Suppression of ELF4 in ulcerative colitis predisposes host to colorectal cancer

Transcription factor ELF4 in physiology and diseases: Molecular roles and clinical implications

Transcription factor E74 like ETS transcription factor 4 (ELF4), a member of the ETS family, is highly expressed in normal human hematopoietic tissue, ovary, placenta, colon, and certain pathological cell lines. During normal physiological processes, ELF4 regulates differentiation in osteogenic, adipocyte, and neuronal types. It also exerts a critical impact on the development of the immune system. However, its function is dysregulated through posttranslational modifications, gene fusions, and complex signaling crosstalk under pathological conditions. Furthermore, serving as a double-edged sword in cancer, ELF4 exhibits both tumor-suppressing and tumor-promoting effects. Specifically, ELF4 plays a critical role in cancer metastasis, proliferation, and modulation of the tumor microenvironment. This review provides an in-depth overview of the molecular structure and post-translational modifications of ELF4. It also summarizes the hallmarks of ELF4 in physiology and diseases, with a particular focus on its significance in oncology. Notably, this review underscores the potential of ELF4 as a prognostic biomarker, highlighting its clinical relevance. Finally, it discusses unresolved questions and future research directions of ELF4. An in-depth understanding of ELF4 biology could facilitate its clinical translation and offer promising targeted therapeutic strategies.

In vitro maturation using porcine follicular fluid-derived exosomes as an alternative to the conventional method

Extracellular vesicles, also known as exosomes, influence numerous cellular functions by regulating different signaling pathways. However, their role in animal reproduction remains understudied. This study aimed to evaluate the effects of porcine follicular fluid-derived exosomes (pff-Exos) on porcine oocyte in vitro maturation and parthenogenetic embryo development. We obtained pff-Exos through mixed-method ultracentrifugation and size-exclusion chromatography. Transmission electron microscopy revealed an increase in the expression of exosome markers in the first four of thirteen fractions. The number of pff-Exo was 2.2 × 106 particles per microliter. The highest maturation rate of porcine oocytes treated with pff-Exo was observed with 1.1 × 107 particles of pff-Exo in the absence of porcine follicular fluid (pFF) culture conditions. Moreover, increased expression of Gdf9 and Bmp15 was observed. The developmental rate was the highest upon treatment with 1.1 × 107 particles of pff-Exo, which increased the total cell number in blastocysts. Embryonic development to the 2-cell stage was similar between the control and pff-Exo groups; however, development to the 4-cell stage and blastocyst was significantly increased in the pff-Exo group (61.6 ± 6.08 % and 29.72 ± 1.41 %, respectively; P < 0.05) compared with that in the control group (42.0 ± 5.19 % and 18.14 ± 1.78 %, respectively). The expression levels of Oct4, Sox2, Bcl2, Elf4, and Gcn5 significantly increased at the pff-Exo 2-cell stage, whereas those of Bax, Hdac1, Hdac6, and Sirt6 decreased. Specifically, the Oct4, Sox2, Elf4, Gcn5, and Hdac6 levels remained stable in pff-Exo 4-cell embryos, whereas those of p53 and Hat1 were reduced and increased, respectively. Treatment with pffExos significantly increased H3K9 and H3K14 acetylation levels. These results demonstrate that pff-Exo affects the in vitro maturation of porcine oocytes and early embryonic development by regulating gene expression.

A Novel Frameshift Variant of the ELF4 Gene in a Patient with Autoinflammatory Disease: Clinical Features, Transcriptomic Profiling and Functional Studies

