Immunoinhibitory effects of hypoxia-driven reprogramming of EGR1hi and EGR3 positive B cells in the nasopharyngeal carcinoma microenvironment.

Regulatory B (Breg) cells is a type of immune cell that exhibit immunosuppressive behavior within the tumor microenvironment. However, the differentiation and regulatory mechanisms of these Breg cells remain unexplored. Single-cell transcriptome sequencing analysis of human nasopharyngeal carcinoma (NPC) revealed a significant enrichment of B cell subset characterized by high expression of EGR1 and EGR3 in the tumor microenvironment. Notably, in the hypoxic microenvironment, these B cells induce MAPK pathway activation, subsequently triggering the activation of transcription factors EGR1 and EGR3, which further modulate the expression of immunosuppressive factors like TGFB1 and IL10. In transplant experiments using primary B cells induced under hypoxia and co-transplanted with cancer cells, a significant increase in tumor growth was observed. Mechanism experiments demonstrated that EGR1hi and EGR3+ B cells further activate the maturation and immunosuppressive function of Treg cells through the secretion of IL16 and TNF-α. Hence, this study identifies the key transcription factors EGR1 and EGR3 as essential regulators and elucidates the differentiation of Breg cells under hypoxic conditions.

EGR3 Inhibits Tumor Progression by Inducing Schwann Cell-Like Differentiation.

The mechanism and function of the expression of Schwann characteristics by nevus cells in the mature zone of the dermis are unknown. Early growth response 3 (EGR3) induces Schwann cell-like differentiation of melanoma cells by simulating the process of nevus maturation, which leads to a strong phenotypic transformation of the cells, including the formation of long protrusions and a decrease in cell motility, proliferation, and melanin production. Meanwhile, EGR3 regulates the levels of myelin protein zero (MPZ) and collagen type I alpha 1 chain (COL1A1) through SRY-box transcription factor 10 (SOX10)-dependent and independent mechanisms, by binding to non-strictly conserved motifs, respectively. Schwann cell-like differentiation demonstrates significant benefits in both in vivo and clinical studies. Finally, a CD86-P2A-EGR3 recombinant mRNA vaccine is developed which leads to tumor control through forced cell differentiation and enhanced immune infiltration. Together, these data support further development of the recombinant mRNA as a treatment for cancer.

EGR3 reduces podocyte inflammatory damage in obesity related glomerulopathy by inhibiting the PRMT1/p-STAT3 pathway. / EGR3通过抑制PRMT1/p-STAT3é€šè·¯å‡è½»è‚¥èƒ–ç›¸å ³æ€§è‚¾ç— è¶³ç»†èƒžç‚Žç—‡æŸä¼¤.

