and RET mutations were identified in one family. EDNRB variants showed an overall higher incidence and penetrance than RET in southern Chinese families cases.

Genetic Underpinnings and Audiological Characteristics in Children With Unilateral Sensorineural Hearing Loss

OBJECTIVE

Unilateral sensorineural hearing loss (USNHL) is a condition commonly encountered in otolaryngology clinics. However, its molecular pathogenesis remains unclear. This study aimed to investigate the genetic underpinnings of childhood USNHL and analyze the associated audiological features.

STUDY DESIGN

Retrospective analysis of a prospectively recruited cohort.

SETTING

Tertiary referral center.

METHODS

We enrolled 38 children with USNHL between January 1, 2018, and December 31, 2021, and performed physical, audiological, imaging, and congenital cytomegalovirus (cCMV) examinations as well as genetic testing using next-generation sequencing (NGS) targeting 30 deafness genes. The audiological results were compared across different etiologies.

RESULTS

Causative genetic variants were identified in 8 (21.1%) patients, including 5 with GJB2 variants, 2 with PAX3 variants, and 1 with the EDNRB variant. GJB2 variants were found to be associated with mild-to-moderate USNHL in various audiogram configurations, whereas PAX3 and EDNRB variants were associated with profound USNHL in flat audiogram configurations. In addition, whole-genome sequencing and extended NGS targeting 213 deafness genes were performed in 2 multiplex families compatible with autosomal recessive inheritance; yet no definite causative variants were identified. Cochlear nerve deficiency and cCMV infection were observed in 9 and 2, respectively, patients without definite genetic diagnoses.

CONCLUSION

Genetic underpinnings can contribute to approximately 20% of childhood USNHL, and different genotypes are associated with various audiological features. These findings highlight the utility of genetic examinations in guiding the diagnosis, counseling, and treatment of USNHL in children.

mRNA sequencing provides new insights into the pathogenesis of Hirschsprung's disease in mice

PURPOSE

The aim of this study is to use RNA sequencing and RT-qPCR to identify the main susceptibility genes linked to the occurrence and development of Hirschsprung disease in the colonic tissues of EDNRBm1yzcm and wild mice.

METHODS

RNA was extracted from colon tissues of 3 mutant homozygous mice and 3 wild mice. RNA degradation, contamination concentration, and integrity were then measured. The extracted RNA was then sequenced using the Illumina platform. The obtained sequence data are filtered to ensure data quality and compared to the reference genome for further analysis. DESeq2 was used for gene expression analysis of the raw data. In addition, graphene oxide enrichment analysis and RT-qPCR validation were also performed.

RESULTS

This study identified 8354 differentially expressed genes in EDNRBm1yzcm and wild mouse colon tissues by RNA sequencing, including 4346 upregulated genes and 4005 downregulated genes. Correspondingly, the results of RT-qPCR analysis showed good correlation with the transcriptome data. In addition, GO and KEGG enrichment results suggested that there were 8103 terms and 320 pathways in all DEGs. When P < 0.05, 1081 GO terms and 320 KEGG pathways reached a significant level. Finally, through the existing studies and the enrichment results of differentially expressed genes, it was determined that axon guidance and the focal adhesion pathway may be closely related to the occurrence of HSCR.

CONCLUSIONS

This study analyzed and identified the differential genes in colonic tissues between EDNRBm1yzcm mice and wild mice, which provided new insight for further mining the potential pathogenic genes of Hirschsprung's disease.

Suppression of PGE2/EP2 signaling alleviates Hirschsprung disease by upregulating p38 mitogen-activated protein kinase activity

Hirschsprung disease (HSCR) is a congenital disorder caused by the failure of enteric neural crest cells (ENCCs) to colonize the distal bowel, resulting in absence of enteric nervous system. While a range of molecules and signaling pathways have been found to contribute to HSCR development, the risk factors and pathogenesis of this disease in many patients remain unknown. We previously demonstrated that increased activity of the prostaglandin E2 (PGE2)/PGE2 receptor subtype EP2 pathway can be a risk factor for HSCR. In this study, an Ednrb-deficient mouse model of HSCR was generated and used to investigate if PGE2/EP2 pathway could be a potential therapeutic target for HSCR. We found that downregulation of PGE2/EP2 signaling by siRNA-mediated ablation of a PGE2 synthase or pharmacologic blockage of EP2 enhanced ENCC colonization in the distal bowel of Ednrb-/- mice and alleviated their HSCR-like symptoms. Furthermore, blockage of EP2 was shown to promote ENCC migration through upregulating p38 mitogen-activated protein kinase activity, which was downregulated in the colon of Ednrb-/- mice and in the distal aganglionic bowel of HSCR patients. These data provide evidence that maternal exposure during embryonic development to an environment with dysregulated activation of the PGE2/EP2 pathway may predispose genetically susceptible offspring to HSCR, and avoidance or early disruption of maternal events (e.g. inflammation) that possibly enhance PGE2/EP2 signaling during pregnancy would reduce the occurrence and severity of this disease. KEY MESSAGES : Knockdown of PTGES alleviates HSCR severity in Ednrb-/- mice. Blockage of EP2-mediated PGE2 signaling alleviates HSCR severity in Ednrb-/- mice. Blockage of EP2-mediated PGE2 signaling promotes ENCC migration via enhancing p38 activity.

