Global gene profiling of (-)-Epigallocatechin-3-gallate (EGCG)-induced neuronal death
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ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Minghui Jessica Chen
PROVIDER: E-GEOD-22996 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:We reported the molecular mechanisms of low combination doses of epigallocatechin-3-gallate and hydroxychavicol (EGCG+HC) in glioma cell lines 1321N1 and LN18. Using high throughput RNA sequencing, combined EGCG+HC exerted its anticancer effect by downregulating the axon guidance process and metabolic pathways, while simultaneously interfering with endoplasmic reticulum unfolded protein response pathway. Furthermore, EGCG+HC exerted its apoptotic effect through the alteration of mitochondrial genes such as MT-CO3 and MT-RNR2 in 1321N1 and LN18 cells respectively. EGCG+HC dynamically altered DYNLL1 alternative splicing expression in 1321N1 and DLD splicing expression in LN18 cell lines.
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Project description:The inhibition of DYRK1A (Dual Specificity Tyrosine-Phosphorylation-Regulated Kinase 1A) activity, triplicated in trisomy 21 subjects, has been proved as a promising therapy for Down syndrome. Epigallocatechin-3-gallate (EGCG), a polyphenol of green tea, is an allosteric inhibitor of DYRK1A that showed beneficial pro-cognitive effects in clinical trials with DS individuals. However, EGCG induces several pharmacological effects, and there is no proof that the observed improvements result from DYRK1A inhibition. Besides, the direct consequences of Dyrk1A overexpression are not well defined. We therefore used quantitative proteomics to decipher the proteome and phosphoproteome alterations resulting from Dyrk1A overexpression and its inhibition to get insight into the mechanism of action of EGCG. Towards this aim, we used mice overexpressing Dyrk1A, and compared the hippocampal proteome and phosphoproteome with their wild type counterparts, in basal conditions, and after treatment with EGCG. Moreover, given that the human clinical trials found that the effects of EGCG potentiated the effects of cognitive stimulation, we also included in our study treatment with environmental enrichment and its combination with EGCG. We found that DYRK1A overexpression leads to alterations in protein and phosphoprotein levels of hundreds of proteins, and that the levels of proteins involved in key postsynaptic pathways are restored by the cognitive enhancer treatments, which could help conceiving new therapeutic strategies.
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Project description:Epigallocatechin-3-gallate (EGCG), a major active polyphenol of green tea, has been shown to downregulate inflammatory responses in macrophages; however, the underlying mechanism has not been understood. Recently, we identified the 67-kDa laminin receptor (67LR) as a cell-surface EGCG receptor that mediates the anti-cancer action of EGCG at physiologically relevant concentrations (0.1-1 mM). Here we show the molecular basis for the downregulation of TLR4 signal transduction by EGCG at 1 mM in macrophages. Anti-67LR antibody treatment or RNAi-mediated silencing of 67LR resulted in abrogation of the inhibitory action of EGCG on LPS-induced activation of downstream signaling pathways and target gene expressions. Additionally, we found that EGCG reduced the TLR4 expression through 67LR. Interestingly, EGCG induced a rapid upregulation of Tollip protein, a negative regulator of TLR-signaling, and this EGCG action was prevented by 67LR silencing or anti-67LR antibody treatment. RNAi-mediated silencing of Tollip impaired the TLR4 signaling inhibitory activity of EGCG. Taken together, these findings demonstrate that 67LR plays a critical role in mediating anti-inflammatory action of a physiologically relevant EGCG and Tollip expression could be modulated through 67LR. These results provide a new insight into the understanding of negative regulatory mechanisms for TLR4 signaling pathway and consequent inflammatory responses which are implicated in the development and progression of many chronic diseases. We quantified expression profile of 210 inflammatory-relating genes in the 67LR-downregulated cells treated with LPS or/and EGCG by microarray
2010-04-20 | E-GEOD-21320 | biostudies-arrayexpress