OBJECTIVES: Obesity related glomerulopathy (ORG) is induced by obesity, but the pathogenesis remains unclear. This study aims to investigate the expression of early growth response protein 3 (EGR3) in the renal cortex tissues of ORG patients and high-fat diet-induced obese mice, and to further explore the molecular mechanism of EGR3 in inhibiting palmitic acid (PA) induced human podocyte inflammatory damage. METHODS: Renal cortex tissues were collected from ORG patients (n=6) who have been excluded from kidney damage caused by other diseases and confirmed by histopathology, and from obese mice induced by high-fat diet (n=10). Human and mouse podocytes were intervened with 150 µmol/L PA for 48 hours. EGR3 was overexpressed or silenced in human podocytes. Enzyme linked immunosorbent assay (ELISA) was used to detcet the levels of interleukin-6 (IL-6) and interleukin-1ß (IL-1ß). Real-time RT-PCR was used to detect the mRNA expressions of EGR3, podocytes molecular markers nephrosis 1 (NPHS1), nephrosis 2 (NPHS2), podocalyxin (PODXL), and podoplanin (PDPN). RNA-seq was performed to detect differentially expressed genes (DEGs) after human podocytes overexpressing EGR3 and treated with 150 µmol/L PA compared with the control group. Co-immunoprecipitation (Co-IP) combined with liquid chromatography tandem mass spectrometry (LC-MS) was used to detect potential interacting proteins of EGR3 and the intersected with the RNA-seq results. Co-IP confirmed the interaction between EGR3 and protein arginine methyltransferases 1 (PRMT1), after silencing EGR3 and PRMT1 inhibitor intervention, the secretion of IL-6 and IL-1ß in PA-induced podocytes was detected. Western blotting was used to detect the expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) after overexpression or silencing of EGR3. RESULTS: EGR3 was significantly upregulated in renal cortex tissues of ORG patients and high-fat diet-induced obese mice (both P<0.01). In addition, after treating with 150 µmol/L PA for 48 hours, the expression of EGR3 in human and mouse podocytes was significantly upregulated (both P<0.05). Overexpression or silencing of EGR3 in human podocytes inhibited or promoted the secretion of IL-6 and IL-1ß in the cell culture supernatant after PA intervention, respectively, and upregulated or downregulated the expression of NPHS1, PODXL, NPHS2,and PDPN (all P<0.05). RNA-seq showed a total of 988 DEGs, and Co-IP+LC-MS identified a total of 238 proteins that may interact with EGR3. Co-IP confirmed that PRMT1 was an interacting protein with EGR3. Furthermore, PRMT1 inhibitors could partially reduce PA-induced IL-6 and IL-1ß secretion after EGR3 silencing in human podocytes (both P<0.05). Overexpression or silencing of EGR3 negatively regulated the expression of PRMT1 and p-STAT3. CONCLUSIONS: EGR3 may reduce ORG podocyte inflammatory damage by inhibiting the PRMT1/p-STAT3 pathway.

The Transcriptome of BT-20 Breast Cancer Cells Exposed to Curcumin Analog NC2603 Reveals a Relationship between EGR3 Gene Modulation and Cell Migration Inhibition.

Breast cancer represents a critical global health issue, accounting for a substantial portion of cancer-related deaths worldwide. Metastasis, the spread of cancer cells to distant organs, is the primary cause of approximately 90% of breast cancer-related fatalities. Despite advances in cancer treatment, conventional chemotherapeutic drugs often encounter resistance and demonstrate limited efficacy against metastasis. Natural products have emerged as promising sources for innovative cancer therapies, with curcumin being one such example. However, despite its therapeutic potential, curcumin exhibits several limitations. Analogous compounds possessing enhanced bioavailability, potency, or specificity offer a promising avenue for overcoming these challenges and demonstrate potent anti-tumor activities. Our study investigates the antimetastatic potential of the curcumin analog NC2603 in breast cancer cells, utilizing BT-20 cells known for their migratory properties. Cell viability assessments were performed using the MTT reduction method, while migration inhibition was evaluated through scratch and Transwell migration assays. Transcriptome analysis via next-generation sequencing was employed to elucidate gene modulation and compound mechanisms, with subsequent validation using RT-qPCR. The IC50 of NC2603 was determined to be 3.5 µM, indicating potent inhibition of cell viability, and it exhibited greater specificity for BT-20 cells compared with non-cancerous HaCaT cells, surpassing the efficacy of doxorubicin. Notably, NC2603 demonstrated superior inhibition of cell migration in both scratch and Transwell assays compared with curcumin. Transcriptome analysis identified 10,620 modulated genes. We validated the expression of six: EGR3, ATF3, EMP1, SOCS3, ZFP36, and GADD45B, due to their association with migration inhibition properties. We hypothesize that the curcumin analog induces EGR3 expression, which subsequently triggers the expression of ATF3, EMP1, SOCS3, ZFP36, and GADD45B. In summary, this study significantly advances our comprehension of the intricate molecular pathways involved in cancer metastasis, while also examining the mechanisms of analog NC2603 and underscoring its considerable potential as a promising candidate for adjuvant therapy.

EGR3 and estrone are involved in the tamoxifen resistance and progression of breast cancer.

