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Human rhinovirus (HRV) infections are the leading cause of disease exacerbations in individuals with chronic pulmonary diseases, primarily due to impaired macrophage functions, resulting in defective bacterial elimination. We previously demonstrated that HRV16 impairs macrophages' functions in an ARL5b-dependent manner. In permissive cells, ARL5b acted as an HRV16 restriction factor and was repressed. Here, we delve into the dual regulation of ARL5b by HRV16 in both cell types. We analyzed the effect of HRV16 on primary human macrophages using neutralizing antibodies, specific inhibitors, siRNA, and chromatin immune precipitation. Our study reveals that, while the virus does not replicate in macrophages, it induces interferon and pro-inflammatory responses. We identify the ICAM-1-PKR-ATF2 signaling axis as crucial for ARL5b induction in macrophages, whereas only ICAM-1 plays a role in ARL5b repression in permissive cells. Furthermore, HRV16 triggers epigenetic reprogramming in both cell types at the ARL5b promoter. In macrophages, epigenetic changes are ATF2 dependent. In conclusion, our findings highlight previously unknown signaling pathways activated by HRV16 in macrophages. Targeting these pathways could offer novel strategies to improve outcomes for individuals with respiratory conditions. [ABSTRACT FROM AUTHOR]

Abstract Background Ankyrin repeat domain 49 (ANKRD49) has been found to be highly expressed in multiple cancer including lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). However, the function of ANKRD49 in the pathogenesis of NSCLC still remains elusive. Previously, ANKRD49 has been demonstrated to promote the invasion and metastasis of A549 cells, a LUAD cell line, via activating the p38-ATF-2-MMP2/MMP9 pathways. Considering the heterogeneity of tumor cells, the function and mechanism of ANKRD49 in NSCLC need more NSCLC-originated cells to clarify. Methods Real-time qPCR was employed to test ANKRD49 expression levels in nine pairs of fresh NSCLC tissues and the corresponding adjacent normal tissues. The function of ANKRD49 was investigated using overexpression and RNA interference assays in lung adenocarcinoma cell line (NCI-H1299) and lung squamous carcinoma cell line (NCI-H1703) through gelatin zymography, cell counting kit-8, colony formation, wound healing, migration and invasion assays mmunoprecipitation was performed to in vitro. Immunoprecipitation was performed to test the interaction of c-Jun and ATF2. Chromatin immunoprecipitation was conducted to assess the transcriptional regulation of ATF2/c-Jun on MMP-2/9. Moreover, the tumorigenicity of ANKRD49 was evaluated in nude mice models and the involved signal molecular was also measured by immunohistochemical method. Results We found that the levels of ANKRD49 in cancerous tissues were higher than those in adjacent normal tissues. in vitro assay showed that ANKRD49 promoted the migration and invasion of NCI-H1299 and NCI-H1703 cells via enhancing the levels of MMP-2 and MMP-9. Furthermore, ANKRD49 elevated phosphorylation of JNK and then activated c-Jun and ATF2 which interact in nucleus to promote the binding of ATF2:c-Jun with the promoter MMP-2 or MMP-9. In vivo assay showed that ANKRD49 promoted lung metastasis of injected-NSCLC cells and the high metastatic rate was positively correlated with the high expression of ANKRD49, MMP-2, MMP-9, p-JNK, p-c-Jun and p-ATF2. Conclusion The present study indicated that ANKRD49 accelerated the invasion and metastasis of NSCLC cells via JNK-mediated transcription activation of c-Jun and ATF2 which regulated the expression of MMP-2/MMP-9. The molecular mechanisms of ANKRD49’s function is different from those found in A549 cells. The current study is a supplement and improvement to the previous research.

Background: Ankyrin repeat domain 49 (ANKRD49) has been found to be highly expressed in multiple cancer including lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). However, the function of ANKRD49 in the pathogenesis of NSCLC still remains elusive. Previously, ANKRD49 has been demonstrated to promote the invasion and metastasis of A549 cells, a LUAD cell line, via activating the p38-ATF-2-MMP2/MMP9 pathways. Considering the heterogeneity of tumor cells, the function and mechanism of ANKRD49 in NSCLC need more NSCLC-originated cells to clarify. Methods: Real-time qPCR was employed to test ANKRD49 expression levels in nine pairs of fresh NSCLC tissues and the corresponding adjacent normal tissues. The function of ANKRD49 was investigated using overexpression and RNA interference assays in lung adenocarcinoma cell line (NCI-H1299) and lung squamous carcinoma cell line (NCI-H1703) through gelatin zymography, cell counting kit-8, colony formation, wound healing, migration and invasion assays mmunoprecipitation was performed to in vitro. Immunoprecipitation was performed to test the interaction of c-Jun and ATF2. Chromatin immunoprecipitation was conducted to assess the transcriptional regulation of ATF2/c-Jun on MMP-2/9. Moreover, the tumorigenicity of ANKRD49 was evaluated in nude mice models and the involved signal molecular was also measured by immunohistochemical method. Results: We found that the levels of ANKRD49 in cancerous tissues were higher than those in adjacent normal tissues. in vitro assay showed that ANKRD49 promoted the migration and invasion of NCI-H1299 and NCI-H1703 cells via enhancing the levels of MMP-2 and MMP-9. Furthermore, ANKRD49 elevated phosphorylation of JNK and then activated c-Jun and ATF2 which interact in nucleus to promote the binding of ATF2:c-Jun with the promoter MMP-2 or MMP-9. In vivo assay showed that ANKRD49 promoted lung metastasis of injected-NSCLC cells and the high metastatic rate was positively correlated with the high expression of ANKRD49, MMP-2, MMP-9, p-JNK, p-c-Jun and p-ATF2. Conclusion: The present study indicated that ANKRD49 accelerated the invasion and metastasis of NSCLC cells via JNK-mediated transcription activation of c-Jun and ATF2 which regulated the expression of MMP-2/MMP-9. The molecular mechanisms of ANKRD49's function is different from those found in A549 cells. The current study is a supplement and improvement to the previous research. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is one of the leading causes of blindness in diabetic patients. However, the pathogenesis of DR is complex, and no firm conclusions have been drawn so far. It has become a hot spot in ophthalmology research to deeply study the mechanism of DR pathological changes and find effective treatment options. Human retinal microvascular endothelial cells (HRMECs) were induced by high glucose (HG) to construct DR cell model. CCK-8 assay was used to detect the viability of HRMECs. Transwell assay was used to detect the migration ability of HRMECs. Tube formation assay was used to identify the tube formation ability of HRMECs. The expressions of USP14, ATF2 and PIK3CD were detected by Western blot analysis and qRT-PCR assay. Immunoprecipitation (IP) was used to ascertain the relationship of USP14 and ATF2. To explore the regulatory relationship between ATF2 and PIK3CD by dual-luciferase reporter gene assay and Chromatin immunoprecipitation (ChIP) assay. High glucose treatment promoted the proliferation, migration, and tube formation of HRMEC, and the expressions of USP14, ATF2 and PIK3CD were significantly up-regulated. USP14 or ATF2 knockdown inhibited HG-induced HRMECs proliferation, migration, and tube formation. USP14 regulated the expression of ATF2, and ATF2 promoted PIK3CD expression. PIK3CD overexpression attenuated the inhibitory effectiveness of USP14 knockdown on proliferation, migration and tube formation of DR cell model. Here, we revealed that USP14 regulated the ATF2/PIK3CD axis to promote proliferation, migration, and tube formation in HG-induced HRMECs. [ABSTRACT FROM AUTHOR]

Amentoflavone (AF) is a natural multifunctional biflavonoid that has been revealed to possess multiple biological activities, including anticancer activity. Here, this work focused on exploring the functions and mechanism of AF in gastric cancer (GC). Levels of genes and proteins were examined by quantitative real‐time PCR and western blotting. Cell proliferation and cell death were analyzed using cell counting kit‐8, colony formation, and lactate dehydrogenase (LDH) release assay, respectively. Cell ferroptosis was evaluated by detecting the levels of malondialdehyde (MDA), reduced glutathione (GSH), Fe2+, and intracellular reactive oxygen species (ROS). The binding between miR‐496 and activating transcription factor 2 (ATF2) was confirmed by using dual‐luciferase reporter assay. Murine xenograft assay was conducted for in vivo experiments. The results showed that AF suppressed the proliferation and induced ferroptotic cell death in GC cells. MiR‐496 expression was decreased in GC tissues and cells, and AF treatment increased miR‐496 expression level in GC cells. Functionally, miR‐496 inhibition reversed the inhibitory effects of AF on GC cell proliferation and promoting effects on ferroptotic cell death. Mechanistically, ATF2 was targeted by miR‐496. ATF2 expression was increased in GC tissues and cells, which was decreased by AF treatment and subsequently rescued by miR‐496 downregulation in GC cells. Moreover, miR‐496 overexpression suppressed the proliferation and induced ferroptotic cell death in GC cells via targeting ATF2. In all, AF suppressed the proliferation and induced ferroptotic cell death in GC cells via miR‐496/ATF2 axis, indicating a novel therapeutic approach for GC patients. [ABSTRACT FROM AUTHOR]