Driver and novel genes correlated with metastasis of non-small cell lung cancer: A comprehensive analysis

Although mutations of genes are crucial events in tumorigenesis and development, the association between gene mutations and lung cancer metastasis is still largely unknown. The goal of this study is to identify driver and novel genes associated with non-small cell lung cancer (NSCLC) metastasis. Candidate genes were identified using a novel comprehensive analysis, which was based on bioinformatics technology and meta-analysis. Firstly, EGFR, KRAS, ALK, TP53, BRAF and PIK3CA were identified as candidate driver genes. Further meta-analysis identified that EGFR (Pooled OR 1.33, 95% CI 1.19, 1.50; P < .001) and ALK (Pooled OR 1.52, 95% CI 1.22, 1.89; P < .001) mutations were associated with distant metastasis of NSCLC. Besides, ALK (Pooled OR 2.40, 95% CI 1.71, 3.38; P < .001) mutation was associated with lymph node metastasis of NSCLC. In addition, thirteen novel gene mutations were identified to be correlated with NSCLC metastasis, including SMARCA1, GGCX, KIF24, LRRK1, LILRA4, OR2T10, EDNRB, NR1H4, ARID4A, PRKCI, PABPC5, ACAN and TLN1. Furthermore, elevated mRNA expression level of SMARCA1 and EDNRB was associated with poor overall survival in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), respectively. Additionally, pathway and protein-protein interactions network analyses found the two genes were correlated with epithelial-mesenchymal transition process. In conclusion, mutations of EGFR and ALK were significantly correlated with NSCLC metastasis. In addition, thirteen novel genes were identified to be associated with NSCLC metastasis, especially SMARCA1 in LUAD and EDNRB in LUSC.

ERN1 knockdown modifies the impact of glucose and glutamine deprivations on the expression of EDN1 and its receptors in glioma cells

Objective. The aim of the present investigation was to study the impact of glucose and gluta-mine deprivations on the expression of genes encoding EDN1 (endothelin-1), its cognate receptors (EDNRA and EDNRB), and ECE1 (endothelin converting enzyme 1) in U87 glioma cells in response to knockdown of ERN1 (endoplasmic reticulum to nucleus signaling 1), a major signaling pathway of endoplasmic reticulum stress, for evaluation of their possible implication in the control of glioma growth through ERN1 and nutrient limitations. Methods. The expression level of EDN1, its receptors and converting enzyme 1 in control U87 glioma cells and cells with knockdown of ERN1 treated by glucose or glutamine deprivation by quantitative polymerase chain reaction was studied. Results. We showed that the expression level of EDN1 and ECE1 genes was significantly up-regulated in control U87 glioma cells exposure under glucose deprivation condition in comparison with the glioma cells, growing in regular glucose containing medium. We also observed up-regulation of ECE1 gene expression in U87 glioma cells exposure under glutamine deprivation as well as down-regulation of the expression of EDN1 and EDNRA mRNA, being more significant for EDN1. Furthermore, the knockdown of ERN1 signaling enzyme function significantly modified the response of most studied gene expressions to glucose and glutamine deprivation conditions. Thus, the ERN1 knockdown led to a strong suppression of EDN1 gene expression under glucose deprivation, but did not change the effect of glutamine deprivation on its expression. At the same time, the knockdown of ERN1 signaling introduced the sensitivity of EDNRB gene to both glucose and glutamine deprivations as well as completely removed the impact of glucose deprivation on the expression of ECE1 gene. Conclusions. The results of this study demonstrated that the expression of endothelin-1, its receptors, and ECE1 genes is preferentially sensitive to glucose and glutamine deprivations in gene specific manner and that knockdown of ERN1 significantly modified the expression of EDN1, EDNRB, and ECE1 genes in U87 glioma cells. It is possible that the observed changes in the expression of studied genes under nutrient deprivation may contribute to the suppressive effect of ERN1 knockdown on glioma cell proliferation and invasiveness.

