Integrin alphavbeta3 is not significantly implicated in the anti-migratory effect of anti-angiogenic urokinase kringle domain.

O, Eunju,Kim, Hyun-Kyung,Hong, Sung Hee,Kim, Chung Kwon,Hong, Yong-Kil,Joe, Young Ae National Hellenic Research Foundation 2008 Oncology reports Vol.20 No.3

<P>The recombinant kringle domain (UK1) of urokinase-type plasminogen activator (uPA) has been shown to possess anti-angiogenic activity in vitro and in vivo. It has also been found to inhibit in vivo malignant glioma growth. In contrast, direct interaction of the kringle domain of uPA and integrin alphavbeta3 has been reported to be involved in plasminogen and leukocyte activation by uPA. Since integrin alphavbeta3 is involved in tumor angiogenesis, we investigated whether integrin alphavbeta3 is involved in the inhibitory function of UK1 in angiogenesis, by examining its anti-migratory activity. In a modified Boyden chamber assay, the Pichia-expressed UK1 dose-dependently inhibited the VEGF-induced migration of human umbilical vein endothelial cells (HUVECs). However, in the absence of growth factor stimulation, soluble UK1 alone did not induce or inhibit HUVEC migration. In cell adhesion, immobilized UK1 promoted HUVEC adhesion and spreading which were compared to BSA. Pretreatment of the anti-alphavbeta3 integrin antibody, significantly inhibited HUVEC binding to immobilized UK1, whereas neither anti-alpha2beta1 nor anti-alpha5beta1 integrin antibody had any effect, although pre-treatment of the soluble UK1 showed no marked alteration of the binding level of anti-alphavbeta3 antibody to HUVECs in FACS analysis. In a modified Boyden chamber assay, the function blocking antibodies against integrins alphavbeta3, alpha2beta1 and alpha5beta1 did not completely prevent the inhibitory effect of UK1 in HUVEC migration. These results suggest that UK1 interacts with integrin alphavbeta3, but its anti-migratory activity on endothelial cells is not significantly mediated by integrin alphavbeta3.</P>

Efficient nonadhesive <i>ex vivo</i> expansion of early endothelial progenitor cells derived from CD34 ⁺ human cord blood fraction for effective therapeutic vascularization

O, Eunju,Lee, Byung Hun,Ahn, Hyun‐,Young,Shin, Jong‐,Chul,Kim, Hyun‐,Kyung,Kim, Myungshin,Park, In‐,Yang,Park, Yong‐,Gyu,Joe, Young Ae Federation of American Society for Experimental Bi 2011 The FASEB Journal Vol.25 No.1

<P>Endothelial progenitor cells (EPCs) have been shown to have therapeutic potential in ischemic disease. However, the number of EPCs for cell therapy is limited. In this study, instead of the typical adherent culture method, we investigated a more efficient, clinically applicable nonadhesive expansion method for early EPCs using cord blood-derived cells to overcome rapid cellular senescence. After a suspension culture of isolated CD34(+) cells in serum-free medium containing each cytokine combination was maintained for 9 d, the number of expanded functional EPCs was assessed by an adherent culture assay. Compared to mononuclear cells, the CD34(+) fraction was superior in its expansion of functional EPCs that could differentiate into acLDL/UEA-1(+) cells without significant cellular senescence, whereas the CD34(-) fraction showed no EPC expansion. Among the cytokine combinations tested for the CD34(+) fraction, a combination (SFIb) consisting of stem cell factor (SCF), FMS-like tyrosine kinase 3 ligand, interleukin-3, and basic fibroblast growth factor resulted in a reproducible 64- to 1468-fold EPC expansion from various cord blood origins. Interestingly, the SFIb combination displayed markedly increased EPC expansion (2.43-fold), with a higher percentage of CD34(+) cells (2.17-fold), undifferentiated blasts (2.38-fold) and CXCR4(+) cells (1.68-fold) compared to another cytokine combination (SCF, thrombopoietin, and granulocyte colony-stimulating factor), although the two cytokine combinations had a similar level of total mononucleated cell expansion ( 10% difference). Accordingly, the cells expanded in the SFIb combination were more effective in recovery of blood flow and neovascularization in hind-limb ischemia in vivo. Taken together, these results suggest that the nonadhesive serum-free culture conditions of the CD34(+) fraction provide an effective EPC expansion method for cell therapy, and an expansion condition leading to high percentages of CD34(+) cells and blasts is likely important in EPC expansion.</P>