Globally, gastric cancer (GC) is a major cause of cancer death. This study is aimed at investigating the biological functions of activating transcription factor 2 (ATF2) and the underlying mechanism in GC. In the present work, GEPIA, UALCAN, Human Protein Atlas and StarBase databases were adopted to analyze ATF2 expression characteristics in GC tissues and normal gastric tissues, and its relationships with tumor grade and patients' survival time. Quantitative real‐time polymerase chain reaction (qRT‐PCR) method was employed to examine ATF2 mRNA expression in normal gastric tissues, GC tissues, and GC cell lines. Cell counting kit‐8 (CCK‐8) and EdU assays were utilized for detecting GC cell proliferation. Cell apoptosis was detected by flow cytometry. PROMO database was applied to predict the binding site of ATF2 with the METTL3 promoter region. The binding relationship between ATF2 and the METTL3 promoter region was verified through dual‐luciferase reporter gene assay and chromatin immunoprecipitation‐quantitative PCR (ChIP‐qPCR) assay. Western blot was performed to evaluate the effect of ATF2 on METTL3 expression. METTL3‐related signaling pathways were predicted using Gene Set Enrichment Analysis (GSEA) in the LinkedOmics database. It was found that, ATF2 level was elevated in GC tissues and cell lines in comparison with normal tissues and correlated with short patients' survival time. ATF2 overexpression facilitated GC cell growth and suppressed the apoptosis, whereas ATF2 knockdown suppressed GC cell proliferation and facilitated the apoptosis. ATF2 bound to the METTL3 promoter region, and ATF2 overexpression promoted the transcription of METTL3, and ATF2 knockdown restrained the transcription of METTL3. METTL3 was associated with cell cycle progression, and ATF2 overexpression enhanced cyclin D1 expression, and METTL3 knockdown reduced cyclin D1 expression. In summary, ATF2 facilitates GC cell proliferation and suppresses the apoptosis via activating the METTL3/cyclin D1 signaling pathway, and ATF2 is promising to be an anti‐drug target for GC. [ABSTRACT FROM AUTHOR]

The differentiation and activation of macrophages are critical regulatory programs that are central to host inflammation and pathogen defense. However, the transcriptional regulatory pathways involved in these programs are not well understood. Herein, we demonstrate that the activity and expression of the transcription factor ATF2 is precisely regulated during primary human monocyte-to-macrophage differentiation and that its activation is linked to M1 polarization and antibacterial responses. Genetic perturbation experiments demonstrated that deletion of ATF2 (THP-ΔATF2) resulted in irregular and abnormal macrophage morphology, whereas macrophages overexpressing ATF2 (THP-ATF2) developed round and pancake-like morphology, resembling classically activated (M1) macrophages. Mechanistically, we show that ATF2 binds to the core promoter of PPM1A, a phosphatase that regulates monocyte-to-macrophage differentiation, to regulate its expression. Functionally, overexpression of ATF2 sensitized macrophages to M1 polarization, resulting in increased production of major histocompatibility complex class II, IL-1β, and IP-10; improved phagocytic capacity; and enhanced control of the intracellular pathogen Mycobacterium tuberculosis. Gene expression profiling revealed that overexpression of ATF2 reprogramed macrophages to promote antibacterial pathways enriched in chemokine signaling, metabolism, and antigen presentation. Consistent with pathways analysis, metabolic profiling revealed that genetic overexpression or stimuli-induced activation of ATF2 alters the metabolic capacity of macrophages and primes these cells for glycolytic metabolism during M1 polarization or bacterial infection. Our findings reveal that ATF2 plays a central role during macrophage differentiation and M1 polarization to enhance the functional capacities of macrophages. [ABSTRACT FROM AUTHOR]

Background: Polymethylmethacrylate (PMMA) bone cement loaded with enoxaparin sodium (PMMA@ES) has been increasingly highlighted to affect the bone repair of bone defects, but the molecular mechanisms remain unclear. We addressed this issue by identifying possible molecular mechanisms of PMMA@ES involved in femoral defect regeneration based on bioinformatics analysis and network pharmacology analysis. Methods: The upregulated genes affecting the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) were selected through bioinformatics analysis, followed by intersection with the genes of ES-induced differentiation of BMSCs identified by network pharmacology analysis. PMMA@ES was constructed. Rat primary BMSCs were isolated and cultured in vitro in the proliferation medium (PM) and osteogenic medium (OM) to measure alkaline phosphatase (ALP) activity, mineralization of the extracellular matrix, and the expression of RUNX2 and OCN using gain- or loss-of-function experiments. A rat femoral bone defect model was constructed to detect the new bone formation in rats. Results: ATF2 may be a key gene in differentiating BMSCs into osteoblasts. In vitro cell assays showed that PMMA@ES promoted the osteogenic differentiation of BMSCs by increasing ALP activity, extracellular matrix mineralization, and RUNX2 and OCN expression in PM and OM. In addition, ATF2 activated the transcription of miR-335-5p to target ERK1/2 and downregulate the expression of ERK1/2. PMMA@ES induced femoral defect regeneration and the repair of femoral defects in rats by regulating the ATF2/miR-335-5p/ERK1/2 axis. Conclusion: The evidence provided by our study highlighted the ATF2-mediated mechanism of PMMA@ES in the facilitation of the osteogenic differentiation of BMSCs and femoral defect regeneration. [ABSTRACT FROM AUTHOR]

The hepatic endoplasmic reticulum (ER)-anchored cytochromes P450 (P450s) are mixed-function oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance. P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover. Such P450 proteolytic turnover occurs through a process known as ER-associated degradation (ERAD) that involves ubiquitin-dependent proteasomal degradation (UPD) and/or autophagic-lysosomal degradation (ALD). Herein, on the basis of available literature reports and our own recent findings of in vitro as well as in vivo experimental studies, we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance. We specifically (i) describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibody pathogenesis in drug-induced acute hypersensitivity reactions and liver injury, or viral hepatitis; (ii) discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates; and (iii) detail the pathophysiological consequences of disrupted P450 ERAD, contributing to non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) under certain synergistic cellular conditions.

Abstract Activating transcription factor 2 (ATF2) is a tumor driver gene implicated in several human malignancies. This study aimed to determine the roles of ATF2 and its related molecules in the tumorigenesis of hepatocellular carcinoma (HCC). According to the Pan‐cancer bioinformatics system, ATF2 is highly expressed in HCC. An increase in the expression of ATF2 was identified in clinically collected tumor tissues and procured HCC cells. The silencing of ATF2 reduced the viability, colony formation, invasion, and death resistance of HepG2 and SNU‐398 cells in vitro. ATF2 promoted the transcription of Wolf‐Hirschhorn syndrome candidate 1 (WHSC1) by binding to its promoter. WHSC1 further increased the expression of DNA topoisomerase II alpha (TOP2A) in HCC by inducing the dimethylation of histone H3 lysine 36 (H3K36me2) in the TOP2A promoter region. TOP2A activated the oncogenic PI3K/AKT signaling pathway. Further overexpression of WHSC1 activated the TOP2A/PI3K/AKT axis and restored the malignant behaviors of HCC cells suppressed by ATF2 silencing in vitro. In summary, this study demonstrated that, depending on WHSC1, ATF2 can activate the TOP2A/PI3K/AKT signaling cascade to promote the tumorigenesis of HCC. ATF2, WHSC1, and TOP2A may serve as potential targets in managing HCC.