Phenotypic diversity and genetic complexity of PAX3-related Waardenburg syndrome

Waardenburg syndrome subtypes 1 and 3 are caused by pathogenic variants in PAX3. We investigated 12 individuals from four unrelated families clinically diagnosed with Waardenburg syndrome type 1/3. Novel pathogenic variants identified in PAX3 included single nucleotide variants (c.166C>T, c.829C>T), a 2-base pair deletion (c.366_367delAA) and a multi-exonic deletion. Two novel variants, c.166C>T and c.829C>T and a previously reported variant, c.256A>T in PAX3 were evaluated for their nuclear localization and ability to activate MITF promoter. The coexistence of two subtypes of Waardenburg syndrome with pathogenic variants in PAX3 and EDNRB was seen in one of the affected individuals. Multiple genetic diagnoses of Waardenburg syndrome type 3 and autosomal recessive deafness 1A was identified in an individual. We also review the phenotypic and genomic spectrum of individuals with PAX3-related Waardenburg syndrome reported in the literature.

LncRNA TGFB2-AS1 regulates lung adenocarcinoma progression via act as a sponge for miR-340-5p to target EDNRB expression

Long non-coding RNA TGFB2-antisense RNA1 (TGFB2-AS1) has been reported could regulate tumorigenesis. However, the roles of TGFB2-AS1 in lung adenocarcinoma (LUAD) remain largely unknown. In this work, we aimed to explore the expression levels of TGFB2-AS1 and mechanisms in regulating LUAD progression. Expression level of TGFB2-AS1 in LUAD tissues and normal tissues was analyzed at StarBase. Moreover, its expression in LUAD cells and normal cell was analyzed with quantitative real-time polymerase chain reaction method. Gain- and loss-of-function studies were conducted to analyze the biological roles of TGFB2-AS1 in LUAD. Results indicated TGFB2-AS1 was evidently downregulated in LUAD tissues and cells. Moreover, as analyzed by cell counting kit-8 assay, wound-healing and transwell invasion assays, results revealed TGFB2-AS1 overexpression could suppress proliferation, migration and invasion abilities of LUAD cells in vitro and tumor growth in vivo. In addition, LncBase V2.0 and TargetScan prediction tools showed TGFB2-AS1 and endothelin receptor type B (EDNRB) shares binding site in microRNA-340-5p (miR-340-5p). Furthermore, luciferase activity reporter assay and RT-qPCR assay validated these prediction results. Furthermore, we showed TGFB2-AS1 functions as sponge for miR-340-5p to regulate EDNRB expression. Collectively, our results indicated TGFB2-AS1/miR-340-5p/EDNRB axis plays crucial roles in regulating LUAD progression, indicating TGFB2-AS1 may be a novel therapeutic target for LUAD.

Endothelin signaling promotes melanoma tumorigenesis driven by constitutively active GNAQ

The G-protein-coupled receptor, endothelin receptor B (EDNRB), is an important regulator of melanocyte survival and proliferation. It acts by stimulating downstream heterotrimeric G proteins, such as Gα_q and Gα₁ . Constitutively active, oncogenic versions of Gα_q and Gα₁₁ drive melanomagenesis, but the role of Ednrb in the context of these mutant G proteins has not been previously examined. In this paper, we used a knock-in mouse allele at the Rosa26 locus to force oncogenic GNAQ^Q209L expression in melanocytes in combination with Ednrb gene knockout. The resulting pathological analysis revealed that every aspect of melanomagenesis driven by GNAQ^Q209L was inhibited. We conclude that even in the presence of oncogenic Gα_q , the Ednrb receptor activates normal Gα_q and Gα₁₁ proteins. This likely promotes tumorigenesis by activating phospholipase C-beta, the immediate effector of Gα_q/11 . These findings suggest that it might be possible to target upstream receptors to offset the effects of hyperactive G proteins, recognized as the cause of a growing number of human disorders.

Role of endothelin receptor type B (EDNRB) in lung adenocarcinoma

BACKGROUND

The five-year survival rate of lung adenocarcinoma patients (LUAD) is very low,and the methods of predicting survival are a great obstacle for LUAD therapies. Endothelin receptor type B (EDNRB) gene is associated with tumorigenesis. In this study, we aimed to evaluate the predictive value of EDNRB on LUAD.

METHODS

Survival analyses was performed to assess the correlation between EDNRB expression and survival of LUAD patients from the Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA) datasets. Gene set enrichment analysis (GSEA) was conducted to illustrate possible biological functions of EDNRB. Laboratory methods were used to verify the function of EDNRB in LUAD.

RESULTS

The TCGA results showed that a low expression of EDNRB was found in LUAD patients which led to poor outcome and worse survival, compared with the high expression in GSEA results which suggested that expression of EDNRB might be associated with regulation of the ERK pathway. Laboratory results suggested that EDNRB could inhibit the proliferation and migration of LUAD H1299 cells.

CONCLUSIONS

EDNRB is a potential prognostic marker for LUAD patients and might exert its functions by regulating the ERK pathway in LUAD.