BACKGROUND: Tamoxifen (Tam) is an effective treatment for estrogen receptor (ER) positive breast cancer. However, a significant proportion of patients develop resistance under treatment, presenting a therapeutic challenge. The study aims to determine the role of early growth response protein (EGR) 3 in tamoxifen resistance (TamR) and elucidate its molecular mechanism. METHODS: TamR cell models were established and NGS was used to screening signaling alternation. Western blot and qRT-PCR were used to analysis the expression of ERα, EGR3, MCL1 and factors associated with apoptosis. CCK8, colony formation and apoptosis assay were used to analysis resistance to Tam. Immunofluorescence, chromatin immunoprecipitation, and dual luciferase assays were used to investigate mechanism of regulation. RESULTS: We observed that EGR3, a deeply rooted ERα response factor, showed increased upregulation in response to both estrone (E1) and Tam in TamR cells with elevated level of E1 and ERα expression, indicating a potential connection between EGR3 and TamR. Mechanically, manipulating EGR3 expression revealed that it imparted resistance to Tam through increased expression of the downstream molecule MCL1 (apoptosis suppressor gene) that it regulated. Mechanismly, EGR3 directly binds to the promoter of the anti-apoptotic factor MCL1 gene, facilitating its transcription. Furthermore, apoptosis assays revealed that E1 reduces Tam induced apoptosis by upregulating EGR3 expression. Importantly, clinical public database confirmed the high expression of EGR3 in breast cancer tissue and in Tam-treated patients. CONCLUSIONS: These findings shed light on the novel estrogen/EGR3/MCL1 axis and its role in inducing TamR in ER positive breast cancer. EGR3 emerges as a promising target to overcome TamR. The elucidation of this mechanism holds potential for the development of new therapeutic modalities to overcome endocrine therapy resistance in clinical settings.

The EGR3 regulome of infant KMT2A-r acute lymphoblastic leukemia identifies differential expression of B-lineage genes predictive for outcome.

KMT2A-rearranged acute lymphoblastic infant leukemia (KMT2A-r iALL) is associated with outsize risk of relapse and relapse mortality. We previously reported strong upregulation of the immediate early gene EGR3 in KMT2A::AFF1 iALL at relapse; now we provide analyses of the EGR3 regulome, which we assessed through binding and expression target analysis of an EGR3-overexpressing t(4;11) cell culture model. Our data identify EGR3 as a regulator of early B-lineage commitment. Principal component analysis of 50 KMT2A-r iALL patients at diagnosis and 18 at relapse provided strictly dichotomous separation of patients based on the expression of four B-lineage genes. Absence of B-lineage gene expression translates to more than two-fold poorer long-term event-free survival. In conclusion, our study presents four B-lineage genes with prognostic significance, suitable for gene expression-based risk stratification of KMT2A-r iALL patients.

Identification of activity-induced Egr3-dependent genes reveals genes associated with DNA damage response and schizophrenia.

Bioinformatics and network studies have identified the immediate early gene transcription factor early growth response 3 (EGR3) as a master regulator of genes differentially expressed in the brains of patients with neuropsychiatric illnesses ranging from schizophrenia and bipolar disorder to Alzheimer's disease. However, few studies have identified and validated Egr3-dependent genes in the mammalian brain. We have previously shown that Egr3 is required for stress-responsive behavior, memory, and hippocampal long-term depression in mice. To identify Egr3-dependent genes that may regulate these processes, we conducted an expression microarray on hippocampi from wildtype (WT) and Egr3-/- mice following electroconvulsive seizure (ECS), a stimulus that induces maximal expression of immediate early genes including Egr3. We identified 69 genes that were differentially expressed between WT and Egr3-/- mice one hour following ECS. Bioinformatic analyses showed that many of these are altered in, or associated with, schizophrenia, including Mef2c and Calb2. Enrichr pathway analysis revealed the GADD45 (growth arrest and DNA-damage-inducible) family (Gadd45b, Gadd45g) as a leading group of differentially expressed genes. Together with differentially expressed genes in the AP-1 transcription factor family genes (Fos, Fosb), and the centromere organization protein Cenpa, these results revealed that Egr3 is required for activity-dependent expression of genes involved in the DNA damage response. Our findings show that EGR3 is critical for the expression of genes that are mis-expressed in schizophrenia and reveal a novel requirement for EGR3 in the expression of genes involved in activity-induced DNA damage response.

