• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1545-1552
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• 2013

This study was conducted to investigate the effects of Trichostatin A (TSA) on cumulus expansion during mouse oocyte maturation. TSA treatment inhibited cumulus expansion and significantly reduced the cumulus expansion index (CEI) (p<0.05). To determine the underlying mechanism, the expression levels of several key factors that play crucial roles in cumulus expansion including components of extracellular matrix (ECM) (Has2, Ptgs2, Ptx3, and Tnfaip6) and Growth differentiation factor 9 (GDF9) were measured in control and TSA treated samples by real-time PCR. The effect of TSA on ERK phosphorylation (p-ERK1/2) in cumulus cells and GDF9 protein level in fully grown oocytes (FGOs) were detected by Western blotting. The expression levels of the ECM genes were significantly decreased (p<0.05) by TSA treatment while GDF9 expression did not response to TSA (p>0.05). TSA treatment blocked the activation of ERK1/2 (p<0.05) and had no significant effect on GDF9 protein expression (p>0.05). Collectively, these results suggested that TSA treatment altered ECM gene expression and blocked ERK1/2 activation to inhibit cumulus expansion in the mouse.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.269-279
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• 2013

Low efficiency of somatic cell nuclear transfer (SCNT) is attributed to incomplete reprogramming of transfered nuclei into oocytes. Trichostatin A (TSA), histone deacetylase inhibitor and 5-aza-2'deoxycytidine (5-aza-dC), DNA methylation inhibitor has been used to enhance nuclear reprogramming following SCNT. However, it was not known molecular mechanism by which TSA and 5-aza-dC improve preimplantation embryo and fetal development following SCNT. The present study investigates embryo viability and gene expression of cloned porcine preimplantation embryos in the presence and absence of TSA and 5-aza-dC as compared to embryos produced by parthenogenetic activation. Our results indicated that TSA treatment significantly improved development. However 5-aza-dC did not improve development. Presence of TSA and 5-aza-dC significantly improved total cell number, and also decreased the apoptotic and autophagic index. Three apoptotic-related genes, Bak, Bcl-xL, and Caspase 3 (Casp3), and three autophagic-related genes, ATG6, ATG8, and lysosomal-associated membrane protein 2 (LAMP2), were measured by real time RT-PCR. TSA and 5-aza-dC treatment resulted in high expression of anti-apoptotic gene Bcl-xL and low pro-apoptotic gene Bak expression compared to untreated NT embryos or parthenotes. Furthermore, LC3 protein expression was lower in NT-TSA and NT-5-aza-dC embryos than those of NT and parthenotes. In addition, TSA and 5-aza-dC treated embryos displayed a global acetylated histone H3 at lysine 9 and methylated DNA H3 at lysine 9 profile similar to the parthenogenetic blastocysts. Finally, we determined that several DNA methyltransferase genes Dnmt1, Dnmt3a and Dnmt3b. NT blastocysts showed higher levels Dnmt1 than those of the TSA and 5-aza-dC blastocysts. Dnmt3a is lower in 5-aza-dC than NT, NTTSA and parthenotes. However, Dnmt3b is higher in 5-aza-dC than NT and NTTSA. These results suggest that TSA and 5-aza-dC positively regulates nuclear reprogramming which result in modulation of apoptosis and autophagy related gene expression and then reduce apoptosis and autophagy. In addition, TSA and 5-aza-dC affects the acetylated and methylated status of the H3K9.

• BMB Reports
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• v.38 no.6
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• pp.755-762
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• 2005

Epstein-Barr virus (EBV) infects more than 90% of the world's population and has a potential oncogenic nature. A histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), has shown potential ability in cancer chemoprevention and treatment, but its effect on EBV-infected Akata cells has not been examined. This study investigated the effect of TSA on the proliferation and apoptosis of the cells. TSA inhibited cell growth and induced cytotoxicity in the EBV infected Akata cells. TSA treatment sensitively induced apoptosis in the cell, which was demonstrated by the increased number of positively stained cells in the TUNEL assay, the migration of many cells to the sub-$G_0/G_1$ phase in flow cytometric analysis, and the ladder formation of genomic DNA. Western blot analysis showed that caspase-dependent pathways are involved in the TSA-induced apoptosis of EBV-infected Akata cells. Overall, this study shows that EBV-infected B lymphomas are quite sensitive to TSA-provoked apoptosis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.88-88
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.178-178
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this Is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to ＋64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6129-6133
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• 2015

