• Biotechnology and Bioprocess Engineering:BBE
• /
• v.1 no.1
• /
• pp.32-35
• /
• 1996

Amoving aeration-membrane (MAM) bioreactor was employed for the production of 2$\mu$g/mL of tissue type Plasminogen Activator (tPA)in serum free medium from normal human fibroblast cells. This system could maintain high cell density for long periods of steady state conditions in perfusion cultivation. Under normal operating condition, shear stress was as low as 0.65 dynes/$\textrm{cm}^2$ at the agitation speed of 80 rpm. Even though cell density gradually decreased with increasing agitation speed, tPA production increased linearly with increasing shear stress within a moderate range. This culture system allowed production of 2$\mu$g tPA/mL while maintaining a high cell denisty of 1.0$\times$107 viable cell/mL.

• Journal of Korean Medicine for Obesity Research
• /
• v.24 no.1
• /
• pp.1-12
• /
• 2024

Objectives: Ephedrae herba (EH) and Coicis semen (CS) has been frequently prescribed for the treatment of obesity. However, effects of combinational extracts of these two herbs on non-alcoholic fatty liver disease are unknown. The aim of the present study was to investigate the effects of EH and CS on lipid accumulation and glucose absorption in free fatty acids (FFAs) or palmitic acid (PA)-treated HepG2 cells. Methods: Five samples of EH and CS were extracted by combination ratios (S1=0:100, S2=25:75, S3=50:50, S4=75:25, S5=100:0). Oil Red O staining was used to measure lipid accumulation in FFAs-induced steatosis cells. Intracellular triglycerides and total cholesterol levels were measured in FFAs-induced steatotic HepG2 cells. In PA-treated cells, intracellular 2-NBDG was detected using a fluorescence microplate reader and flow cytometry. Phosphorylation of key metabolism-related factors of AMP-activated protein kinase and acetyl-CoA carboxylase, expression of key lipid synthesis-related factors carnitine palmitoyltransferase 1 alpha (CPT1α), sterol regulatory element-binding protein 1 (SREBP1), peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer binding protein alpha (C/EBPα) were confirmed by western blot. Results: Treatment of EH-CS combination in the FFAs-induced steatotic HepG2 cells significantly reduced lipid accumulation. As the relative ratio of Ephedrae herba increased, the lipid-lowering effects of the combination were increased. However, S1 and S5 of Ephedrae herba and Coicis semen did not significantly reduce triglycerides and total cholesterol induced by FFAs. However, the combination of Ephedrae herba and Coicis semen restored glucose absorption in PA-induced HepG2 cells. Major makers of SREBP1, PPARγ, C/EBPα, and CPT1α expression tended to decrease with EH ratio. Conclusions: The EH-CS combination has advantages over sole EH and CS extracts in improving lipid and glucose metabolism in liver steatosis models.

• Biomolecules & Therapeutics
• /
• v.15 no.1
• /
• pp.16-26
• /
• 2007

Tissue plasminogen activator (tPA) is a serine protease catalyzing the proteolytic conversion of plasminogen into plasmin, which is involved in thrombolysis. During last two decades, the role of tPA in brain physiology and pathology has been extensively investigated. tPA is expressed in brain regions such as cortex, hippocampus, amygdala and cerebellum, and major neural cell types such as neuron, astrocyte, microglia and endothelial cells express tPA in basal status. After strong neural stimulation such as seizure, tPA behaves as an immediate early gene increasing the expression level within an hour. Neural activity and/or postsynaptic stimulation increased the release of tPA from axonal terminal and presumably from dendritic compartment. Neuronal tPA regulates plastic changes in neuronal function and structure mediating key neurologic processes such as visual cortex plasticity, seizure spreading, cerebellar motor learning, long term potentiation and addictive or withdrawal behavior after morphine discontinuance. In addition to these physiological roles, tPA mediates excitotoxicity leading to the neurodegeneration in several pathological conditions including ischemic stroke. Increasing amount of evidence also suggest the role of tPA in neurodegenerative diseases such as Alzheimer's disease and multiple sclerosis even though beneficial effects was also reported in case of Alzheimer's disease based on the observation of tPA-induced degradation of $A{\beta}$ aggregates. Target proteins of tPA action include extracellular matrix protein laminin, proteoglycans and NMDA receptor. In addition, several receptors (or binding partners) for tPA has been reported such as low-density lipoprotein receptor-related protein (LRP) and annexin II, even though intracellular signaling mechanism underlying tPA action is not clear yet. Interestingly, the action of tPA comprises both proteolytic and non-proteolytic mechanism. In case of microglial activation, tPA showed non-proteolytic cytokine-like function. The search for exact target proteins and receptor molecules for tPA along with the identification of the mechanism regulating tPA expression and release in the nervous system will enable us to better understand several key neurological processes like teaming and memory as well as to obtain therapeutic tools against neurodegenerative diseases.

