• 대한의생명과학회지
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• 제17권3호
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• pp.267-271
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• 2011

P19 cells are pluripotent embryonal carcinoma cells and can be differentiated into neuronal cell type by treatment with retinoic acid (RA) and aggregation culture. Cannabinoids are the active components of Cannabis sativa and they have diverse pharmacologic activities, such as pain control, anti-inflammatory effects, neuro-protection effects and tumor regression. Cannabinoids also involved in neuronal proliferation, migration, differentiation and survival in developing brain. Here, we studied the role of cannabinoids on neuronal differentiation of P19 cells. Treatment with cannabinoids increased the neuronal differentiation induced by RA and also promoted transcriptional activity of neurogenin 1, key transcription factor for neuronal differentiation of P19 cells. These results suggest that the cannabinoids can accelerate neuronal differentiation of P19 cells.

• 생명과학회지
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• 제19권7호
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• pp.976-982
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• 2009

고대부터 식품으로 많이 이용되어 왔던 마늘의 성분중의 하나인 alliin의 혈관 생리활성을 조사하기 위해 다양한 실험을 수행하였다. Alliin은 혈관내피세포의 증식과 이동을 증진시키는 기능이 있으며, 이는 alliin이 혈관형성을 촉진하고 혈관의 상처 치유에 도움을 줄 수 있음을 의미한다. 또한 alliin은 염증반응을 일으키는 과정에 나타나는 THP-1 세포의 혈관내피세포 부착을 억제하며, 혈전을 형성하는 THP-1 동종세포간 응집을 억제하는 기능도 갖고 있음이 확인되었다. 이와 같은 alliin의 세포 기능은 혈관의 주요 질환인 동맥경화의 발생 및 뇌졸증이나 심근경색의 원인이 되는 혈전의 형성 등을 억제할 수 있음을 의미한다. 한편 혈관의 주요 조절자 중의 하나인 산화질소의 생산에는 alliin이 관여하지 않음을 확인하였다. 종합해 보면, alliin은 혈관세포의 여러 가지 생리기능을 조절하는 혈관생리기능 개선제로 활용할 가능성이 있는 물질이다.

• Biomolecules & Therapeutics
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• 제31권3호
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• pp.285-297
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• 2023

Alzheimer's disease (AD) is a neurodegenerative disease with progressive memory loss and the cognitive decline. AD is mainly caused by abnormal accumulation of misfolded amyloid β (Aβ), which leads to neurodegeneration via a number of possible mechanisms such as down-regulation of brain-derived neurotrophic factor-tropomyosin-related kinase B (BDNF-TRKB) signaling pathway. 7,8-Dihydroxyflavone (7,8-DHF), a TRKB agonist, has demonstrated potential to enhance BDNF-TRKB pathway in various neurodegenerative diseases. To expand the capacity of flavones as TRKB agonists, two natural flavones quercetin and apigenin, were evaluated. With tryptophan fluorescence quenching assay, we illustrated the direct interaction between quercetin/apigenin and TRKB extracellular domain. Employing Aβ folding reporter SH-SY5Y cells, we showed that quercetin and apigenin reduced Aβ-aggregation, oxidative stress, caspase-1 and acetylcholinesterase activities, as well as improved the neurite outgrowth. Treatments with quercetin and apigenin increased TRKB Tyr516 and Tyr817 and downstream cAMP-response-element binding protein (CREB) Ser133 to activate transcription of BDNF and BCL2 apoptosis regulator (BCL2), as well as reduced the expression of pro-apoptotic BCL2 associated X protein (BAX). Knockdown of TRKB counteracted the improvement of neurite outgrowth by quercetin and apigenin. Our results demonstrate that quercetin and apigenin are to work likely as a direct agonist on TRKB for their neuroprotective action, strengthening the therapeutic potential of quercetin and apigenin in treating AD.

• Clinical and Experimental Reproductive Medicine
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• 제39권2호
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• pp.58-67
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• 2012

Objective: Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). Methods: We evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi). Results: Despite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process. Conclusion: We concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3052-3058
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• 2014

In this article, we have designed and synthesized a novel donor-${\pi}$-acceptor (D-${\pi}$-A) type porphyrin-based sensitizer (denoted UI-5), in which a carboxyl anchoring group and a 9,9-dimethyl fluorene were introduced at the meso-positions of porphyrin ring via phenylethynyl and ethynyl bridging units, respectively. Long alkoxy chains in ortho-positions of the phenyls were supposed to reduce the degree of dye aggregation, which tends to affect electron injection yield in a photovoltaic cell. The cyclic voltammetry was employed to determine the band gap of UI-5 to be 1.41 eV based on the HOMO and LUMO energy levels, which were estimated by the onset oxidation and reduction potentials. The incident monochromatic photon-to-current conversion efficiency of the UI-5 DSSC assembled with double-layer (20 nm-sized $TiO_2$/400 nm-sized $TiO_2$) film electrodes appeared lower upon overall ranges of the excitation wavelengths, but exhibited a higher value over the NIR ranges (${\lambda}$ = 650-700 nm) compared to the common reference sensitizer N719. The UI-5-sensitized cell yielded a relatively poor device performance with an overall conversion efficiency of 0.74% with a short circuit photocurrent density of $3.05mA/cm^2$, an open circuit voltage of 0.54 mV and a fill factor of 0.44 under the standard global air mass (AM 1.5) solar conditions. However, our report about the synthesis and the photovoltaic characteristics of a porphyrin-based sensitizer in a D-${\pi}$-A structure demonstrated a significant complex relationship between the sensitizer structure and the cell performance.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1267-1272
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• 2005