We described the diagnosis and treatment of a patient with autoinflammatory disease, named "Deficiency in ELF4, X-linked (DEX)". A novel ELF4 variant was discovered and its pathogenic mechanism was elucidated. The data about clinical, laboratory and endoscopic features, treatment, and follow-up of a patient with DEX were analyzed. Whole exome sequencing and Sanger sequencing were performed to identify potential pathogenic variants. The mRNA and protein levels of ELF4 were analyzed by qPCR and Western blotting, respectively. The association of ELF4 frameshift variant with nonsense-mediated mRNA decay (NMD) in the pathogenesis DEX was examined. Moreover, RNA-seq was performed to identify the key molecular events triggered by ELF4 variant. The relationship between ELF4 and IFN-β activity was validated using a dual-luciferase reporter assay and a ChIP-qPCR assay. An 11-year-old boy presented with a Behçet's-like phenotype. The laboratory abnormality was the most obvious in elevated inflammatory indicators. Endoscopy revealed multiple ileocecal ulcers. Intestinal histopathology showed inflammatory cell infiltrations. The patient was treated with long-term immunosuppressant and TNF-α blocker (adalimumab), which reaped an excellent response over 16 months of follow-up. Genetic analysis identified a maternal hemizygote frameshift variant (c.1022del, p.Q341Rfs*30) in ELF4 gene in the proband. The novel variant decreased the mRNA level of ELF4 via the NMD pathway. Mechanistically, insufficient expression of ELF4 disturbed the immune system, leading to immunological disorders and pathogen susceptibility, and disrupted ELF4-activating IFN-β responses. This analysis detailed the clinical characteristics of a Chinese patient with DEX who harbored a novel ELF4 frameshift variant. For the first time, we used patient-derived cells and carried out transcriptomic analysis to delve into the mechanism of ELF4 variant in DEX.

[Two Cases of Behcet's Disease-Like Syndrome with Gene Deficiency in ELF4]

The patient 1, a 13-year-old boy, was admitted due to "recurrent oral ulcers for 3 years, abdominal pain for 8 months, and perianal ulcers for 10 days"; The patient 2, a 3-year-old boy, was admitted due to "recurrent abdominal pain, diarrhea, and fever for over 3 months". Genetic testing of both patients revealed "deficiency in ELF4, X-linked" (DEX), and the patients were diagnosed with Behcet's disease-like syndrome due to deficiency in ELF4, accordingly. The patient 1 was successively given intravenous methylprednisolone pulses and oral prednisone and mesalazine for symptomatic treatment. The patient 2 was successively treated with corticosteroids combined with enteral nutrition, as well as oral mercaptopurine. Subsequently, both patients showed improvements in symptoms and were discharged.

Current understanding of ELF4 deficiency: a novel inborn error of immunity

BACKGROUND

ELF4 deficiency has been recently recognized as a novel disorder within the spectrum of inborn errors of immunity (IEIs), specifically categorized as a "disease of immune dysregulation." Cases of this condition, reported by our team and others, are very limited worldwide. As such, our current knowledge of this new disease remains preliminary. This review aims to provide a brief overview of the clinical manifestations, pathogenesis, and treatment strategies for this novel IEI.

DATA SOURCES

A comprehensive review was conducted after an extensive literature search in the PubMed/Medline database and websites concerning transcriptional factor ELF4 and reports concerning patients with ELF4 deficiency. Our search strategy was "ELF4 OR ETS-related transcription factor Elf-4 OR EL4-like factor 4 OR myeloid Elf-1-like factor" as of the time of manuscript submission.

RESULTS

The current signature manifestations of ELF4 deficiency disorder are recurrent and prolonged oral ulcer, abdominal pain, and diarrhea in pediatric males. In some cases, immunodeficiency and autoimmunity can also be prominent. Targeted Sanger sequencing or whole exome sequencing can be used to detect variation in ELF4 gene. Western blotting for ELF4 expression of the patient's cells can confirm the pathogenic effect of the variant. To fully confirm the pathogenicity of the variant, further functional test is strongly advised. Glucocorticoid and biologics are the mainstream management of ELF4 deficiency disorder.

CONCLUSIONS

Pediatric males presenting with recurring ulcerations in digestive tract epithelium with or without recurrent fever should be suspected of DEX. When atypical presentations are prominent, variations in ELF4 gene should be carefully evaluated functionally due to the complex nature of ELF4 function. Experience of treating DEX includes use of glucocorticoid and biologics and more precise treatment needs more patients to identify and further mechanistic study.

