• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.59-59
• /
• 2015

Cryptococcus neoformans causes life-threatening meningoencephalitis in humans, but the treatment of cryptococcosis remains challenging. To develop novel therapeutic targets and approaches, signaling cascades controlling pathogenicity of C. neoformans have been extensively studied but the underlying biological regulatory circuits remain elusive, particularly due to the presence of an evolutionarily divergent set of transcription factors (TFs) in this basidiomycetous fungus. In this study, we constructed a high-quality of 322 signature-tagged gene deletion strains for 155 putative TF genes, which were previously predicted using the DNA-binding domain TF database (http://www.transcriptionfactor.org/). We tested in vivo and in vitro phenotypic traits under 32 distinct growth conditions using 322 TF gene deletion strains. At least one phenotypic trait was exhibited by 145 out of 155 TF mutants (93%) and approximately 85% of the TFs (132/155) have been functionally characterized for the first time in this study. Through high-coverage phenome analysis, we discovered myriad novel TFs that play critical roles in growth, differentiation, virulence-factor (melanin, capsule, and urease) formation, stress responses, antifungal drug resistance, and virulence. Large-scale virulence and infectivity assays in insect (Galleria mellonella) and mouse host models identified 34 novel TFs that are critical for pathogenicity. The genotypic and phenotypic data for each TF are available in the C. neoformans TF phenome database (http://tf.cryptococcus.org). In conclusion, our phenome-based functional analysis of the C. neoformans TF mutant library provides key insights into transcriptional networks of basidiomycetous fungi and ubiquitous human fungal pathogens.

• Journal of Life Science
• /
• v.25 no.10
• /
• pp.1081-1090
• /
• 2015

Diabetes has been one of major health risks in industrialized countries. Allium hookeri is a wild herb distributed in India and Myanmar. The root of the plant has been used as food and medicine in Southeast Asia. We investigated Allium hookeri extract improves type 2 diabetes mellitus in C57BL/KSJ db/db obese mouse. C57BL/KSJ db/db obese mouse arise out of Type 2 diabetes and we treated Allium hookeri methanol extract 400 mg/kg (AH 400), 800 mg/kg (AH 800), positive control group (thiazolidinedine;TZDs) were administered orally for 8weeks. AH treated group normalized lipid enzyme system (triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol) and serum glucose, HbA1c and plasma insulin level. AH treated group recovered β-cell damage by hyperglycemia and fatty liver disease. AH treated group significantly up regulated expression of Peroxisome proliferator-activated receptor gamma (PPAR-γ), pyruvate dehydrogenase kinase4 (PDK4), Sterol regulatory element-binding protein 1c (SREBP 1) and fork head box O1 (FOX 01) proteins in C57BL/KSJ db/db obese mouse liver. And we found that AH treated group decreased hepatic malondialdehyde formation in C57BL/KSJ db/db obese mouse liver. These results indicate that Allium hookeri methanol extract might be a potential anti-diabetic agent and could be useful in the treatment of type 2 diabetes mellitus.

• Journal of Life Science
• /
• v.21 no.5
• /
• pp.720-728
• /
• 2011

Garlic (Allium sativum) has been used as a source food as well as a traditional folk medicine ingredient since ancient times. Aged black garlic is a type of fermented garlic and is expected to have stronger anticancer and antioxidant activities than raw garlic. However, the mechanisms of their inhibitory effects on adipocyte differentiation and adipogenesis are poorly understood. In the present study, the effects and mechanisms of water extracts of raw garlic (WERG) and aged black garlic (WEABG) on adipocyte differentiation and adipogenesis in 3T3-L1 preadipocytes were investigated. Treatment with WEABG significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner as confirmed by a decrease in lipid droplet number and lipid content through Oil Red O staining, however WERG had no such effect. In addition, WEABG reduced accumulation of cellular triglyceride, which is associated with a significant inhibition of key pro-adipogenic transcription factors including peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}$ (C/EBP${\alpha}$) and C/EBP${\beta}$. Taken together, these results provide important new insight that aged black garlic might inhibit adipogenesis by suppressing the pro-adipogenic transcription factors in 3T3-L1 preadipocytes, and further studies will be needed to identify the active compounds that confer the anti-obesity activity of aged black garlic.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.4
• /
• pp.342-356
• /
• 1992