Genome-wide association studies for iris pigmentation and heterochromia patterns in Large White pigs

Eye colour genetics have been extensively studied in humans since the rediscovery of Mendel's laws. This trait was first interpreted using simplistic genetic models but soon it was realised that it is more complex. In this study, we analysed eye colour variability in a Large White pig population (n = 897) and report the results of GWASs based on several comparisons including pigs having four main eye colour categories (three with both pigmented eyes of different brown grades: pale, 17.9%; medium, 14.8%; and dark, 54.3%; another one with both eyes completely depigmented, 3.8%) and heterochromia patterns (heterochromia iridis - depigmented iris sectors in pigmented irises, 3.2%; heterochromia iridum - one whole eye iris of depigmented phenotype and the other eye with the iris completely pigmented, 5.9%). Pigs were genotyped with the Illumina PorcineSNP60 BeadChip and GEMMA was used for the association analyses. The results indicated that SLC45A2 (on chromosome 16, SSC16), EDNRB (SSC11) and KITLG (SSC5) affect the different grades of brown pigmentation of the eyes, the bilateral eye depigmentation defect and the heterochromia iridis defect recorded in this white pig population respectively. These genes are involved in several mechanisms affecting pigmentation. Significant associations for the eye depigmented patterns were also identified for SNPs on two SSC4 regions (including two candidate genes: NOTCH2 and PREX2) and on SSC6, SSC8 and SSC14 (including COL17A1 as candidate gene). This study provided useful information to understand eye pigmentation mechanisms, further valuing the pig as animal model to study complex phenotypes in humans.

EDNRB Reverses Methylprednisolone-Mediated Decrease in Neural Progenitor Cell Viability via Regulating PI3K/Akt Pathway and lncRNA Expression

OBJECTIVE

To investigate the functions and mechanisms of methylprednisolone (MP) through endothelin receptor B (EDNRB) on the cell proliferation of neural progenitor cells (NPCs) to regulate spinal cord injury.

METHODS

Primary NPCs were isolated from fetal mice and subjected to treatments with MP and IRL-1620 (EDNRB agonist). The cell viability was determined using the MTS assay. Total RNA was extracted from the cells, and RNA-seq was performed to screen for lncRNAs. The targets of the candidate lncRNAs were predicted by GO and KEGG analyses, and the expressions of lncRNAs were validated via qPCR. Furthermore, protein levels of the PI3K-AKT pathway were determined via Western blotting, and the expression of lncRNAs was detected after inhibiting the pathway with AKT inhibitor.

RESULTS

MTS assays revealed that MP decreased the cell viability of NPCs, whereas the EDNRB agonist reversed this effect of MP. NPCs were used for RNA-seq in the following three groups: normal control (NC), MP, and MP combined with EDNRB agonist (MP + EDNRB). Our results suggested that the NONRATT030699.2, NONRATT004088.2, and NONRATT005601.2 lncRNAs might be involved in the signaling pathway that is correlated to MP and the EDNRB agonist. GO and KEGG pathway analyses revealed that this was the PI3K/AKT pathway. The relevant genes involved in the pathway were validated by Western blotting. The EDNRB agonist promoted cell proliferation mainly via the activation of the PI3K/AKT pathway; however, it suppressed the expression of p-ERK, thereby increasing the expression of cyclin D1 and attenuating the effect of MP in suppressing cell proliferation. Meanwhile, after the AKT signal pathway was inhibited, these lncRNA expressions were consistent with those in the MP + EDNRB group.

CONCLUSION

MP inhibits NPC proliferation, whereas EDNRB activation reverses the effect of MP via lncRNA.

Ultrastable and Biofunctionalizable Conjugated Polymer Nanoparticles with Encapsulated Iron for Ferroptosis Assisted Chemodynamic Therapy

We report the development of novel tumor-targeted conjugated polymer nanoparticles (CPNPs) carrying iron for chemodynamic therapy (CDT). Tumor cell killing proceeds through ferroptosis, a reactive oxygen species (ROS) mechanism that is not dependent on external activation by, for example, light, as is the case in photodynamic therapy (PDT). The ferroptosis mechanism is also not heavily reliant on oxygen availability and is, therefore, promising for the treatment of hypoxic tumors. In this work, we apply this development to the case study of melanoma, a difficult to treat cancer in advanced stages due to resistance to chemotherapy. The iron-carrying CPNPs reported here are targeted to endothelin-B receptors (EDNRB) through endothelin-3 surface moieties (EDN3-CPNPs). Our results show excellent targeting to tumor cells that overexpress EDNRB, specifically for melanoma and bladder tumor cells. In these cases, efficient cell killing, over 80% at higher doses, was found. Conversely, tumor cells not targeted by the EDN3-CPNPs show little effects of CDT, with tumor cell death under 20% in most cases. The outcomes of our work demonstrate that EDN3-CPNPs enable ferroptosis-assisted CDT and present a new therapeutic avenue for tumor treatment.

