EBF1 Limits the Numbers of Cochlear Hair and Supporting Cells and Forms the Scala Tympani and Spiral Limbus during Inner Ear Development.

Early B-cell factor 1 (EBF1) is a basic helix-loop-helix transcription factor essential for the differentiation of various tissues. Our single-cell RNA sequencing data suggest that Ebf1 is expressed in the sensory epithelium of the mouse inner ear. Here, we found that the murine Ebf1 gene and its protein are expressed in the prosensory domain of the inner ear, medial region of the cochlear duct floor, otic mesenchyme, and cochleovestibular ganglion. Ebf1 deletion in mice results in incomplete formation of the spiral limbus and scala tympani, increased number of cells in the organ of Corti and Kölliker's organ, and aberrant course of the spiral ganglion axons. Ebf1 deletion in the mouse cochlear epithelia caused the proliferation of SOX2-positive cochlear cells at E13.5, indicating that EBF1 suppresses the proliferation of the prosensory domain and cells of Kölliker's organ to facilitate the development of appropriate numbers of hair and supporting cells. Furthermore, mice with deletion of cochlear epithelium-specific Ebf1 showed poor postnatal hearing function. Our results suggest that Ebf1 is essential for normal auditory function in mammals.

[EBF1 Promotes the Sensitivity of Cervical Cancer Cells to Cisplatin via Activating FBN1 Transcription].

Cisplatin (DDP) is widely used in the chemotherapy of cervical cancer (CC), the fourth most common female malignancy worldwide. However, some patients progress to chemotherapy resistance, which leads to chemotherapy failure, tumor recurrence, and poor prognosis. Therefore, strategies to identify the regulatory mechanisms underlying CC development and increase tumor sensitivity to DDP will help improve patient survival. This research was designed to ascertain the mechanism of EBF1-dependent regulation of FBN1 which promotes chemosensitivity of CC cells. The expression of EBF1 and FBN1 was measured in CC tissues resistant or sensitive to chemotherapy and in DDP-sensitive or -resistant cells (SiHa and SiHa-DDP cells). SiHa-DDP cells were transduced with lentiviruses encoding EBF1 or FBN1 to evaluate the influence of these two proteins on cell viability, expression of MDR1 and MRP1, and cell aggressiveness. Moreover, the interaction between EBF1 and FBN1 was predicted and demonstrated. Finally, to further verify the EBF1/FB1-dependent mechanism of DDP sensitivity regulation in CC cells a xenograft mouse model of CC was established using SiHa-DDP cells transduced with lentiviruses carrying EBF1 gene and shRNA directed to FBN1 EBF1 and FBN1 showed decreased expression in CC tissues and cells, particularly in those resistant to chemotherapy. Transduction of SiHa-DDP cells with lentiviruses encoding EBF1 or FBN1 lead to decreased viability, IC50, proliferation capacity, colony formation ability, aggressiveness, and increased cell apoptosis. We have shown that EBF1 activates FBN1 transcription by binding to FBN1 promoter region. Additionally, it was revealed that FBN1 silencing reversed the promoting effect of EBF1 overexpression on chemosensitivity of CC cells in vivo. EBF1 facilitated chemosensitivity in CC cells by activating FBN1 transcription.

Inactivated STAT5 pathway underlies a novel inhibitory role of EBF1 in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (CLL) is a disease caused by gradual accumulation of functionally incompetent lymphocytes. The majority of CLL cases are accompanied by chemoresistance. Early B cell factor 1 (EBF1) is a crucial contributor to B-cell lymphopoiesis. This study is to explore the effect of EBF1 on CLL cell progression and its involvement in regulating the signal transducers and activators of transcription 5 (STAT5) pathway. We conducted a correlation analysis between EBF1 and the clinical characteristics of CLL patients. Subsequently, EBF1 was overexpressed by transfection with EBF1 overexpression plasmid and the STAT5 pathway was also blocked by treatment with SH-4-54 in isolated CD20+ B lymphocytes to investigate their roles in the regulation of cellular functions. STAT5, Janus kinase 2 (JAK2) expression and their phosphorylation levels were determined by quantitative PCR and Western blot analyses. The in vivo effects of EBF1 on tumor growth were evaluated using a xenotransplant model. Downregulation of EBF1 was observed in CD20+ B lymphocytes of CLL patients. EBF1 overexpression disrupted the activation of STAT5 pathway, as evidenced by decreased expression and phosphorylation levels of STAT5 and JAK2. Furthermore, overexpression of EBF1 repressed viability and cell cycle entry, and increased apoptosis of CD20+ B lymphocytes by inhibiting the STAT5 pathway. Finally, EBF1 exerted antitumor effects in nude mice. Overall, our study elucidates the inhibitory role of EBF1 in CLL through inactivation of the STAT5 pathway, which may provide new targets for CLL treatment.

Defining B Cell Chromatin: Lessons from EBF1.

