• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.457-462
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• 2002

Low Electromagnetic Field (EMF) intensity in the range of $1{\mu}T\;to\;10{\mu}T$(Tesla) was found to enhance the growth of CHO cells and the production of tPA in batch and perfusion cultivations. At $1{\mu}T\;intensity,\;1.3{\times}10^7$ viable cells/ml of maximum cell density and 80 mg/l of maximum tPA production were obtained in batch cultivation, compared to $2.8{\times}10^6$ viable cells/ml and 59 mg tPA/1 in unexposed case (control). A similar trend was observed in the perfusion process, where it was possible to obtain $1.2{\times}10^7$ viable cells/ml of maximum cell density and 81 mg tPA/l of maximum tPA production by more than 80 days of cultivation. However, there was not much difference between $1{\mu}T\;and\;10{\mu}T$ in perfusion cultivation, possibly due to better environmental growth conditions being maintained by continuous feeding of fresh medium into the reactor. On the contrary, both cell growth and tPA production were severely inhibited at higher than 1 mT intensity, showing no growth at 10 mT exposure. Specific growth rate was linearly correlated to specific tPA production rate at $1{\mu}T$EMF intensity, which represents a partially growth-related relationship. It was also found that a large amount of $Ca^2+$ was released at low EMF intensity, even though the cell growth was not much affected. Low EMF intensity significantly improved both cell growth and tPA production, and tPA production seemed to be more affected than the cell growth, possibly due to the changes of cell membrane characteristics. It can be concluded that the elaboration of EMF intensity less than $10{\mu}T$ could improve cell growth and tPA production, but mainly tPA secretion through batch or perfusion process in a bioreactor.

• BMB Reports
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• v.46 no.10
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• pp.484-489
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• 2013

Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit anti-hyperlipidemic, antiplatelet and anti-melanogenic activities. Here, the anticoagulant activities of PL were examined by monitoring activated-partial-thromboplastin-time (aPTT), prothrombin-time (PT), and the activities of thrombin and activated factor X (FXa). The effects of PL on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) activated HUVECs. The results showed that PL prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. PL inhibited the generation of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, PL prolonged in vivo bleeding time and inhibited TNF-${\alpha}$ induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by PL. Collectively, our results suggest that PL possesses antithrombotic activities and that the current study could provide bases for the development of new anticoagulant agents.

• BMB Reports
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• v.48 no.10
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• pp.577-582
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• 2015

Cyclopia subternata is a medicinal plant commonly used in traditional medicine to relieve pain. Here, the anticoagulant effects of scolymoside, an active compound in C. subternata, were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of thrombin and activated factor X (FXa). The effects of scolymoside on plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) expression were evaluated in tumor necrosis factor (TNF)-α-activated human endothelial cells. Treatment with scolymoside resulted in prolonged aPTT and PT and the inhibition of thrombin and FXa activities and production. In addition, scolymoside inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. Scolymoside also elicited anticoagulant effects in mice, including a significant reduction in the PAI-1 to t-PA ratio. Collectively, these findings indicate that scolymoside possesses anticoagulant activities and could be developed as a novel anticoagulant.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.126-131
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• 1996

HL-60 was cultivated to produce tPA (tissue-type plasminogen activator) and study the mechanism of cell death. Maximum cell density and tPA production were obtained as $5.27{\times}10^6$ cells/ml and 324ng/ml, respectively under perfusion cultivation. tPA production was enhanced to 420ng/ml in adding 160nM of phorbol ester. The cells were gradually differentiated to granulocytes rather than proliferation. By Fluorescent microscope, apoptosis was prevailed except the death phase and in high agitation speed, but necrosis was prevailed in thawed cells and during the latter periods of the cultivation. It was also proved that tPA was most produced in apoptosis. To obtain higher tPA productivity, the cells must be maintained in apoptosis, not necrosis phase when the cells were dying.

• The Journal of Korean Physical Therapy
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• v.25 no.4
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• pp.224-231
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• 2013

Purpose: The purpose of this case study was to investigate three poor fibrinolytic responders with chronic ischemic stroke to acute exercise intensity and time. Methods: Three ischemic stroke patients (male) from the stroke center located at Busan metropolitan area in Republic of Korea volunteered at this study. They performed two single session exercises that were a VO2peak test and a single bout treadmill walking (70-75%HRpeak, 30 min, 50min). Fasting blood samples for determination of tissue Plasminogen Activator (tPA) and Plasminogen Activator Inhibitor-1 (PAI-1) were obtained before, immediately after, 30min after acute exercise. SPSS 12.0 was used for analyzing of data and computing mean and standard deviation, and change rate was conducted between times. Results: In fibrinolytic activity according to the intensity and time of acute exercise, tPA change increased steadily during the recovery stage after the VO2peak in the cases, but PAI-1 activity showed different patterns among the cases. In a single bout treadmill walking (70-75%HRpeak, 30 min, 50min), tPA change increased between 30min and 50min. Conclusion: In conclusion, these results suggest that the exercise prescription for poor fibrinolytic responder with three male chronic ischemic stroke patients without motor disability recommend at 70-75%HRpeak, over 30min.