The heterozygous EDNRB mutation in a Chinese family with Waardenburg syndrome type I

The genovariation of endothelin receptor type B (EDNRB) was identified in a Chinese family with Waardenburg syndrome type I (WS1) in the present study. WS1 was diagnosed in a 19-year-old young man, his older sister and aunt according to WS consortium criteria. After extracting genomic DNA from the peripheral blood samples, the coding exons and intronic regions of EDNRB were sequenced. A missense heterozygous mutation was found in the coding region of exon 2 in the EDNRB gene on chormosome 13q22.3 of the proband. The same mutation was detected in the proband's afflicted paternal aunt and first older sister. Subsequent polyphen analysis and three-dimensional modeling confirmed that the c.469A>G heterozygous mutation in EDNRB was possibly pathogenic. This is the first report of EDNRB mutation as a potential disease-causing mutation in Chinese patients with WS1.

Growth factor and receptor malfunctions associated with human genetic deafness

A variety of different signaling pathways are necessary for development and maintenance of the human auditory system. Normal hearing allows for the detection of soft sounds within the frequency range of 20 to 20 000 Hz, but more importantly to perceive the human voice frequency band of 250 to 6000 Hz. Loss of hearing is common, and is a clinically heterogeneous disorder that can be caused by environmental factors such as exposure to loud noise, infections and ototoxic drugs. In addition, variants of hundreds of genes have been reported to disrupt processes required for hearing. Noncoding regulatory variants and variants of additional genes necessary for hearing remain to be discovered as many individuals with inherited deafness are without a genetic diagnosis, despite the advent of whole exome sequencing. Here, we discuss in detail some of these deafness-causing variants of genes encoding a ligand or its receptor. Spotlighted in this review are three growth factor-receptor-pairs EDN3/EDNRB, HGF/MET and JAG/NOTCH, which individually are necessary for normal hearing. We also offer our perspective on unanswered questions, future challenges and potential opportunities for treatments emerging from molecular genetic and mechanistic studies of deafness due to these causes.

The effect of miR-124-3p on cell proliferation and apoptosis in bladder cancer by targeting EDNRB

INTRODUCTION

Endothelin receptor type B (EDNRB) is a potential target gene of miR-124-3p, but the association between miR-124-3p and EDNRB has not yet been reported. The aim of this study was to investigate the role of miR-124-3p in bladder cancer (BC) and to determine whether miR-124-3p regulates cell proliferation by targeting EDNRB.

MATERIAL AND METHODS

Bladder cancer tissues and cell lines were obtained in order to analyze the miR-124-3p and EDNRB expression through quantitative RT-PCR (qRT-PCR) and western blotting analysis. The dual-luciferase reporter assay was employed to confirm the relationship between miR-124-3p and EDNRB. The manipulation of miR-124-3p and EDNRB expression was achieved through cell transfection. Cell proliferation and apoptosis were evaluated by MTS assay, colony forming assay and flow cytometry. A nude mouse tumorigenicity assay was used to detect the effects of miR-124-3p in vivo.

RESULTS

There was an inverse correlation between the expression of miR-124-3p and EDNRB; miR-124-3p was down-regulated and EDNRB was up-regulated in BC tissues and cell lines. MiR-124-3p was observed to target EDNRB and suppress its expression. Other studies have suggested that the transfection of miR-124-3p mimics and EDNRB siRNA can suppress BC cell proliferation and induce cell apoptosis.

CONCLUSIONS

miR-124-3p regulates the proliferation and apoptosis of BC cells by suppressing EDNRB expression.

Associations of EDNRA and EDNRB Polymorphisms with Intracerebral Hemorrhage

OBJECTIVE

The most potent vasoconstrictor, endothelin-1 and its receptors, endothelin receptor A (EDNRA) and endothelin receptor B (EDNRB) are involved in hypertension. Hypertension is a major risk factor of intracerebral hemorrhage (ICH). Recent studies have demonstrated increased plasma endothelin-1 level in ICH patients and relationships between EDNRA and EDNRB genetic variants and ischemic stroke. The aim of the current study was to investigate whether EDNRA and EDNRB polymorphisms are associated with ICH by interacting with blood pressure levels.

METHODS

Five EDNRA and EDNRB polymorphisms were genotyped in this case-control study.

RESULTS

We identified that EDNRA rs5333 T allele might be a protective factor of ICH (adjusted odds ratio [OR] = 0.638, 95% CI: 0.417-0.977, P = 0.038), while EDNRB rs5351 A allele could be a risk factor of ICH (adjusted OR = 1.476, 95% CI: 1.042-2.089, P = 0.028). Moreover, we only found that the GG genotype of EDNRA rs5335 had higher diastolic blood pressure than the GC + CC genotypes in ICH patients (91.69 ± 18.77 vs. 84.71 ± 21.48, P = 0.004).

