• Journal of Ginseng Research
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• v.48 no.5
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• pp.511-519
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• 2024

Background: The cycle of seasonal dormancy of perennating buds is an essential adaptation of perennial plants to unfavorable winter conditions. Plant hormones are key regulators of this critical biological process, which is intricately connected with diverse internal and external factors. Recently, global warming has increased the frequency of aberrant temperature events that negatively affect the dormancy cycle of perennials. Although many studies have been conducted on the perennating organs of Panax ginseng, the molecular aspects of bud dormancy in this species remain largely unknown. Methods: In this study, the molecular physiological responses of three P. ginseng cultivars with different dormancy break phenotypes in the spring were dissected using comparative genome-wide RNA-seq and network analyses. These analyses identified a key role for abscisic acid (ABA) activity in the regulation of bud dormancy. Gene set enrichment analysis revealed that a transcriptional network comprising stress-related hormone responses made a major contribution to the maintenance of dormancy. Results: Increased expression levels of cold response and photosynthesis-related genes were associated with the transition from dormancy to active growth in perennating buds. Finally, the expression patterns of genes encoding ABA transporters, receptors (PYRs/PYLs), PROTEIN PHOSPHATASE 2Cs (PP2Cs), and DELLAs were highly correlated with different dormancy states in three P. ginseng cultivars. Conclusion: This study provides evidence that ABA and stress signaling outputs are intricately connected with a key signaling network to regulate bud dormancy under seasonal conditions in the perennial plant P. ginseng.

• Journal of Web Engineering
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• v.14 no.23
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• pp.4997-5013
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• 2022

The clinical application of cisplatin, one of the most effective chemotherapeutic agents used to treat various cancers, has been limited by the risk of adverse effects, notably nephrotoxicity. Despite intensive research for decades, there are no effective approaches for alleviating cisplatin nephrotoxicity. This study aimed to investigate the protective effects and potential mechanisms of a Gynostemma pentaphyllum leaves hydrodistillate (GPHD) and its major component, damulin B, against cisplatin-induced nephrotoxicity in vitro and in vivo. A hydro-distillation method can extract large amounts of components within a short period of time using non-toxic, environmentally friendly solvent. We found that the levels of AMP-activated protein kinase α1 (AMPKα1), reactive oxygen species (ROS), and apoptosis were tightly associated with each other in HEK293 cells treated with cisplatin. We demonstrated that AMPKα1 acted as an anti-oxidant factor and that ROS generated by cisplatin suppressed the expression of AMPKα1 at the transcriptional level, thereby resulting in induction of apoptosis. Treatment with GPHD or damulin B effectively prevented cisplatin-induced apoptosis of HEK293 cells and cisplatin-induced acute kidney injury in mice by suppressing oxidative stress and maintaining AMPKα1 levels. Therefore, our study suggests that GPHD and damulin B may serve as prospective adjuvant agents against cisplatin-induced nephrotoxicity.

• Oncology Letters
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• v.17 no.4
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• pp.3981-3989
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• 2019

Tamoxifen (TAM) is the most widely used treatment for estrogen receptor-positive breast cancer patients. Unfortunately, the majority of these patients exhibit TAM resistance following treatment. We previously reported that proliferation and migration were greater in TAM-resistant MCF-7 (TAMR-MCF-7) cells than in parental MCF-7 cells. Janus kinases (JAKs) are cytosolic tyrosine kinases that transduce signals from plasma membrane cytokines and growth factor receptors. JAK2 selectively phosphorylates signal transducer and activator of transcription (STAT)-3, and the JAK2-STAT3 signaling pathway is known as a crucial signaling pathway for the regulation of cancer progression and metastasis. In the present study, basal phosphorylation of STAT3 was revealed to be greater in TAMR-MCF-7 cells than in control MCF-7 cells. Ruxolitinib, a potent JAK2 inhibitor, was demonstrated to attenuate STAT3 phosphorylation and the proliferation of TAMR-MCF-7 cells. Ruxolitinib also suppressed the enhanced cell migration of TAMR-MCF-7 cells through the inhibition of epithelial mesenchymal transition. Vascular endothelial growth factor (VEGF), a representative target gene of the JAK2-STAT3 pathway, functions as a key regulator of invasion and angiogenesis. Ruxolitinib significantly inhibited VEGF mRNA expression and transcriptional activity. The present study also performed a chick embryo chorioallantoic membrane assay to assess tumor growth and angiogenesis in TAMR-MCF-7 cells. Ruxolitinib reduced tumor weight and the number of blood vessels produced by TAMR-MCF-7 cells in a concentration-dependent manner. These results indicated that JAK2 could be a new therapeutic target for TAM-resistant breast cancer.