Kinetic studies using stirred-flow methods were conducted with the Luisiana soil at three pH levels(pH 5, 6.5, and 8) and three temperature levels(10, 25, and $40^{\circ}C$) to explore effects on the rate of silica retention and release and to find out reaction mechanisms. In this study the maximum silica retention could not be obtained for long enough experimental time. The silica sorption isorption was C type fitted well to Freundlich equation. The pH of the soil suspension increased by the silica release process at low pH treatments(pH 5 and 6.5), while decreased at high pH treatment(pH 8). From the above findings It can be deduced that the mechanism of silica retention is a multilayer forming process to change the ligand form depending on pH condition. In the proposed mechanism the sorbed silica provide new binding sites for additional sorption of silica, while the activation energy for the formation of subsequent layers increases correspondingly. The silica retention and release process were well described by first-order and parabolic diffusion equation. However, clear interpretation for silica sorption mechanism using these equations could not be made. The validity of the fraction term (Fa and Fd) included in first-order and parabolic diffusion equation requires further examinations because the temperature effect on apparent rate constant shows no constant trends among temperature treatments, while there was a good trend in Elovich and modified Freundlich equation where the fraction term was not included.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.1
• /
• pp.75-85
• /
• 2016

Pectin, a naturally occurring polysaccharide, has in recent years attracted considerable attention. Its benefits are increasingly appreciated by scientists and consumers due to its safety and usefulness. The chemistry and gel-forming characteristics of pectin have enabled to be used in pharmaceutical industry, health promotion and treatment. Yet, it has been rarely used in cosmetics because of its incompatibility with many cosmetic ingredients, including alcohols, and unstable viscosity of pectin gels under various pH and salt conditions. However, low-molecular-weight pectin oligomers have excellent biological activities, and depolymerization of pectin to produce cosmetic ingredients would be very useful. In this study, we attempted the development of cosmetic ingredients using pectin with an excellent effect on human skin. We developed a bio-conversion process that uses enzymatic hydrolysis to produce pectin hydrolysates containing mainly low-molecular-weight pectin oligomers. Gel permeation chromatography was used to determined the ratio of hydrolysis. The molecular weight of the pectin hydrolysates obtained varied between 200 and 2,700 Da. The two newly developed low-molecular-weight pectin hydrolysates, LMPH A and B, had higher anti-oxidative activities than pectin or D-galacturonic. Exposure to UVB radiation induces apoptotic cell death in epidermal cells. Annexin V binding and propidium iodide uptake were measured by flow cytometry to evaluate UVB-induced cell death in HaCaT cells. Both LMPH A and B reduced UVB-induced cell death and increased cell proliferation by 22% and 30% at 0.5% concentration respectively, while pectin had no significant activity. In conclusion, this study suggests that the newly developed low-molecular-weight pectin hydrolysates can be used as safe and biologically active cosmetic ingredients.

• Molecules and Cells
• /
• v.37 no.2
• /
• pp.178-186
• /
• 2014

Differential transcription of the clusterin (CLU) gene yields two CLU isoforms, a nuclear form (nCLU) and a secretory form (sCLU), which play crucial roles in prostate tumorigenesis. Pro-apoptotic nCLU and anti-apoptotic sCLU have opposite effects and are differentially expressed in normal and cancer cells; however, their regulatory mechanisms at the transcriptional level are not yet known. Here, we examined the transcriptional regulation of nCLU in response to hypoxia. We identified three putative hypoxia response elements (HREs) in the human CLU promoter between positions -806 and +51 bp. Using a luciferase reporter, electrophoretic gel mobility shift, and chromatin immunoprecipitation assays, we further showed that hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) bound directly to these sites and activated transcription. Exposure to the hypoxia-mimetic compound $CoCl_2$, incubation under 1% $O_2$ conditions, or overexpression of HIF-$1{\alpha}$ enhanced nCLU expression and induced apoptosis in human prostate cancer PC3M cells. However, LNCaP prostate cancer cells were resistant to hypoxia-induced cell death. Methylation-specific PCR analysis revealed that the CLU promoter in PC3M cells was not methylated; in contrast, the CLU promoter in LNCap cells was methylated. Co-treatment of LNCaP cells with $CoCl_2$ and a demethylating agent promoted apoptotic cell death through the induction of nCLU. We conclude that nCLU expression is regulated by direct binding of HIF-$1{\alpha}$ to HRE sites and is epigenetically controlled by methylation of its promoter region.

• Toxicological Research
• /
• v.24 no.3
• /
• pp.175-182
• /
• 2008

DNA-dependent protein kinase(DNA-PK) is involved in joining DNA double-strand breaks induced by ionizing radiation or V(D)J recombination and is activated by DNA ends and composed of a DNA binding subunit, Ku, and a catalytic subunit, DNA-PKcs. It has been suggested that DNA-PK might be $2^{nd}$ upstream kinase for protein kinase B(PKB). In this report, we showed that Ser473 phosphorylation in the hydrophobic-motif of PKB is blocked in DNA-PK knockout mouse embryonic fibroblast cells(MEFs) following insulin stimulation, while there is no effect on Ser473 phosphorylation in DNA-PK wild type MEF cells. The observation is further confirmed in human glioblastoma cells expressing a mutant form of DNA-PK(M059J) and a wild-type of DNA-PK(M059K), indicating that DNA-PK is indeed important for PKB activation. Furthermore, the treatment of cells with doxorubicin, DNA-damage inducing agent, leads to PKB phosphorylation on Ser473 in control MEF cells while there is no response in DNA-PK knockout MEF cells. Together, these results proposed that DNA-PK has a potential role in insulin signaling as well as DNA-repair signaling pathway.