Uncontrolled CD21low age-associated and B1 B cell accumulation caused by failure of an EGR2/3 tolerance checkpoint.

CD21low age-associated or atypical memory B cells are autoantibody enriched and poised for plasma cell differentiation. These cells overaccumulate in chronic infections, autoimmune disease, and immunodeficiency, posing the question of what checkpoints normally oppose their accumulation. Here, we reveal a critical role for paralogous calcium-NFAT-regulated transcription factors EGR2 and EGR3 that are induced in self-reactive B cells. CD21low and B1 B cells lacking EGR2 and EGR3 accumulate and circulate in young mice in numbers 10- to 20-fold greater than normal and overexpress a large set of EGR2 ChIP-seq target genes, including known drivers of plasma cell differentiation. Most follicular B cells constitutively express Egr2 proportionally to surface IgM downregulation by self-antigens, and EGR2/3 deficiency abolishes this cardinal feature of B cell anergy. These results explain the cardinal features of B cell anergy, define a key transcriptional checkpoint repressing CD21low B cell formation, and inform how NFATC1 or EGR2 mutations promote B1 cell-derived chronic lymphocytic leukemias.

Differential biological effects of aromatase inhibitors: Apoptosis, autophagy, senescence and modulation of the hormonal status in breast cancer cells.

Estrogen receptor-positive (ER+) breast carcinomas are the most common subtype, corresponding to 60% of the cases in premenopausal and 75% in postmenopausal women. The third-generation of aromatase inhibitors (AIs), the non-steroidal Anastrozole (Ana) and Letrozole (Let) and the steroidal Exemestane (Exe), are considered a first-line endocrine therapy for postmenopausal women. Despite their clinical success, the development of resistance is the major setback in clinical practice. Nevertheless, the lack of cross-resistance between AIs hints that these drugs may act through distinct mechanisms. Therefore, this work studied the different effects induced by AIs on biological processes, such as cell proliferation, death, autophagy and senescence. Moreover, their effects on the regulation of the hormonal environment were also explored. The non-steroidal AIs induce senescence, through increased YPEL3 expression, on aromatase-overexpressing breast cancer cells (MCF-7aro), whereas Exe promotes a cytoprotective autophagy, thus blocking senescence induction. In addition, in a hormone-enriched environment, the non-steroidal AIs prevent estrogen signaling, despite up-regulating the estrogen receptor alpha (ERα), while Exe down-regulates ERα and maintains its activation. In these conditions, all AIs up-regulate the androgen receptor (AR) which blocks EGR3 transcription in Exe-treated cells. On the other hand, in hormone-depleted conditions, a crosstalk between AR and ERα occurs, enhancing the estrogenic effects of Exe. This indicates that Exe modulates both ERα and AR, while Ana and Let act as pure AIs. Thus, this study highlights the potential clinical benefit of combining AR antagonists with Exe and discourages the sequential use of Exe as second-line therapy in postmenopausal breast cancer.

EGR3-HDAC6-IL-27 Axis Mediates Allergic Inflammation and Is Necessary for Tumorigenic Potential of Cancer Cells Enhanced by Allergic Inflammation-Promoted Cellular Interactions.