The effects of coexpression of GroEL/ES and DnaK/DnaJ/GrpE chaperones on the productivity of the soluble form of human granulocyte colony stimulating factor (hG-CSF) in E. coli were examined. Recombinant hG-CSF protein was coexpressed with DnaK/DnaJ/GrpE or GroEL/ES chaperones under the control of the araB or Pzt-1 promoter, respectively. The optimal concentration of L-arabinose for the expression of DnaK/DnaJ/GrpE was found to be 1 mg/ml. When L-arabinose was added at $OD_{600}$=0.2 (early-exponential phase), soluble hG-CSF production was greatly increased. In addition, it was observed that the DnaK/DnaJ/GrpE and GroEL/ES chaperones had no synergistic effects on preventing aggregation of hG-CSF protein. Consequently, by coexpression of the DnaK/DnaJ/GrpE chaperone, the signal intensity of the hG-CSF protein band in the soluble fraction of cell lysate was increased from $3.5\%\;to\;13.9\%$, and Western blot analysis also revealed about a 4-5-fold increase of production of soluble hG-CSF over the non-induction case of DnaK/DnaJ/GrpE.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.765-785
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• 1999

Bone morphogenetic protein-2/4 (BMP-2/4) are members of Transforming Growth $Factor-{\beta}\;(TGF-{\beta})$ superfamily and they may differentiate the osteoprogenitor cell and induce formation of cartilage and bone in vivo. This study was performed to investigate the effects of bone morphogenetic protein-2/4 on the characteristics of rat periodontal ligament cells(RPDL) and rat calvaria cells(RCV). In the control group, the cells were cultured alone with Dulbeco's Modified Eagle's Medium contained with 20% fetal bovine serum, $100{\mu}/ml$ penicillin, $100{\mu}/ml$ streptomycin. In the experimental groups, recombinant human bone morphogenetic protein-2/4 (25ng, 100ng, 250ng/ml) were added into the above culture condition. And then each group was characterized by examing the cell proliferation at 1, 2, 3, 5, 7th day, the amount of total protein synthesis and alkaline phosphatase activity at 2, 5, 7th day. And also, the calcified nodule was examed. The results were as follows ; 1 . Both RCV and RPDL cells in both control and experimental groups proliferated during the entire experimental period, but there is no stastically significant difference according to the BMP-2/4 concentration. 2 . Amount of total protein synthesis of both cells in both groups was steadily increased until 5th day, but all experimental groups were significantly different from the control group at 7th day. 3. Alkaline phosphatase activity of both cells in both groups was increased during the entire experiment period. In RCV cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 7th day. In RPDL cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 5th day, and all experimental groups were significantly different from the control group at 7th day. 4. In the both of the cultured Rat Periodontal ligament and calvaria cell treated with BMP-2/4 to compared with control group, it revealed more rapid cell polarization, cell aggregation and hyperchromatic stained on HE agent, and even though only 1 day treated with BMP-2/4 both RPDL and RCV showed more rapid cell reaction than control group. More sensivitve cell reaction of RCV were observed than RPDL in this experiment. From the above results, we could conclude that BMP-2/4 influenced the induction, proliferation and differentiation of bone forming cells

• 한국발생생물학회지:발생과생식
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• 제19권4호
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• pp.227-234
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• 2015

The objective of this study was to investigate the expression of bovine luteum expressed sequence tags (ESTs), vascular endothelial growth factor (VEGF), and tumor necrosis factor receptor 1 (TNFR1) and the presence of functional ESTs in the bovine corpus luteum (CL) during different stages of the estrus cycle. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed a difference in the expression of ESTs during the CL stage. Concentration of ESTs in the CL tissue increased significantly from the mid-luteal stage and decreased thereafter. RT-PCR analysis showed higher levels of the EST genes in the CL of the mid-luteal stage than in other stages, and the same level of expression of VEGF. Immunohistochemistry analysis of the tissue from CL formation to regression showed low cytosol and aggregation of the nucleus. And activity caspase 3 (apoptosis detector) was most strongly detected in the CL1 stage of bovine. During the estrous cycle, the cytosol was magnified and differentiation of the nucleus was clearly manifested. The ESTs affected the CL, and the relationship between VEGF and TNFR1 played a pivotal role for CL development and activation, dependent on the stage of CL. These results suggest local production of ESTs, the presence of functional ESTs in the bovine CL, and that ESTs play a role in regulating the function of cell death in bovine CL.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권3호
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• pp.218-228
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• 2010

