• Journal of Periodontal and Implant Science
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• 제38권sup2호
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• pp.343-354
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• 2008

Purpose: Aggregatibacter actinomycetemcomitans is associated with localized aggressive periodontitis. It produces cytolethal distending toxin (CDT), which induces cell cycle arrest in the G2/M phase. The CDT holotoxin is composed of CdtA, CdtB, and CdtC. CdtB has structural homology to human DNase I and is an active component of the CDT complex acting as a DNase. In particular, the pattern homology seen in the CdtB subunit has been associated with specific DNase I residues involved in enzyme catalysis, DNA binding, and metal ion binding. So, to study the functions and regulation of recombinant CdtB, we made up a quantity of functional recombinant CdtB and tested it in relation to the metal ion effect. Materials and Methods: We constructed the pET28a-cdtB plasmid from A. actinomycetemcomitans Y4 by genomic DNA PCR and expressed it in the BL21 (DE3) Escherichia coli system. We obtained the functional recombinant CdtB by the refolding system using the dialysis method and then analyzed the DNase activity and investigated the metal ion effect from plasmid digestion. Results: The recombinant CdtB subunit was expressed as the inclusion bodies. We were able to obtain functional recombinant CdtB subunit using refolding system. We confirmed that our refolded recombinant CdtB had DNase activity and was influenced by the metal ions $Mg^{2+}$ and $Ca^{2+}$. Conclusion: We suggest that the factors influencing recombinant CdtB may contribute to CDT associated diseases, such as periodontitis, endocarditic, meningitis, and osteomyelitis.

• Archives of Pharmacal Research
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• 제24권2호
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• pp.144-149
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• 2001

N-acetylsphingosine (C2-ceramide) is a synthetic water-soluble ceramide mimicking the activity of natural ceramides. By fixing chiral conformation on carbon numbers 2 and 3 in the ceramide structure, four chiral C2-ceramides naming d-erythro-, I-erythro-, d-threo-and 1-three C2-ceramide were synthesized. We have investigated the chiral effects of these C2-ceramides on the sphingolipid metabolism, particularly on both the sphingolipid bio- synthetic pathway and on the degradation pathway. In both HL-60 and U937 cells, the chiral C2-ceramide ($10{\mu}\textrm{m}$) showed sphingosine accumulation monitored fluoromatrically by a high performance liquid chromatographic separation of the sphingoid bases. Most importantly, in HL-60 cells, l-erythro C2-ceramide induced a 50 fold increase in sphingosine as compared to the control, while l-threo C2-ceramide exhibited a minimal 7-fold in-crease. In contrast, sphinganine, another sphingoid base, showed less accumulation by any chiral C2-ceramide tested under the same conditions. These results suggested that chiral C2-ceramide primarilyacts on the sphingolipid degradation pathway rather than on the sphingolipid biosynthetic route. The strong $C_0/G_1$ phase arrest in the cell cycle by treatment of I-erythro C2-ceramide indicates that the blockade of the sphingolipid degradation pathway might be concomitantly involved in the dysfunction of the cell cycle. On the other hand, the fact that all chiral C2-ceramides tested failed to inhibit the activity of sphingosine kinase acting on the removal of sphingosine by producing sphingosine-1 -phosphate demonstrates that chiral C2- ceramides may increase sphingosine by activating various ceramidases by which natural ceramides are divided into sphingosine and free fatty acids. However, the precise steps involved in this interaction are still unknown.

• 대한한방부인과학회지
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• 제19권2호
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• pp.199-213
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• 2006

Purpose : This study was aimed to investigate the inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : This study was evaluated the number of death cells treated with indicated concentration of Sparganii Rhizoma and investigated cell death rate by MTS assay. Furthermore, fluorescence-activated cell sorter analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results :1) The inhibitory effect on the growth of uterine leiomyoma cell treated with Sparganii Rhizoma was increased in a dose dependent manner. 2) As the result of FACS analysis, subG1 phase incrase was observed 23.49% inuterine leiomyoma cell treated with Sparganii Rhizoma at $500\;{\mu}g/ml$ compared to control.. 3) The gene expression of p53, p21 related cell apoptosis was increased according to increasing concentration but p27 was none exchanged. 4) The expression of cyclin A, D and E was decreased in a concentration proportional and then the dephosphorylation of pRb was increased. 5) The character of apoptosis, DNA fragmentation was significantly observed according to increasing concentration. 6) The expression of pro-caspase3 were decreased dependent on treatment concentration and activated PARP took place. Conclusion : The inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells was observed with apoptosis and cell cycle arrest. These data suggest that Sparganii Rhizoma might be candidate of medical therapy for uterine leiomyoma.

