• BMB Reports
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• 제42권2호
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• pp.86-90
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• 2009

Deletion of smpd3 induces osteogenesis and dentinogenesis imperfecta in mice. smpd3 is highly elevated in the parietal bones of developing mouse calvaria, but not in sutural mesenchymes. Here, we examine the mechanism of smpd3 regulation, which involves BMP2 stimulation of Runx2. smpd3 mRNA expression increased in response to BMP2 treatment and Runx2 transfection in C2C12 cells. The Runx2-responsive element (RRE) encoded within the -562 to -557 region is important for activation of the smpd3 promoter by Runx2. Electrophoretic mobility shift assays revealed that Runx2 binds strongly to the -355 to -350 RRE and less strongly to the -562 to -557 site. Thus, the smpd3 promoter is activated by BMP2 and is directly regulated by the Runx2 transcription factor. This novel description of smpd3 regulation will aid further studies of bone development and osteogenesis.

• BMB Reports
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• 제40권4호
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• pp.554-561
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• 2007

Shen and colleagues (Lin et al., 2004) have recently shown that overexpression of the Drosophila DNA methyltransferase 2 isoform C, dDnmt2c, extended life span of fruit flies, probably due to increased expression of small heat shock proteins such as Hsp22 or Hsp26. Here, I demonstrate with immunoprecipitations that overexpressed dDnmt2c interacts with endogenous Hsp70 protein in vivo in S2 cells. However, its C-terminal half, dDnmt2c(178-345) forms approximately 10-fold more Hsp70-containing protein complexe than wild-type dDnmt2c. Overexpressed dDnmt2c(178-345) but not the full length dDnmt2c is able to increase endogenous mRNA levels of the small heat shock proteins, Hsp26 and Hsp22. I provide evidence that dDnmt2c(178-345) increases Hsp26 promoter activity via two heat shock elements, HSE6 and HSE7. Simultaneously overexpressed Hsp40 or a dominant negative form of heat shock factor abrogates the dDnmt2c(178-345)-dependent increase in Hsp26 transcription. The data support a model in which the activation of heat shock factor normally found as an inactive monomer bound to chaperones is linked to the overexpressed C-terminus of dDnmt2c. Despite the differences observed in flies and S2 cells, these findings provide a possible explanation for the extended lifespan in dDnmt2c-overexpressing flies with increased levels of small heat shock proteins.

• 생명과학회지
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• 제5권4호
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• pp.162-169
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• 1995

The glpD genes encoding gly-3-p dehydrogenase is essential for the aerobic growth of E. coli on glycerol or gly-3-p. The glpE gene, the function of which is unknownm is transcribed divergently with respect to glpD gene. Expression of the adjacent but divergently transcribed glpD the glpE genes is positively regulated by the cAMP-CRP complex. In this study, for a precise investigation of the functional elements in the regulatory region for transcription activation by cAMP-CRP, deletion mutation have been introducted into the regulatory region. The effect of the deletion mutant on transcriptional regulation was tested in vivo by $\beta$-galctosidase activity. Deletion mutants in the regulatory region of glpD demonstrated that the presence of the CRP-binding site resulted in an sixfold increase in promoter activity. And also deletion mutants of glpE gene demonstrated that the presence of the CRP-binding site resulted in an eightfold increase in promoter activity. Insertion of 22 bp oligomer in the deletion mutants has shown that the CRP binding site is need for maximal expression of glpD and glpE genes. glpD and glpE gene, cAMP-CRP complex, deletion mutant, transcriptional regulation.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1852-1859
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• 2019