The transcription factor ELF4 alleviates inflammatory bowel disease by activating IL1RN transcription, suppressing inflammatory TH17 cell activity, and inducing macrophage M2 polarization

Background

Inflammatory bowel disease (IBD) is a chronic immune-mediated disorder affecting millions worldwide. Due to the complexity of its pathogenesis, the treatment options for IBD are limited. This study focuses on ELF4, a member of the ETS transcription factor family, as a target to elucidate its role in IBD and investigate its mechanism of action in alleviating IBD symptoms by activating IL1RN transcription to suppress the activity of inflammatory TH17 cells.

Methods

Using the GEO database, this study examined LPS-induced intestinal inflammatory genes and their regulation mechanisms. We examined the colon length of LPS-treated mice and derived the Disease Activity Index (DAI). H&E staining, ELISA, and flow cytometry were used to detect mice colon tissue damage, inflammatory factor levels in mouse serum, mouse macrophage types and inflammatory TH17 cell activity. RT-qPCR and Western blot detected ELF4, IL1RN, M1, and M2 polarization markers. In Vitro, using dual-luciferase and ChIP assays, we tested mouse bone marrow-derived macrophages (BMDMs) and mouse intestinal epithelial cells for IL1RN promoter activity and ELF4 enrichment.

Results

Bioinformatics showed that LPS-induced colitis animals have reduced ELF4 expression in their colon tissue. In vivo tests confirmed reduced ELF4 expression in mice with LPS-induced colitis. ELF4 overexpression reduced mouse intestinal inflammation. ELF4 activated IL1RN transcription in bioinformatics and in vitro tests. ELF4 promoted IL1RN transcription and macrophage M2 polarization to limit intestinal epithelial cell death and inflammation and reduce mouse intestinal inflammation in vitro. ELF4 also reduced the Th17/Treg ratio by increasing IL1RN transcription.

Conclusion

ELF4 activates IL1RN transcription, suppresses inflammatory TH17 cells, and induces macrophage M2 polarization to treat IBD.

Comprehensive analysis of E47‑like factors and verification of ELF4 in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most prominent subtype of renal cancer and E47-like factors (ELFs) are important in tumorigenesis; however, the specific role of key ELFs in ccRCC remains unclear. The present study comprehensively analyzed RNA sequencing and clinical data from multiple databases, and identified differentially expressed ELFs (ELF3-5) in ccRCC. The DNA promoter methylation, genetic variation and clinical significance of ELF3-5 in ccRCC were analyzed using the cBioPortal and UALCAN databases. The association between ELF3-5 and multiple immune cell infiltration was analyzed using Tumor Immune Estimation Resource. Subsequently, ELF4 was selected and its association with biological functions was assessed. Cell counting kit-8 (CCK-8), colony formation, Transwell, macrophage chemotaxis and polarization assays were conducted to validate the functions of ELF4. Notably, the mRNA expression levels of ELF4 were significantly upregulated in ccRCC, whereas ELF3 and ELF5 mRNA expression levels were significantly downregulated. Clinical significance analysis revealed that ELF4 showed a high clinical significance with tumor grade, clear cell type A and B subtypes, and incidence rates of amplification in genetic variation. Further analyses indicated that ELF4 may be involved in multiple immune cell differentiation. Additionally, cell experiments revealed that ELF4 inhibition downregulated 769-P and 786-O proliferation, migration and invasion. Knockdown of ELF4 in cancer cells also inhibited M2 macrophage polarization and chemotaxis towards 769-P and 786-O cells. Conclusively, the present findings indicated the clinical significance of ELF4 in ccRCC, and verified its key role in driving cell proliferation, migration and invasion, and promoting M2 macrophage polarization and chemotaxis in ccRCC.