• 한국식품영양과학회지
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• 제31권2호
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• pp.329-332
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• 2002

본 연구는 사람의 간암세포인 HepG2 세포를 대상으로 강력한 암 예방 효과물질을 함유하고 있을 것으로 추측되는 향버섯 메탄올 추출물의 암세포 성장 저해 효과를 검토하고 또한 암세포 성장 억제 효과의 분자생물학적 기전을 파악하기 위하여 암세포주의 세포주기 조절인자들의 발현을 조사하였다. 향버섯 메탄을 추출물의 HePG2세포에 대한 성장 저해 효과를 MTT assay로 검토한 결과 높은 암세포 성장 저해 효과를 나타내었으며 사람의 정상 간세포인 Chang cell에서는 세포독성이 나타나지 않았다. 또한 향버섯 추출물의 작용으로 HepG2 세포에서 cyclin A와 Dl 단백질의 발현이 억제 되었으며 cyclin Bl 단백질의 발현은 증가하는 경향을 나타내었다. 그리고 암 억제 단백질인 p53의 발현은 전반적으로 증가되었으며, 이와 대조적으로 PCNA 단백질은 감소하는 경향을 나타내었고 세포분열 억제 단백질 p27의 발현은 증가 하는 경향을 나타내었다. 이러한 결과로 볼 때 향버섯 메탄올 추출물은 간암세포의 세포주기 중 Gl기 에서 S기로의 진행을 조절하는 인자인 cyclin A와 cyclin Dl 발현을 억제시키고 p53, p27 단백질을 활성화 시킴과 동시에 PCNA 작용을 억제 함으로써 세포주기 중 Gl/S기 차단을 유도하여 암세포 증식을 억제한 것으로 추정된다.

• BMB Reports
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• 제48권10호
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• pp.583-588
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• 2015

Microtubule actin crosslinking factor 1 (MACF1), a widely expressed cytoskeletal linker, plays important roles in various cells by regulating cytoskeleton dynamics. However, its role in osteoblastic cells is not well understood. Based on our previous findings that the association of MACF1 with F-actin and microtubules in osteoblast-like cells was altered under magnetic force conditions, here, by adopting a stable MACF1-knockdown MC3T3-E1 osteoblastic cell line, we found that MACF1 knockdown induced large cells with a binuclear/multinuclear structure. Further, immunofluorescence staining showed disorganization of F-actin and microtubules in MACF1-knockdown cells. Cell counting revealed significant decrease of cell proliferation and cell cycle analysis showed an S phase cell cycle arrest in MACF1-knockdown cells. Moreover and interestingly, MACF1 knockdown showed a potential effect on cellular MTT reduction activity and mitochondrial content, suggesting an impact on cellular metabolic activity. These results together indicate an important role of MACF1 in regulating osteoblastic cell morphology and function.

• 한국동물학회지
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• 제32권2호
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• pp.153-162
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• 1989

난자성숙 재개와 1-세포기 배아의 세포주기에서, cAMP-의존성 protein kinase A와 diacylglycerol-의존성 protein kinase C가 핵막붕괴에 미치는 영향을 조사하였다. 난자성숙 재기는 dbcAMP, IBMX, TPA, 또는 diacyllycerol에 의해 억제되었다. 또한 protein kinase A와 protein kinase C 활성제를 같이 처리하면 난자성숙이 더욱 억제되었다. 그러나 1-세포기 배아의 전핵막붕괴에는 아무런 영향도 미치지 못하였으며, 단지 protein kinase C 활성제만이 세포질 분열을 억제하였다. 이상의 결과로부터, protein kinase A와 protein kinase C에 의한 단백질 인산화 양상이 GV난자의 핵막붕괴와 1-세포기 배아의 전핵막붕괴에 미치는 세포내 작용기작은 상이함을 알 수 있었으며, 전기영동 결과, 81 KD 단백질이 난자성숙 재개에 중요한 역할을 하리라 사료되었다.