• Reproductive and Developmental Biology
• /
• v.33 no.2
• /
• pp.107-111
• /
• 2009

The transfection efficiency of a transgene into pig and goat fetal fibroblast cells (PFF and GFF, respectively) was tested using co-transfection of a human tissue-type plasminogen activator (tPA) transgene and neomycin-resistant ($Neo^r$) gene, followed by G418 selection. To initially test G418 resistance, GFF and PFF were incubated in culture medium containing different concentration of G418 for 2 weeks, and cell survival was monitored over time. Based on the obtained results, the concentrations chosen for G418 selection were 800 ug/ml and 200 ug/ml for GFF and PFF, respectively. For co-transfection experiments, the pBC1/tPA and $Neo^r$ vectors were co-transfected into GFF and PFF ($1{\times}10^6$ cells in each case) using the FuGENE6 transfection reagent, and resistant colonies were obtained following 14 days of G418 selection. We obtained 96 and 93 drug-resistant colonies of GFF and PFF, respectively, only 54 and 39 of which, respectively, continued proliferating after drug selection. PCR-based screening revealed that 23 out of 54 analyzed GFF colonies and 5 out of 39 analyzed PFF colonies contained insertion of the tPA gene. Thus, the experimentally determined transfection efficiencies for tPA gene co-transfection with the $Neo^r$ gene were 42.6% for GFF and 12.8% for PFF. These findings suggest that co-transfection of a transgene with the $Neo^r$ gene can aid in the successful integration of the transgene into fetal fibroblast cells.

• Animal cells and systems
• /
• v.2 no.2
• /
• pp.249-258
• /
• 1998

Obesity, one of the most common metabolic diseases in industrial countries is characterized by an increase in the number or size of adipocytes. In an effort to create transgenic mouse models for the study of obesity we developed a novel technique in which adipose tissue can be ablated genetically at will, at any specific developmental stage and/or physiological condition, by the treatment of ganciclovir. We made a series of adipocytespecific expression vectors using minimal regulatory regions of brown adipocyte-specific uncoupling protein (UCP-1) gene and adipocyte-specific aP2 gene, and then analyzed their expression characteristics in cultured cell lines. When both constructs pUCP-LacZ and paP2-LacZ were transfected transiently into differentiating 3T3-L1 (pre-while adipocytes) and HIB-1B (pre-brown adipocytes) cell lines in vitro and then monitored by X-gal staining of cells, these regulatory regions were sufficient to show proper differentiation stage-specific expression in adipocvtes. To confirm that adipocytes expressing HSV-TK controlled by these minimal requlatory elements are sufficient to kill themselves with ganciclovir treatment pUCP-TK and paP2-TK expression constructs were transfected stably into HIB-1B and 3T3-L1 cells, respectively, and their ganciclovir sensitivities were tested during in vitro differentiation of cells. As expected more than 80% of cells were dead by the 7th day of treatment with ganciclovir while negative control cells were not affected at all. The data suqqest that the constructed vectors are suitable for obtaining novel obese transqenic models based on a conditional genetic tissue ablation method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.10
• /
• pp.754-759
• /
• 2013

Aluminum oxide($Al_2O_3$) film deposited by atomic layer deposition (ALD) is known to supply excellent surface passivation properties on crystalline Si surfaces. Since $Al_2O_3$ has fixed negative charge, it forms effective surface passivation by field effect passivation on the rear side in p-type silicon solar cell. However, $Al_2O_3$ layer formed by ALD process needs very long process time, which is not applicable in mass production of silicon solar cells. In this paper, plasma-assisted ALD(PA-ALD) was applied to form $Al_2O_3$ to reduce the process time. $Al_2O_3$ synthesized by ALD on c-Si (100) wafers contains a very thin interfacial $SiO_2$ layer, which was confirmed by FTIR and TEM. To improve passivation quality of $Al_2O_3$ layer, the deposition temperature was changed in range of $150{\sim}350^{\circ}C$, then the annealing temperature and time were varied. As a result, the silicon wafer with aluminum oxide film formed in $250^{\circ}C$, $400^{\circ}C$ and 10 min for the deposition temperature, the annealing temperature and time, respectively, showed the best lifetime of 1.6ms. We also observed blistering with nanometer size during firing of $Al_2O_3$ deposited on p-type silicon.