Purpose: Prostate cancer (PC) is a heterogeneous malignancy that greatly threatens man's health. E3 ubiquitin-protein ligase neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) imparts an regulatory role in various malignancies. This study focused on the modulatory mechanism of NEDD4L in proliferation of prostate cancer cells (PCCs) via regulating histone demethylase plant homeodomain finger protein 8 (PHF8/KDM7B) through the ubiquitin–proteasome system. Methods: The expression levels of NEDD4L, PHF8, H3 lysine 9 dimethylation (H3K9me2) and activating transcription factor 2 (ATF2) in PC tissues and cell lines were detected via real-time quantitative polymerase chain reaction and Western blotting. After transfection of pcDNA3.1-NEDD4L, pcDNA3.1-PHF8, and pcDNA3.1-ATF2 into PCCs, cell proliferation was assessed via the cell counting kit-8 and 5-ethynyl-2'-deoxyuridine assays. Interaction between NEDD4L and PHF8 was identified via the protein immunoprecipitation. The ubiquitination level of PHF8 was determined via the ubiquitination detection. The enrichments of H3K9me2 and PHF8 in the ATF2 promotor region were detected via the chromatin-immunoprecipitation assay. Results: PHF8 and ATF2 were highly expressed while NEDD4L was poorly expressed in PC tissues and cells. NEDD4L overexpression reduced proliferation of PCCs. NEDD4Linduced degradation of PHF8 via ubiquitination. PHF8 limited the enrichment of H3K9me2 in the ATF2 promotor region and enhanced ATF2 transcription. Upregulation of PHF8 or ATF2 abolished the inhibitory role of NEDD4L in proliferation of PCCs. Conclusion: NEDD4L facilitated degradation of PHF8 to limit ATF2 transcription, thereby suppressing proliferation of PCCs. [ABSTRACT FROM AUTHOR]

Abstract Background Activating transcription factor-2 (ATF2) is a member of the basic leucine zipper family of DNA-binding proteins, which exhibits both oncogenic and tumor suppression activity in different tumors. However, the molecular mechanism of its dual function in cancer chemotherapy especially in gastric cancer has still not been elucidated. Methods The protein expression and location of ATF2 in gastric cancer tissues was detected with immunohistochemistry assay, and the clinical significance was analyzed using TCGA and GEO database. The activation and impact of ATF2 in cisplatin treated cells were evaluated with western blot, incucyte live cell analysis, clone formation and tumor xenografts assays. Interaction between ATF2 and p53 was confirmed with immunoprecipitation and GST-pull down. Potential molecular mechanism of ATF2 in different p53 status cells was analyzed with RNA sequencing and real-time quantitative PCR. Results ATF2 mainly located in the nucleus of cancer cells, higher ATF2 level was associated with poor five-year survival of gastric patients, especially in those undergone chemotherapy treatment. Cisplatin treatment significantly activated ATF2 in p53 mutant cells. ATF2 could interact with the trans-activation domain of p53 and enhance cisplatin sensitivity in p53 wild type cell lines, while promoted cell survival in mutant p53 cancer cells by affecting ERK1/2 pathway. Conclusions This study confirmed the effect of ATF2 on cisplatin sensitivity was associated with the functional status of p53 in gastric cancer cells. Integrated analysis of ATF2 expression and P53 status could be used to evaluate the chemotherapy sensitivity and prognosis of gastric cancer patients.

Distant metastasis is a prevalent cause of mortality in gastric cancer (GC) patients. Anoikis, a process that induces cell death when cells get detached from the extracellular matrix (ECM), acts as a barrier to tumor metastasis. To survive in the circulatory system and metastasize, tumor cells must acquire anoikis resistance. It is crucial to identify the molecular processes that cause resistance to anoikis in GC since this might lead to the discovery of novel treatment targets and improve the long-term survival of GC patients. In this study, we employed quantitative proteomics to identify growth differentiation factor 15 (GDF15) as a key factor in GC anoikis resistance. We found that GDF15 enhances protective autophagy, thereby promoting anoikis resistance in GC cells. Furthermore, through DNA pull down assay, activating transcription factor 2 (ATF2) was found to be a critical regulator of GDF15 expression, acting as a transcriptional activator of GDF15. Collectively, these discoveries indicate that ATF2 and GDF15 have great potential as target candidates for developing therapeutic strategies to address the metastasis of GC. • GDF15 plays an important role in anoikis resistance and metastasis of gastric cancer. • Autophagy can protect GC cells from anoikis. • GDF15 promotes anoikis resistance and metastasis of gastric cancer through protective autophagy. • ATF2 can transcriptionally activate GDF15 in gastric cancer. [ABSTRACT FROM AUTHOR]

Sorafenib, a tyrosine kinase inhibitor, has an important antitumor effect as a ferroptosis inducer in multiple cancers, including gastric cancer (GC). However, the status of sorafenib as a ferroptosis inducer has recently been questioned. There is very limited information about the relationship between ferroptosis and ATF2, and the role of ATF2 in sorafenib-induced ferroptosis has not been studied. In this study, we investigated the role and underlying molecular mechanisms of ATF2 in sorafenib-induced ferroptosis in GC. We found that ATF2 was significantly upregulated in GC tissues and predicted a poor clinical prognosis. Silencing ATF2 significantly inhibited the malignant phenotype of GC cells. In addition, we observed that ATF2 was activated during sorafenib-induced ferroptosis in GC cells. ATF2 knockdown promoted sorafenib-induced ferroptosis, while ATF2 overexpression showed the opposite results in GC cells. Using ChIP-Seq and RNA-Seq, we identified HSPH1 as a target of ATF2 and further validated it by ChIP‒qPCR analysis. HSPH1 can interact with SLC7A11 (cystine/glutamate transporter) and increase its protein stability. Importantly, knockdown of HSPH1 partly reversed the effects caused by ATF2 overexpression on sorafenib-induced ferroptosis in GC cells. In addition, the results from the tumor xenograft model showed that ATF2 knockdown can effectively enhance sorafenib sensitivity in vivo. Collectively, our study reveals a novel mechanism by which sorafenib induces ferroptosis in GC.

Activating transcription factor 2 (ATF2) is a tumor driver gene implicated in several human malignancies. This study aimed to determine the roles of ATF2 and its related molecules in the tumorigenesis of hepatocellular carcinoma (HCC). According to the Pan‐cancer bioinformatics system, ATF2 is highly expressed in HCC. An increase in the expression of ATF2 was identified in clinically collected tumor tissues and procured HCC cells. The silencing of ATF2 reduced the viability, colony formation, invasion, and death resistance of HepG2 and SNU‐398 cells in vitro. ATF2 promoted the transcription of Wolf‐Hirschhorn syndrome candidate 1 (WHSC1) by binding to its promoter. WHSC1 further increased the expression of DNA topoisomerase II alpha (TOP2A) in HCC by inducing the dimethylation of histone H3 lysine 36 (H3K36me2) in the TOP2A promoter region. TOP2A activated the oncogenic PI3K/AKT signaling pathway. Further overexpression of WHSC1 activated the TOP2A/PI3K/AKT axis and restored the malignant behaviors of HCC cells suppressed by ATF2 silencing in vitro. In summary, this study demonstrated that, depending on WHSC1, ATF2 can activate the TOP2A/PI3K/AKT signaling cascade to promote the tumorigenesis of HCC. ATF2, WHSC1, and TOP2A may serve as potential targets in managing HCC. [ABSTRACT FROM AUTHOR]

Abstract Background Hepatocellular carcinoma (HCC) is a common cause of cancer mortality worldwide. Recent studies have shown that the polytopic enzyme membrane associated ring-CH-type finger 6 (MARCH6) participates in tumorigenesis, but its function in HCC development needs to be investigated. This study aimed to explore the role of MARCH6 in HCC. Methods Expression of MARCH6 in human HCC samples was checked by immunohistochemical staining assay. Clinical relevance of MARCH6 and activating transcription factor 2 (ATF2) was analyzed from TCGA database. CCK-8, EdU staining, colony formation and transwell were performed to assess cell proliferation, growth and migration. Xenografted tumorigenesis was used to examine in vivo role MARCH6. Immunoblotting was applied to detect protein abundance. Results We found that MARCH6 expression was elevated in human HCC samples. Over-expression of MARCH6 was associated with poor prognosis of HCC patients. Up-expression of MARCH6 promoted cell growth and migration of HCC cells. In contrast, the HCC cell growth and migration were suppressed by MARCH6 knockdown. Furthermore, the DNA synthesis was enhanced by MARCH6. The expression of ATF2 was potentiated by MARCH6 over-expression, while it was suppressed by MARCH6 silencing. TCGA database showed positive correlation between the expression of MARCH6 and ATF2. Importantly, ATF2 expression contributed to the oncogenic function of HCC cells. Conclusion Our findings suggest that MARCH6-mediated ATF2 up-regulation contributes to HCC development. MARCH6 may be a promising target for the diagnosis and treatment of HCC.