CONCLUSIONS

These findings support the important role of EDNRA and EDNRB polymorphisms in ICH, and suggest that they do not interact with blood pressure levels on altering ICH risk.

Expression of endothelin type B receptors (EDNRB) on smooth muscle cells is controlled by MKL2, ternary complex factors, and actin dynamics

The endothelin type B receptor (ET_B or EDNRB) is highly plastic and is upregulated in smooth muscle cells (SMCs) by arterial injury and following organ culture in vitro. We hypothesized that this transcriptional plasticity may arise, in part, because EDNRB is controlled by a balance of transcriptional inputs from myocardin-related transcription factors (MRTFs) and ternary complex factors (TCFs). We found significant positive correlations between the TCFs ELK3 and FLI1 versus EDNRB in human arteries. The MRTF MKL2 also correlated with EDNRB. Overexpression of ELK3, FLI1, and MKL2 in human coronary artery SMCs promoted expression of EDNRB, and the effect of MKL2 was antagonized by myocardin (MYOCD), which also correlated negatively with EDNRB at the tissue level. Silencing of MKL2 reduced basal EDNRB expression, but depolymerization of actin using latrunculin B (LatB) or overexpression of constitutively active cofilin, as well as treatment with the Rho-associated kinase (ROCK) inhibitor Y27632, increased EDNRB in a MEK/ERK-dependent fashion. Transcript-specific primers indicated that the second EDNRB transcript (EDNRB_2) was targeted, but this promoter was largely unresponsive to LatB and was inhibited rather than stimulated by MKL2 and FLI1, suggesting distant control elements or an indirect effect. LatB also reduced expression of endothelin-1, but supplementation experiments argued that this was not the cause of EDNRB induction. EDNRB finally changed in parallel with ELK3 and FLI1 in rat and human carotid artery lesions. These studies implicate the actin cytoskeleton and ELK3, FLI1, and MKL2 in the transcriptional control of EDNRB and increase our understanding of the plasticity of this receptor.

Genetic analysis of a Chinese family with members affected with Usher syndrome type II and Waardenburg syndrome type IV

AIMS

The purpose of this study was to identify the genetic causes of a family presenting with multiple symptoms overlapping Usher syndrome type II (USH2) and Waardenburg syndrome type IV (WS4).

METHODS

Targeted next-generation sequencing including the exon and flanking intron sequences of 79 deafness genes was performed on the proband. Co-segregation of the disease phenotype and the detected variants were confirmed in all family members by PCR amplification and Sanger sequencing.

RESULTS

The affected members of this family had two different recessive disorders, USH2 and WS4. By targeted next-generation sequencing, we identified that USH2 was caused by a novel missense mutation, p.V4907D in GPR98; whereas WS4 due to p.V185M in EDNRB. This is the first report of homozygous p.V185M mutation in EDNRB in patient with WS4.

CONCLUSION

This study reported a Chinese family with multiple independent and overlapping phenotypes. In condition, molecular level analysis was efficient to identify the causative variant p.V4907D in GPR98 and p.V185M in EDNRB, also was helpful to confirm the clinical diagnosis of USH2 and WS4.

Allergic Inflammation Leads to Neuropathic Pain via Glial Cell Activation

Allergic and atopic disorders have increased over the past few decades and have been associated with neuropsychiatric conditions, such as autism spectrum disorder and asthmatic amyotrophy. Myelitis presenting with neuropathic pain can occur in patients with atopic disorder; however, the relationship between allergic inflammation and neuropathic pain, and the underlying mechanism, remains to be established. We studied whether allergic inflammation affects the spinal nociceptive system. We found that mice with asthma, atopic dermatitis, or atopic diathesis had widespread and significantly more activated microglia and astroglia in the spinal cord than those without atopy, and displayed tactile allodynia. Microarray analysis of isolated microglia revealed a dysregulated phenotype showing upregulation of M1 macrophage markers and downregulation of M2 markers in atopic mice. Among the cell surface protein genes, endothelin receptor type B (EDNRB) was most upregulated. Immunohistochemical analysis revealed that EDNRB expression was enhanced in microglia and astroglia, whereas endothelin-1, an EDNRB ligand, was increased in serum, lungs, and epidermis of atopic mice. No EDNRA expression was found in the spinal cord. Expression of FBJ murine osteosarcoma viral oncogene homolog B was significantly higher in the dorsal horn neurons of asthma mice than nonatopic mice. The EDNRB antagonist BQ788 abolished glial and neural activation and allodynia. We found increased serum endothelin-1 in atopic patients with myelitis and neuropathic pain, and activation of spinal microglia and astroglia with EDNRB upregulation in an autopsied case. These results suggest that allergic inflammation induces diffuse glial activation, influencing the nociceptive system via the EDNRB pathway.

