• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.323-328
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• 2017

Angiogenesis is a process including members of the angiogenic factors. In particular, fibroblast growth factor 2 (FGF2) is considered the most potent angiogenic factor because it promotes cell proliferation and tube formation. A recent study reported that fucoidan derived from marine plant potentiated FGF-2 induced tube formation in human endothelial cells. On the other hand, the molecular mechanisms involved in the angiogenic activity of fucoidan and FGF2 are unknown. In this study, a fucoidan treatment promoted angiogenesis induced by FGF2. The effects of fucoidan on FGF2-induced angiogenesis were confirmed by a proliferation assay using a CellTiter96 Aqueous One solution after a treatment with fucoidan and FGF2. The tube formation and wound healing assay for the angiogenic activity were also confirmed. Reverse transcription PCR showed a change in the mRNA of vascular endothelial growth factor-A (VEGF-A), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase9 (MMP9), and the signal transducer and activator of transcription3 (STAT3). In summary, the Fucoidan/FGF2 treatment induced an increase in cell proliferation, improved the tube formation and wound healing activity, and altered the STAT3, VEGF-A, ICAM-1, and MMP9 mRNA expression levels. Further research will be needed to provide a scientific explanation in terms of cell-signaling and confirm the present findings.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.588-596
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• 2009

Background: To clarify the effect of hypoxia on vascular contractility, we tried to show whether hypoxia induced the release of endothelium-derived relaxing factor (EDRF) and the nature of the underlying mechanism for this release. Material and Method: Isometric contractions were observed in rabbit aorta, and the released EDRF from the rabbit aorta was bioassayed by using rabbit denuded carotid artery. The intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) in the cultured rabbit aortic endothelial cells was recorded by a microfluorimeter with using Fura-2/AM. Hypoxia was evoked to the blood vessels or endothelial cells by eliminating the $O_2$ in the aerating gases in the external solution. Chemical hypoxia was evoked by applying deoxyglucose or $CN^-$. Result: Hypoxia relaxed the precontracted rabbit thoracic aorta that had its endothelium, and the magnitude of the relaxation was gradually increased by repetitive bouts of hypoxia. In contrast, hypoxia-induced relaxation was not evoked in the aorta that was denuded of endothelium. In a bioassay experiment, hypoxia released endothelium-derived relaxing factor (EDRF) and the release was inhibited by L-NAME or the $K^+$ channel blocker tetraethylammonium (TEA). In the cultured endothelial cells, hypoxia augmented the ATP-induced increase of the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) and this increase was inhibited by TEA. Furthermore, chemical hypoxia also increased the $Ca^{2+}$ influx. Conclusion: From these results, it can be concluded that hypoxia might induce the release of NO from rabbit aortic endothelial cells by increasing $[[Ca^{2+}]_i$.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.249-249
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• 1994

PAF (Platelet-activating factor: 혈소판 활성화인자)는 1972년 Benveniste등에 의해 토끼의 호중구 배양 상청액중에서 발견되어 1979년 그 구조가 1-alkyl-2-acethyl-sn glycero-3-phosphocholine의 구조를 갖는 에테르형 인 지질임이 밝혀졌다. 그후 혈소판 이외 과립구, 단구나 macrophage, 혈관내피세포등 조직의 염증담당세포가 다양한 자극에 응하여 PAF를 생성됨이 보고되었다. PAF가 나타내는 대표적 활성으로는 혈소판, 호중구, 단구들의 활성화, 호중구의 유주 활성, 혈관투과성 항진, 혈압강하작용. 기관지 수축 등이 알려졌으며. 또한 염증, 알러지, 천식 endotoxin shock 등 여러질병에 직·간접적으로 관여함이 알려졌다. 이와같은 여러 생리 현상은 PAF의 특이적수용체를 개재하여 일어난다는 것이 밝혀졌다. 따라서 PAF의 다양한 질병의 관여가 밝혀짐으로서, PAF길항제의 개발이 활발히 진행되어왔다. 지금까지 PAF길항제의 개발은 PAF 구조 유사체. benzodiazepam유도체, thiazole유도체 등과 같은 합성품과 ginkolide, kadsurenone과 같은 천연물 유리의 것이 알려져 in vivo model에서도 그 효능이 확인되었다. 본 연구는 이와 같은 배경에서 20여 종의 생약에서 PAF 길항제를 검색하던 중 5종류의 생약에서 PAF 길항작용을 갖는 분획을 찾았기에 이에 보고한다.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.887-893
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• 2003