• Applied Biological Chemistry
• /
• v.49 no.1
• /
• pp.65-69
• /
• 2006

With extracted Aloe vera and Aloe arborescens, anti-inflammatory effect was examined in phosphatidic acid-stimulated Raw 264.7 cells. Phosphatidic acid $(50\;{\mu}g/ml)$ treatment increased inflammation related 264.7 cells. The extracts of $80\;{\mu}g/ml$ concentration from Aloe arborescens reduced the expression of iNOS. Aloe vera and Aloe arborescens also reduced the expression of COX-2, it seems that anti-inflammatory effects of Aloe extracts is partly due to the inhibition of COX-2 expression by inhibiting in Raw 264.7 cells.

• Molecules and Cells
• /
• v.28 no.6
• /
• pp.583-588
• /
• 2009

The peroxiredoxin family of peroxidase has six mammalian members (Prx 1-6). Considering their frequent up-regulation in cancer cells, Prxs may contribute to cancer cells' survival in face of oxidative stress. Here, we show that Prx 6 promotes the invasiveness of lung cancer cells, accompanied by an increase in the activity of phosphoinositide 3-kinase (PI3K), the phosphorylation of p38 kinase and Akt, and the protein levels of uPA. Functional studies reveal that these components support Prx 6-induced invasion in the sequence p38 kinase/PI3K, Akt, and uPA. The findings provide a new understanding of the action of Prx 6 in cancer.

• Journal of Life Science
• /
• v.17 no.7 s.87
• /
• pp.1019-1022
• /
• 2007

Thrombolytic therapy with tissue plasminogen activator (tPA) can improve the clinical outcome of ischemic stroke patients. However, its clinical application is limited by narrow therapeutic time windows and elevated risks of cerebral hemorrhage and brain injury. In part, these effects of tPA has been related to matrix metalloproteinase-9 (MMP-9) dysregulation. Here, we investigate that the effects of alteplase (tPA with short half-life) and pamiteplase (a modified tPA with long half-life) on the MMP-9 regulation in neurovascualr unit. The total levels of MMP-2 and MMP-9 in neuronal cells are lower than astrocytes. Alteplase (1-10 ${\mu}g/ml$) induced upregulation of MMP-2 and MMP-9 in rat cortical neurons and astrocytes, respectively. Whereas pamiteplase in a wide range of dose did not affect the MMP-2 and MMP-9 responses in both of cells. These results suggest that pamiteplase with long half-life can be provided as a agent that overcome the side effects of alteplase.

• Proceedings of the KSAR Conference
• /
• 2003.06a
• /
• pp.60-60
• /
• 2003

소의 난포란과 난구세포의 체외배양시 plasminogen activators(PAs)의 생산을 보고하였다 (Choi 등, 1998). 따라서 본 연구는 돼지 난포란 및 난구세포의 체외성숙시 PAs의 생산을 SDS-PAGE와 Zymogram을 이용하여 조사하였다. PCOCs는 도축암퇘지의 난소로부터 채취하여, 난구세포가 충실한 것만 선별하였으며, 실험구에 사용될 난구세포는 pipetting에 의해 분리하여 이용하였다. 돼지 신선정액은 D-PBS로 1,500 rpm, 5분간 2회 원심분리하여 정장물질을 제거하고, 3회째는 5mM caffein이 함유된 BO(Brackett과 Oliphant, 1985) 배양액으로 세정하였다. 처리한 돼지 정액은 1$\times$$10^{8}$ cells/$m\ell$로 조정하여 20${\mu}\ell$씩 분주하고 0, 1, 2, 3 또는 4시간 동안 39$^{\circ}C$ 5% $CO_2$, 95% 공기인 배양기에서 수정능획득을 유도하였다. 배양이 완료된 정액은 20${\mu}\ell$의 sample buffer(5% SDS, 20% glycerol, 0.0025% bromophenol blue 그리고 0.125M Tris HC1 buffer)에 넣어 -7$0^{\circ}C$ 동결기에 보관하였다. 전기영동은 4% stacking gel과 10% separating gel로 분리하였으며, 20 mA에서 90분간 실시하였다. Zymogram은 Choi 등(1988)의 방법에 따라 실시하여 PAs의 생산을 확인하였으며, 이상의 실험은 3반복을 실시하였다. 시험구 전체에서 urokinase type plasminogen activator(uPA)가 확인되었으며, 체외수정능 획득시간에는 차이가 없었다. 두 종류의 고분자량의 uPA의존성 영역이 나타났으며, 분자량은 65kD과 62 kD이었다. 이러한 결과로 볼 때 Hart 등(1986)이 uPA의 경우 다양한 영역의 분자량 변이를 확인할 수 있었다고 한 것과 동일하였으며, 돼지 정자가 체외수정능 획득시 uPA를 생산하는 것을 확인할 수 있었다.