아귀 추출물의 항산화 및 항유전독성 활성

이석희(Suck?Hee Lee),신진화(Jin?Hwa Shin),구명오(Myoung?O Koo),정은실(Eun?Sil Jung),전경임(Geong?Im Jeon),박은주(Eunju Park),박해룡(Hae?Ryong Park),이승철(Seung?Cheol Lee) 한국식품영양과학회 2007 한국식품영양과학회지 Vol.36 No.10

생 아귀와 마른 아귀를 부위별로 구분하여 여러 용매를 이용하여 추출물을 제조한 후 항산화 활성과 항유전독성 활성을 조사하였다. 아귀의 수분함량을 조사한 결과 생 아귀의 껍질, 살, 위 부분은 모두 85% 이상의 수분을 함유하였으나, 간은 53.5%이었다. 마른 아귀의 경우 껍질 부위가 생것의 경우보다 21.2%가 낮은 66.7%이었고, 살 부위는 생것의 경우보다 7.9% 낮은 77.7%이었다. 추출수율은 마른 아귀 껍질분쇄물 100 g으로부터 물을 이용하여 추출하였을 때 6.76 g의 추출물이 얻어진 경우로 이 조건이 가장 수율이 높았다. 항산화 활성을 1, 20, 40 ㎎/mL의 농도에서 측정하였을 때 라디칼 소거능, 환원력은 각각 농도에 의존하여 결과값이 향상되었으며, 라디칼 소거능에서는 생 아귀의 껍질, 살 및 위 부분과 말린 아귀의 껍질, 살에서는 모두 아세톤 추출물에서 가장 높은 활성을 보였다. 한편, 생 아귀의 간부위에서는 메탄올 추출물과 물 추출물에서 높은 활성을 보였고, 에탄올과 아세톤 추출물에서도 비교적 높은 활성을 보였다. 환원력에서는 껍질, 살 및 위 부분에서 아세톤 추출물에서 가장 높은 활성을 보였다. 생 아귀의 간부위에서는 모든 추출물에서 높은 환원력을 보였다. 그리고 다양한 아귀 추출물을 50 ㎍/mL의 농도로 백혈구에 처리한 후 H₂O₂ 200 ㎛의 농도로 DNA 손상을 유도한 결과 손상된 DNA tail 부분의 DNA 함량을 측정한 % fluorescence in tail이 위의 메탄올, 아세톤 및 물 추출물을 제외하고는 각 부위의 모든 추출물에서 H₂O₂ 처리 양성대조구인 32.1±6.7%에 비해 유의적으로 감소하였다. 한편, 추출용매별로 아귀 각 부위의 항유전독성 효과를 비교한 결과 메탄올, 에탄올, 물 추출물은 부위에 따른 항유전독성효과의 차이가 없었으나, 아세톤 추출물의 경우 마른 살이 위에 비해 DNA 손상정도가 유의적으로 낮았다. 따라서 이번 연구결과는 생리활성 물질을 탐색함에 있어서 해양생물이 중요한 천연자원이 될 수 있다는 가능성을 확인할 수 있었다. Antioxidant activities of extracts from anglerfish (Lophiius litulon) were evaluated. Each part of fresh (skin, flesh, stomach, and liver) or dried (skin and flesh) anglerfish was extracted by four different solvents (methanol, ethanol, acetone, and distilled water). Antioxidant activities of the extracts were determined by radical scavenging activity (RSA) and reducing power (RP). Relatively higher RSA and RP were found in methanol and water extract of fresh anglerfish liver. Antigenotoxic effect of the extracts, which was measured by Comet assay, was shown in most of the extracts except methanol, acetone and distilled water extracts of fresh stomach sample. These results indicated that antioxidant and antigenotoxic properties of extracts from angler fish were variable depending on parts, solvent, and/or physicochemical state. The appropriate extraction process could provide some valuable bioactive materials from anglerfish.

상류 분사 공동 화염 지지부를 가지는 스크램제트 엔진에 관한 실험적 연구

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byrne,A.F.P. Houwing 한국연소학회 2006 한국연소학회지 Vol.11 No.4

The model cavity scramjet engine experiments are carried out using T3 free-piston shock tunnel. Upstream hydrogen fuel is injected before the cavity with different injection pressure. OH planar laser-induced fluorescence is used to investigate the combustion zone and piezoelectric pressure transducers are used to define the pressure rise due to the combustion. Main combustion region is a mixing layer which is between air and fuel. Also high OH fluorescence signal is appeared in the shear layer above the cavity in high equivalence ratio. From the OH signal in the cavity, this fuel injection system can be a role as a flame-holder.