Background: Activating transcription factor-2 (ATF2) is a member of the basic leucine zipper family of DNA-binding proteins, which exhibits both oncogenic and tumor suppression activity in different tumors. However, the molecular mechanism of its dual function in cancer chemotherapy especially in gastric cancer has still not been elucidated. Methods: The protein expression and location of ATF2 in gastric cancer tissues was detected with immunohistochemistry assay, and the clinical significance was analyzed using TCGA and GEO database. The activation and impact of ATF2 in cisplatin treated cells were evaluated with western blot, incucyte live cell analysis, clone formation and tumor xenografts assays. Interaction between ATF2 and p53 was confirmed with immunoprecipitation and GST-pull down. Potential molecular mechanism of ATF2 in different p53 status cells was analyzed with RNA sequencing and real-time quantitative PCR. Results: ATF2 mainly located in the nucleus of cancer cells, higher ATF2 level was associated with poor five-year survival of gastric patients, especially in those undergone chemotherapy treatment. Cisplatin treatment significantly activated ATF2 in p53 mutant cells. ATF2 could interact with the trans-activation domain of p53 and enhance cisplatin sensitivity in p53 wild type cell lines, while promoted cell survival in mutant p53 cancer cells by affecting ERK1/2 pathway. Conclusions: This study confirmed the effect of ATF2 on cisplatin sensitivity was associated with the functional status of p53 in gastric cancer cells. Integrated analysis of ATF2 expression and P53 status could be used to evaluate the chemotherapy sensitivity and prognosis of gastric cancer patients. [ABSTRACT FROM AUTHOR]

Aim: Due to high invasion and metastasis, hepatocellular carcinoma (HCC) is known as one of the most fatal carcinomas. We aim to further investigate regulatory mechanisms of invasion and metastasis to elucidate HCC pathogenesis and develop novel medications. Methods: Patient specimens were collected for assessing gene expression and correlation between gene expressions. The expression of Ki67 and E‐cadherin in subcutaneous xenograft tumor were examined by immunohistochemistry staining. The expression of activating transcription factor 2 (ATF2), miR‐548p and TUFT1 were determined using Real‐time quantitative reverse transcription polymerase chain reaction. Epithelial‐mesenchymal transition and PI3K/AKT signaling‐associated markers were examined with western blot. The proliferation, migration and invasion were assessed by 3‐(4, 5‐dimethylthiazolyl‐2)‐2, 5‐diphenyltetrazolium bromide, colony formation and transwell assays, respectively. Cell apoptosis was assessed via Annexin V and propidium iodide staining. Gene interaction was confirmed using chromatin immunoprecipitation and luciferase activity assays. Subcutaneous and intravenous xenograft mouse models were established for analyzing HCC growth and metastasis in vivo. Results: ATF2 was up‐regulated in HCC patients and cells. ATF2 promoted HCC cell proliferation, migration and invasion and inhibited cell apoptosis through directly targeting miR‐548p and controlling its expression. miR‐548p suppressed HCC cell proliferation, migration and invasion and enhanced cell apoptosis. miR‐548p directly bound to the 3′UTR of TUFT1 to restrain its expression and subsequently suppress the PI3K/AKT signaling. ATF2 knock‐down significantly suppressed the growth and metastasis of HCC. Conclusion: ATF2 accelerates HCC progression by promoting cell proliferation, migration, invasion and metastasis, which is dependent on regulating the miR‐548p/TUFT1 axis. [ABSTRACT FROM AUTHOR]

Abstract Background Activating transcription factor 2 (ATF2), a member of the activator protein 1 (AP-1) transcription factor family, has been shown to be involved in the pathobiology of numerous cancers. However, the biological role and mechanism of ATF2 in lung adenocarcinoma (LUAD) remains to be elucidated. Methods The expression of ATF2, NEAT1 and miR-26a-5p in LUAD tissues and cell lines was detected by qRT-PCR and western blotting. The interaction between ATF2, NEAT1, and miR-26a-5p was validated by chromatin immunoprecipitation, luciferase reporter assay and RNA immunoprecipitation. Cell proliferation, invasion and tumorigenesis of LUAD cells were analyzed by using CCK8, transwell invasion assay and xenograft tumor model. Results We confirmed that ATF2 expression was increased in LUAD tissues compared with normal adjacent lung tissues. Functional experiments showed that ATF2 positively regulated cell proliferation and invasion in LUAD cells. Moreover, we identified that NEAT1 expression was increased in LUAD tissues and positively correlated with ATF2 expression. Mechanistically, ATF2 could bind to the promoter of NEAT1 to promote its transcription. Rescue experiments showed that ATF2 exerted its oncogenic function in LUAD, at least, partly through NEAT1 upregulation. In turn, NEAT1 could positively regulate ATF2 expression and form a positive feedback loop in LUAD cells. Furthermore, we demonstrated that NEAT1 positively regulated ATF2 expression via sponging miR-26a-5p. Conclusion ATF2 and NEAT1 form a positive feedback loop mediated by miR-26a-5p and coordinately contribute to LUAD progression.

Abstract Background Activating transcription factor-2 (ATF2), a member of the leucine zipper family of DNA binding proteins, has been implicated as a tumour suppressor in breast cancer. However, its exact role in breast cancer endocrine resistance is still unclear. We have previously shown that silencing of ATF2 leads to a loss in the growth-inhibitory effects of tamoxifen in the oestrogen receptor (ER)-positive, tamoxifen-sensitive MCF7 cell line and highlighted that this multi-faceted transcription factor is key to the effects of tamoxifen in an endocrine sensitive model. In this work, we explored further the in vitro role of ATF2 in defining the resistance to endocrine treatment. Materials and methods We knocked down ATF2 in TAMR, LCC2 and LCC9 tamoxifen-resistant breast cancer cell lines as well as the parental tamoxifen sensitive MCF7 cell line and investigated the effects on growth, colony formation and cell migration. We also performed a microarray gene expression profiling (Illumina Human HT12_v4) to explore alterations in gene expression between MCF7 and TAMRs after ATF2 silencing and confirmed gene expression changes by quantitative RT-PCR. Results By silencing ATF2, we observed a significant growth reduction of TAMR, LCC2 and LCC9 with no such effect observed with the parental MCF7 cells. ATF2 silencing was also associated with a significant inhibition of TAMR, LCC2 and LCC9 cell migration and colony formation. Interestingly, knockdown of ATF2 enhanced the levels of ER and ER-regulated genes, TFF1, GREB1, NCOA3 and PGR, in TAMR cells both at RNA and protein levels. Microarray gene expression identified a number of genes known to mediate tamoxifen resistance, to be differentially regulated by ATF2 in TAMR in relation to the parental MCF7 cells. Moreover, differential pathway analysis confirmed enhanced ER activity after ATF2 knockdown in TAMR cells. Conclusion These data demonstrate that ATF2 silencing may overcome endocrine resistance and highlights further the dual role of this transcription factor that can mediate endocrine sensitivity and resistance by modulating ER expression and activity.

Abstract Background MicroRNAs are ~ 22-nucleotide-long biological modifiers that act as the post-transcriptional modulator of gene expression. Some of them are identified to be embedded within the introns of protein-coding genes, these miRNAs are called the intronic miRNAs. Previous findings state that these intronic miRNAs are co-expressed with their host genes. This co-expression is necessary to maintain the robustness of the biological system. Till to date, only a few experiments are performed discretely to elucidate the functional relationship between few co-expressed intronic miRNAs and their associated host genes. Results In this study, we have interpreted the underlying modulatory mechanisms of intronic miRNA hsa-miR-933 on its target host gene ATF2 and found that aberration can lead to several disease conditions. A protein-protein interaction network-based approach was adopted, and functional enrichment analysis was performed to elucidate the significantly over-represented biological functions and pathways of the common targets. Our approach delineated that hsa-miR-933 might control the hyperglycemic condition and hyperinsulinism by regulating ATF2 target genes MAP4K4, PRKCE, PEA15, BDNF, PRKACB, and GNAS which can otherwise lead to the development of type II diabetes mellitus. Moreover, we showed that hsa-miR-933 can regulate a target of ATF2, brain-derived neurotrophic factor (BDNF), to modulate the optimal expression of ATF2 in neuron cells to render neuroprotection for the inhibition of neurodegenerative diseases. Conclusions Our in silico model provides interesting resources for experimentations in a model organism or cell line for further validation. These findings may extend the common perception of gene expression analysis with new regulatory functionality.

Lei Li, Guohua Lv, Bing Wang, Hong Ma Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, People’s Republic of ChinaCorrespondence: Hong Ma Tel +86 731-85295124Email spinema@csu.edu.cnBackground: Chordoma, a rare bone tumor, occurs most commonly at the sacrococcygeal and skull base region. To date, chemotherapy is used to treat patients with advanced-stage chordoma. However, multidrug resistance (MDR) greatly hinders the effect of chemotherapy in chordoma. Here, we studied the correlation between KCNQ1OT1 and chemotherapy resistance.Methods: RT-PCR assay was used to examine KCNQ1OT1, miR-27b-3p, and ATF2 mRNA expression. CCK8 assay was exercised to detect IC50 values of cisplatin in chordoma cells. ATF2 protein expression was detected by Western blot.Results: KCNQ1OT1 was increased in chemotherapy-resistant patients and cisplatin-resistant cells, and downregulation of KCNQ1OT1 expression weakened MDR in chordoma. In addition, KCNQ1OT1 promoted MDR in chordoma by sponging miR-27b-3p and subsequently increasing ATF2 expression.Conclusion: KCNQ1OT1 is proved to be strikingly raised in the chemotherapy-resistant group and to promote MDR in chordoma. Our findings demonstrated the role of the KCNQ1OT1/miR-27b-3p/ATF2 axis in MDR of chordoma, which provides new insight into the molecular mechanism of chordoma MDR, and may determine the effect of therapy after receiving chemotherapy by detecting the expression of KCNQ1OT1 in serum.Keywords: KCNQ1OT1, MDR, miR-27b-3p, ATF2, chordoma