발암물질로 알려진 Hydroquinone (HQ)은 치과용 합성수지를 구성하는 중요한 성분으로서 지금까지 치과용 재료영역에서 널리 사용되고 있으며 구강 내에서 HQ의 유출이 일어나는 것으로 확인 되었다. 따라서 구강암의 기원이 되는 인체상피세포의 발암화에 HQ가 미치는 영향을 평가하였다. HQ에 의한 인체세포 독성을 평가하기위해 LDH assay를 실시하고 세포 독성이 높지 않은 용량을 실험 용량으로 설정하였다. 인체 세포의 발암화를 평가하기 위해 세포 발암화 지표로서 cell saturation density, soft-agar colony formation 및 cell aggregation의 분석을 사용한 결과 고용량인 50 ${\mu}M$을 제외한 모든 용량에서 발암화 지표의 변화를 나타내지 않아 HQ의 발암력은 매우 낮은 것으로 추정된다. 그러나 발암촉진제인 TPA와 함께 투여 시 발암력의 증가를 보여 주변 환경의 여건에 따라 발암력이 증가할 수 있음을 입증하였다. HQ를 노출 후 세포사멸화를 측정하기 위해 DNA fragmentation변화를 분석한 결과 10 ${\mu}M$부터 50 ${\mu}M$까지 노출 시간 의존형의 증가를 나타내었으며 50 ${\mu}M$과 같은 고용량 농도에서는 노출시간 의존적 세포사멸 효과를 보였다. 따라서 세포 발암화를 일으킨 용량에서 세포사멸도 함께 일어나 HQ에 의한 발암화에 세포사멸이 관여함을 보였다. HQ는 ROS를 생성하였으며 Trolox, NAC와 같은 항산화물에 의한 ROS의 차단 효과와 BSO와 같은 GSH 고갈 유발 물질에 따른 ROS의 급격한 증가는 HQ가 인체세포에서 ROS를 효율적으로 생성함을 입증하는 결과이다. 세포간의 신호전달기작 조절에 중요한 역할을 하는 효소인 protein kinase C (PKC)를 immunoblot으로 분석한 결과 PKC-${\alpha}$의 활성이 증가 된 반면 PKC-${\beta}II$의 영향은 나타나지 않았다. 따라서 특정 이성질체에 대한 특이적인 효소반응이 발암화에 관여할 것으로 추정된다. 본 연구결과 치과용 합성수지 구성성분인 HQ 유출에 따른 인체상피세포의 발암성은 매우 낮은 것으로 추정되나 발암촉진제 등과의 상호작용에 의한 발암성 증가는 HQ의 구강암 발생 평가에 고려되어야 할 사항이다. 따라서 본 연구는 구강암의 예방을 위한 과학적인 접근 방법 및 기반 자료를 제시하였고 치과용 합성수지사용의 적정성에 대한 과학적인 판단을 할 수 있는 근거를 제공 하였다. 또한 본 연구 결과는 새로운 치과용 합성수지 개발의 필요성 및 개선방향을 제시 할 수 있는 근거로 활용될 수 있을 것으로 사료된다.

• Molecules and Cells
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• 제24권1호
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• pp.69-75
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• 2007

Alzheimer's disease is a neurodegenerative disorder associated with progressive loss of cognitive function and memory. Amyloid beta peptide ($A{\beta}$) is the major component of senile plaques and is known to exert its cytotoxic effect mainly by producing $H_2O_2$. Vascular endothelial growth factor (VEGF) is elevated in the cerebrospinal fluid (CSF) and brain of AD patients, and $H_2O_2$ is one of the factors that induce VEGF. Therefore, we tested whether $A{\beta}$ might be responsible for the increased VEGF synthesis. We found that $A{\beta}$ induced the production of $H_2O_2$ in vitro. Comparison of the amount of $H_2O_2$ required to induce VEGF synthesis in HN33 cells and the amount of $H_2O_2$ produced by $10{\mu}M\;A{\beta}_{1-42}$ in vitro suggested that a toxic concentration of $A{\beta}$ might induce VEGF synthesis in these cells. However, toxic concentrations of $A{\beta}$ failed to induce VEGF synthesis in several cell systems. They also had no effect on antioxidant enzymes such as glutathione peroxidase, catalase, and peroxiredoxin in HN33 cells. $Cu^{2+}$, $Zn^{2+}$ and $Fe^{3+}$ are known to accumulate in the brains of AD patients and promote aggregation of $A{\beta}$, and $Cu^{2+}$ by itself induces synthesis of VEGF. However, there was no synergistic effect between $Cu^{2+}$ and $A{\beta}_{1-42}$ in the induction of VEGF synthesis and $Zn^{2+}$ and $Fe^{3+}$ also had no effect on the synthesis of VEGF, alone or in combination with $A{\beta}$.