scholarly journals Ginsenoside Rb1 Lessens Gastric Precancerous Lesions by Interfering With β-Catenin/TCF4 Interaction

2021 ◽  
Vol 12 ◽  
Author(s):  
Jinhao Zeng ◽  
Xiao Ma ◽  
Ziyi Zhao ◽  
Yu Chen ◽  
Jundong Wang ◽  
...  

Background: Seeking novel and effective therapies for gastric precancerous lesions (GPL) is crucial to reducing the incidence of gastric cancer. Ginsenoside Rb1 (GRb1) is a major ginsenoside in ginseng and has been proved to possess multiple bioactivities. However, whether GRb1 could protect against GPL and the underlying mechanisms have not been explored.Methods: We evaluated the effects of GRb1 on gastric precancerous lesions in rats on macroscopic, microscopic and ultramicroscopic levels. Then, an antibody array was employed to screen differential expression proteins (DEPs). Validation for the targeting DEP and investigation for the possible mechanism was conducted using immunohistochemistry, qRT-PCR, TUNEL apoptosis assay, immunoprecipitation and immunoblotting.Results: GRb1 was found to reverse intestinal metaplasia and a portion of dysplasia in the MNNG-induced GPL rats. The antibody array assay revealed seven DEPs in GPL rats as compared to control rats (5 DEPs were up-regulated, while two DEPs were down-regulated). Among the DEPs, β-catenin, beta-NGF and FSTL1 were significantly down-regulated after GRb1 administration. Our validation results revealed that enhanced protein expression and nuclear translocation of β-catenin were present in animal GPL samples. In addition, analysis of human gastric specimens demonstrated that β-catenin up-regulation and nuclear translocation were significantly associated with advanced GPL pathology. GRb1 intervention not only decreased protein expression and nuclear translocation of β-catenin, but interfered with β-catenin/TCF4 interaction. Along with this, declined transcriptional and protein expression levels of downstream target genes including c-myc, cyclin D1 and Birc5 were observed in GRb1-treated GPL rats.Conclusion: GRb1 is capable of preventing the occurrence and progression of GPL, which might be contributed by diminishing protein expression and nuclear translocation of β-catenin and interfering with β-catenin/TCF4 interaction.

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yang Chen ◽  
Tao Sun ◽  
Junzhen Wu ◽  
Bill Kalionis ◽  
Changcheng Zhang ◽  
...  

The aim of the study was to investigate the effect of icariin (ICA) on cardiac aging through its effects on the SIRT6 enzyme and on the NF-κB pathway. Investigating the effect of ICA on the enzymatic activity of histone deacetylase SIRT6 revealed a concentration of 10−8 mol/L ICA had a maximum activating effect on histone deacetylase SIRT6 enzymatic activity. Western analysis showed that ICA upregulated SIRT6 protein expression and downregulated NF-κB (p65) protein expression in animal tissues and cell models. ICA upregulated the expression of SIRT6 and had an inhibitory effect on NF-κB inflammatory signaling pathways as shown by decreasing mRNA levels of the NF-κB downstream target genes TNF-α, ICAM-1, IL-2, and IL-6. Those effects were mediated directly or indirectly by SIRT6. We provided evidence that inflammaging may involve a novel link between the effects of ICA on SIRT6 (a regulator of aging) and NF-κB (a regulator of inflammation).


2006 ◽  
Vol 26 (4) ◽  
pp. 1414-1423 ◽  
Author(s):  
Hong Duan ◽  
Hanh T. Nguyen

ABSTRACT Skeletal muscle formation in Drosophila melanogaster requires two types of myoblasts, muscle founders and fusion-competent myoblasts. Lame duck (Lmd), a member of the Gli superfamily of transcription factors, is essential for the specification and differentiation of fusion-competent myoblasts. We report herein that appropriate levels of active Lmd protein are attained by a combination of posttranscriptional mechanisms. We provide evidence that two different regions of the Lmd protein are critical for modulating the balance between its nuclear translocation and its retention within the cytoplasm. Activation of the Lmd protein is also tempered by posttranslational modifications of the protein that do not detectably change its subcellular localization. We further show that overexpression of Lmd protein derivatives that are constitutively nuclear or hyperactive results in severe muscle defects. These findings underscore the importance of regulated Lmd protein activity in maintaining proper activation of downstream target genes, such as Mef2, within fusion-competent myoblasts.