• Development and Reproduction
• /
• v.11 no.3
• /
• pp.245-251
• /
• 2007

Vinclozolin(VCZ), a systemic dicarboximide fungicide, has been used in the control of diseases caused by microorganism of some species in fruits, vegatables and ornamental plants. Although VCZ itself is a very weak antagonist for androgen receptor binding, both melabolites M1 and M2 are effective antagonists. The present study was undertaken to examine whether prepubertal exposure to VCZ affects on the onset of puberty and the associated reproductive parameters such as hormone receptor expressions in female rats. VCZ(10 mg/kg/day) was administered daily from postnatal day 21(PND 21) through the day when the first vaginal opening(V.O.) was observed. Gross anatomy and weight of reproductive tissues were compared to test the VCZ's effects on the cell proliferation. Furthermore, histological studies were performed to assess the structural alterations in the tissues. To determine the transcriptional changes in progesterone receptor(PR), total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction(RT-PCR). As a result, delayed V.O. was shown in the VCZ group(PND $34.00{\pm}1.22$) compared to the control group(PND $38.20{\pm}1.92$; p<0.01). VCZ treatment significantly decreased the wet weight of ovaries and uteri compared to the control group(p<0.01). Graafian follicles and corpora lutea were observed only in the ovaries from the control animals, while numerous primary, secondary follicles and small atretic follicles were observed in the ovaries from VCZ group. Similarly, hypotrophy of luminal and glandular uterine epithelium was found in the VCZ group. In the semi-quantitative RT-PCR studies, the transcriptional activity of PR in ovary(p<0.01) from VCZ group were significantly lower than those from the control group while in uterus were similar compared with the control group. The present studies demonstrated that the acute exposure to VCZ during the critical period of prepubertal stage could inactivate the reproductive system resulting delayed puberty in female rats.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.7
• /
• pp.790-800
• /
• 2017

As men get older, total testosterone levels decline gradually, and concentrations of free and bioavailable testosterone decline sharply with each decade beyond their 30s. Andropause or testosterone deficiency syndrome (TDS) is defined as a decrease in sexual satisfaction or decline in general well-being accompanied by low levels of testosterone in older men. This male climacteric is characterized by nervousness, reduced potency, decreased libido, irritability, fatigue, depression, memory problems, sleep disturbances, and hot flushes. Cirsium japonicum (CJ) is used as a traditional medicine for hemorrhage, blood congestion, and inflammation in Korea. However, there is no report on the efficacy of CJ treatment for TDS. In this study, we observed the mitigating effect of CJ extract (CE) and fermented CJ extract (FCE) on symptoms of TDS. In elderly male rats, total and testosterone levels, hind limbs muscles, forced swimming time, and total and motile sperm counts significantly increased after daily intake of CE and FCE for 6 weeks. In contrast, sex hormone binding globulin, retroperitoneal fat, total serum cholesterol, and triglyceride levels were significantly reduced in CE and FCE groups. However, there was no difference in prostate specific antigen, aspartate aminotransferase, and alanine aminotransferase levels among all groups, which means CE and FCE did not have putative adverse effects. In a cell experiment, we also observed that CE and FCE enhanced expression of genes related to testosterone biosynthesis but reduced genes involved in testosterone conversion. On the whole, these positive effects on TDS were greater in FCE compared to CE. Thus, these results suggest the potential of FCE as a promising natural product for recovering testosterone levels and alleviating TDS.

• Journal of Life Science
• /
• v.23 no.5
• /
• pp.609-615
• /
• 2013

Glyceollin I has gained attention as a useful therapy for various dermatological diseases. However, the binding property of glyceollin I to the mammalian adenylyl cyclase (hereafter mAC), a critical target enzyme for the down-regulation of skin melanogenesis, has not been fully explored. To clarify the action mechanism between glyceollin I and mAC, we first investigated the molecular docking property of glyceollin I to mAC and compared with that of SQ22,536, a well-known mAC inhibitor, to mAC. Glyceollin I showed superiority by forming three hydrogen bonds with Asp 1018, Trp 1020, and Asn 1025, which exist in the catalytic site of mAC. However, SQ22,536 formed only two hydrogen bonds with Asp 1018 and Asn 1025. Secondly, we confirmed that glyceollin I effectively inhibits the formation of forskolin-induced cAMP and the phosphorylation of PKA from a cell-based assay. Long term treatment with glyceollin I had little effect on the cell viability. The findings of the present study also suggest that glyceollin I may be extended to be used as an effective inhibitor of hyperpigmentation.