Project description:The epigenetic regulation of transcription factor genes is critical for T cell lineage specification. A specific methylation pattern within a conserved region of the lineage specifying transcription factor gene FOXP3, the Treg-specific demethylated region (TSDR), is restricted to regulatory T (Treg) cells and required for stable expression of FOXP3 and suppressive function. We analyzed the impact of hypomethylating agents 5-Aza-2`-deoxycytidine and Epigallocatechin-3-gallate (EGCG) on human CD4+CD25- T for generating Treg cell specific DNA methylation pattern within FOXP3-TSDR and inducing functional Treg cells. Gene expression, including lineage specifying transcription factors of the major T cell lineages and their leading cytokines, functional properties and global transcriptome changes were analyzed. 5-Aza-2`-deoxycytidine induced FOXP3-TSDR methylation and expression of Treg cell specific genes FOXP3 and LRRC32. Proliferation of 5-Aza-2´deoxycytidine treated cells was reduced, but they did not show suppressive function. Hypomethylation was not restricted to FOXP3-TSDR and expression of master transcription factors and leading cytokines of Th1 and Th17 cells were induced. EGCG induced global DNA hypomethylation to a lower degree than 5-Aza-2´deoxycitidine, but no relevant hypomethylation within FOXP3-TSDR or expression of Treg cell specific genes. Both DNMT inhibitors did not induce full functional human Treg cells. Although 5-Aza-2`-deoxycytidine treated cells phenotypically appeared to be Treg cells, they did not suppress proliferation of responder cells, which is an essential capability to be used in Treg cell transfer therapy. In this study we analyze the potency of the two hypomethylating agents 5-Aza-2`-deoxycytidine (5-Aza-dC) and Epigallocatechin-3-gallate (EGCG) for in vitro induction of functional Treg cell cells through generation of a specific methylation pattern within FOXP3-TSDR. We analyzed the expression of Treg cell specific genes and for their functional properties from CD4+CD25- T cells. 5-Aza-dC is a derivative of 5-Azacytidine. Both substances are inhibitors of DNA methyltransferases (DNMTs) and used for therapy of patients with myelodysplastic syndrome and acute myeloid leukaemia. In these patients, 5-Azacytidine has been reported to augment regulatory T cell expansion in blood. EGCG is the most abundant catechin of green tea and has been reported to have cardio protective, anti-cancer, anti-infective properties and protective effects on autoimmune diseases. EGCG has also been described as a potent inhibitor of DNMTs and to induce Foxp3 in Jurkat T cell line.
2013-12-19 | E-GEOD-53448 | biostudies-arrayexpress
Project description:Epigallocatechin gallate (EGCG), the major green tea polyphenol, has been a subject of global interest as a potential chemopreventive or chemotherapeutic supplement for breast cancer. While on one hand epidemiological studies suggest inverse correlation between green tea consumption and breast cancer risk, investigations using cell culture and animal models of breast carcinogenesis on the other hand have demonstrated antiproliferative, antitumor, anti-invasive and anti-metastatic properties of EGCG. Mechanism of how EGCG affects cell proliferation, apoptosis, migration and cell cycle by affecting the function of a wide range of molecular targets have also been studied. However, the question as to how EGCG impacts on estrogen responsive genes has not been addressed. This issue is of relevance to our notion of EGCG as a potential chemopreventive or chemotherapeutic agent against breast cancer, which is estrogen dependent in majority of the newly diagnosed cases. Here, using the estrogen receptor α (ERα) positive MCF-7 breast cancer cells as a model, we have examined the effect of EGCG on the estrogen regulated genes. MCF7 cells were treated with vehicle (Ethanol) or EGCG in the presence or absence of estrogen for 24hrs. Total RNA was extracted; Cy3 labeled cRNA was hybridized to Genotypic Technology designed Custom Human Whole Genome 8x60k Microarray (Agilent-027114). Median signal intensities were used for the analysis. After background subtraction (normexp) and normalization (quantile) differentially expressed genes were identified using linear models.
2015-04-01 | E-GEOD-56245 | biostudies-arrayexpress
Project description:Epigallocatechin gallate (EGCG), the major green tea polyphenol, has been a subject of global interest as a potential chemopreventive or chemotherapeutic supplement for breast cancer. While on one hand epidemiological studies suggest inverse correlation between green tea consumption and breast cancer risk, investigations using cell culture and animal models of breast carcinogenesis on the other hand have demonstrated antiproliferative, antitumor, anti-invasive and anti-metastatic properties of EGCG. Mechanism of how EGCG affects cell proliferation, apoptosis, migration and cell cycle by affecting the function of a wide range of molecular targets have also been studied. However, the question as to how EGCG impacts on estrogen responsive genes has not been addressed. This issue is of relevance to our notion of EGCG as a potential chemopreventive or chemotherapeutic agent against breast cancer, which is estrogen dependent in majority of the newly diagnosed cases. Here, using the estrogen receptor α (ERα) positive MCF-7 breast cancer cells as a model, we have examined the effect of EGCG on the estrogen regulated genes.