2020 ◽  
Vol 27 (5) ◽  
pp. 411-418 ◽  
Author(s):  
Meiyu Qiu ◽  
Tao Li ◽  
Binhu Wang ◽  
Hongbin Gong ◽  
Tao Huang

Background: microRNAs (miRNAs) are a small, endogenous non-coding RNAs that are involved in post-transcriptional gene regulation of many biological processes, including embryo implantation and placental development. In our previous study, miR-146a-5p was found expressed higher in the serum exosomes of pregnant sows than non-pregnant. The research on miR-146a-5p has been mainly related to human diseases, but there are few studies on its effects on the reproduction of sows in early pregnancy. Objective: In this article, our motivation is to study the role of miR-146a-5p in the early pregnancy of sows on the cell proliferetion and apoptosis by targeting SMAD3 and SMAD4. Methods: Bioinformatics software was used to identify the target genes of miR-146a-5p. The wildtype and mutant-type recombinant plasmids of dual-luciferase reporter with 3'-UTR of Smad3 or 3'- UTR of Smad4 were constructed, and co-transfected in porcine kidney cell (PK-15 cell) with miR- 146a-5p mimic, mimic-NC(M-NC), inhibitor and inhibitor-NC(IN-NC), then dual-luciferase activity analysis, qRT-PCR and Western blot were performed to verify the target genes. After the transfection of BeWo choriocarcinoma cell (BeWo cell) with miR-146a-5p mimic, M-NC, inhibitor and IN-NC, the mRNA expression of Caspase-3, BAX and Bcl-2 was measured using qRT-PCR, and the cell proliferation was measured using CCK-8 kit. Results: The luciferase, mRNA and protein expression of Smad3 in PK-15 cells treated by Smad3- 3'-UTR-W co-transfected with miR-146a-5p mimic were significantly lower than that with miR- 146a-5p M-NC, and the results of Smad4 were similar to Smad3, but the protein expression had a trend to lower in mimic group. The expression level of Bcl-2 in the miR-146a-5p mimic group was significantly lower than that in the miR-146a-5p M-NC group, but the expression pattern of Caspase-3 was just opposite. The mimic of miR-146a-5p reduced the proliferation of BeWo cells, however the inhibitor increased. Conclusion: Smad3 and Smad4 are the direct target genes of miR-146a-5p. The expression of Smad3 and Smad4 were affected by the mimic and inhibitor of miR-146a-5p. miR-146a-5p affects cell apoptosis and proliferation by regulating their target genes. This study provided new data to understand the regulation mechanism of early pregnancy in sows.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4122-4122
Author(s):  
Melanie Märklin ◽  
Jonas S. Heitmann ◽  
David Worbs ◽  
Alexandra Poljak ◽  
Claude Evouna ◽  
...  