• Journal of Life Science
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• v.19 no.5
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• pp.620-624
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• 2009

D-Ala2-Leu5-enkephalin (DADLE), a hibernation inducer, can induce hibernation-like state in vivo and in vitro. We treated U937 human leukemia cancer cells with DADLE and investigated its possible effect on transcription and proliferation. Treatment of U937 cells with DADLE resulted in growth inhibition and induction of apoptotic cell death on high-dose as measured by MTT assay and DNA flow cytometer analysis. Bcl-XL, c-IAP-2 and survivin genes especially showed decreases in mRNA levels. DADLE treatment also inhibited the levels of cyclooxygenase (COX)-2 mRNA without alteration of COX-1 expression. DNA flow cytometer analysis revealed that DADLE caused arrest of the cell cycle on low-dose, which was associated with a down-regulation of cyclin E at the transcriptional level. DADLE treatment induced a marked down-regulation of cyclin-dependent kinase (Cdk)-2, -4 and -6. In addition, treatment with DADLE decreased telomere associated genes such as, c-myc and TERT, and increased TEP-1 in U937 cells. These results suggest that DADLE can be an inhibition agent in the cell cycle of the human leukemia cancer U937 cell.

• Biomolecules & Therapeutics
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• v.21 no.2
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• pp.107-113
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• 2013

Plasminogen activator inhibitor-1 (PAI-1) is a member of serine protease inhibitor family, which regulates the activity of tissue plasminogen activator (tPA). In CNS, tPA/PAI-1 activity is involved in the regulation of a variety of cellular processes such as neuronal development, synaptic plasticity and cell survival. To gain a more insights into the regulatory mechanism modulating tPA/PAI-1 activity in brain, we investigated the effects of proteasome inhibitors on tPA/PAI-1 expression and activity in rat primary astrocytes, the major cell type expressing both tPA and PAI-1. We found that submicromolar concentration of MG132, a cell permeable peptide-aldehyde inhibitor of ubiquitin proteasome pathway selectively upregulates PAI-1 expression. Upregulation of PAI-1 mRNA as well as increased PAI-1 promoter reporter activity suggested that MG132 transcriptionally increased PAI-1 expression. The induction of PAI-1 downregulated tPA activity in rat primary astrocytes. Another proteasome inhibitor lactacystin similarly increased the expression of PAI-1 in rat primary astrocytes. MG132 activated MAPK pathways as well as PI3K/Akt pathways. Inhibitors of these signaling pathways reduced MG132-mediated upregulation of PAI-1 in varying degrees and most prominent effects were observed with SB203580, a p38 MAPK pathway inhibitor. The regulation of tPA/PAI-1 activity by proteasome inhibitor in rat primary astrocytes may underlie the observed CNS effects of MG132 such as neuroprotection.

• Journal of Life Science
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• v.8 no.3
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• pp.263-271
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• 1998

One of the better-characterized transcription factor of E. coli is the cAMP receptor protein(CRP) and the CRP binds cAMP and DNA. The cAMP-CRP complex is involved in regulation of many genes at bacteria. The cAMP-CRP regulatory element represents, in some respects, a global regulatory network. The aim of this work was to study the structure and the mechanisms controlling the expression of CRP in Serratia marcescens. We have been get 5 different clones from Serratia which stimulated the cells to use maltose as a sole carbon source in E. coli TP2139. The crp gene clone, pCKB12, was confirmed by Southern hybridization with E. coli crp gene. The location of the crp gene was determined by construction subclones carrying various portions of pCKB12. To investigate the potential role of CRP in E. coli, lacZ fused plasmids were constructed and investigated the ${\beta}$-galactosidase activity of the fused plasmid. The Serratiamarcescens cAMP receptor protein can substitute the E. coli CRP in transcriptional activation at the lacZ gene. These results suggest that Serratia marcescens cAMP receptor protein complex functions to regulate several promoters in E. coli.

