• BMB Reports
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• v.34 no.6
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• pp.537-543
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• 2001

In the present study, an in vitro ELISA system to assess the interaction between Src homology (SH)2 domains and phosphotyrosine that contain peptides was established using purified GST-conjugated SH2 proteins and synthetic biotinylated phosphotyrosine that contain oligopeptides. The SH2 domains bound the relevant phosphopeptides that were immobilized in the streptavidin-coated microtiter plate in a highly specific and dose-dependent manner. The epidermal growth factor receptor (EGFR)-, T antigen (T Ag)-, and platelet-derived growth factor receptor (PDGFR)-derived phosphopeptides interacted with the growth factor receptor binding protein (Grb)2/SH2, Lck/SH2, and phosphatidyl inositol 3-kinase (PI3K) p85/SH2, respectively. No cross-reactions were observed. Competitive inhibition experiments showed that a short phosphopeptide of only four amino acids was long enough to determine the binding specificity. Optimal concentrations of the GST-SH2 fusion protein and phosphopeptide in this new ELISA system for screening the binding blockers were chosen at 2nM and 500nM, respectively. When two candidate compounds were tested in our ELISA system, they specifically inhibited the Lck/SH2 and/or p85/SH2 binding to the relevant phosphopeptides. Our results indicate that this ELISA system could be used as an easy screening method for the discovery of specific binding blockers of protein-protein interactions via SH2 domains.

• Journal of Animal Science and Technology
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• v.54 no.3
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• pp.165-174
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• 2012

For horse breeders or managers, it is critical to understand the estrous cycle of mares. Breeding of mares cannot be successfully achieved throughout the whole year as mares breed seasonally. Mares are only able to breed when day length is more than 16 h, and this period is known as the breeding season. Their estrous cycle is approximately 21 days with 5-7 days of estrus and 14 to 15 days of a diestrus period. The estrous cycle of the mare is mainly controlled by gonadotropins, which control follicular development and ovulation. Mares exhibit unique ovulatory events which are not observed in other species. A LH surge occurs for several days, with levels of LH reaching their peak after ovulation. The LH level at the time of LH peak is lower than most other species. The unique anatomical structure of the ovaries of mares is known to limit the number of eggs ovulated. Several attempts have been made to develop chemical/hormonal agents which might be used to manipulate the timed ovulation of mares. Agents that have been tested include hCG, native GnRH, Deslorelin (Ovuplant, GnRH-agonist), Buserelin (GnRH analogue), equine pituitary extracts and equine chorionic gonadotropin (eCG or PMSG). However, the function, purity or stability of these agents is not reliable. Recombinant equine LH, an alternative agent for the timed ovulation, has been developed and tested for its biological activities, through the use of both in vitro and in vivo experiments. The reLH was suggested to be a reliable agent in inducing ovulation within 48 h after being administered through injection, when the size of dominant follicle is 35 mm in diameter.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.27-32
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• 2002

The purpose of this study was to evacuate the effects of the number of tied hollow fibers in a novel membrane oxygenator that satisfied the limiting factor of minimizing the friction loss in the intravascular blood flow Pattern. The membrane oxygenator is a bundle consisted of several hundred ho1low fibers haying the outside diameter of 380 $\mu m$ and the axial jacket length of 600 mm. The eight different variation of tied hollow fibers in a bundle were designed. and the liquid flow pattern was controlled by a pump. The liquid pressure drop was measured by in vitro experiments using water and g1ycero1. Uniform blood flow pattern was observed for each number of tied hollow fibers. Pressure drop was 13-16 mmHg outside of the membrane oxygenator consisting of up to 700 ho1low fibers. More effective contact of liquid with the tied ho1low fibers was observed as a decrease in the number of the tied hollow fibers. and resulted in the enhancement of the friction tractor

• Molecules and Cells
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• v.22 no.1
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• pp.70-77
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• 2006