External stimuli increases intracellular (IC) $Ca^{2+}$, which increases extracellular (EC) $K^{+}$. To verify $K^{+}$ effects on the vascular contraction, we performed an experiment using mouse aortic endothelial cell. Meterial and Method: We examined the mouse aortic contractility changes as we measured the IC $Ca^{2+}$ change and ionic current by using the voltage clamp technique under different conditions such as: increasing EC $K^{+}$, removing endothelial cell, giving L-NAME (N-nitro-L-arginine methyl ester) which suppress nitric oxide formation, Ouabain which control N $a^{+}$ - $K^{+}$ pump and N $i^{2+}$ which repress N $a^{+}$-C $a^{2+}$ exchanger Result: When we increased EC $K^{+}$ from 6 to 12 mM, there was no change in aortic contractility. Aorta contracted with more than 12 mM of EC $K^{+}$. Ace-tylcholine (ACh) induced relaxation was inhibited with EC $K^{+}$ from 6 to 12 mM, but was not found after de-endothelialization or L-NAME treatment. ATP or ACh increased IC $Ca^{2+}$ in cultured endothelium. After maximal increase of IC $Ca^{2+}$, increasing EC $K^{+}$ from 6 to 12 mM made IC $Ca^{2+}$ decrease and re-decreasing EC $K^{+}$ to 6 mM made IC $Ca^{2+}$ increase. Ouabain and N $i^{2+}$ masked the inhibitory effect of endothelium dependent relaxation by increased EC $K^{+}$. Conclusion: These data indicate that increase in EC $K^{+}$ relaxes vascular smooth muscle and reduces $Ca^{2+}$ in the endothelial cells which inhibit endothelium dependent relaxation. This inhibitory mechanism may be due to the activation of N $a^{+}$- $K^{+}$ pump and N $a^{+}$-C $a^{2+}$ exchanger. $a^{+}$-C $a^{2+}$ exchanger.r.

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.135-142
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• 2004

Objectives: The purpose of this study was to evaluate for prognostic significance of VEGF expression and tumor angiogenesis in papillary carcinomas of the thyroid. Materials and Methods: The materials were 79 cases of papillary thyroid carcinomas, and age, sex, tumor size, multiplicity of tumor, capsular invasion, lymph node metastasis, recurrence, TNM stage, DeGroot stage and AMES scale were evaluated. An immunohistochemical stains for CD 34 to estimate microvessel density (MVD), and VEGF were done. MVD was defined as an average count of vessels per ${\times}400$ power field in the most vascularized area. VEGF expression was interpreted as 1+ and 2+ according to staining intensity and percentages of positive cells. Results: Mean score of MVD was $39.7{\pm}16.9.$ MVD were significantly higher in cases with capsular invasion (p=0.0001), lymph node metastasis (p=0.0001), TNM stage III (p=0.0022), DeGroot stage III (p=0.0163) and high risk group by AMES scale (p=0.0001). VEGF 2+ expression rate was significantly increased in cases with capsular invasion and lymph node metastasis (p=0.0006, p=0.0013), and in cases with TNM stage III, DeGroot stage III and high risk group by AMES scale (p=0.0236, p=0.0003, p=0.0293). In VEGF 2 + expression group, MVD was significantly higher than in VEGF 1 + group (p=0.0008), and MVD showed positive relation to VEGF 2 + expression (r=0.4616). Conclusion: VEGF expression and high MVD were significantly correlated to capsular invasion, lymph node metastasis, TNM stage III, DeGroot stage III and high risk group by AMES scale. The expression of VEGF and high MVD could be considered to be one of prognostic factor in papillary thyroid carcinomas.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.691-701
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• 2004