• 동의생리병리학회지
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• 제26권4호
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• pp.527-531
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• 2012

The flowers and leaves buds of Buddleja officinalis are used to treat eye troubles, hernia, gonorrhea and liver troubles in Asia. The present study investigated the effect of aqueous extract of Buddleja officinalis (ABO) on indoxyl sulfate (IS)-induced inhibition of cell proliferation in HK-2 cells. The HK-2 cells were incubated with 5 mM IS 5 mM in the absence or presence of ABO (2, 5, 10, 20 ${\mu}g/ml$) for 24 hr. The effect of ABO on IS-treated HK-2 cells was investigated by using MTT assay, flow cytometric analysis and Western blot. IS-induced proliferation inhibition was recovered dose-dependently by treatment with ABO. ABO reduced S and G2/M phase cell cycle arrest induced by IS. Recovery effect of ABO on inhibition of cell proliferation by IS is related to the decrease of p21 expression. Taken together, these results suggest that recovery effect of ABO on proliferation of IS-treated HK-2 cells be associated with cell cycle progression through down-regulation of p21 levels.

• 대한한방부인과학회지
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• 제18권1호
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• pp.181-191
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• 2005

Purpose : ${\beta}$-sitosterol is kind of phytosterols or plant which are structurally similar to cholesterol. This study was aimed to investigate the inhibitory effect of the ${\beta}$-sitosterol on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of death cells treated with indicated time of the ${\beta}$-sitosterol and investigated cell death rate by cell count assay. Furthermore, flow cytometry analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the growth of uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ was increased in a time dependent. 2) The result of flow cytometry analysis, subG1 phase arrest related cell apoptosis was investigated 16.97% in uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ and showed the fashion of proportional time dependent. 3) The gene expression of p27, p21 related cell cycle was increased according to increasing time interval but cyclin E-CDK2 complex was decreased expression. 4) The character of apoptosis, DNA fragmentation was significantly observed on the time dependent. 5) The expression of pro-caspase 3 and PARP were decreased dependent on treatment with time dependent. Conclusion : This study showed that the ${\beta}$-sitosterol have the inhibitory effect on the proliferation of human uterine leiomyoma cell and the effect was related with apoptosis.

• Biomolecules & Therapeutics
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• 제28권5호
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• pp.465-472
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• 2020

Colorectal cancer (CRC) is one of the most malignant type of cancers and its incidence is steadily increasing, due to life style factors that include western diet. Abnormal activation of canonical Wnt/β-catenin signaling pathway plays an important role in colorectal carcinogenesis. Therefore, targeting Wnt/β-catenin signaling has been considered a crucial strategy in the discovery of small molecules for CRC. In the present study, we found that Nodosin, an ent-kaurene diterpenoid isolated from Isodon serra, effectively inhibits the proliferation of human colon cancer HCT116 cells. Mechanistically, Nodosin effectively inhibited the overactivated transcriptional activity of β-catenin/T-cell factor (TCF) determined by Wnt/β-catenin reporter gene assay in HEK293 and HCT116 cells. The expression of Wnt/β-catenin target genes such as Axin2, cyclin D1, and survivin were also suppressed by Nodosin in HCT116 cells. Further study revealed that a longer exposure of Nodosin induced the G₂/M phase cell cycle arrest and subsequently apoptosis in HCT116 cells. These findings suggest that the anti-proliferative activity of Nodosin in colorectal cancer cells might in part be associated with the regulation of Wnt/β-catenin signaling pathway.

• Molecules and Cells
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• 제23권3호
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• pp.391-397
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• 2007

FAM92A1 (named FAM92A1-271) belongs to the family of proteins with conserved DUF1208 domains. Its function remains elusive. We identified two novel transcript variants (FAM92A1-251, FAM92A1-289) of FAM92A1. The presence of these transcripts in cancerous and normal cells, as well as their influence on cell prolifera-tion and apoptosis, were investigated. The subcellular location of FAM92A1 was determined by fluorescence microscopy. We found that FAM92A1-271 and FAM92A1-289 were highly expressed in both normal and cancerous cells, but FAM92A1-251 was only expressed at a mo-derate level in both types of cell. Overexpression of FAM92A1-271, FAM92A1-251 and FAM92A1-289 inhibited cell proliferation, caused S-phase arrest and induced apoptosis. Subcellular localization showed that FAM92A1 localizes to the nucleus. Our results show that FAM92A1 has different splicing variants, and that it may take part in regulating cell proliferation and apoptosis.