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.295-298
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• 1996

Under glutamine-limited condition, $2\times10^6$ (viable cells/ml) of maximum cell density and 13.5 ($\mu g$/ml) of tissue-type Plasminogen Activators (tPA) production were maintained by spike feeding fresh medium in fed-batch cultivation of human recombinant melanoma cells. It showed that tPA production was much seriously affected than cell growth according to initial glutamine concentrations. Above 3.4 (mmol/I) of glutamine concentration both cell growth and tPA production were not much affected by increasing initial glutamine concentration. Glutamine depleted situation was occurred at latter periods of batch and fed-batch cultivations below 5.4 (mmole/I) of initial glutamine concentration. It also showed that maximum glutamine consumption and ammonia evolution rates were closely related to initial glutamine concentrations. Maximum specific tPA production rate was estimated as $8.1\times19^{-6}$ ($\mu g$/cells/h) at 3.4(mmol/I) of glutamine concentration, which is higher than that from other batch and fed-batch processes.

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

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.30-37
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• 2009

Tissue-type plasminogen activator (t-PA) is a thrombolytic agent important in fibirn clot lysis. T-PA causes fibirn-specific plasminogen activation. Six binary vectors harboring t-PA and its derivative genes were cloned and expressed in transgenic alfalfa plants. The insertion of the t-PA and its derivative genes in genomic DNA of alfalfa plants was confirmed by PCR. The presence of the t-PA and its derivative transcripts in total RNAs of the transgenic alfalfa leaves was verified by RT-PCR. ELISA experiments demonstrated that the highest level of recombinant t-PA expression was $75.1{\mu}g$/ total soluble protein (mg) in alfalfa plants. The amount of recombinant t-PA and its derivative proteins in transgenic plants was estimated to range from 9.7 to $39.5{\mu}g$/ total soluble proteins (mg). Western blot analysis of the transformed alfalfa leaves revealed bands of approximately 68-kDa recombinant t-PA and its derivative proteins. The fibrinolysis of recombinant t-PA and its derivative proteins was confirmed by a fibrin plate assay (range from 3.2 to 8.1 cm). The results presented provide information for the development of an additional production of recombinant human proteins having pharmaceutical applications using transgenic plants.

• Biomolecules & Therapeutics
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• v.14 no.1
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• pp.30-35
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• 2006

Tissue-type plasminogen activator (t-PA) is a multidomain serine protease containing two kringle domains, TK1-2. Previously, Pichia-derived recombinant human TK1-2 has been reported as an angiogenesis inhibitor although t-PA plays an important role in endothelial and tumor cell invasion. In this work, in order to improve in vivo efficacy of TK1-2 through elimination of immune reactivity, we mutated wild type TK1-2 into non-glycosylated form (NE-TK1-2) and examined whether it retains anti-angiogenic activity. The plasmid expressing NE-TK1-2 was constructed by replacing $Asn^{l17}\;and\;Asn^{184}$ with glutamic acid residues. After expression in Pichia pastoris, the secreted protein was purified from the culture broth using S-sepharose and UNO S1-FPLC column. The mass spectrum of NE-TK1-2 showed closely neighboring two peaks, 19631.87 and 19,835.44 Da, and it migrated as one band in SDS-PAGE. The patterns of CD-spectra of these two proteins were almost identical. Functionally, purified NE-TK1-2 was shown to inhibit endothelial cell migration in response to bFGF stimulation at the almost same level as wild type TK1-2. Therefore, the results suggest that non-glycosylated NETK1-2 can be developed as an effective anti-angiogenic and anti-tumor agent devoid of immune reactivity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.123-129
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• 2000

A high cell density culture system for the anchorage dependent CHO cells was developed based on the combination of in removal of ammonium ion and microcarrier culture system, and semi-fed-batch feeding of glucose and glutamine was employed to the developed culture system. The glass bead was selected as an optimum microcarrier in terms of cell growth. An ammonium ion selective zeolite, Phillipsite-Gismondine, was packed in a dialysis menium ion. The semi-fed-batch operation was employer to the novel culture system for the high density cell culture, and the results showed the cell growth was improved by 32% and tPA productivity by 250%.