The objective of this study was to investigate mechanisms of allergic inflammation both in vitro and in vivo in details. For this, RNA sequencing was performed. Early growth response 3 gene (Egr3) was one of the most highly upregulated genes in rat basophilic leukemia (RBL2H3) cells stimulated by antigen. The role of Egr3 in allergic inflammation has not been studied extensively. Egr3 was necessary for passive cutaneous anaphylaxis (PCA) and passive systemic anaphylaxis (PSA). Egr3 promoter sequences contained potential binding site for NF-κB p65. NF-κB p65 directly regulated Egr3 expression and mediated allergic inflammation in vitro. Histone deacetylases (HDACs) is known to be involved in allergic airway inflammation. HDAC6 promoter sequences contained potential binding site for EGR3. EGR3 showed binding to promoter sequences of HDAC6. EGR3 was necessary for increased expression of histone deacetylase 6 (HDAC6) in antigen-stimulated RBL2H3 cells. HDAC6 mediated allergic inflammation in vitro and PSA. TargetScan analysis predicted that miR-182-5p was a negative regulator of EGR3. Luciferase activity assay confirmed that miR-182-5p was a direct regulator of EGR3. MiR-182-5p mimic inhibited allergic inflammation both in vitro and in vivo. Cytokine array showed that HDAC6 was necessary for increased interleukin-27 (IL-27) expression in BALB/C mouse model of PSA. Antigen stimulation did not affect expression of EBI3, another subunit of IL-27 in RBL2H3 cells or BALB/C mouse model of PCA or PSA. IL-27 receptor alpha was shown to be able to bind to HDAC6. IL-27 p28 mediated allergic inflammation in vitro, PCA, and PSA. Mouse recombinant IL-27 protein promoted features of allergic inflammation in an antigen-independent manner. HDAC6 was necessary for tumorigenic and metastatic potential enhanced by PSA. PSA enhanced the metastatic potential of mouse melanoma B16F1 cells in an IL-27-dependent manner. Experiments employing culture medium and mouse recombinant IL-27 protein showed that IL-27 mediated and promoted cellular interactions involving B16F1 cells, lung macrophages, and mast cells during allergic inflammation. IL-27 was present in exosomes of antigen-stimulated RBL2H3 cells. Exosomes from antigen-stimulated RBL2H3 cells enhanced invasion of B16F1 melanoma cells in an IL-27-dependemt manner. These results present evidence that EGR3-HDAC6-IL-27 axis can regulate allergic inflammation by mediating cellular interactions.

XIST promotes apoptosis and the inflammatory response in CSE-stimulated cells via the miR-200c-3p/EGR3 axis.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a disease that causes obstructed airways and abnormal inflammatory responses in the lungs. Early growth response 3 (EGR3) has been revealed to play a vital role in the regulation of the inflammatory response in certain diseases. We aimed to explore the role of EGR3 and its upstream mechanism in COPD. METHODS AND RESULT: In the present study, 16HBE cells were treated with cigarette smoke extract (CSE) to mimic the inflammatory response in vitro. RT-qPCR revealed that the expression of EGR3 was upregulated in lungs from COPD patients. EGR3 expression in 16HBE cells was increased by CSE treatment. Moreover, flow cytometry analysis and western blot analysis showed that EGR3 downregulation inhibited 16HBE cell apoptosis. EGR3 silencing decreased the protein levels of IL-6, TNF-α, IL-1ß and COX2 in CSE-stimulated 16HBE cells. In addition, EGR3 was targeted by microRNA-200c-3p (miR-200c-3p) in 16HBE cells. MiR-200c-3p expression was significantly decreased in lung tissues from COPD patients compared to that in healthy controls. Furthermore, miR-200c-3p bound to lncRNA X-inactive specific transcript (XIST) in 16HBE cells. Additionally, XIST expression was elevated in lung tissues from COPD patients. Rescue assays indicated that EGR3 overexpression counteracted the effects of XIST downregulation on apoptosis and inflammation in CSE-stimulated 16HBE cells. CONCLUSION: The XIST/miR-200c-3p/EGR3 axis facilitated apoptosis and inflammation in CSE-stimulated 16HBE cells. These findings may provide novel insight for treating COPD by alleviating lung inflammation.

Overexpression of miR-874-3p alleviates LPS-induced apoptosis and inflammation in alveolar epithelial cell by targeting EGR3/NF-κB.

