• Journal of Ginseng Research
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• 제37권4호
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• pp.413-424
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• 2013

Korean Red Ginseng extract (KRGE) is a traditional herbal medicine utilized to prevent endothelium dysfunction in the cardiovascular system; however, its underlying mechanism has not been clearly elucidated. We here examined the pharmacological effect and molecular mechanism of KRGE on apoptosis of human umbilical vein endothelial cells (HUVECs) in a serum-deprived apoptosis model. KRGE protected HUVECs from serum-deprived apoptosis by inhibiting mitochondrial cytochrome c release and caspase-9/-3 activation. This protective effect was significantly higher than that of American ginseng extract. KRGE treatment increased antiapoptotic Bcl-2 and Bcl-$X_L$ protein expression and Akt-dependent Bad phosphorylation. Moreover, KRGE prevented serum deprivation-induced subcellular redistribution of these proteins between the mitochondrion and the cytosol, resulting in suppression of mitochondrial cytochrome c release. In addition, KRGE increased nitric oxide (NO) production via Akt-dependent activation of endothelial NO synthase (eNOS), as well as inhibited caspase-9/-3 activities. These increases were reversed by co-treatment of cells with inhibitors of eNOS and phosphoinositide 3-kinase (PI3K) and pre-incubation of cell lysates in dithiothreitol, indicating KRGE induces NO-mediated caspase modification. Indeed, KRGE inhibited caspase-3 activity via S-nitrosylation. These findings suggest that KRGE prevents serum deprivation-induced HUVEC apoptosis via increased Bcl-2 and Bcl-$X_L$ protein expression, PI3K/Akt-dependent Bad phosphorylation, and eNOS/NO-mediated S-nitrosylation of caspases. The cytoprotective property of KRGE may be valuable for developing new pharmaceutical means that limit endothelial cell death induced during the pathogenesis of vascular diseases.

• BMB Reports
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• 제42권9호
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• pp.561-567
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• 2009

Although many plant-derived phenolic compounds display antioxidant effects in biological systems, their mechanism of action remains controversial. In this study, the mechanism by which p-coumaric acid (p-CA) performs its antioxidant action was investigated in bovine aortic endothelial cells under oxidative stress due to high levels of glucose (HG) and arachidonic acid (AA), a free fatty acid. p-CA prevented lipid peroxidation and cell death due to HG+AA without affecting the production of reactive oxygen species. The antioxidant effect of p-CA was not decreased by buthionine-(S,R)-sulfoximine, an inhibitor of cellular GSH synthesis. In contrast, pretreatment with p-CA caused the induction of peroxidases that decomposed t-butyl hydroperoxide in a p-CA-dependent manner. Furthermore, the antioxidant effect of p-CA was significantly mitigated by methimazole, which was shown to inhibit the catalytic activity of 'p-CA peroxidases' in vitro. Therefore, it is suggested that the induction of these previously unidentified 'p-CA peroxidases' is responsible for the antioxidant effect of p-CA.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.158-164
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• 2012

Inhibiting the bioactivities of circulating endothelial progenitor cells (EPCs) results in significant inhibition of neovessel formation during tumor angiogenesis. To investigate the potential effect of phloroglucinol as an EPC inhibitor, we performed several in vitro functional assays using $CD34^+$ cells isolated from human umbilical cord blood (HUCB). Although a high treatment dose of phloroglucinol did not show any cell toxicity, it specifically induced the cell death of EPCs under serum free conditions through apoptosis. In the EPC colony-forming assay (EPC-CFA), we observed a significant decreased in the small EPC-CFUs for the phloroglucinol group, implying that phloroglucinol inhibited the early stage of EPC commitment. In addition, in the in vitro expansion assay using $CD34^+$ cells, treatment with phloroglucinol was shown to inhibit endothelial lineage commitment, as demonstrated by the decrease in endothelial surface markers of EPCs including $CD34^+$, $CD34^+/CD133^+$, $CD34^+/CD31^+$ and $CD34^+/CXCR4^+$. This is the first report to demonstrate that phloroglucinol can inhibit the functional bioactivities of EPCs, indicating that phloroglucinol may be used as an EPC inhibitor in the development of biosafe anti-tumor drugs that target tumor angiogenesis.