SIGNIFICANCE STATEMENT

The prevalence of allergic disorders has markedly increased over the past few decades. Allergic disorders are associated with neuropsychiatric conditions; however, the relationship between allergic inflammation and CNS complications is unknown. A peculiar myelitis presenting with persistent neuropathic pain has been reported in patients with allergic disorders. We studied how atopy exerts substantial influence on the nociceptive system. We found that mice with allergic disorders had severe allodynia with activated astroglia and microglia, and showed marked upregulation of endothelin-1 (ET-1) receptor type B (EDNRB) in the spinal cord. A selective EDNRB antagonist prevented allodynia and glial activation. Our findings suggest a novel mechanism whereby atopy induces glial activation and neuropathic pain via an ET-1/EDNRB pathway.

Homozygous EDNRB mutation in a patient with Waardenburg syndrome type 1

OBJECTIVE

To examine and expand the genetic spectrum of Waardenburg syndrome type 1 (WS1).

METHODS

Clinical features related to Waardenburg syndrome (WS) were examined in a five-year old patient. Mutation analysis of genes related to WS was performed in the proband and her parents. Molecular modeling of EDNRB and the p.R319W mutant was conducted to predict the pathogenicity of the mutation.

RESULTS

The proband showed sensorineural hearing loss, heterochromia iridis, and dystopia canthorum, fulfilling the clinical criteria of WS1. Genetic analyses revealed that the proband had no mutation in PAX3 which has been known as the cause of WS1, but had a homozygous missense mutation (p.R319W) in endothelin receptor type B (EDNRB) gene. The asymptomatic parents had the mutation in a heterozygote state. This mutation has been previously reported in a heterozygous state in a patient with Hirschsprung's disease unaccompanied by WS, but the patient and her parents did not show any symptoms in gastrointestinal tract. Molecular modeling of EDNRB with the p.R319W mutation demonstrated reduction of the positively charged surface area in this region, which might reduce binding ability of EDNRB to G protein and lead to abnormal signal transduction underlying the WS phenotype.

CONCLUSIONS

Our findings suggested that autosomal recessive mutation in EDNRB may underlie a part of WS1 with the current diagnostic criteria, and supported that Hirschsprung's disease is a multifactorial genetic disease which requires additional factors. Further molecular analysis is necessary to elucidate the gene interaction and to reappraise the current WS classification.

Aberrant methylated EDNRB can act as a potential diagnostic biomarker in sporadic colorectal cancer while KISS1 is controversial

Cancers are among the most serious threats of human health worldwide. Survival and mortality rates of colorectal cancer (CRC) strongly depend on the early diagnosis. The aberrant methylation pattern of genes as a diagnostic biomarker can serve as a practical option for timely detection and contribute subsequently to the enhancement of survival rate in CRC patients, since methylation changes are not only frequent but also can occur in initial tumorogenesis stages. It has been indicated that EDNRB and KISS1 genes are hypermethylated through progression and development of CRC. In current study, after extraction of genomic DNA from 45 paired tumor and adjacent non-cancerous tissue samples and treatment with bisulfite conversion, the methylation status of EDNRB and KISS1 CpG rich regions were assessed quantitatively using MS-HRM assay to determine practicability of these aberrant methylations for diagnosis of sporadic CRC and its discrimination from corresponding normal tissues. The results showed that the methylation distribution differences, comparing tumor tissues with their adjacent non-cancerous tissues, were statistically significant in all selected locations within EDNRB gene promoter (P < 0.001); they had also some correlations with tumor stage and grade. Nonetheless, methylation distribution in KISS1 gene CpG rich region revealed no statistically significant differences between CRC and adjacent non-cancerous tissues (P = 0.060). Overall, it can be concluded that aberrant methylated EDNRB can be a promising potential diagnostic biomarker for CRC, while KISS1 is controversial and needs to be more investigated.

Gnaq and Gna11 in the Endothelin Signaling Pathway and Melanoma

In this article, we first briefly outline the function of G protein coupled receptors in cancer, and then specifically examine the roles of the seven transmembrane G protein coupled Endothelin B receptor (Ednrb) and the G proteins, GNAQ and GNA11, in both melanocyte development and melanoma. Ednrb plays an essential role in melanocyte development. GNAQ and GNA11 are oncogenes when mutated in certain types of melanocytic lesions, being extremely frequent in uveal melanoma, which forms from melanocytes located in the eye. Previously, we reported that in mice, Schwann cell precursor derived melanocytes colonize the dermis and hair follicles, while the inter-follicular epidermis is populated by other melanocytes. A pattern has emerged whereby melanocytes whose activities are affected by gain-of-function mutations of the Endothelin 3 ligand and Gα_q/11 are the same subset that arise from Schwann cell precursors. Furthermore, the forced expression of the constitutively active human GNAQ^Q209L oncogene in mouse melanocytes only causes hyper-proliferation in the subset that arise from Schwann cell precursors. This has led us to hypothesize that in Schwann cell precursor derived melanocytes, Ednrb signals through Gα_q/11. Ednrb is promiscuous and may signal through other G protein alpha subunits in melanomas located in the inter-follicular epidermis.