Abstract Chronic Lymphocytic Leukemia (CLL) is a hematological malignancy of mature B cells and constitutes the most common leukemia in adults. It is characterized by a progressive accumulation of clonal B cells, which coexpress CD19, CD23 and CD5. The clinical course of CLL can be predicted by serveral prognostic markers like CD38, ZAP70 and cytogenetic abnormalities. While the treatment of CLL has significantly improved during recent years, it remains an essentially incurable disease and the molecular events that lead to its development are still largely elusive. NFAT is a family of highly phosphorylated transcription factors residing in the cytoplasm of resting cells. Upon dephosphorylation NFAT proteins translocate to the nucleus where they orchestrate developmental and activation programs in diverse cell types. NFAT is inactivated by a network of several kinases. Several recent studies have demonstrated that Ca2+/NFAT signaling is involved in the pathogenesis of a wide array of different tumor types including pancreatic adenocarcinoma, breast cancer and Non Hodgkin´s lymphoma. In this study we investigated the significance of the Ca2+/NFAT signaling pathway in B-CLL. For this purpose, we analyzed CLL cell lines (MEC-1, JVM-3) as well as primary blood samples from patients with CLL (n=30). The analyzed patient population exhibited a representative distribution of age, sex, Binet stage, WBC count, cytogenetics and IGVH mutational status. We detected a profound overexpression of NFAT2 mRNA as well as NFAT2 protein in all CLL samples. Using qRT-PCR we found that CD19+CD5+ CLL cells exhibited an at least three fold overexpression of NFAT2 as compared to CD19+ B cells isolated from healthy donors. In one case, NFAT2 expression in CLL cells was 200 times higher than in the corresponding controls. This profound overexpression of NFAT2 in CLL cells could be confirmed on the protein level using Western Blotting and Immunocytochemistry. We could further demonstrate that even under resting conditions significant amounts of NFAT2 protein had translocated to the nucleus in CLL cells, whereas virtually all NFAT2 was in the cytoplasm in healthy B cells. NFAT2 nuclear translocation could be inhibited using pretreatment with Cyclosporin A demonstrating that this process was still calcineurin-dependent in CLL cells. We could further show that nuclear NFAT2 in CLL cells was able to bind DNA using electrophoretic mobility shift assays (EMSA). To assess the transcriptional activity of NFAT2 in human CLL we determined the expression of the apoptosis regulators OX40L, osteopontin and PD-L2, which we previously identified as NFAT2 target genes in a gene expression analysis with CD19+CD5+ CLL cells from TCL1 transgenic mice with intact NFAT2 and NFAT2 deletion, respectively. Interestingly, qRT-PCR revealed a tremendous reduction of all three target genes in the analyzed CLL samples as compared to control B cells from healthy donors. This is particularly remarkable, since in the TCL1 mouse model we observed a similar reduction of the expression of these genes in CLL cells with NFAT2 ablation. In summary, these results provide strong evidence that the Ca2+/NFAT signaling axis is constitutively activated in CD19+CD5+ CLL cells. Our data suggest that the profound overexpression of NFAT2 in CLL cells leads to its targeting to aberrant genetic loci different from its phsiological target genes resulting in a consecutive knock out phenotype with respect to the expression of the apoptosis regulators OX40, osteopontin and PD-L2 in CLL. Further investigation is therefore warranted to decipher the therapeutic potential of modulating the Ca2+/Calcineurin/NFAT signaling pathway in this disease. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 117 (16) ◽  
pp. 4338-4348 ◽  
Author(s):  
Ewa Surdziel ◽  
Maciej Cabanski ◽  
Iris Dallmann ◽  
Marcin Lyszkiewicz ◽  
Andreas Krueger ◽  
...  

Abstract MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression by sequence-specific targeting of multiple mRNAs. Although lineage-, maturation-, and disease-specific miRNA expression has been described, miRNA-dependent phenotypes and miRNA-regulated signaling in hematopoietic cells are largely unknown. Combining functional genomics, biochemical analysis, and unbiased and hypothesis-driven miRNA target prediction, we show that lentivirally over-expressed miR-125b blocks G-CSF–induced granulocytic differentiation and enables G-CSF–dependent proliferation of murine 32D cells. In primary lineage-negative cells, miR-125b over-expression enhances colony-formation in vitro and promotes myelopoiesis in mouse bone marrow chimeras. We identified Stat3 and confirmed Bak1 as miR-125b target genes with approximately 30% and 50% reduction in protein expression, respectively. However, gene-specific RNAi reveals that this reduction, alone and in combination, is not sufficient to block G-CSF–dependent differentiation. STAT3 protein expression, DNA-binding, and transcriptional activity but not induction of tyrosine-phosphorylation and nuclear translocation are reduced upon enforced miR-125b expression, indicating miR-125b–mediated reduction of one or more STAT3 cofactors. Indeed, we identified c-Jun and Jund as potential miR-125b targets and demonstrated reduced protein expression in 32D/miR-125b cells. Interestingly, gene-specific silencing of JUND but not c-JUN partially mimics the miR-125b over-expression phenotype. These data demonstrate coordinated regulation of several signaling pathways by miR-125b linked to distinct phenotypes in myeloid cells.