Chikungunya virus (CHIKV) is a single-stranded positive-sense RNA virus, belonging to the genus Alphavirus of the Togaviridae family. It causes multiple symptoms, including headache, fever, severe joint and muscle pain, and arthralgia. Since CHIKV was first isolated in Tanzania in 1952, there have been multiple outbreaks of chikungunya fever. However, its pathogenesis and mechanisms of viral immune evasion have been poorly understood. In addition, the exact roles of individual CHIKV genes on the host innate immune response remain largely unknown. To investigate if CHIKV-encoded genes modulate the type I interferon (IFN) response, each and every CHIKV gene was screened for its effects on the induction of the IFN-β promoter. Here we report that CHIKV nsP2, E2 and E1 strongly suppressed activation of the IFN-β promoter induced by the MDA5/RIG-I receptor signaling pathway, suggesting that nsP2, E2, and E1 are the major antagonists against induction of IFN-β. Delineation of underlying mechanisms of CHIKV-mediated inhibition of the IFN-β pathway may help develop virus-specific therapeutics and vaccines.

• Molecules and Cells
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• 제37권7호
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• pp.532-539
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• 2014

We isolated a rice (Oryza sativa L.) WRKY gene which is highly upregulated in senescent leaves, denoted OsWRKY42. Analysis of OsWRKY42-GFP expression and its effects on transcriptional activation in maize protoplasts suggested that the OsWRKY42 protein functions as a nuclear transcriptional repressor. OsWRKY42-overexpressing (OsWR KY42OX) transgenic rice plants exhibited an early leaf senescence phenotype with accumulation of the reactive oxygen species (ROS) hydrogen peroxide and a reduced chlorophyll content. Expression analysis of ROS producing and scavenging genes revealed that the metallothionein genes clustered on chromosome 12, especially OsMT1d, were strongly repressed in OsWRKY42OX plants. An OsMT1d promoter:LUC construct was found to be repressed by OsWRKY42 overexpression in rice protoplasts. Finally, chromatin immunoprecipitation analysis demonstrated that OsWRKY42 binds to the W-box of the OsMT1d promoter. Our results thus suggest that OsWRKY42 represses OsMT1d-mediated ROS scavenging and thereby promotes leaf senescence in rice.

• 약학회지
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• 제54권6호
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• pp.481-487
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• 2010

The proteasome plays a major role in the degradation of abnormal proteins within the cell. Therefore, repressed proteasome function is accepted as one of factors contributing the pathogenesis of multiple degenerative diseases. In the present study, we have observed that xanthohumol C, which is one of prenylated flavonoids from hops, increases the expression of the proteasome subunits through the Nrf2 pathway. Treatment of murine renal epithelial TCMK-1 cells with xanthohumol C and its methoxymethoxy-derivative elevated the expression of the Antioxidant Response Element (ARE)-driven reporter gene, as well as Nrf2-target genes including NAD(P)H: quinoneoxidoreductaes 1 (Nqo1). Transcript levels for the catalytic subunits of the proteasome Psmb5 and Psmb6 were increased by these compounds. The activation of the psmb5 promoter by xanthohumol C was abolished when the ARE in this promoter was mutated, indicating that proteasome induction was mediated by the Nrf2-ARE pathway. These results suggest that xanthohumol compounds from hops have a potential benefit on various oxidative stress-associated human diseases through the induction of the proteasome.

• 동의생리병리학회지
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• 제26권4호
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• pp.437-440
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• 2012

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that Cryptotanshione(CT), a tanshinone from oriental traditional medicinal herb Danshen (Salvia miltiorrhiza Bunge), had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. CT inhibited the protein expression of hypoxia-inducible factor-1alpha (HIF-$1{\alpha}$) under hypoxic condition. Consistently, CT blocked hypoxia-induced phosphorylation and nuclear accumulation of STAT3. In addition, CT reduced cellular of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Of note, chromatin immunoprecipitation (ChiP) assay revealed that CT inhibited binding of STAT3 to VEGF promoter. Taken together, our results suggest that CT has anti-angiogenic activity by disturbing the binding STAT3 to the VEGF promoter in PC-3 cells.