Hematopoiesis is regulated by signals from the microenvironment, transcription factor networks, and changes of the epigenetic landscape. Transcription factors interact with and shape chromatin to allow for lineage- and cell type-specific changes in gene expression. During B lymphopoiesis, epigenetic regulation is observed in multilineage progenitors in which a specific chromatin context is established, at the onset of the B cell differentiation when early B cell factor 1 (EBF1) induces lineage-specific changes in chromatin, during V(D)J recombination and after antigen-driven activation of B cells and terminal differentiation. In this review, we discuss the epigenetic changes underlying B cell differentiation, focusing on the role of transcription factor EBF1 in B cell lineage priming.

Long intergenic noncoding RNA 00844 promotes apoptosis and represses proliferation of prostate cancer cells through upregulating GSTP1 by recruiting EBF1.

Accumulating evidence have suggested the function of long noncoding RNAs as crucial players in the pathogenesis of prostate cancer (PC), a urologic tumor in male with poor prognosis. This study was designed to explore the functions of long intergenic noncoding RNA 00844 (LINC00844) in PC progression. The expression of LINC00844 and glutathione S-transferase P1-1 (GSTP1) was detected by reverse transcription quantitative polymerase chain reaction, followed by the identification of the relationship among LINC00844, GSTP1, and early B cell factor 1 (EBF1) by dual luciferase reporter gene assay, RNA immunoprecipitation assay, electrophoretic mobility shift assay, and chromatin immunoprecipitation assay. Using loss- and gain-of-function assays, the effects of LINC00844, GSTP1, and EBF1 on the biological characteristics of PC cells were assessed by cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Lastly, the results from in vitro experiments were verified in vivo by establishing a xenograft tumor model in nude mice. LINC00844 and GSTP1 both displayed low expression in PC tissues and cells. LINC00844 positively regulated the expression of GSTP1 via recruiting EBF1. Overexpression of LINC00844 reduced proliferation and elevated apoptosis of PC cells through recruiting EBF1, which subsequently upregulated GSTP1. In vivo experiments confirmed that LINC00844 or GSTP1 upregulation attenuated tumor growth. LINC00844 elevated GSTP1 expression by recruiting EBF1 to the promoter region of GSTP1, thereby suppressing PC progression. Hence, LINC00844 is a novel therapeutic target for the development of new treatment protocols for PC.

Association in a Chinese population of a genetic variation in the early B-cell factor 1 gene with coronary artery disease.

BACKGROUND: Early B-cell factor 1 (EBF1) is a transcription factor expressed primarily during early B cell development. Previous studies have shown EBF1 regulates blood glucose and lipid metabolism in mice with diabetes and central adiposity. Recently, a genetic variation (rs36071027) located in an EBF1 gene intron was associated with carotid artery intima-media thickness. However, whether this polymorphism is actually linked with coronary artery disease (CAD) and its severity remains unclear. METHODS: This study includes 293 CAD cases and 262 controls without CAD. All participants were devided into two groups based on their coronary angiography results. A polymerase chain reaction-ligase detection reaction was used to identify genotypes at rs36071027, and CAD patients were further divided into subgroups with one-, two-, or three-vessel stenosis reflective of CAD severity. RESULTS: The frequency of the rs36071027 TT genotype was significantly higher in CAD cases versus controls (4.8% vs. 1.5%, 95% CI: 1.13-10.81 P = 0.029). Subjects with a variant genotype T allele had an increased risk of CAD compared to C allele carriers (additive model: 95% CI: 1.13-2.23, P = 0.008). After adjustment for cardiovascular risk factors, analysis of the additive and dominant models involving rs36071027 also revealed that T allele carriers had a significantly higher risk for CAD than C allele carriers (additive model: OR 1.56, 95% CI 1.10-2.22, P = 0.013; dominant model: OR 1.60, 95% CI 1.07-2.41, P = 0.023). Furthermore, both diabetes and the CT + TT rs36071027 genotype were significantly associated with three-vessel stenosis. CONCLUSION: Our results in a Chinese population suggest that the TT genotype and T alleles in rs36071027 in the EBF1 gene are associated with an increased risk of CAD and its severity.

WITHDRAWN: Effect of shRNA­mediated knockdown EBF1 gene expression on the proliferation of lung cancer cell line A549 in vitro and in vivo.

The paper entitled "Effect of shRNA­mediated knockdown EBF1 gene expression on the proliferation of lung cancer cell line A549 in vitro and in vivo" by Lin Wang et al, which was published online on 16 March 2023, has been withdrawn at the authors' request.

Long noncoding RNA IL6-AS1 is highly expressed in chronic obstructive pulmonary disease and is associated with interleukin 6 by targeting miR-149-5p and early B-cell factor 1.