Platelets are anucleate cytoplasmic fragments derived from bone marrow megakaryocytes, and endothelial cells constitute the barrier between bloodstream and adjacent tissues. Although platelets are thought to regulate the biological functions of endothelial cells, the molecular mechanisms involved are poorly understood. With human umbilical vein endothelial cells and freshly isolated platelets, we established an in vitro model of platelet-induced endothelial cell proliferation. Platelets stimulated endothelial cell proliferation in a dose-dependent manner and transwell experiments with semi-permeable membranes suggested that direct cell-to-cell contacts were required. We developed mAbs against platelets and selected a mAb that blocks their proliferative effect. We purified the antigen by immunoprecipitation and identified it by Q-TOF MS analysis as the tetraspanin CD9. Since both platelets and endothelial cells expressed CD9 strongly on their surfaces we carried out a pre-treatment experiment that showed that CD9 molecules on the endothelial cells participate in the mitogenic effect of the platelets. The inhibitory effect of our mAb was comparable to that of a well-known functional anti-CD9 mAb. These results suggest that the tetraspanin CD9 plays an important role in endothelial regeneration.

• Molecules and Cells
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• v.22 no.2
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• pp.210-219
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• 2006

Dynamin-related protein 2A (AtDRP2A, formally ADL6), a member of the dynamin family, is critical for protein trafficking from the TGN to the central vacuole. However, the mechanism controlling its activity is not well understood in plant cells. We isolated Arabidopsis sec13 homolog1 (AtSeh1) that interacts with AtDRP2A by a yeast two-hybrid screening. AtSeh1 has four WD40 motifs and amino acid sequence homology to Sec13, a component of COPII vesicles. Coimmunoprecipitation and protein pull-down experiments demonstrated specific interaction between AtSeh1 and AtDRP2A. AtSeh1 bound to the pleckstrin homology domain of AtDRP2A in competition with the C-terminal domain of the latter, and this resulted in inhibition of the interaction between AtDRP2A and PtdIns3P in vitro. AtSeh1 localized to multiple locations: the nucleus, the prevacuolar compartment and the Golgi complex. Based on these results we propose that AtSeh1 plays a role in regulating cycling of AtDRP2A between membrane-bound and soluble forms.

• The Journal of Advanced Prosthodontics
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• v.1 no.2
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• pp.91-96
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• 2009

STATEMENT OF PROBLEM. The aim of this study was to study the effects of various surface treatments to a titanium surface on the expression of Runx2 in vitro. MATERIAL AND METHODS. Human Osteosarcoma TE-85 cells were cultured on machined, sandblasted, or anodic oxidized cpTi discs. At various times of incubation, the cells were collected and then processed for the analysis of mRNA expression of Runx2 using reverse transcription-PCR. RESULTS. The expression pattern of Runx2 mRNA was differed according to the types of surface treatment. When the cells were cultured on the untreated control culture plates, the gene expression of Runx2 was not increased during the experiments. In the case of that the cells were cultured on the machined cpTI discs, the expression level was intermediate at the first day, but increased constitutively to day 5. In cells on sandblasted cpTi discs, the expression level was highest in the first day sample and the level was maintained to 5 days. In cells on anodized cpTi discs, the expression level increased rapidly to 3 days, but decreased slightly in the 5-th day sample. CONCLUSION. Different surface treatments may contribute to the regulation of osteoblast function by influencing the level of gene expression of key osteogenic factors.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.88-90
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• 1996

The right and left atrial pressures are important parameters in automatic control of a total artificial heart (TAH) within normal physiological ranges. Our TAH is composed of a moving actuator, right and left ventricles and the interventricular space enclosed by a semi-rigid housing. During operation of the TAH, the jnterventpicular space's volume is changed dynamically by the difference between the ejection volume of one ventricle and the inflow volume of the other. Therefore, the changes in pressure of the interventricular space is related to both atrial pressures. We measured the interventricular pressure (IVP) waveform using a pressure sensor and attempted to indirectly estimate the changes of atrial pressures. This method has an advantage that the sensor does not contact the blood directly. Furthermore, the IVP waveforms have its zero baseline in each pump cycle, thus the pressure measurements are free from the transducer drift problems by measuring the peak pressure from these baseline values. From the In vitro experiments, we found that the IVP waveform contained several useful parameters such as negative peak, dP/dT on the initial break, the area enclosed by the profile in each stroke, which are associated with atrial pressures and the filling conditions of the ventricles. The measured atrial pressures were linearly related to the negative peak of the interventricular pressure.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.6-15
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• 2004