OBJECTIVE: MicroRNA (miRNA) is implicated in the pathogenic mechanism of pneumonia. Role of miR-874-3p in pediatric pneumonia was therefore evaluated in this study. METHODS: Expression levels of miR-874-3p in the serum samples from pediatric patients with pneumonia and LPS-treated HPAEpiC were determined by RT-qPCR (reverse transcription quantitative real-time PCR). Secretion of inflammatory factors in LPS-treated HPAEpiC were determined by qRT-PCR and ELISA. Cell viability and apoptosis were evaluated by CCK8 and flow cytometry, respectively. HPAEpiC was used for the validation of binding target of miR-874-3p. Mechanism was determined by NF-κB promoter activity assay. RESULTS: MiR-874-3p was reduced in serum samples of pediatric patients with pneumonia, and LPS treatment dose-dependently decreased miR-874-3p expression in HPAEpiC. TNF-α and IL-1ß expression levels were increased in HPAEpiC post LPS treatment. Over-expression of miR-874-3p attenuated LPS-induced increase of TNF-α and IL-1ß and reversed LPS-induced decrease of cell viability and increase of cell apoptosis in HPAEpiC. EGR3 (early growth response 3), increased in LPS-induced HPAEpiC, was a target gene of miR-874-3p. EGR3 over-expression reversed miR-874-3p over-expression-induced increase of cell viability, decrease of cell apoptosis, TNF-α and IL-1ß in LPS-induced HPAEpiC. Over-expression of miR-874-3p reduced p65 expression and NF-κB promoter activity in LPS-induced HPAEpiC, while EGR3 over-expression reversed these suppressive effects. CONCLUSION: MiR-874-3p negatively regulates EGR3 expression to promote cell viability and inhibit apoptosis as well as inflammation in LPS-treated HPAEpiC via suppression of NF-κB pathway, suggesting a potential therapeutic strategy for pneumonia.

Early Growth Response Gene Upregulation in Epstein-Barr Virus (EBV)-Associated Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic multisystem disease exhibiting a variety of symptoms and affecting multiple systems. Psychological stress and virus infection are important. Virus infection may trigger the onset, and psychological stress may reactivate latent viruses, for example, Epstein-Barr virus (EBV). It has recently been reported that EBV induced gene 2 (EBI2) was upregulated in blood in a subset of ME/CFS patients. The purpose of this study was to determine whether the pattern of expression of early growth response (EGR) genes, important in EBV infection and which have also been found to be upregulated in blood of ME/CFS patients, paralleled that of EBI2. EGR gene upregulation was found to be closely associated with that of EBI2 in ME/CFS, providing further evidence in support of ongoing EBV reactivation in a subset of ME/CFS patients. EGR1, EGR2, and EGR3 are part of the cellular immediate early gene response and are important in EBV transcription, reactivation, and B lymphocyte transformation. EGR1 is a regulator of immune function, and is important in vascular homeostasis, psychological stress, connective tissue disease, mitochondrial function, all of which are relevant to ME/CFS. EGR2 and EGR3 are negative regulators of T lymphocytes and are important in systemic autoimmunity.

Egr2 regulation in T cells is mediated through IFNγ/STAT1 and IL-6/STAT3 signalling pathway.

The immune system is a host defence system to protect the body against foreign invaders. T cells are one of the major components of the immune cells and they are essential for immune responses. Early growth response gene (Egr2) in T cells is important for maintaining immune functions of T cells by promoting adaptive immune responses while controlling inflammation and preventing the development of autoimmune diseases. A study by our group demonstrated the function of Egr2 as a checkpoint regulator controlling the proliferation and differentiation of the T cells. In association, Egr2 and 3 play indispensable role in T cell immune response, but the mechanism regulating Egr2 expression in T cells is still unclear. In this study, we analysed the Egr2 expression mechanism in CD4 T cells under antigen stimulation. We found that Egr2 expression is regulated by different cytokines including IL-2 and IL-4, which increased Egr2 induction in activated T cells. However, inflammatory cytokines, including INFγ and IL-6, suppressed Egr2 expression through STAT1 and STAT3 signalling pathway respectively, highlighting a mechanism for tolergenic immune response on T cells.

Piezo2 expressed in proprioceptive neurons is essential for skeletal integrity.

In humans, mutations in the PIEZO2 gene, which encodes for a mechanosensitive ion channel, were found to result in skeletal abnormalities including scoliosis and hip dysplasia. Here, we show in mice that loss of Piezo2 expression in the proprioceptive system recapitulates several human skeletal abnormalities. While loss of Piezo2 in chondrogenic or osteogenic lineages does not lead to human-like skeletal abnormalities, its loss in proprioceptive neurons leads to spine malalignment and hip dysplasia. To validate the non-autonomous role of proprioception in hip joint morphogenesis, we studied this process in mice mutant for proprioceptive system regulators Runx3 or Egr3. Loss of Runx3 in the peripheral nervous system, but not in skeletal lineages, leads to similar joint abnormalities, as does Egr3 loss of function. These findings expand the range of known regulatory roles of the proprioception system on the skeleton and provide a central component of the underlying molecular mechanism, namely Piezo2.