miR-129-2 is frequently downregulated in multiple cancers. However, how it is silenced in cancers remains unclear. Here we investigated the expression profile and potential biological function of miR-129-2 in glioblastoma (GBM), the most common and lethal form of brain tumors in adults. We showed that miR-129-2 is lost in GBM patient specimens and cultured cell lines. miR-129-2 expression could be restored upon treatment with a histone deadetylase inhibitor (trichostatin A) but not a DNA methylation inhibitor (5-Aza-2'-deoxycytidine), and more profound effect was observed with the treatment of these two drugs in combination. Furthermore, forced expression of miR-129-2 repressed the expression of major oncogenic genes such as PDGFRa and Foxp1 in GBMs. Consistently, expression of miR-129-2 significantly inhibits GBM cell proliferation in vitro. These results reveal that miR-129-2 is epigenetically regulated and functions as a tumor suppressor gene in GBMs, suggesting it may serve as a potential therapeutic target for GBM treatment.

• BMB Reports
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• v.44 no.3
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• pp.176-181
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• 2011

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heat-shock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

• Environmental Mutagens and Carcinogens
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• v.24 no.4
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• pp.171-179
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• 2004

Cytochrome P4503A4(CYP3A4) is the most abundnat CYPs in human liver, comparising approximately 30% of the total liver CYPs contents ans is involbed in the metabolism of more than 60% of currently used therapeutic drugs. The expression of CYP3A4 is induced by a variety of structurally unrelated xonobiotics including the antibiotic rifampicin and endogenous hormones, and might be mediated through steroid and xenobiotic receptor(SXR) system. The molecular mechanisms underlying regulation of CYP3A4 gene expression hae not been understood. In order to gain the insight of the molecular mechanism of CYP3A4 gene expression, study has been undertaken to investigate if the histone deacelylation is involved in the regulation of CYP3A4 gene expression by proximal promoter or not. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. HepG2 or Hena-I cells were transfected with a plasmid containing~1kb of the CYP3A4 proximal promoter region (-863 to +64bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR or hER. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, or with estradiol, in order to exmine to regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In HepG2 cells, CYP3A4 inducers and estradiol increased significantly the luciferase activity by CYP3A4 proximal promoter, only when TSA was co-treated after SXR cotransfection. In the case of Hepa-I cells CYP3A4 inducers and estradiol incressed modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection in contrast to HepG2 cells. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Futher a trans-activation by SXR may demand other species-specific transcription factors.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.787-794
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• 2010

Calcium plays a role as a signaling molecule in various cellular events. It has been reported that calcium suppresses adipocyte differentiation only in the early phase of adipogenesis. Herein, we demonstrate that treatment of A23187, a mobilizer of intracellular calcium, on day 4 post adipocyte differentiation could still reduce lipid accumulation in differentiating 3T3-L1 cells for 48 h. In addition, luciferase reporter gene and RT-Q-PCR assays demonstrate that A23187 can selectively inhibit transcriptional activities and expression of PPAR$\gamma$ and LXR$\alpha$, suggesting that A23187 may reduce lipid accumulation in the late phase of adipogenesis via downregulation of PPAR$\gamma$ and LXR$\alpha$ expression and transactivation. Moreover, inhibition of HDAC activity by trichostatin A (TSA) partially blocked A23187-mediated downregulation of transcriptional activities of PPAR$\gamma$ and LXR$\alpha$. Together, our data demonstrate that calcium mobilization inhibits expression and transcriptional activities of PPAR$\gamma$ and LXR$\alpha$, resulting in reduced lipid accumulation in differentiating adipocytes, and thus, mobilization of intracellular calcium in adipocytes may serve as a new preventive and therapeutic approach for obesity.

• Development and Reproduction
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• v.17 no.4
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• pp.379-387
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• 2013

Embryonic stem (ES) cells can self-renew and differentiate to various cells depending on the culture condition. Although ES cells are a good model for cell type specification and can be useful for application in clinics in the future, studies on ES cells have many experimental restraints including low transfection efficiency and transgene expression. Here, we observed that transgene expression after transfection was enhanced by treatment with histone deacetylse (HDAC) inhibitors such as trichostatin A, sodium butyrate, and valproic acid. Transfection was performed using conventional transfection reagents with a retroviral vector encoding GFP under the control of CMV promoter as a reporter. Treatment of ES cells with HDAC inhibitors after transfection increased population of GFP positive cells up to 180% compared with untreated control. ES cells showed normal expression of stem cell markers after treatment with HDAC inhibitors. Transgene expression was further enhanced by modifying transfection procedure. GFP positive cells selected after transfection were proved to have the stem cell properties. Our improved protocol for enhanced gene delivery and expression in mouse ES cells without hampering ES cell properties will be useful for study and application of ES cells.