• 대한방사선치료학회지
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• 제14권1호
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• pp.165-174
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• 2002

혈관내피세포 성장 인자(Vascular endothelial growth factor, VEGF)는 혈관내피세포 특이하게 성장요인으로 작용하는 물질로 알려져 있다. 전리방사선에 대한 혈관내피세포의 효과는 정상조직에 대한 반응에 있어 아주 중요한 요소일 것으로 생각된다. 본 연구는 방사선 조사에 의해 배양시킨 혈관내피세포에서 apoptosis가 유도되는지, 유도가 된다면 VEGF에 의해 apoptosis가 억제되는지 그리고 apoptosis의 억제가 어떤 경로를 경유하는지를 실험하였다. 혈관내피세포에 방사선를 조사한 결과, 대조군에 비하여 선량이 증가함에 따라 apoptosis가 증가하였다. 같은 조건하에서 VEGF는 농도 의존적으로 apoptosis를 억제하였다. Antiapoptotic factor로서 VEGF가 어떤 신호 과정을 경유하는지를 밝히고자, 혈관내피세포에 방사선을 조사하여 apoptosis를 유도하면서 Flt-1과 Flk-1/KDR receptor를 처리하였다. 그결과 VEGF에 유도된 apoptosis 억제효과가 차단되었다. Phosphatidylinositol 3'-kinase(PI3-kinase) 특정 억제 물질인 Wortmanin과 LY294002를 방사선 조사한 혈관내피에 VEGF와 함께 처리했을 때 VEGF에 의해 유도된 apoptosis를 억제하였다. 이같은 결과는 VEGF가 방사선 조사로 일어나는 세포 치사를 억제하는 중요한 역할을 담당하며, In Vivo의 실험이 더 이루어져야 할 것으로 생각된다.

• 생명과학회지
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• 제30권7호
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• pp.651-659
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• 2020

허혈성 심혈관질환은 전 세계적으로 치사율이 높은 질병 중 하나이다. 이를 치료하기 위해 수술적 방법이 시행되고 있으나, 손상된 심근조직 회복의 어려움과 수술 후 부작용의 한계가 남아있다. 이러한 한계점을 극복하기 위해, 최근 줄기세포를 기반으로 한 심혈관질환의 세포치료제가 각광받고 있는데 그 중에서도 특히 혈관내피전구세포(EPC)는 높은 증식능과 분화능을 기반으로 손상된 혈관을 재생하고, 주변 조직의 재생을 돕는다는 장점이 있다. 또, EPC는 임상적으로 안전하며, 환자의 심근 기능을 회복시켜주기에 잠재적인 심혈관질환 치료제로서의 가능성이 대두되었다. 하지만, 환자 유래 EPC를 이용한 치료법은, 고령, 흡연 여부, 기저질환 등의 이유로 환자의 EPC 기능이 저하되어 있어, 그 치료 효능을 기대하기 어렵다. 따라서, 최근에는 세포 프라이밍 기법, 오가노이드 배양법과 같이 EPC의 생리학적 활성도를 올리는 체외 배양법의 개발과 3D 바이오프린팅 기법을 이용한 EPC의 이식 효율을 높여 치료 효능을 개선시킬 수 있는 새로운 접근법이 연구되고 있다. 본 연구에서는 EPC의 특징과 세포치료제로서의 임상적용 가능성에 대해 살펴보고자 한다.

• 생명과학회지
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• 제20권6호
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• pp.914-921
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• 2010

항산화 기능과 면역 억제 기능을 갖는 것으로 알려진 melatonin이 혈관 내피층에서는 어떤 기능을 갖는지 알기 위한 일련의 실험을 수행하였다. 본 연구의 실험 결과, 혈관기능과 관련된 혈관내피세포의 성장, 사멸, 이동에 melatonin은 특이적인 효과를 나타내지 않았고, 백혈구의 혈관내피세포 부착과 백혈구 동종간의 응집에도 melatonin의 역할이 관찰되지 않았다. 이와는 대조적으로 melatonin은 PP2A를 통해 eNOS의 활성을 억제하여 산화질소의 양을 감소시키고, 이로 인해 혈관내피세포의 탈착이 유발되는 효과가 있음을 확인할 수 있었다. 종합해보면, 혈액 내 고농도의 melatonin은 PP2A 및 eNOS의 활성을 변화시켜 혈관내피세포의 탈착을 상승시킴으로써 혈관내에서 발생할 수 있는 혈전 형성에 의한 병리적 현상을 유발할 수 있다.

• Preventive Nutrition and Food Science
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• 제18권1호
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• pp.38-44
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• 2013

The protective effect of Polyopes lancifolia extract on high glucose-induced oxidative stress was investigated using human umbilical vein endothelial cells (HUVECs). High concentration of glucose (30 mM) treatment induced HUVECs cell death, but Polyopes lancifolia extract, at concentrations of 25, 50, and $100{\mu}g/mL$, protected cells from high glucose-induced damage. Furthermore, thiobarbituric acid reactive substances, intracellular reactive oxygen species, and nitric oxide levels increased by high glucose treatment were effectively decreased by treatment with Polyopes lancifolia extract in a dose-dependent manner. Also, Polyopes lancifolia extract treatment reduced the overexpressions of inducible nitric oxide synthase, cyclooxygenase-2, and nuclear factor-kappa B proteins activation that was induced by high glucose in HUVECs. These results indicate that Polyopes lancifolia extract is a potential therapeutic material that will reduce the damage caused by high glucose-induced-oxidative stress associated with diabetes.