The Genetics of Deafness in Domestic Animals

Although deafness can be acquired throughout an animal's life from a variety of causes, hereditary deafness, especially congenital hereditary deafness, is a significant problem in several species. Extensive reviews exist of the genetics of deafness in humans and mice, but not for deafness in domestic animals. Hereditary deafness in many species and breeds is associated with loci for white pigmentation, where the cochlear pathology is cochleo-saccular. In other cases, there is no pigmentation association and the cochlear pathology is neuroepithelial. Late onset hereditary deafness has recently been identified in dogs and may be present but not yet recognized in other species. Few genes responsible for deafness have been identified in animals, but progress has been made for identifying genes responsible for the associated pigmentation phenotypes. Across species, the genes identified with deafness or white pigmentation patterns include MITF, PMEL, KIT, EDNRB, CDH23, TYR, and TRPM1 in dog, cat, horse, cow, pig, sheep, ferret, mink, camelid, and rabbit. Multiple causative genes are present in some species. Significant work remains in many cases to identify specific chromosomal deafness genes so that DNA testing can be used to identify carriers of the mutated genes and thereby reduce deafness prevalence.

A novel mutation in the endothelin B receptor gene in a moroccan family with shah-waardenburg syndrome

Waardenburg syndrome (WS) is a neurocristopathy disorder combining sensorineural deafness and pigmentary abnormalities. The presence of additional signs defines the 4 subtypes. WS type IV, also called Shah-Waardenburg syndrome (SWS), is characterized by the association with congenital aganglionic megacolon (Hirschsprung disease). To date, 3 causative genes have been related to this congenital disorder. Mutations in the EDNRB and EDN3 genes are responsible for the autosomal recessive form of SWS, whereas SOX10 mutations are inherited in an autosomal dominant manner. We report here the case of a 3-month-old Morrocan girl with WS type IV, born to consanguineous parents. The patient had 3 cousins who died in infancy with the same symptoms. Molecular analysis by Sanger sequencing revealed the presence of a novel homozygous missense mutation c.1133A>G (p.Asn378Ser) in the EDNRB gene. The proband's parents as well as the parents of the deceased cousins are heterozygous carriers of this likely pathogenic mutation. This molecular diagnosis allows us to provide genetic counseling to the family and eventually propose prenatal diagnosis to prevent recurrence of the disease in subsequent pregnancies.

Gene methylation in gastric cancer

Gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. Over 70% of new cases and deaths occur in developing countries. In the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. Epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Recent advancements in the rapidly evolving field of cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer, including DNA methylation, histone modifications, nucleosome positioning, noncoding RNAs, and microRNAs. Aberrant DNA methylation in the promoter regions of gene, which leads to inactivation of tumor suppressor and other cancer-related genes in cancer cells, is the most well-defined epigenetic hallmark in gastric cancer. The advantages of gene methylation as a target for detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as serum and gastric washes have led to many studies of application in gastric cancer. This review focuses on the most common and important phenomenon of epigenetics, DNA methylation, in gastric cancer and illustrates the impact epigenetics has had on this field.

Pleiotropic effects of coat colour-associated mutations in humans, mice and other mammals

The characterisation of the pleiotropic effects of coat colour-associated mutations in mammals illustrates that sensory organs and nerves are particularly affected by disorders because of the shared origin of melanocytes and neurocytes in the neural crest; e.g. the eye-colour is a valuable indicator of disorders in pigment production and eye dysfunctions. Disorders related to coat colour-associated alleles also occur in the skin (melanoma), reproductive tract and immune system. Additionally, the coat colour phenotype of an individual influences its general behaviour and fitness. Mutations in the same genes often produce similar coat colours and pleiotropic effects in different species (e.g., KIT [reproductive disorders, lethality], EDNRB [megacolon] and LYST [CHS]). Whereas similar disorders and similar-looking coat colour phenotypes sometimes have a different genetic background (e.g., deafness [EDN3/EDNRB, MITF, PAX and SNAI2] and visual diseases [OCA2, RAB38, SLC24A5, SLC45A2, TRPM1 and TYR]). The human predilection for fancy phenotypes that ignore disorders and genetic defects is a major driving force for the increase of pleiotropic effects in domestic species and laboratory subjects since domestication has commenced approximately 18,000 years ago.