Expression and prognostic value of the transcription factors EGR1 and EGR3 in gliomas.

Most glioblastoma patients have a dismal prognosis, although some survive several years. However, only few biomarkers are available to predict the disease course. EGR1 and EGR3 have been linked to glioblastoma stemness and tumour progression, and this study aimed to investigate their spatial expression and prognostic value in gliomas. Overall 207 gliomas including 190 glioblastomas were EGR1/EGR3 immunostained and quantified. A cohort of 21 glioblastomas with high P53 expression and available tissue from core and periphery was stained with double-immunofluorescence (P53-EGR1 and P53-EGR3) and quantified.EGR1 expression increased with WHO-grade, and declined by 18.9% in the tumour periphery vs. core (P = 0.01), while EGR3 expression increased by 13.8% in the periphery vs. core (P = 0.04). In patients with high EGR1 expression, 83% had methylated MGMT-promoters, while all patients with low EGR1 expression had un-methylated MGMT-promoters. High EGR3 expression in MGMT-methylated patients was associated with poor survival (HR = 1.98; 95%CI 1.22-3.22; P = 0.006), while EGR1 high/EGR3 high, was associated with poor survival vs. EGR1 high/EGR3 low (HR = 2.11; 95%CI 1.25-3.56; P = 0.005). EGR1 did not show prognostic value, but could be involved in MGMT-methylation. Importantly, EGR3 may be implicated in cell migration, while its expression levels seem to be prognostic in MGMT-methylated patients.

Two faces of bivalent domain regulate VEGFA responsiveness and angiogenesis.

The bivalent domain (BD) at promoter region is an unique epigenetic feature poised for activation or repression during cell differentiation in embryonic stem cell. However, the function of BDs in already differentiated cells remains exclusive. By profiling the epigenetic landscape of endothelial cells during VEGFA (vascular endothelial growth factor A) stimulation, we discovered that BDs are widespread in endothelial cells and preferentially marked genes responsive to VEGFA. The BDs responsive to VEGFA have more permissive chromatin environment comparing to other BDs. The initial activation of bivalent genes depends on RNAPII pausing release induced by EZH1 rather than removal of H3K27me3. The later suppression of bivalent gene expression depended on KDM5A recruitment by its interaction with PRC2. Importantly, EZH1 promoted both in vitro and in vivo angiogenesis by upregulating EGR3, whereas KDM5A dampened angiogenesis. Collectively, this study demonstrates a novel dual function of BDs in endothelial cells to control VEGF responsiveness and angiogenesis.

Overexpressing miR­335 inhibits DU145 cell proliferation by targeting early growth response 3 in prostate cancer.

MicroRNA­335 (miR­335) was reported to suppress cell proliferation in prostate cancer (PC), a common malignancy in males. The expression of early growth response 3 (EGR3) was determined to be elevated in human PC tissues; however, the possible effects and underlying mechanism of miR­335 on PC remains unknown. In the present study, miR­335 mimics and miR­335 inhibitors were respectively transfected into DU145 cells. Stable silencing of EGR3 was observed in DU145 cells following transfection with small interfering RNA. We also used Cell Counting Kit­8 and in vitro angiogenesis assays to determine the viability and revascularization potential of DU145 cells. The expression levels of EGR and caspase­3 activity were analyzed by immunohistochemistry and immunocytochemistry, respectively. We predicted the target of miR­335 by bioinformatics analysis and a dual­luciferase reporter gene assay. Western blot and quantitative real­time polymerase chain reaction analyses were performed to determine the protein and mRNA expression of molecules. miR­335 expression was downregulated in PC tissues and cell lines. Overexpression of miR­335 significantly reduced the viability and the formation of regenerative tubes of DU145 cells, and inhibited the expression of inflammatory factors. EGR3 was proposed as a possible target of miR­335, and was negatively regulated by miR­335. Silencing EGR3 suppressed the viability and angiogenesis of DU145 cells, and reduced the activity of caspase­3 and inflammatory factor expression. miR­335 inhibition along with EGR3 silencing EGR3 inhibited the cell proliferation. Furthermore, miR­335 inhibited the formation of a PC solid tumor xenograft in vivo. Thus, miR­335 may exert an antitumor effect on DU145 cells by regulating the expression of EGR3. The findings of the present study may provide insight into a novel therapeutic strategy for the treatment of prostatic carcinoma.