Update and latest advances in mechanisms and management of colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CAC) is defined as a specific cluster of colorectal cancers that develop as a result of prolonged colitis in patients with inflammatory bowel disease (IBD). Patients with IBD, including ulcerative colitis and Crohn's disease, are known to have an increased risk of developing CAC. Although the incidence of CAC has significantly decreased over the past few decades, individuals with CAC have increased mortality compared to individuals with sporadic colorectal cancer, and the incidence of CAC increases with duration. Chronic inflammation is generally recognized as a major contributor to the pathogenesis of CAC. CAC has been shown to progress from colitis to dysplasia and finally to carcinoma. Accumulating evidence suggests that multiple immune-mediated pathways, DNA damage pathways, and pathogens are involved in the pathogenesis of CAC. Over the past decade, there has been an increasing effort to develop clinical approaches that could help improve outcomes for CAC patients. Colonoscopic surveillance plays an important role in reducing the risk of advanced and interval cancers. It is generally recommended that CAC patients undergo endoscopic removal or colectomy. This review summarizes the current understanding of CAC, particularly its epidemiology, mechanisms, and management. It focuses on the mechanisms that contribute to the development of CAC, covering advances in genomics, immunology, and the microbiome; presents evidence for management strategies, including endoscopy and colectomy; and discusses new strategies to interfere with the process and development of CAC. These scientific findings will pave the way for the management of CAC in the near future.

Layered Clay Minerals in Cancer Therapy: Recent Progress and Prospects

Cancer is one of the deadliest diseases, and current treatment regimens suffer from limited efficacy, nonspecific toxicity, and chemoresistance. With the advantages of good biocompatibility, large specific surface area, excellent cation exchange capacity, and easy availability, clay minerals have been receiving ever-increasing interests in cancer treatment. They can act as carriers to reduce the toxic side effects of chemotherapeutic drugs, and some of their own properties can kill cancer cells, etc. Compared with other morphologies clays, layered clay minerals (LCM) have attracted more and more attention due to adjustable interlayer spacing, easier ion exchange, and stronger adsorption capacity. In this review, the structure, classification, physicochemical properties, and functionalization methods of LCM are summarized. The state-of-the-art progress of LCM in antitumor therapy is systematically described, with emphasis on the application of montmorillonite, kaolinite, and vermiculite. Furthermore, the property-function relationships of LCM are comprehensively illustrated to reveal the design principles of clay-based antitumor systems. Finally, foreseeable challenges and outlook in this field are discussed.

Knockdown of ELF4 aggravates renal injury in ischemia/reperfusion mice through promotion of pyroptosis, inflammation, oxidative stress, and endoplasmic reticulum stress

BACKGROUND

Renal ischemia/reperfusion (I/R) injury is a major cause of acute kidney injury (AKI). Dysfunction of E74-like ETS transcription factor 4 (ELF4) leads to inflammation. This research intended to look into the function and mechanisms of ELF4 in I/R and oxygen-glucose deprivation/reperfusion (OGD/R) model.

RESULTS

In I/R and OGD/R model, ELF4 expression was downregulated. ELF4 knockout aggravated I/R-induced kidney injury, oxidative stress (OS), endoplasmic reticulum stress (ERS), apoptosis, inflammation, and pyroptosis in mice. In HK-2 cells treated with OGD/R, suppression of ELF4 expression inhibited cell proliferation and promoted cell apoptosis, OS, ERS, inflammation, and pyroptosis. Moreover, ELF4 overexpression led to the opposite results.

CONCLUSION

ELF4 deficiency aggravated I/R induced AKI, which was involved in apoptosis, OS, ERS, inflammation, and pyroptosis. Targeting ELF4 may be a promising new therapeutic strategy for preventing inflammation after IR-AKI.