Objective: Osteosarcoma is a common primary highly malignant bone tumor. Kinesin family member 18B (KIF18B) has been identified as a potential oncogene involved in the development and metastasis of several cancer types. While KIF18B overexpression in osteosarcoma tissue is clearly detected, its specific function in the disease process remains to be established. Methods: KIF18B expression was assessed in osteosarcoma tissues and cells. We additionally evaluated the effects of KIF18B on proliferation, migration, and invasion of osteosarcoma cells, both in vitro and in vivo. Results: Our results showed overexpression of KIF18B in osteosarcoma tissues and cells. Knockdown of KIF18B induced G1/S phase arrest and significantly inhibited proliferation, migration, and invasion of osteosarcoma cells, both in vitro and in vivo. KIF18B regulated β-catenin expression at the transcriptional level by controlling nuclear aggregation of ATF2 and at the post-transcriptional level by interacting with the adenomatous polyposis coli (APC) tumor suppressor gene in osteosarcoma cells. Conclusions: KIF18B plays a carcinogenic role in osteosarcoma by regulating expression of β-catenin transcriptionally via decreasing nuclear aggregation of ATF2 or post-transcriptionally through interactions with APC. Our collective findings support the potential utility of KIF18B as a novel prognostic biomarker for osteosarcoma.

Abstract Background Recent studies have shown 6'-O-galloylpaeoniflorin (GPF), a nature product extracted from the roots of paeoniflorin exerts anti-oxidant and anti-inflammatory activities. However, the effects of GPF on the proliferation and invasion in non-small cell lung cancer (NSCLC) cells have not been clarified. Methods MTT assay was performed to determine the cytotoxicity of GPF treatment on NSCLC cells. Colony formation assay, cell scratch test and transwell assay were performed to determine the proliferation and invasion of NSCLC cells in vitro, respectively. An A549 cell xenograft mouse model was performed to confirm the growth of NSCLC cells in vivo. Western blotting was used to measure the levels of activating transcription factor 2 (ATF2), AMP-activated protein kinase (AMPK) and phosph-AMPK (p-AMPK). Luciferase assay was used to validate the binding of miR-299-5p on the 3' untranslated region (UTR) of ATF2. Results Administration of GPF (50 or 100 μM) was significantly cytotoxic to A549 cells and H1299 cells, as well as inhibited the clonality, invasion and metastasis of NSCLC cells in vitro. GPF treatment also inhibited the tumor growth of NSCLC cell mouse xenografts in vivo. Exotic expression of miR-299-5p significantly inhibited the growth of NSCLC cells in vitro and in vivo. Downregulation of miR-299-5p expression attenuated the inhibition of the proliferation and metastasis of non-small cell lung cancer cells by GPF treatment. miR-299-5p significantly decreased ATF2 mRNA and protein levels in A549 cells (p

Background: Mitochondrial biogenesis is related to Ppargc-1α and Atf2 genes. Endurance training through PGC-1α and Atf2 induces mitochondrial biogenesis, but it seems that air pollution has the opposite effect. Therefore, this study aimed to investigate the effect of endurance training in air pollution on PGC-1α and Atf2 genes expression in brain cortex mitochondria of Wistar male rats. Materials and Methods: In this experimental study, 32 eight-week-old rats (weight: 180.77±10.65) divided into four groups: control, training, pollution, and training+pollution. In order to expose animals to air pollution, a 9000-liter chamber was used. The training was performed for eight weeks. 24 hours after last session, brain cortex was extracted. The expression of genes was measured using RT-PCR. The two-way ANOVA was used to analyze the data. Results: Atf2 gene expression was significantly different in the training+pollution group compared to the control group (P=0.04). In addition, Atf2 gene expression was significantly different in the training group compared to the control group (P

BACKGROUND: AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine protein kinase that is activated by cellular perturbations associated with ATP depletion or stress. While AMPK modulates the activity of a variety of targets containing a specific phosphorylation consensus sequence, the number of AMPK targets and their influence over cellular processes is currently thought to be limited. RESULTS: We queried the human and the mouse proteomes for proteins containing AMPK phosphorylation consensus sequences. Integration of this database into Gaggle software facilitated the construction of probable AMPK-regulated networks based on known and predicted molecular associations. In vitro kinase assays were conducted for preliminary validation of 12 novel AMPK targets across a variety of cellular functional categories, including transcription, translation, cell migration, protein transport, and energy homeostasis. Following initial validation, pathways that include NAD synthetase 1 (NADSYN1) and protein kinase B (AKT2) were hypothesized and experimentally tested to provide a mechanistic basis for AMPK regulation of cell migration and maintenance of cellular NAD(+) concentrations during catabolic processes. CONCLUSIONS: This study delineates an approach that encompasses both in silico procedures and in vitro experiments to produce testable hypotheses for AMPK regulation of cellular processes.

BackgroundLong intergenic non-protein coding RNA 882 (LINC00882) are abnormally expressed in several tumors. Our research aimed to uncover the functions and the potential mechanisms of LINC00882 in hepatocellular carcinoma (HCC) progression.MethodsRT-qPCR was applied to identify LINC00882 and miR-214-3p levels in HCC specimens and cells. Luciferase reporter was applied for the exploration of whether activating transcription factor 2 (ATF2) could bind to the promoter region of LINC00882. Cell proliferation, invasion, and migration were evaluated. In vivo tumor xenograft models were constructed to assess tumorigenicity. RT-PCR, Western blot and Luciferase reporter assays were conducted to examine the regulatory relationships among LINC00882, miR-214-3p and ATF2.ResultsLINC00882 was markedly upregulated in HCC cells and clinical specimens. Additionally, ATF2 could bind directly to the LINC00882 promoter region and activate its transcription. Loss-of-function studies further demonstrated that LINC00882 knockdown inhibited proliferation, invasion, and migration of HCC cells. Mechanistically, LINC00882 adsorbed miR-214-3p, thus promoting the expressions of CENPM. Rescue assays demonstrated that functions of LINC00882 deficiency in HCC cells were reversed through suppressing miR-214-3p.ConclusionOur group identified a novel regulatory axis of ATF2/LINC00882/miR-214-3p/CENPM, which may provide potential therapeutic targets for HCC.

COVID‐19 is often characterized by dysregulated inflammatory and immune responses. It has been shown that the Traditional Chinese Medicine formulation Qing‐Fei‐Pai‐Du decoction (QFPDD) is effective in the treatment of the disease, especially for patients in the early stage. Our network pharmacology analyses indicated that many inflammation and immune‐related molecules were the targets of the active components of QFPDD, which propelled us to examine the effects of the decoction on inflammation. We found in the present study that QFPDD effectively alleviated dextran sulfate sodium‐induced intestinal inflammation in mice. It inhibited the production of pro‐inflammatory cytokines IL‐6 and TNFα, and promoted the expression of anti‐inflammatory cytokine IL‐10 by macrophagic cells. Further investigations found that QFPDD and one of its active components wogonoside markedly reduced LPS‐stimulated phosphorylation of transcription factor ATF2, an important regulator of multiple cytokines expression. Our data revealed that both QFPDD and wogonoside decreased the half‐life of ATF2 and promoted its proteasomal degradation. Of note, QFPDD and wogonoside down‐regulated deubiquitinating enzyme USP14 along with inducing ATF2 degradation. Inhibition of USP14 with the small molecular inhibitor IU1 also led to the decrease of ATF2 in the cells, indicating that QFPDD and wogonoside may act through regulating USP14 to promote ATF2 degradation. To further assess the importance of ubiquitination in regulating ATF2, we generated mice that were intestinal‐specific KLHL5 deficiency, a CUL3‐interacting protein participating in substrate recognition of E3s. In these mice, QFPDD mitigated inflammatory reaction in the spleen, but not intestinal inflammation, suggesting CUL3‐KLHL5 may function as an E3 for ATF2 degradation. [ABSTRACT FROM AUTHOR]