2015-04-01 | GSE56245 | GEO
Project description:Epigallocatechin-3-gallate (EGCG), a major active polyphenol of green tea, has been shown to downregulate inflammatory responses in macrophages; however, the underlying mechanism has not been understood. Recently, we identified the 67-kDa laminin receptor (67LR) as a cell-surface EGCG receptor that mediates the anti-cancer action of EGCG at physiologically relevant concentrations (0.1-1 mM). Here we show the molecular basis for the downregulation of TLR4 signal transduction by EGCG at 1 mM in macrophages. Anti-67LR antibody treatment or RNAi-mediated silencing of 67LR resulted in abrogation of the inhibitory action of EGCG on LPS-induced activation of downstream signaling pathways and target gene expressions. Additionally, we found that EGCG reduced the TLR4 expression through 67LR. Interestingly, EGCG induced a rapid upregulation of Tollip protein, a negative regulator of TLR-signaling, and this EGCG action was prevented by 67LR silencing or anti-67LR antibody treatment. RNAi-mediated silencing of Tollip impaired the TLR4 signaling inhibitory activity of EGCG. Taken together, these findings demonstrate that 67LR plays a critical role in mediating anti-inflammatory action of a physiologically relevant EGCG and Tollip expression could be modulated through 67LR. These results provide a new insight into the understanding of negative regulatory mechanisms for TLR4 signaling pathway and consequent inflammatory responses which are implicated in the development and progression of many chronic diseases.
2010-04-20 | GSE21320 | GEO
Project description:Mi(cro)RNAs are small non-coding RNAs of 18-25 nucleotides in length that modulate gene expression at the post-transcriptional level. These RNAs have been shown to be involved in a several biological processes, human diseases and metabolic disorders. Proanthocyanidins, which are the most abundant polyphenol class in the human diet, have positive heath effects on a variety of metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. The present study aimed to evaluate whether proanthocyanidin-rich natural extracts modulate miRNA expression. Using microarray analysis and Q-PCR, we investigated miRNA expression in HepG2 cells treated with proanthocyanidins. Our results showed that when HepG2 cells were treated with grape seed proanthocyanidin extract (GSPE), cocoa proanthocyanidin extract (CPE) or pure epigallocatechin gallate isolated from green tea (EGCG), fifteen, six and five differentially expressed miRNAs, respectively, were identified out of 904 mRNAs. Specifically, miR-30b* was downregulated by the three treatments, and treatment with GSPE or CPE upregulated miR-1224-3p, miR-197 and miR-532-3p. Therefore, these results provide evidence of the capacity of dietary proanthocyanidins to influence microRNA expression, revealing a new mechanism of action of proanthocyanidins. microRNA profiling of Human hepatocellular liver carcinoma cell line (HepG2) comparing control untreated HepG2 cells with cells treated with grape seed proanthocyanidin extract (100 mg/L, 5h), cacao proanthocyanidin extract (100 mg/L, 5h) or epigallocatechin gallate (50 mg/L, 5h). Two biologival replicates were used for control and treated cells with one replicate per array.
2014-07-01 | E-GEOD-30575 | biostudies-arrayexpress
Project description:Background: Hepatocellular carcinoma (HCC) is increasing in incidence and treatment is often unsuccessful. Thus, prevention in high-risk patients with established cirrhosis has been proposed as an alternative strategy. It has been suggested that the increased inflammation and fibrogenesis observed during cirrhosis predisposes the liver to future malignant transformation to HCC through a “field effect”. A growing body of evidence indicates that the green tea polyphenol, (-)-epigallocatechin gallate (EGCG), can reduce inflammation and fibrogenesis during chronic liver injury. Here, we test the hypothesis that EGCG administered in the setting of cirrhosis can prevent future HCC development. Methods: A rat model of diethylnitrosamine (DEN)-induced cirrhosis was used to examine the efficacy of EGCG for inhibition of HCC formation in these cirrhotic livers. DEN (50 mg/kg) was administered weekly throughout the study while 0.02% EGCG was given in drinking water beginning at the onset of cirrhosis. At the end of the study, rats were sacrificed, livers were sectioned and stained to analyze disease progression and tumor nodules were counted. Liver function tests were performed to determine liver injury and overall liver function. Finally, genome-wide gene expression profiling on the surrounding, non-tumoral liver tissue was used to monitor the “field effect” in response to EGCG. Results: EGCG significantly (p < 0.01) prevented the development of HCC tumor nodules from on average 18.8 in vehicle controls to on average 9.1 in EGCG-treated animals. EGCG also reduced liver injury and improved liver function as assessed by serum chemistry tests. Finally, a gene expression signature predictive of poor survival and HCC development in human cirrhosis patients was reversed in response to EGCG. Conclusions: Our data are consistent with the growing body of evidence suggesting that EGCG has protective effects in liver disease. Further, our results suggest that EGCG is a potentially effective HCC prevention strategy that can be monitored using gene expression signatures.
2020-03-10 | GSE67880 | GEO