• Journal of Life Science
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• v.26 no.5
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• pp.531-536
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• 2016

We previously showed that NAD(P)H:quinone oxidoreductase 1 (NQO1) knockout (KO) mice exhibited spontaneous inflammation with markedly increased mucosal permeability in the gut, and that NQO1 is functionally associated with regulating tight junctions in the mucosal epithelial cells that govern the mucosal barrier. Here, we confirm the role of NQO1 in the formation of tight junctions by human colonic epithelial cells (HT29). We treated HT29 cells with a chemical inhibitor of NQO1 (dicumarol; 10 μM), and examined the effect on the transepithelial resistance of epithelial cells and the protein expression levels of ZO1 and occludin (two known regulators of tight junctions between gut epithelial cells). The dicumarol-induced inhibition of NQO1 markedly reduced transepithelial resistance (a measure of tight junctions) and decreased the levels of the tested tight junction proteins. In vivo, luminal injection of dicumarol significantly increased mucosal permeability and decreased ZO1 and occludin protein expression levels in mouse guts. However, in contrast to the previous report that the epithelial cells of NQO1 KO mice showed marked down-regulations of the transcripts encoding ZO1 and occludin, these transcript levels were not affected in dicumarol-treated HT29 cells. This result suggests that the NQO1-depedent regulation of tight junction molecules may involve multiple processes, including both transcriptional regulation and protein degradation processes such as those governed by the ubiquitination/proteasomal, and/or lysosomal systems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1237-1245
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• 2004

Agaricus blazei Murill is a medicinal mushroom native to Brazil. It used to be a source of antitumor and immunoactive compounds and considered a health food in many countries. In the present study, it was examined the effects of water extract of A. blazei (WEAB) on the growth of human lung carcinoma cell line A549 in order to investigate the anti-proliferative mechanism by WEAB. Treatment of A549 cells to WEAB resulted in the growth inhibition, morphological change and induction of apoptotic cell death in a dose-dependent manner as measured by MTT assay and flow cytometric analysis. Flow cytometric analysis revealed that WEAB caused G2/M phase arrest of the cell cycle, which was associated with a down-regulation of cyclin A in both transcriptional and translational levels. WEAB treatment induced a marked up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21, however, the levels of Cdk2, Cdc2, Wee1, Cdc25C and p53 expression were remained unchanged in WEAB treated cells. In addition, WEAB treatment inhibited the levels of cyclooxygenase (COX)-2 mRNA and protein without alteration of COX-l expression. Taken together, these findings suggest that WEAB may be a potential chemotherapeutic agent for the control of human lung carcinorma cells and further studies will be needed to identify the active compounds that confer the anti-cancer activity of WEAB. Once such compounds are identified, the mechanisms by which they exert their effects can begin to be characterized.

• Development and Reproduction
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• v.14 no.2
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• pp.123-129
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• 2010

Embryonic stem (ES) cells can self-renew maintaining the undifferentiated state. Self-renewal requires many factors such as OCT4, SOX2, and NANOG. It is previously known that OCT4 and SOX2 can bind to NANOG promoter and support Nanog gene expression in mouse ES cells by the detailed studies using the mouse Nanog promoter. Here, we constructed serial deletion mutant promoter-reporter constructs to investigate the human Nanog gene promoter in detail. The highest promoter activity was obtained in the 0.6 kb (-253/+365) promoter-reporter construct which includes the binding sites of OCT4 and SOX2. To further confirm contribution of OCT4 and SOX2 in Nanog gene expression, we introduced site- directed mutation(s) in the OCT4 and/or SOX2 binding sites of the human Nanog promoter 0.6 kb (-253/+365) and checked the influence of the mutation on the promoter activity using human EC cell line NCCIT. Mutation either in OCT4 binding site or SOX2 binding site significantly reduced the activity of Nanog promoter which directly confirmed that OCT4 and SOX2 binding is essential in human Nanog gene expression.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.5
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• pp.275-282
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• 2005

By using differential display, we identified one of the genes encoding the multi-subunit complex protein V-ATPase, c subunit gene (ATP6L), and showed alterations of the gene expression by oxidative stresses. Expression of the ATP6L gene in Neuro-2A cells was increased by the treatment with $H_2O_2$ and incubation in hypoxic chamber, implying that the expression of the ATP6L gene is regulated by oxidative stresses. To examine mechanisms involved in the regulation of the gene expression by oxidative stresses, the transcriptional activity of the rat ATP6L promoter was studied. Transcription initiation site was determined by primer extension analysis and DNA sequencing, and promoter of the rat ATP6L and its deletion clones were constructed in reporter assay vector. Significant changes of the promoter activities in Neuro-2A cells were observed in two regions within the proximal 1 kbp promoter, and one containing a suppressor was in -195 to -220, which contains GC box that is activated by binding of Sp1 protein. The suppression of promoter activity was lost in mutants of the GC box. We confirmed by electrophoretic mobility shift and supershift assays that Sp1 protein specifically binds to the GC box. The promoter activity was not changed by the $H_2O_2$ treatment and incubation in hypoxic chamber, however, $H_2O_2$ increased the stability of ATP6L mRNA. These data suggest that the expression of the ATP6L gene by oxidative stresses is regulated at posttranscriptional level, whereas the GC box is important in basal activities of the promoter.