Chronic obstructive pulmonary disease is a complex condition with multiple etiologies, including inflammation. We identified a novel long noncoding RNA (lncRNA), interleukin 6 antisense RNA 1 (IL6-AS1), which is upregulated in this disease and is associated with airway inflammation. We found that IL6-AS1 promotes the expression of inflammatory factors, especially interleukin (IL) 6. Mechanistically, cytoplasmic IL6-AS1 acts as an endogenous sponge by competitively binding to the microRNA miR-149-5p to stabilize IL-6 mRNA. Nuclear IL6-AS1 promotes IL-6 transcription by recruiting early B-cell factor 1 to the IL-6 promoter, which increases the methylation of the H3K4 histone and acetylation of the H3K27 histone. We propose a model of lncRNA expression in both the nucleus and cytoplasm that exerts similar effects through differing mechanisms, and IL6-AS1 probably increases inflammation via multiple pathways.

EBF1 gene polymorphism and its interaction with smoking and drinking on the risk of coronary artery disease for Chinese patients.

Objective: Early B-cell factor 1 (EBF1) is a transcription factor that is expressed in early B-cells, adipocytes, and olfactory neurons, and is essential for the maturation of early B lymphocytes. The present study analyzes the influence of EBF1 gene polymorphism and its interaction with smoking and drinking on the risk of coronary artery disease (CAD). Methods: In the present study, 243 CAD cases were enrolled as the CAD group and 215 non-CAD patients as the control group by case-control study. We analyzed their genotypes of the rs987401919, rs36071027, and rs1056065671 loci of the EBF1 gene by Sanger sequencing and detected their content of HDL-C, LDL-C, and TG. Results: The C allele at the rs987401919 and rs36071027 loci of EBF1 was found to be the risk factor for CAD (Odds ratio, OR = 1.233; 95% confidence interval, CI: 1.039-1.421; P=0.017; OR = 1.487; 95% CI: 1.015-1.823; P=0.042). The interaction between single nucleotide polymorphisms (SNP) of the rs987401919 and rs36071027 loci and smoking and drinking were distinctly associated with the incidence of CAD (P<0.05). The content of systolic blood pressure (SBP), diastolic blood pressure (DBP), HDL-C, LDL-C, and TG was distinctly changed after gene mutation at the rs987401919 and rs36071027 loci (P<0.05). Conclusion: The results of the present study show that the mutation (CT+TT) at the rs987401919 and rs36071027 loci of EBF1 and its interaction with smoking and drinking are risk factors for CAD, and that the mechanism may be related to the changes in blood pressure and blood lipid content.

Replication of Early B-cell Factor 1 (EBF1) Gene-by-psychosocial Stress Interaction Effects on Central Adiposity in a Korean Population.

OBJECTIVES: Central obesity plays a major role in the development of many chronic diseases, including cardiovascular disease and cancer. Chronic stress may be involved in the pathophysiology of central obesity. Although several large-scale genome-wide association studies have reported susceptibility genes for central adiposity, the effects of interactions between genes and psychosocial stress on central adiposity have rarely been examined. A recent study focusing on Caucasians discovered the novel gene early B-cell factor 1 (EBF1), which was associated with central obesity-related traits via interactions with stress levels. We aimed to evaluate EBF1 gene-by-stress interaction effects on central adiposity traits, including visceral adipose tissue (VAT), in Korean adults. METHODS: A total of 1467 Korean adults were included in this study. We selected 22 single-nucleotide polymorphisms (SNPs) in the EBF1 gene and analyzed their interactions with stress on central adiposity using additive, dominant, and recessive genetic modeling. RESULTS: The four SNPs that had strong linkage disequilibrium relationships (rs10061900, rs10070743, rs4704967, and rs10056564) demonstrated significant interactions with the waist-hip ratio in the dominant model (pint<0.007). In addition, two other SNPs (rs6556377 and rs13180086) were associated with VAT by interactions with stress levels, especially in the recessive genetic model (pint<0.007). As stress levels increased, the mean values of central adiposity traits according to SNP genotypes exhibited gradual but significant changes (p<0.05). CONCLUSIONS: These results suggest that the common genetic variants for EBF1 are associated with central adiposity through interactions with stress levels, emphasizing the importance of managing stress in the prevention of central obesity.

Protein kinase Cθ gene expression is oppositely regulated by GCN5 and EBF1 in immature B cells.

In this study, we revealed that GCN5 and early B cell factor 1 (EBF1) participate in regulation of protein kinase Cθ (PKCθ) gene expression in an opposite manner in immature B cells. GCN5-deficiency in DT40 caused drastic down-regulation of transcription of PKCθ. In contrast, EBF1-deficiency brought about remarkable up-regulation of that of PKCθ, and re-expression of EBF1 dramatically suppressed transcription of PKCθ. Chromatin immunoprecipitation assay revealed that GCN5 binds to the 5'-flanking region of the chicken PKCθ gene and acetylates histone H3, and EBF1 binds to the 5'-flanking region of the gene surrounding putative EBF1 binding motifs.

Regulation of chick early B-cell factor-1 gene expression in feather development.

The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.