Background: Long intergenic non-protein coding RNA 882 (LINC00882) are abnormally expressed in several tumors. Our research aimed to uncover the functions and the potential mechanisms of LINC00882 in hepatocellular carcinoma (HCC) progression. Methods: RT-qPCR was applied to identify LINC00882 and miR-214-3p levels in HCC specimens and cells. Luciferase reporter was applied for the exploration of whether activating transcription factor 2 (ATF2) could bind to the promoter region of LINC00882. Cell proliferation, invasion, and migration were evaluated. In vivo tumor xenograft models were constructed to assess tumorigenicity. RT-PCR, Western blot and Luciferase reporter assays were conducted to examine the regulatory relationships among LINC00882, miR-214-3p and ATF2. Results: LINC00882 was markedly upregulated in HCC cells and clinical specimens. Additionally, ATF2 could bind directly to the LINC00882 promoter region and activate its transcription. Loss-of-function studies further demonstrated that LINC00882 knockdown inhibited proliferation, invasion, and migration of HCC cells. Mechanistically, LINC00882 adsorbed miR-214-3p, thus promoting the expressions of CENPM. Rescue assays demonstrated that functions of LINC00882 deficiency in HCC cells were reversed through suppressing miR-214-3p. Conclusion: Our group identified a novel regulatory axis of ATF2/LINC00882/miR-214-3p/CENPM, which may provide potential therapeutic targets for HCC. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) is a common cause of cancer mortality worldwide. Recent studies have shown that the polytopic enzyme membrane associated ring-CH-type finger 6 (MARCH6) participates in tumorigenesis, but its function in HCC development needs to be investigated. This study aimed to explore the role of MARCH6 in HCC.Methods: Expression of MARCH6 in human HCC samples was checked by immunohistochemical staining assay. Clinical relevance of MARCH6 and activating transcription factor 2 (ATF2) was analyzed from TCGA database. CCK-8, EdU staining, colony formation and transwell were performed to assess cell proliferation, growth and migration. Xenografted tumorigenesis was used to examine in vivo role MARCH6. Immunoblotting was applied to detect protein abundance.Results: We found that MARCH6 expression was elevated in human HCC samples. Over-expression of MARCH6 was associated with poor prognosis of HCC patients. Up-expression of MARCH6 promoted cell growth and migration of HCC cells. In contrast, the HCC cell growth and migration were suppressed by MARCH6 knockdown. Furthermore, the DNA synthesis was enhanced by MARCH6. The expression of ATF2 was potentiated by MARCH6 over-expression, while it was suppressed by MARCH6 silencing. TCGA database showed positive correlation between the expression of MARCH6 and ATF2. Importantly, ATF2 expression contributed to the oncogenic function of HCC cells.Conclusion: Our findings suggest that MARCH6-mediated ATF2 up-regulation contributes to HCC development. MARCH6 may be a promising target for the diagnosis and treatment of HCC. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the role of microRNA-125b (miR-125b) and its mechanism in spinal cord injury (SCI) by targeting Smurf1. After loss-and gain-function approaches were conducted in SCI rat models and neural stem cells (NSCs) isolated from foetal rats, the Basso-Beattie-Bresnahan (BBB) score was calculated, and related protein expression was determined by Western blot analysis and cell apoptosis by TUNEL staining. NSC viability was detected by CCK-8, migration abilities by Transwell assay and apoptosis by flow cytometry. The relationship between miR-125b, Smurf1 and KLF2 was evaluated by dual-luciferase reporter gene experiments, Co-IP and in vivo ubiquitin modification assays. Inhibition of miR-125b and KLF2 and the up-regulation of Smurf1 and ATF2 were observed in SCI rats. BBB scores were elevated, the expression of Nestin, NeuN, GFAP, NF-200 and Bcl-2 protein was enhanced but that of Bax protein was reduced, and cell apoptosis was inhibited in SCI rats after up-regulating miR-125b or silencing ATF2. Smurf1 was a target gene of miR-125b, which promoted KLF2 degradation through its E3 ubiquitin ligase function, and KLF2 repressed the expression of ATF2 in NSCs. The results in vivo were replicated in vitro. miR-125b overexpression promotes neurological function recovery after SCI. [ABSTRACT FROM AUTHOR]

Psoriasis is an immune-mediated chronic inflammatory skin disease. Current research suggests that the long-term persistence and recurrence of psoriasis are closely related to the feedback loop formed between keratinocytes and immune cells, especially in Th 17 or DC cells expressing CCR6. CCL20 is the ligand of CCR6. Therefore, drugs that block the expression of CCL20 or CCR6 may have a certain therapeutic effect on psoriasis. Glycyrrhetinic acid (GA) is the main active ingredient of the plant drug licorice and is often used to treat autoimmune diseases, including psoriasis. However, its mechanism of action is still unclear. Psoriasis like skin lesion model was established by continuously applying imiquimod on the back skin of normal mice and CCR6-/- mice for 7 days. The therapeutic and preventive effects of glycyrrhetinic acid (GA) on the model were observed and compared. The severity of skin injury is estimated through clinical PASI scores and histopathological examination. qRT-PCR and multiple cytoline assay were explored to detect the expression levels of cytokines in animal dorsal skin lesions and keratinocyte line HaCaT cells, respectively. The dermis and epidermis of the mouse back were separated for the detection of CCL20 expression. Transcription factor assay was applied to screen, and luciferase activity assay to validate transcription factors regulated by GA. Technology of surface plasmon laser resonance with LC-MS (SPR-MS), molecular docking, and enzyme activity assay were used to identified the target proteins for GA. Finally, we synthesized different derivatives of 18beta-GA and compared their effects, as well as glycyrrhetinic acid (GL), on the skin lesion of imiquimod-induced mice to evaluate the active groups of 18beta-GA. 18β-glycyrrhetinic acid (GA) improved IMQ-induced psoriatic lesions, and could specifically reduce the chemokine CCL20 level of the epidermis in lesion area, especially in therapeutic administration manner. The process was mainly regulated by transcription factor ATF2 in the keratinocytes. In addition, GUSB was identified as the primary target of 18βGA. Our findings indicated that the subject on molecular target research of glycyrrhizin should be glycyrrhetinic acid (GA) instead of glycyrrhizic acid (GL), because GL showed little activity in vitro or in vivo. Apart from that, α, β, -unsaturated carbonyl in C11/12 positions was crucial or unchangeable to its activity of 18βGA, while proper modification of C3 or C30 position of 18βGA may vastly increase its activity. Our research indicates that 18βGA exerted its anti-psoriasis effect mainly by suppressing ATF2 and downstream molecule CCL20 predominately through α, β, -unsaturated carbonyl at C11/12 position binding to GUSB in the keratinocytes, and then broke the feedback loop between keratinocytes and CCR6-expressing immune cells. GA has more advantages than GL in the external treatment of psoriasis. A highlight of this study is to investigate the influence of special active groups on the pharmacological action of a natural product, inspired by the molecular docking result. [ABSTRACT FROM AUTHOR]

BET inhibitor (BETi) has potential therapeutic effects on human cancer especially in breast cancer. However, the detailed mechanisms remain unclear. Herein, we found that BETi JQ1 and I-BET-151 (I-BET) activated ATF2 through JNK1/2 pathway in breast cancer cells MDA-MB-231 (MB-231). In addition, overexpression of ATF2 blocked the reduction of cell viability induced by JQ1 or I-BET in breast cancer MB-231 and BT-549 cells, cervical cancer HeLa cells and lung cancer A549 cells. The induction of cell death by BETi was also attenuated by ATF2 in MB-231 and BT-549 cells. By contrast, depletion of ATF2 increased cancer cell sensitivity to BETi. In MB-231 cells xenograft model, ATF2 significantly inhibited the anti-tumor effects of JQ1. By detection of the oxidized form gluthione, malondialdehyde and lipid ROS, we showed that overexpression of ATF2 inhibited ferroptosis induced by BETi, whereas depletion of ATF2 promoted ferroptosis by BETi. Furthermore, the underlying mechanisms of ATF2-reduced ferroptosis were investigated. Overexpressed and depleted ATF2 were found to significantly upregulate and downregulate NRF2 protein and mRNA expression, respectively. The significantly positive correlations between NRF2 and ATF2 gene expression were found in breast, lung and cervical cancer tissues from TCGA database. In NRF2-depleted MB-231 cells, ATF2 failed to attenuate JQ1-stimulated ferroptosis. All these results suggested that ATF2 inhibited BETi-induced ferroptosis by increasing NRF2 expression. Altogether, our findings illustrated ATF2 suppressed ani-tumor effects of BETi in a negative feedback manner by attenuating ferroptosis. BETi combined with ATF2 or NRF2 inhibitor might be a novel strategy for treatment of human cancer. • BET inhibitors activates ATF2 by JNK1/2 pathway. • ATF2 prevents anti-cancer effects of BET inhibitors. • ATF2 attenuates ferroptosis induced by BETi. • Upregulation of NRF2 is involved ATF2-inhibited ferroptosis. [ABSTRACT FROM AUTHOR]