Progression of myocardial ischemia leads to unique changes in immediate-early gene expression in the spinal cord dorsal horn.

The pathological consequences of ischemic heart disease involve signaling through the autonomic nervous system. Although early activation may serve to maintain hemodynamic stability, persistent aberrant sympathoexcitation contributes to the development of lethal arrhythmias and heart failure. We hypothesized that as the myocardium reacts and remodels to ischemic injury over time, there is an analogous sequence of gene expression changes in the thoracic spinal cord dorsal horn, the processing center for incoming afferent fibers from the heart to the central nervous system. Acute and chronic myocardial ischemia (MI) was induced in a large animal model of Yorkshire pigs, and the thoracic dorsal horn of treated pigs, along with control nonischemic pigs, was harvested for transcriptome analysis. We identified 32 differentially expressed genes between healthy and acute ischemia cohorts and 46 differentially expressed genes between healthy and chronic ischemia cohorts. The canonical immediate-early gene c-fos was upregulated after acute MI, along with fosB, dual specificity phosphatase 1 and 2 ( dusp1 and dusp2), and early growth response 2 (egr2). After chronic MI, there was a persistent yet unique activation of immediate-early genes, including fosB, nuclear receptor subfamily 4 group A members 1-3 ( nr4a1, nr4a2, and nr4a3), egr3, and TNF-α-induced protein 3 ( tnfaip3). In addition, differentially expressed genes from the chronic MI signature were enriched in pathways linked to apoptosis, immune regulation, and the stress response. These findings support a dynamic progression of gene expression changes in the dorsal horn with maturation of myocardial injury, and they may explain how early adaptive autonomic nervous system responses can maintain hemodynamic stability, whereas prolonged maladaptive signals can predispose patients to arrhythmias and heart failure. NEW & NOTEWORTHY Activation of the autonomic nervous system after myocardial injury can provide early cardiovascular support or prolonged aberrant sympathoexcitation. The later response can lead to lethal arrhythmias and heart failure. This study provides evidence of ongoing changes in the gene expression signature of the spinal cord dorsal horn as myocardial injury progresses over time. These changes could help explain how an adaptive nervous system response can become maladaptive over time.

Transcription factors early growth response gene (Egr) 2 and 3 control inflammatory responses of tolerant T cells.

INTRODUCTION: Impaired proliferation and production of IL2 are the hallmarks of experimental T cell tolerance. However, in most autoimmune diseases, auto-reactive T cells do not display hyper proliferation, but inflammatory phenotypes. METHODS: We have now demonstrated that the transcription factors Egr2 and 3 are important for the control of inflammatory cytokine production by tolerant T cells, but not for tolerance induction. RESULTS: In the absence of Egr2 and 3, T cell tolerance, as measured by impaired proliferation and production of IL2, can still be induced, but tolerant T cells produced high levels of inflammatory cytokines. Egr2 and 3 regulate expression of differentiation repressors and directly inhibit T-bet function in T cells. Indeed, decreased expression of differentiation repressors, such as Id3 and Tcf1, and increased expression of inflammatory transcription factors, such as RORγt and Bhlhe40 were found in Egr2/3 deficient T cells under tolerogenic conditions. In addition, T-bet was co-expressed with Egr2 in tolerant T cells and Egr2/3 defects leads to production of high levels of IFNγ in tolerant T cells. CONCLUSIONS: Our findings demonstrated that despite impaired proliferation and IL2 production, tolerant T cells can display inflammatory responses in response to antigen stimulation and this is controlled at least partly by Egr2 and 3.