This study was performed to evaluate the hemopoietic effects of 6 species of deer antlers from origins and parts in vitro. CD34 positive cells were isolated and confirmed the its population by FACS analysis. In a week liquid culture, there was any statistical significance between extracts of three parts of six species of deer antlers in the experiments as colony forming assay, proliferation assay, differentiation assay and observation of morphology. However, after 2 weeks- culture with extracts of three parts of six species of deer antlers, colonies were counted. six species of deer antlers, such as middle part of Korean nippon deer, upper part of Chinese nippon deer, upper part of Newzealand horse deer, middle part of Korea horse deer and middle part of Newzealand red deer, significantly increased the CFU-GM (colony forming unit garnulocyte-macrophage) of CD34 positive cells re1atεd to production of leucocytes such as eosinophil, basophil and neutrophil, while only middle part of Korea horse deer significantly increased the BFU-E (burst forming unit-erythroid) at 1 mg/ml seggesting progenting red blood cells (RBC). In the molecular study with CD34+ cells pretreated with cyclophosphamide, antagonist of hemopoietic activity, upper Part of Korean nippon deer and upper part of Chinese nippon deer effectively increased TPO involved in a late pathway of hematopoiesis just like in ELISA assay of IL-3, TPO and GM-CSF. Taken together, these results indicate exσacts of deer antler had some hemopoietic activity still proposing more clinical study and more basic mechanism research.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.1
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• pp.47-54
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• 2019

Estrogen withdrawal in post-menopausal women leads to overactivation of osteoclasts, which contributes to the development of osteoporosis. Inflammatory cytokines are known as one of mechanisms of osteoclast activation after estrogen deficiency. SPA0355 is a thiourea derivative that has been investigated for its antioxidant and anti-inflammatory activities. However, its efficacy in bone resorption has not been previously investigated. The aim of this study was to investigate the impact of SPA0355 on the development of osteoporosis and to explore its mode of action. In vitro experiments showed that SPA0355 inhibited receptor activator of $NF-{\kappa}B$ ligand (RANKL)-induced osteoclastogenesis in primary bone marrow-derived macrophages. This effect appears to be independent of estrogen receptor activation as ICI 180,782 failed to abrogate its effects on osteoclasts. Further signaling studies revealed that SPA0355 suppressed activation of the MAPKs, Akt, and $NF-{\kappa}B$ pathways. SPA0355 also increased osteoblastic differentiation, as evidenced by its effects on alkaline phosphatase activity and mineralization nodule formation. Intraperitoneal administration of SPA0355 to ovariectomized mice prevented bone loss, as verified by three-dimensional images and bone morphometric parameters derived from ${\mu}CT$ analysis. Noticeably, SPA0355 did not show hepatotoxicity and nephrotoxicity and also had little effect on hematological parameters. Taken together, the results indicate that SPA0355 may protect against bone loss in ovariectomized mice by stimulation of osteoblast differentiation and by inhibition of osteoclast resorption. Therefore, SPA0355 is a safe and potential candidate for management of postmenopausal osteoporosis.

• The Korean Journal of Food And Nutrition
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• v.35 no.2
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• pp.116-126
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• 2022

The purpose of this study was to analyze the anti-inflammatory effect of Chung-Dae Indigo Pulverata Levis, indigo naturalis) produced during indigo dyeing. As a result of in vitro cytotoxicity experiments using RAW 264.7 cell, Chung-Dae extract did not inhibit cell proliferation in Raw 264.7 cells in the range of 1~32 ㎍/mL. NO production was significantly reduced when Chung-Dae extracts were treated at concentrations of 2, 8, and 32 ㎍/mL (p<0.05). The pro-inflammatory cytokines TNF-α, IL-6, IL-1β and IFN-γ significantly decreased when the Chung-Dae extract was treated at concentrations of 2, 8, and 32 ㎍/mL compared to the LPS group, and similarly, the TNFα and IL-6 mRNA levels also decreased. Additionally, the mRNA level of COX-2 was also suppressed. At the protein expression level, the expression of TNF-α, IL-6, iNOS and COX-2 were observed with LPS and Chung-Dae extract significantly decreased compared to the group treated with only LPS (p<0.05). From the above results, it shows that Chung-Dae extract, a plant-derived compound, inhibits the inflammatory response induced by LPS in RAW 264.7 cells. and in particular, regulates the inflammatory response by inhibiting the expression of pro-inflammatory cytokines and inflammation-related enzymes.