Aims: To genetically engineer the oleaginous yeast Yarrowia lipolytica for de novo production of tetraacetylphytosphingosine (TAPS), a precursor of phytosphingosine, and optimization of fermentation conditions for high yield. Methods and Results: We successfully constructed a TAPS‐producing Y. lipolytica CE3 strain by co‐expression of Wickerhamomyces ciferrii‐derived acetyl transferases, Sli1p and Atf2p. Next, we optimized several environmental factors including temperature, initial pH and C/N ratio for TAPS production in a shake culture. Deletion of LCB4 in CE3 strain increased the volumetric TAPS titre and cell‐specific yield to 142·1 ± 10·7 mgTAPS l−1 and 3·08 ± 0·11 mgTAPS gDCW−1, respectively, in a shake flask culture incubated for 120 h at 28°C with glycerol as the carbon source. Finally, we developed a 5‐l fed‐batch process with NaOH‐mediated pH control and olive oil as a carbon source, exhibiting 650 ± 24 mgTAPS l−1 of TAPS production within 56 h of the fermentation. Conclusions: The introduction of codon‐optimized Sli1p and Atf2p, deletion of LCB4 gene and sexual hybridization, accompanied by specific fermentation conditions, enhanced TAPS yield in Y. lipolytica. Significance and Impact of the Study: Our results highlight Y. lipolytica as a promising candidate for the industrial production of TAPS, an important component of cosmetic formulations. [ABSTRACT FROM AUTHOR]

Activating transcription factor 2(ATF2), a transcription factor belonging to the AP-1 family, plays an important role in inflammation. However, its biological functions and underlying molecular mechanisms in rheumatoid arthritis (RA) remain unclear. Western blot and immunohistochemistry were used to identify the expression of ATF2 and Sprouty2(SPRY2) in RA synovial tissues. SW982 cells were stimulated by TNF-α to establish an in vitro RA fibroblast-like synoviocyte (RA-FLS) model. Transwell and monolayer wound-healing were used to detect cell migration and invasion. RNA interference (si-ATF2) and adenovirus vector (Ad-SPRY2) methods were employed to manipulate ATF2 or SPRY2 expression in SW982 cells. The protein expression and phosphorylation levels in SW982 cells were evaluated by western blot. ATF2 expression and phosphorylation were upregulated in the RA synovial tissues. In RA-FLS model, ATF2 expression and phosphorylation were increased in a time-dependent manner. ATF2 knockdown inhibited the migration and invasion of RA-FLS model, reducing the inflammatory factors, which was consistent with the influence on cell behaviors caused by SPRY2 overexpression. Moreover, SPRY2 overexpression inhibited the TNF-α-induced phosphorylation of ERK and ATF2 in SW982 cells. The high expression and phosphorylation of ATF2 promoted migration and invasion of RA-FLSs. SPRY2 might inhibited the inflammatory responses of RA-FLSs via suppressing ERK-ATF2 pathway. [ABSTRACT FROM AUTHOR]

Neonatal encephalopathy with seizures (NEwS) is an epileptic encephalopathy with an autosomal recessive inheritance pattern found in Standard Poodle puppies. The causal genetic variant for NEwS has been identified as a homozygous missense mutation in ATF2 (c.152T>G, p.Met51Arg), and a pathological cerebellar change has been reported. Magnetic resonance imaging showed reduced whole-brain size, dilated ventricles, developmental abnormalities of the white matter of the cerebrum, white matter signal abnormalities in the occipital lobe, and abnormal morphology of the cerebellum. Histopathology included previously unrecognized irregular neuronal migration in the subventricular zone around the lateral ventricles in the frontal lobe and white matter rarefaction especially at the level of the occipital lobe in the cerebrum in addition to the cerebellar cortical dysplasia that has been previously described. The findings of this case may highlight the critical role of ATF2 in neurodevelopmental processes in the canine brain.

Abstract Background Global cerebral ischemia triggers neurodegeneration in the hippocampal CA1 region, but the mechanism of neuronal death remains elusive. The epsilon isoform of protein kinase C (PKCε) has recently been identified as a master switch that controls the nucleocytoplasmic trafficking of ATF2 and the survival of melanoma cells. It is of interest to assess the role of PKCε–ATF2 signaling in neurodegeneration. Results Phosphorylation of ATF2 at Thr-52 was reduced in the hippocampus of PKCε null mice, suggesting that ATF2 is a phosphorylation substrate of PKCε. PKCε protein concentrations were significantly reduced 4, 24, 48 and 72 h after transient global cerebral ischemia, resulting in translocation of nuclear ATF2 to the mitochondria. Degenerating neurons staining positively with Fluoro-Jade C exhibited cytoplasmic ATF2. Conclusions Our results support the hypothesis that PKCε regulates phosphorylation and nuclear sequestration of ATF2 in hippocampal neurons during ischemia-induced neurodegeneration.

We investigated the functional role of ATF2, a transcription factor normally activated via its phosphorylation in response to phospho-ERK/MAPK signals, in the outgrowth of urothelial cancer. In both neoplastic and non-neoplastic urothelial cells, the expression levels of androgen receptor (AR) correlated with those of phospho-ATF2. Dihydrotestosterone treatment in AR-positive bladder cancer cells also induced the expression of phospho-ATF2 and phospho-ERK as well as nuclear translocation and transcriptional activity of ATF2. Meanwhile, ATF2 knockdown via shRNA resulted in significant decreases in cell viability, migration and invasion of AR-positive bladder cancer lines, but not AR-negative lines, as well as significant increases and decreases in apoptosis or G0/G1 cell cycle phase and S or G2/M phase, respectively. Additionally, the growth of AR-positive tumors expressing ATF2-shRNA in xenograft-bearing mice was retarded, compared with that of control tumors. ATF2 knockdown also resulted in significant inhibition of neoplastic transformation induced by a chemical carcinogen 3-methylcholanthrene, as well as the expression of Bcl-2/cyclin-A2/cyclin-D1/JUN/MMP-2, in immortalized human normal urothelial SVHUC cells stably expressing AR, but not AR-negative SVHUC cells. Finally, immunohistochemistry in surgical specimens demonstrated significant elevation of ATF2/phospho-ATF2/phospho-ERK expression in bladder tumors, compared with non-neoplastic urothelial tissues. Multivariate analysis further showed that moderate/strong ATF2 expression and phospho-ATF2 positivity were independent predictors for recurrence of low-grade tumors (hazard ratio (HR) = 2.956, P = 0.045) and cancer-specific mortality of muscle-invasive tumors (HR = 5.317, P = 0.012), respectively. Thus, ATF2 appears to be activated in urothelial cells through the AR pathway and promotes the development and progression of urothelial cancer.

Abstract Background Next-generation sequencing of the exome and genome of prostate cancers has identified numerous genetic alterations. SPOP (Speckle-type POZ Protein) is one of the most frequently mutated genes in primary prostate cancer, suggesting that SPOP may be a potential driver of prostate cancer. The aim of this work was to investigate how SPOP mutations contribute to prostate cancer development and progression. Methods To identify molecular mediators of the tumor suppressive function of SPOP, we performed a yeast two-hybrid screen in a HeLa cDNA library using the full-length SPOP as bait. Immunoprecipitation and Western Blotting were used to analyze the interaction between SPOP and ATF2. Cell migration and invasion were determined by Transwell assays. Immunohistochemistry were used to analyze protein levels in patients’ tumor samples. Results Here we identified ATF2 as a bona fide substrate of the SPOP-CUL3-RBX1 E3 ubiquitin ligase complex. SPOP recognizes multiple Ser/Thr (S/T)-rich degrons in ATF2 and triggers ATF2 degradation via the ubiquitin-proteasome pathway. Strikingly, prostate cancer-associated mutants of SPOP are defective in promoting ATF2 degradation in prostate cancer cells and contribute to facilitating prostate cancer cell proliferation, migration and invasion. Conclusion SPOP promotes ATF2 ubiquitination and degradation, and ATF2 is an important mediator of SPOP inactivation-induced cell proliferation, migration and invasion.

Abstract Background Activating transcription factor 2 (ATF2) is a member of the leucine zipper family of DNA binding proteins and is widely distributed in tissues. Several recent studies have demonstrated that this protein is involved in mechanisms that are related to pain and inflammation. However, unclear is whether polymorphisms of the ATF2 gene, which encodes the human ATF2 protein, influence pain or analgesic sensitivity. This study examined associations between the analgesic effect of fentanyl in the cold pressor‐induced pain test and polymorphisms in the ATF2 gene in 355 Japanese subjects. Results In this study, 33 single nucleotide polymorphisms (SNPs) were selected, and a total of 2 linkage disequilibrium blocks with 6 Tag SNPs (rs1153702, rs7583431, rs2302663, rs3845744, rs268214, and rs1982235) were observed in the region within and around the ATF2 gene. We further analyzed associations between these Tag SNPs and clinical data. Even after multiple testing with Bonferroni adjustments, an increase in the analgesic effect of fentanyl in the cold pressor‐induced pain test was significantly associated with a greater number of the A allele of the rs7583431 SNP (linear regression, P = .001). Conclusions The present findings may contribute to adequate pain relief in individual patients. Although more research on the genetic factors that influence opioid sensitivity is needed, analgesic requirements may be predicted by analyzing ATF2SNPs, together with other polymorphisms of genes that are reportedly associated with opioid sensitivity, such as CREB1, OPRM1, and GIRK2.