2019 ◽  
Author(s):  
Wenjuan Li ◽  
Baolei Li ◽  
Tingting Li ◽  
Ergeng Zhang ◽  
Qingjie Wang ◽  
...  

Abstract Background: The protein Kruppel-like factor 13 (KLF13) is a member of the KLF family that has been identified as a novel cardiac transcription factor which is involved in heart development. However, the relationship between KLF13 variants and CHDs in humans remains largely unknown. The present study aimed to screen the KLF13 variants in CHDs patients and genetically analyze the function of these variants. Methods: KLF13 variants were sequenced in a cohort of 309 CHD patients and population-matched healthy controls (n = 200) using targeted sequencing. To investigate the effect of variants on the functional ability of the KLF13 protein, the expressions and subcellular localization of protein, as well as the transcriptional activities of downstream genes and physically interacted with other transcription factor were assessed. Results: Two novel heterozygous variants, c.487C>T (P163S) and c.467G>A (S156N), were identified in two out of 309 CHDs patients with Tricuspid-valve atresia and transposition of the great arteries, respectively. No variants were found among healthy controls. The variant c.467G>A (S156N) increased protein expression and enhanced functionality compared with that of wild-type, without affecting the subcellular localization. The other variant, c.487C>T (P163S), did not show any abnormalities in protein expression and subcellular localization, however it eliminated the transcriptional activities of downstream target genes and physically interacted with TBX5, another cardiac transcription factor. Conclusion: Our results show that the S156N and P163S variants contributed to CHD etiology. Additionally, our findings suggest that KLF13 may be a potential gene contributing to congenital heart disease.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Mennatallah Elfar ◽  
Asma Amleh

miRNAs are small non-coding RNA sequences of 18-25 nucleotides. They can regulate different cellular pathways by acting on tumor suppressors, oncogenes, or both. miRNAs are mostly tissue-specific, and their expression varies depending on the cancer or the tissue in which they are found. hsa-miR-590-3p was found to be involved in several types of cancers. In this study, we identified potential downstream target genes of hsa-miR-590-3p computationally. Several bioinformatics tools and more than one approach were used to identify potential downstream target genes of hsa-miR-590-3p. CX3CL1, SOX2, N-cadherin, E-cadherin, and FOXA2 were utilized as potential downstream target genes of hsa-miR-590-3p. SNU449 and HepG2, hepatocellular carcinoma cell lines, were used to carry out various molecular techniques to further validate our in silico results. mRNA and protein expression levels of these genes were detected using RT-PCR and western blotting, respectively. Co-localization of hsa-miR-590-3p and its candidate downstream target gene, SOX2, was carried out using a miRNA in situ hybridization combined with immunohistochemistry staining through anti-SOX2. The results show that there is an inverse correlation between hsa-miR-590-3p expression and SOX2 protein expression in SNU449. Subsequently, we suggest that SOX2 can be a direct downstream target of has-miR-590-3p indicating that it may have a role in the self-renewal and self-maintenance of cancer cells. We also suggest that CX3CL1, E-cadherin, N-cadherin, and FOXA2 show a lot of potential as downstream target genes of hsa-miR-590-3p signifying its role in epithelial-mesenchymal transition. Studying the expression of hsa-miR-590-3p downstream targets can enrich our understanding of the cancer pathogenesis and how it can be used as a therapeutic tool.


1998 ◽  
Vol 9 (12) ◽  
pp. 3309-3319 ◽  
Author(s):  
Xing Shen ◽  
Patrick Pei-chih Hu ◽  
Nicole T. Liberati ◽  
Michael B. Datto ◽  
Joshua P. Frederick ◽  
...  