FGF19-mediated ELF4 overexpression promotes colorectal cancer metastasis through transactivating FGFR4 and SRC

Background: Metastasis accounts for the high lethality of colorectal cancer (CRC) patients. Unfortunately, the molecular mechanism manipulating metastasis in CRC is still elusive. Here, we investigated the function of E74-like factor 4 (ELF4), an ETS family member, in facilitating CRC progression. Methods: The expression of ELF4 in human CRC samples and CRC cell lines was determined by quantitative real-time PCR, immunohistochemistry and immunoblotting. The migratory and invasive phenotypes of CRC cells were evaluated by in vitro transwell assays and in vivo metastatic models. The RNA sequencing was used to explore the downstream targets of ELF4. The luciferase reporter assays and chromatin immunoprecipitation assays were used to ascertain the transcriptional regulation related to ELF4. Results: We found elevated ELF4 was positively correlated with distant metastasis, advanced AJCC stages, and dismal outcomes in CRC patients. ELF4 expression was also an independent predictor of poor prognosis. Overexpression of ELF4 boosted CRC metastasis via transactivating its downstream target genes, fibroblast growth factor receptor 4 (FGFR4) and SRC proto-oncogene, non-receptor tyrosine kinase, SRC. Fibroblast growth factor 19 (FGF19) upregulated ELF4 expression through the ERK1/2/SP1 axis. Clinically, ELF4 expression had a positive correlation with FGF19, FGFR4 and SRC, and CRC patients who positively coexpressed FGF19/ELF4, ELF4/FGFR4, or ELF4/SRC exhibited the worst clinical outcomes. Furthermore, the combination of the FGFR4 inhibitor BLU-554 and the SRC inhibitor KX2-391 dramatically suppressed ELF4-mediated CRC metastasis. Conclusions: We demonstrated the essentiality of ELF4 in the metastatic process of CRC, and targeting the ELF4-relevant positive feedback circuit might represent a novel therapeutic strategy.

Human PARP1 substrates and regulators of its catalytic activity: An updated overview

Poly (ADP-ribose) polymerase 1 (PARP1) is a key DNA damage sensor that is recruited to damaged sites after DNA strand breaks to initiate DNA repair. This is achieved by catalyzing attachment of ADP-ribose moieties, which are donated from NAD⁺, on the amino acid residues of itself or other acceptor proteins. PARP inhibitors (PARPi) that inhibit PARP catalytic activity and induce PARP trapping are commonly used for treating BRCA1/2-deficient breast and ovarian cancers through synergistic lethality. Unfortunately, resistance to PARPi frequently occurs. In this review, we present the novel substrates and regulators of the PARP1-catalyzed poly (ADP-ribosyl)ation (PARylatison) that have been identified in the last 3 years. The overall aim is the presentation of protein interactions of potential therapeutic intervention for overcoming the resistance to PARPi.

Gender-related differentially expressed genes in pancreatic cancer: possible culprits or accomplices?

Pancreatic cancer (PC) is one of the leading causes of cancer mortality worldwide, and its incidence and mortality rate in several regions is higher in male patients. Although numerous efforts have been made to enhance the clinical outcomes of existing therapeutic regimens, their efficiency is still low, and drug resistance usually occurs in many patients. In addition, the exact underlying molecular basis that makes PC slightly more prevalent among males remains unknown. Providing information regarding the possible association between gender and PC tumorigenesis may offer important clues for how certain molecular cross-talks can affect PC initiation and/or progression. In this study, we used several microarray expression data to identify the common up- and downregulated genes within one specific gender, which were also specified to have binding sites for androgen and/or estrogen receptors. Using functional enrichment analysis among the others, for all the gene sets found in this study, we have shed light on the plausible importance of the androgenic effectors in tumorigenesis, such as the androgen-regulated expression of the GLI transcription factor and the potential role of testosterone in the extracellular matrix (ECM)–cell interaction, which are known for their importance in tumorigenesis. Moreover, we demonstrated that the biological process axon guidance was highlighted regarding the upregulated genes in male patients. Overall, identification of gene candidates as the possible link between gender and PC progression or survival rates may help in developing strategies to reduce the incidence of this cancer.