• Biomolecules & Therapeutics
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• 제14권3호
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• pp.148-151
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• 2006

We have previously reported that 2.4 kb of L-plastin promoter (LP) could regulate the expression of adenoviral vector (AV) exogenous genes in a tumor cell specific manner. In the present study, we tested if the replication competent AdLPE1A vector results in a direct cytotoxic effect in hepatocelluar carcinoma (HCC) cells. In vitro cytotoxicity tests were carried out with replication-competent (AdLPE1A) and -incompetent (AdLPCD) LP-driven vectors. AdLPE1A is an AV in which LP was inserted 5' to the E1A and E1B genes. The AdLPCD vector contains LP and the E. coli cytosine deaminase (CD) gene in transcription unit. Exposure of cells to AdLPE1A generated a significant cytotoxic effect as compared to the control. Almost 90% of the cell had manifested the characteristic cytopatic effect on day 9 after infection of cells with 10 MOI of AdLPE1A. On the other hand, almost 35% of the cells were left when the cells had been treated with 100 MOI of AdLPCD together with 5-FC on day 9 when compared with the cells which had never been exposed neither 5-FC nor AdLPCD. These results showed that the replication competent AdLPE1A vector could kill the HepG2 cells directly by the oncolytic effect of the virus. The replication competent AV vector carrying viral E1A generated greater cytotoxic effect than the replication incompetent AV, which contains the CD prodrug activation transcription unit without E1A, in HepG2 cells.

• 생명과학회지
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• 제15권2호
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• pp.186-191
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• 2005

Previous studies have demonstrated that expression of galectin-3, a member of family of beta-galactoside-binding animal lectin, is associated with pathological conditions including cancer, atherosclerosis, and viral infection. An increase of this lectin has been observed after infection by Kirsten murine sarcoma, human T lymphotropic virus-l (HTLV-l), and human immunodeficiency virus-l (HIV-l). Viral transactivation protein Tax of HTLV-l mediates the increase in the lectin. In case of HIV-1, there are evidences that Tat would be related with increase in galectin-3. We investigated whether Tat directly induced galectin-3 expression in cells. We found that HIV-l tat gene activated galectin-3 promoter in RAW264.7 cells. To demonstrate direct induction of galectin-3 by HIV-l tat, we transfected the tat into a rabbit smooth muscle cell line (Rb1) and obtained RblTatCl-2, a clone of cell stably transfected with tat gene. The Rb1TatCl-2 cells exhibited activation of LTR promoter and up-regulation of galectin-3 transcript as well as protein. Our results indicate that HIV-l tat alone is sufficient to induce the expression of galectin-3. The Rb1TatCl-2 cells could be valuable for study of the effect of HIV-1 tat on expression of cellular genes.

• 한방안이비인후피부과학회지
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• 제22권1호
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• pp.33-45
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• 2009

Objective : Lacca Sinic: Exsiccate (LSE) extracted from Rhus vemicitlus Stokes (RVS) has been used traditionally as a remedy for inflammation in Korea, China, and Japan. However, as yet there is no clear explanation of how LSE affects the production of inflammatory cytokines. This study was to determine the effects of LSE on the mast cell-mediated inflammatory responses. Method : We measured the amount of inflammatory cytokine production induced by the phorbol myristate acetate (PMA) plus calcium ionophore(A231S7) in the human mast cell line (HMC-l) incubated with various concentrations of Laces Sinica Exsiccate (LSE). The $TNF-\alpha$, IL-6 and IL-8 secreted protein levels were measured by the ELISA assay. The $TNF-\alpha$, IL-6 and IL-8 mRNA levels were measured by the RT-PCR analysis. Nuclear and cytoplasmic proteins were examined by Western blot analysis. The NF-${\kappa}B$ promoter activity was examined by a luciferase assay. Result : LSE inhibited the PMA + A231S7-induced $TNF-\alpha$, IL-6, and IL-8 expression and suppressed NF-${\kappa}B$ activation in the stimulated-HMC-1. In addition, LSE inhibited induction of NF-${\kappa}B$ promoter-mediated luciferase activity. Conclusion : In this study, we have found that LSE is an inhibitor of NF-${\kappa}B$ and cytokines on the mast cell-mediated inflammatory responses.