• BMB Reports
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• 제43권9호
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• pp.584-592
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• 2010

Tetrahydrobiopterin (BH4) is a multifunctional cofactor of aromatic amino acid hydroxylases and nitric oxide synthase (NOS) as well as an intracellular antioxidant in animals. Through regulation of NOS activity BH4 plays a pivotal role not only in a variety of normal cellular functions but also in the pathogenesis of cardiovascular and neurodegenerative diseases, which develop under oxidative stress conditions. It appears that a balanced interplay between BH4 and NOS is crucial for cellular fate. If cellular BH4 homeostasis maintained by BH4 synthesis and regeneration fails to cope with increased oxidative stress, NOS is uncoupled to generate superoxide rather than NO and, in turn, exacerbates impaired BH4 homeostasis, thereby leading to cell death. The fundamental biochemical events involved in the BH4-NOS interplay are essentially the same, as revealed in mammalian endothelial, cardiac, and neuronal cells. This review summarizes information on the cellular BH4 homeostasis in mammals, focusing on its regulation under normal and oxidative stress conditions.

• 동의생리병리학회지
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• 제25권1호
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• pp.71-77
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• 2011

Gastric ulcer has multifactorial etiology, and the development of ulcer is known to be caused by gastric acidity, pepsin secretion, gastric motility and gastric mucosal blood flow. The ulcer results from the tissue necrosis and apoptotic cell death triggered by mucosal ischemia, free radical formation and cessation of nutrient delivery. The gastric mucosa is usually exposed to a wide range of aggressive insults, and has developed efficient mechanisms to repair tissue injury. The apoptotic process of gastric mucosa is triggered by the induction of such proapoptotic gene expression, such as BAX. The Bcl-2 family of proteins plays a pivotal role in the regulation of apoptosis. The maintenance of gastric mucosa integrity depends upon the ratio between cell proliferation and cell death. Stress-inducing factors may affect Bcl-2/BAX ratio and thus the rate of apoptosis through modulation of the expression of both proteins depends upon the experimental model. In addition to the regulation of apoptosis, new vessels have to be generated in order to ensure an adequate supply of oxygen and nutrients to the healing gastric mucosa. This events are regulated by several factors. Among them, such polypeptide growth factors, such as vascular endothelial growth factor (VEGF) regulates essential cell functions involved in tissue healing including cell proliferation and differentiation. The purpose of this study was carried to investigate whether Rhei Rhizoma administration might protect apoptotic cell death and promote angiogenesis in gastric mucosa. Sprague-Dawley rats were randomly divided into 4 groups; normal, saline, cimetidine and Rhei Rhizoma-treated group. The saline, cimetidine and Rhei Rhizoma extracts were orally administrated to each group and gastric ulcer was induced by HCl-EtOH solution. After 1 hour, the stomachs were collected for histological observation and immunohistochemistry. In results, Rhei Rhizoma proves to promote to heal wound in gastric ulcer in conclusion and the significant changes of BAX, Bcl-2 and VEGF quantity in gastric mucosa were observed. These results suggest that Rhei Rhizoma extract may promote incision wound healing and has protective effects on gastric ulcer in rats.

• 생명과학회지
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• 제23권7호
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• pp.926-932
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• 2013

글루타민과 혈청은 세포의 생존과 증식에 기본적으로 요구되지만, 그들의 양적 변화에 따른 내피세포 반응에 관한 신호전달 관련 연구는 거의 이루어지지 않았다. 본 연구에서는 인체 재대정맥 내피세포(human umbilical vein endothelial cells, HUVECs)의 증식에 미치는 글루타민과 혈청의 결핍에 관한 영향을 조사하였다. 본 연구의 결과에 의하면 글루타민 및 혈청이 결핍된 조건에서 배양된 HUVECs의 증식 억제는 apoptosis 유발과 연관성이 있었음을 DAPI staining에 의한 핵의 형태 변화와 유세포 분석을 통하여 확인하였다. 비록 혈청이 결핍된 조건보다 글루타민 결핍에 의한 apoptosis 유발 정도가 더 높게 나타났으나, 두 현상에 의한 apoptosis의 유발은 anti-apoptotic Bcl-2 및 Bcl-xL의 발현 저하와 pro-apoptotic Bax의 발현 증가, IAP family 단백질의 발현 감소, caspase의 활성 증가에 따른 PARP 단백질의 단편화와 연관성이 있었다. 또한 이러한 조건에서 HUVECs의 Bid 발현의 감소 또는 tBid 발현의 증가 현상이 관찰되어, 글루타민 또는 혈청 결핍에 의한 HUVECs의 apoptosis 유발은 세포막 수용체 및 미토콘드리아 활성 경로를 동시에 통하여 이루어지고 있음을 알 수 있었다. 그러나 글루타민과 혈청이 동시에 결핍된 조건에서 배양된 HUVECs의 증식 억제 현상은 각각의 조건에 비하여 증가되었으나 apoptosis는 유발되지 않았다.