ELF4 is critical to zygotic gene activation and epigenetic reprogramming during early embryonic development in pigs

Zygotic gene activation (ZGA) and epigenetic reprogramming are critical in early embryonic development in mammals, and transcription factors are involved in regulating these events. However, the effects of ELF4 on porcine embryonic development remain unclear. In this study, the expression of ELF4 was detected in early porcine embryos and different tissues. By knocking down ELF4, the changes of H3K9me3 modification, DNA methylation and ZGA-related genes were analyzed. Our results showed that ELF4 was expressed at all stages of early porcine embryos fertilized in vitro (IVF), with the highest expression level at the 8-cell stage. The embryonic developmental competency and blastocyst quality decreased after ELF4 knockdown (20.70% control vs. 17.49% si-scramble vs. 2.40% si-ELF4; p < 0.001). Knockdown of ELF4 induced DNA damage at the 4-cell stage. Interfering with ELF4 resulted in abnormal increases in H3K9me3 and DNA methylation levels at the 4-cell stage and inhibited the expression of genes related to ZGA. These results suggest that ELF4 affects ZGA and embryonic development competency in porcine embryos by maintaining genome integrity and regulating dynamic changes of H3K9me3 and DNA methylation, and correctly activating ZGA-related genes to promote epigenetic reprogramming. These results provide a theoretical basis for further studies on the regulatory mechanisms of ELF4 in porcine embryos.

Intestinal ELF4 Deletion Exacerbates Alcoholic Liver Disease by Disrupting Gut Homeostasis

Alcohol liver disease (ALD) is characterized by intestinal barrier disruption and gut dysbiosis. Dysfunction of E74-like ETS transcription factor 4 (ELF4) leads to colitis. We aimed to test the hypothesis that intestinal ELF4 plays a critical role in maintaining the normal function of intestinal barrier and gut homeostasis in a mouse model of ALD. Intestinal ELF4 deficiency resulted in dysfunction of the intestinal barrier. Elf4^−/− mice exhibited gut microbiota (GM) dysbiosis with the characteristic of a larger proportion of Proteobacteria. The LPS increased in Elf4^−/− mice and was the most important differential metabolite between Elf4^−/− mice and WT mice. Alcohol exposure increased liver-to-body weight ratio, and hepatic inflammation response and steatosis in WT mice. These deleterious effects were exaggerated in Elf4^−/− mice. Alcohol exposure significantly increased serum levels of TG, ALT, and AST in Elf4^−/− mice but not in WT mice. In addition, alcohol exposure resulted in enriched expression of genes associated with cholesterol metabolism and lipid metabolism in livers from Elf4^−/− mice. 16S rRNA sequencing showed a decrease abundance of Akkermansia and Bilophila in Elf4^−/− mice. In conclusion, intestinal ELF4 is an important host protective factor in maintaining gut homeostasis and alleviating alcohol exposure-induced hepatic steatosis and injury.

Loss of Function Mutation in ELF4 Causes Autoinflammatory and Immunodeficiency Disease in Human

Monogenic autoinflammatory diseases (mAIDs) are a heterogeneous group of diseases affecting primarily innate immunity, with various genetic causes. Genetic diagnosis of mAIDs can assist in the patient's management and therapy. However, a large number of sporadic and familial cases remain genetically uncharacterized. Deficiency in ELF4, X-linked (DEX) is recently identified as a novel mAID. Here, we described a pediatric patient suffering from recurrent viral and bacterial respiratory infection, refractory oral ulcer, constipation, and arthritis. Whole-exome sequencing found a hemizygous variant in ELF4 (chrX:129205133 A > G, c.691 T > C, p.W231R). Using cells from patient and point mutation mice, we showed mutant cells failed to restrict viral replication effectively and produced more pro-inflammatory cytokines. RNA-seq identified several potential critical antiviral and anti-inflammation genes with decreased expression, and ChIP-qPCR assay suggested mutant ELF4 failed to bind to the promoters of these genes. Thus, we presented the second report of DEX.