Background: Activating transcription factor 2 (ATF2), a member of the activator protein 1 (AP-1) transcription factor family, has been shown to be involved in the pathobiology of numerous cancers. However, the biological role and mechanism of ATF2 in lung adenocarcinoma (LUAD) remains to be elucidated. Methods: The expression of ATF2, NEAT1 and miR-26a-5p in LUAD tissues and cell lines was detected by qRT-PCR and western blotting. The interaction between ATF2, NEAT1, and miR-26a-5p was validated by chromatin immunoprecipitation, luciferase reporter assay and RNA immunoprecipitation. Cell proliferation, invasion and tumorigenesis of LUAD cells were analyzed by using CCK8, transwell invasion assay and xenograft tumor model. Results: We confirmed that ATF2 expression was increased in LUAD tissues compared with normal adjacent lung tissues. Functional experiments showed that ATF2 positively regulated cell proliferation and invasion in LUAD cells. Moreover, we identified that NEAT1 expression was increased in LUAD tissues and positively correlated with ATF2 expression. Mechanistically, ATF2 could bind to the promoter of NEAT1 to promote its transcription. Rescue experiments showed that ATF2 exerted its oncogenic function in LUAD, at least, partly through NEAT1 upregulation. In turn, NEAT1 could positively regulate ATF2 expression and form a positive feedback loop in LUAD cells. Furthermore, we demonstrated that NEAT1 positively regulated ATF2 expression via sponging miR-26a-5p. Conclusion: ATF2 and NEAT1 form a positive feedback loop mediated by miR-26a-5p and coordinately contribute to LUAD progression. [ABSTRACT FROM AUTHOR]

Distal cholangiocarcinoma (dCCA) is a biliary tract cancer with a dismal prognosis and is often preceded by biliary intraepithelial neoplasia (BilIN), representing the most common biliary non‐invasive precursor lesion. BilIN are histologically well defined but have not so far been characterised systematically at the molecular level. The aim of this study was to determine miRNA‐regulated genes in cholangiocarcinogenesis via BilIN. We used a clinicopathologically well‐characterised cohort of 12 dCCA patients. Matched samples of non‐neoplastic biliary epithelia, BilIN and invasive tumour epithelia of each patient were isolated from formalin‐fixed paraffin‐embedded tissue sections by laser microdissection. The resulting 36 samples were subjected to total RNA extraction and the expression of 798 miRNAs was assessed using the Nanostring® technology. Candidate miRNAs were validated by RT‐qPCR and functionally investigated following lentiviral overexpression in dCCA‐derived cell lines. Potential direct miRNA target genes were identified by microarray and prediction algorithms and were confirmed by luciferase assay. We identified 49 deregulated miRNAs comparing non‐neoplastic and tumour tissue. Clustering of these miRNAs corresponded to the three stages of cholangiocarcinogenesis, supporting the concept of BilIN as a tumour precursor. Two downregulated miRNAs, i.e. miR‐451a (−10.9‐fold down) and miR‐144‐3p (−6.3‐fold down), stood out by relative decrease. Functional analyses of these candidates revealed a migration inhibitory effect in dCCA cell lines. Activating transcription factor 2 (ATF2) and A disintegrin and metalloproteinase domain‐containing protein 10 (ADAM10) were identified as direct miR‐451a target genes. Specific ATF2 inhibition by pooled siRNAs reproduced the inhibitory impact of miR‐451a on cancer cell migration. Thus, our data support the concept of BilIN as a direct precursor of invasive dCCA at the molecular level. In addition, we identified miR‐451a and miR‐144‐3p as putative tumour suppressors attenuating cell migration by inhibiting ATF2 in the process of dCCA tumorigenesis. © The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Myocardial infarction (MI) is a cardiovascular disease that seriously endangers human health. Exosomes secreted by stem cells have big potential for the treatment of many diseases. The purpose of this study was to study the therapeutic effects of exosomes derived from lipopolysaccharide (LPS)-stimulated bone marrow mesenchymal stem cells (BMSCs) on MI. PATIENTS AND METHODS: The surface markers of BMSCs were detected by Western blot. After BMSCs were stimulated with LPS for 2 days, the exosomes secreted by BMSCs were extracted and observed by transmission electron microscopy (TEM), and their specific surface markers were detected by Western blot. H9c2 cells were co-cultured with exosomes for 24 hours, and then, treated with H2O2 for 4 hours. Next, H9c2 cells were transfected with miRNA-181a- 5p mimic (MIM) or negative control (NC). Inflammation and oxidative stress of H9c2 cells were detected by Western blot, cell staining, reactive oxygen species (ROS) quantification, and SOD activity assay. At last, miR-181a-5p expression in BMSCs, exosomes, and H9c2 cells was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). RESULTS: The results revealed that the expression of miR-181a-5p was increased in LPS-stimulated BMSCs (L-BMSC) and in their secreted exosomes. Besides, the expressions of TNF-α and IL-1β were decreased, while those of SOD1 and SOD2 were increased in H9c2 cells co-cultured with exosomes secreted by LPS-stimulated BMSCs (L-EXO) and transfected with MIM. Moreover, the fluorescence intensity of IL-1β immunofluorescence was decreased in H9c2 cells co-cultured with L-EXO or transfected with MIM. The level of ROS was also decreased in H9c2 cells co-cultured with L-EXO or transfected with MIM. Furthermore, miR-181a-5p was found to target ATF2 through target gene prediction databases and Western blot and Dual-Luciferase reporter assays. CONCLUSIONS: LPS stimulation can increase the expression of miR-181a-5p in BMSCs, and miR-181a-5p inhibits myocardial inflammation and oxidative stress by targeting ATF2. [ABSTRACT FROM AUTHOR]

Activating transcription factors 2 (ATF2) is a transcription factor of the members of ATF/CREB family that is phosphorylated and activated by the mitogen-activated protein kinase (MAPK) in responding to the stimulation of stimuli. In present study, Sp ATF2 from mud crab (Scylla paramamosain) was identified and studied. The open reading frame of Sp ATF2 with 2136 bp in length encodes a protein with 711 amino acids. The Sp ATF2 protein includes the putative zinc finger domain in the N-terminus and bZIP type DNA-binding domain in the C-terminal. Tissue distribution of Sp ATF2 transcripts showed that Sp ATF2 was ubiquitously expressed in all examined tissues of the untreated mud crabs, with the highest expression levels in muscle and hepatopancreas. The transcriptional level of Sp ATF2 was up-regulated in the hemocytes after Vibrio parahemolyticus or WSSV infection. Reporter gene assays indicated that Sp ATF2 could activate the expression of dual oxidase (Sp Duox1) in S. paramamosain. The RNA interference (RNAi) of Sp ATF2 significantly decreased the expression of Sp Duox1, and consequently reduced reactive oxygen species production thereby significantly increased the bacterial load in the hemolymph of mud crabs. Similarly, significant reduction in bacterial clearance of hemolymph was observed after the V. parahemolyticus infection in Sp ATF2 knockdown mud crabs. This study showed that Sp ATF2 played a vital role in maintaining homeostasis of the hemolymph microbiota through regulating the expression of dual oxidase of mud crab. • Sp ATF2 regulates the expression of S. paramamosain Doux1 in transcription level. • Sp ATF2 participates in maintaining the homeostasis of the hemolymph microbiota in mud crabs. • The bacterial clearance of hemolymph was significantly reduced in the Sp ATF2 knockdown crabs. [ABSTRACT FROM AUTHOR]

Activating Transcription Factor 2 (ATF2) is a member of the ATF/CREB bZIP family of transcription factors and an oncogene in prostate cancer. ATF2 has been reported to be a critical substrate of the CUL3-SPOP-RBX1 E3 ubiquitin ligase complex and the recurrent somatic mutation of SPOP has been believed to be a key feature of prostate cancer. However, the deubiquitinating enzyme required for ATF2 stabilization is still unknown. Here, we show that ATF2 is associated with ubiquitin-specific protease 14 (USP14), which increased the protein abundance and transcriptional activity of ATF2. Pharmacologic inhibition or siRNA-mediated depletion of USP14 resulted in the decline and inactivation of ATF2. USP14 deubiquitinates and activates ATF2, resulting in enhanced prostate cancer cells proliferation both in vitro and in vivo. Importantly, silencing of ATF2 largely attuned USP14-mediated prostate cancer cells proliferation. Thus, our data revealed a critical role of USP1-ATF2 axis in the progress of prostate cancer and the inhibition of USP14 might be a promising strategy against prostate cancer. • USP14 is associated with ATF2. • USP14 deubiquitinates and stabilizes ATF2. • USP14 regulates the transcriptional activity of ATF2. • USP14 promotes prostate cancer cells proliferation partially dependent on ATF2. [ABSTRACT FROM AUTHOR]