Smads are intermediate effector proteins that transduce the TGF-β signal from the plasma membrane to the nucleus, where they participate in transactivation of downstream target genes. We have shown previously that coactivators p300/CREB-binding protein are involved in TGF-β–mediated transactivation of two Cdk inhibitor genes, p21 and p15. Here we examined the possibility that Smads function to regulate transcription by directly interacting with p300/CREB-binding protein. We show that Smad3 can interact with a C-terminal fragment of p300 in a temporal and phosphorylation-dependent manner. TGF-β–mediated phosphorylation of Smad3 potentiates the association between Smad3 and p300, likely because of an induced conformational change that removes the autoinhibitory interaction between the N- and C-terminal domains of Smad3. Consistent with a role for p300 in the transcription regulation of multiple genes, overexpression of a Smad3 C-terminal fragment causes a general squelching effect on multiple TGF-β–responsive reporter constructs. The adenoviral oncoprotein E1A can partially block Smad-dependent transcriptional activation by directly competing for binding to p300. Taken together, these findings define a new role for phosphorylation of Smad3: in addition to facilitating complex formation with Smad4 and promoting nuclear translocation, the phosphorylation-induced conformational change of Smad3 modulates its interaction with coactivators, leading to transcriptional regulation.


2021 ◽  
Author(s):  
He Ren ◽  
Chaobing Ma ◽  
Haoran Peng ◽  
Bo Zhang ◽  
Lulin Zhou ◽  
...  

Abstract SARS-CoV-2 infection could cause severe acute respiratory syndrome, largely attributed to dysregulated immune activation and extensive lung tissue damage. However, the underlying mechanisms are not fully understood. Here, we reported that viral infection could induce syncytia formation within cells expressing ACE2 and the SARS-CoV-2 spike protein, leading to the production of micronuclei with an average rate of about 4 per syncytium (> 93%). Remarkably, these micronuclei were manifested with a high level of activation of both DNA damage response and cGAS -STING signaling, as indicated by micronucleus translocation of gH2Ax and cGAS, and upregulation of their respective downstream target genes. Since activation of these signaling pathways were known to be associated with cellular catastrophe and aberrant immune activation, these findings help explain the pathological effects of SARS-CoV-2 infection at cellular and molecular levels, and provide novel potential targets for COVID-19 therapy.


2021 ◽  
Author(s):  
Zhen Huang ◽  
Mingzhu Jia ◽  
Peng Jiang ◽  
Ying Deng ◽  
Shanshan Ding ◽  
...  

Abstract We aim to investigate the methylation status, protein expression and clinical significance of the steroidogenic factor-1(SF-1) in endometrial carcinoma (EC), and explore the effect of abnormal methylation of SF-1 on the biological behaviour of EC. Bisulfite sequencing (BSP), western blotting (WB), and immunohistochemical were used to detect the methylation status and protein expression of SF-1 in EC tissues, paracancerous tissues and normal endometrial tissues. DNA methyltransferase inhibitor 5-Aza-CdR were used to treat HEC-1-A cell lines to demethylate SF-1. After treatment, WB and qPCR were used to detect the expression of SF-1 and its downstream target genes. Cell proliferation and apoptosis were detected by the EdU fluorescent labelling method and flow cytometry between the groups. Compared with paracancerous tissues and normal endometrial tissues, the expression of SF-1 protein in EC tissues was significantly increased (P﹤0.05). The percentage of methylated cytosine in the promoter region of the SF-1 gene in EC tissues (8.2%) was significantly lower than that in paracancerous tissues by 40.9% (P<0.05). Compared with the control group, after 5-Aza-CdR treatment, the methylation level of the SF-1 gene was significantly reduced (P﹤0.05), the expressions of SF-1 and its downstream target genes were significantly increased (P <0.05), the cell proliferation was enhanced and the cell apoptosis was significantly reduced (P <0.05). In conclusion, in EC, SF-1 gene was hypomethylated and the expression of SF-1 was increased, which promotes cell proliferation and inhibits cell apoptosis. SF-1 may become a new molecular target for early diagnosis and treatment in EC.


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