스크램제트 엔진 내 후퇴각 공동의 주파수 특성 분석

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byme,A.F.P. Houwing,강상훈(Sang-Hun Kang),양수석(Soo-Seok Yang) 한국추진공학회 2007 한국추진공학회 학술대회논문집 Vol.2007 No.11

공동 상류 경사 분사를 이용한 초음속 연소기의 실험적 연구, Part 2 : 압력 측정

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O’Byrne,A.F.P Houwing 한국연소학회 2007 한국연소학회지 Vol.12 No.1

The supersonic combustion experiments are carried out using T3 free-piston shock tunnel. Different shock tube fill pressures have various inflow conditions. 15˚ inclined hydrogen fuel injection is located before the cavity. Oblique shock is generated at the trailing edge of the cavity and reflects off the top and bottom wall. For non-reacting flow, static pressures in low equivalence ratio are similar to those in no fuel injection. As equivalence ratio is increased, static pressures are increased in the duct. In the similar equivalence ratio, static pressures are increased when total enthalpy is decreased. For reacting flow, the flame is occurred near the cavity. The combustion is weak locally in the middle of the duct. The up and down pressure distribution in the duct means that the supersonic combustion is generated.

상류 분사 공동 화염 지지부를 가지는 스크램제트 엔진에 관한 실험적 연구

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byrne,A.F.P. Houwing 한국연소학회 2006 KOSCOSYMPOSIUM논문집 Vol.- No.-

The model cavity scramjet engine experiments are carried out using T3 free-piston shock tunnel. Upstream hydrogen fuel is injected before the cavity with different injection pressure. OH planar laser-induced fluorescence is used to investigate the combustion zone and piezoelectric pressure transducers are used to define the pressure rise due to the combustion. Main combustion region is a mixing layer which is between air and fuel. Also high OH fluorescence signal is appeared in the shear layer above the cavity in high equivalence ratio. From the OH signal in the cavity, this fuel injection system can be a role as a flame-holder.

초음속 유입 유동 조건에 따른 공동을 포함한 덕트 내 초음속 연소 현상에 관한 실험적 연구

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byrne,A.F.P Houwing 한국연소학회 2006 KOSCOSYMPOSIUM논문집 Vol.- No.-

The supersonic combustion experiments are carried out using T3 free-piston shock tunnel. Different shock tube fill pressures have various inflow conditions. 15° inclined hydrogen fuel injection is located before the cavity. Oblique shock is generated at the trailing edge of the cavity and reflects off the top and bottom wall. For non-reacting flow, static pressures in low equivalence ratio are similar to those in no fuel injection. As equivalence ratio is increased, static pressures are increased in the duct. In the similar equivalence ratio, static pressures are increased when total enthalpy is decreased. For reacting flow, the flame is occurred near the cavity. The combustion is weak locally in the middle of the duct. The up and down pressure distribution in the duct means that the supersonic combustion is generated.

마하 4 유동장 내 연료 분사 위치에 따른 초음속 연소 현상 연구

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byrne,A.F.P. Houwing 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-

Supersonic combustion experiments have been performed using three different hydrogen-fuel injection configurations in a cavity-based combustor at three combustor-entrance flow conditions. Angled injection is located upstream of the cavity with 15° angle, parallel injection is positioned on the front step, and upstream injection is on the rear ramp. Planar laser-induced fluorescence of the hydroxyl radical is used to investigate the flow characteristics. Angled injection generates a weak bow shock in front of the injector and recirculation zone to maintain the combustion as the equivalence ratio increases. Parallel and upstream injection tests show similar flame structure over the cavity at low equivalence ratio. Upstream injection enhances the fuel diffusion arid enables ignition with a shorter delay length than with parallel injection. The presence of a flame near the cavity is sensitive to the fuel injection location, the equivalence ratio and total enthalpy of the air flow. The flame characteristics agree with the correlation plot of the stable flame limit of non-premixed conditions.

공동 내부로의 평행분사방법을 이용한 초음속 연소의 실험적 연구

정은주(Eunju Jeong),정인석(In-Seuck Jeung),Sean O"Byrne,A.F.P Houwing 한국연소학회 2007 KOSCOSYMPOSIUM논문집 Vol.- No.-

The supersonic combustion experiments are carried out using T3 free-piston shock tunnel. Hydrogen Fuel is injected in the cavity parallel with air(or nitrogen fuel) flow. The equivalence ratios in this study are 0.132 and 0.447. Experimental measurements use OH-PLIF near the cavity and pressures in the combustor. For parallel fuel injection case, direct fuel add into cavity leads to increase of cavity pressure. And Flame exists just near the bottom wall for low equivalent ratio. There is no flame in the cavity because of no mixing in it. Compared to the inclined fuel injection, ignition delay length is longer for low equivalence ratio in both case. OH distribution is not a single line but a repeatable fluctuation flame structure by turbulence. Pressure distributions have nothing to do with the fuel injection position.