Background: Tissue hypoxia is a characteristic of many human malignant neoplasms, and hypoxia inducible factor-1 (HIF-1) plays a pivotal role in essential adaptive response to hypoxia, and activates a signal pathway for the expression of the hypoxia-regulated genes, resulting in increased oxygen delivery or facilitating metabolic adaptation to hypoxia. Increased level of HIF-1 a has been reported in many human malignancies, but in esophageal squamous cell carcinoma, the influence of HIF-1 a on tumor biology, including neovascularization, is not still defined. Material and Method: The influence of HIF-1 a expression on angiogenic factors, correlation between the tumor proliferation and HIF-1 a expression, interaction of HIF-1 a expression and p53, and correlation between HIF-1 a expression and clinicopathological prognostic parameters were investigated, using immunohistochemical stains for HIF-1 a, VEGF, CD34, p53, and Ki-67 on 77 cases of resected esophageal squamous cell carcinoma. Result: HIF-1 a expression in cancer cells was found in 33 of 77 esophageal squamous cell carcinoma cases. The 33 cases (42.9%) showed positive stain for HIF-1 a. High HIF-1 a expression was significantly associated with several pathological parameters, such as histologic grade (p=0.032), pathological TMN stage (p=0.002), the depth of tumor invasion (p=0.022), regional lymph node metastasis (p=0.002), distant metastasis (p=0.049), and lymphatic invasion (p=0.004). High HIF-1 a expression had significant VEGF immunoreactivity (p=0.008) and Ki-67 labeling index (p<0.001), but was not correlated with microvascular density within tumors (p=0.088). The high HIF-1 a expression was correlated with aberrant p53 accumulation with a marginal significance (p=0.056). The overall 5-year survival rate was 34.9%. The survival rate of patients with a high HIF-1 a expression was worse than that of patients with low-expression tumors (log-rank test, p=0.0001). High HIF-1 a expression was independent unfavorable factors although statistical significance is marginal in multivariate analysis. Conclusion: It is suggested that (1) high HIF-1 a expression in esophageal squamous cell carcinoma is associated with tumor hypoxia, or with genetic alteration in early carcinogenesis and progressive stages, (2) high HIF-1 a expression may be associated with intratumoral neovascularization through HIF-VEGF pathway, and (3) high HIF-1 a expression is associated with poor prognosis in patients with esophageal squamous cell carcinoma and may playa role as biomarker for regional lymph node metastasis.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.375-383
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• 2014

This study aimed to investigate the effects of 50% ethanol extract of ripe black raspberry (Rubus occidentalis, RBR) on hypertension in human umbilical vein endothelial cells (HUVECs) and in spontaneously hypertensive rats (SHR). Angiotensin converting enzyme (ACE) inhibition and activation of nitric oxide production by endothelial nitric oxide synthase were significantly regulated by RBR in HUVEC cells. Moreover, the SHR showed significantly higher levels of blood pressure, ACE, renin, endothelin-1, and interleukin-6 than Wistar Kyoto rats (WKY). However, treatment with captopril and RBR decreased the levels of these hypertension-related events in the SHR. The renal arteriole showed greater media thickness/lumen diameter (%) in the SHR than in the WKY. However, media thickness/lumen diameter (%) was reduced in SHR by treatment with captopril and RBR. In addition, the number of eosinophilic cardiac muscle cells was decreased in the heart muscles after treatment with captopril and RBR. Therefore, this study suggests that 50% ethanol extract of RBR may be useful for the prevention and treatment of high blood pressure.

• Journal of Life Science
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• v.23 no.6
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• pp.743-750
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• 2013

The aim of this study is to develop a supplementary therapeutic agent capable of promoting vascular circulation. The effects of Acai berry ethanolic extracts (ABEE) on activity of angiotensin converting enzyme from rabbit lung, production of nitro oxide in both murine macrophage cells and vascular endothelial cells as well as antioxidant effects were investigated in this study. First of all, it was observed the direct effects of ABEE on reducing power and antioxidant effect lipid peroxidation. In addition, ABEE showed a protective effect on DNA oxidation induced by hydroxyl radical. Furthermore, ABEE at 0.01% exerted approximately 50% inhibition on activity of angiotensin converting enzyme. ABEE increased the production of nitric oxide in endothelial cells, but decreased the induction of nitric oxide stimulated by lipopolysaccharide in microphage. The expression levels of superoxide dismutase (SOD)-2 and -3 were enhanced by ABEE treatment, however, the expression level of SOD-1 remained constant. Moreover, the expression level of nitric oxide synthases-1 (NOS-1), a constitutive enzyme, was increased by ABEE, but that of NOS-2, a inducible enzyme, was constant. It was also found that the level of Nrf-2, a transcription factor of SOD, was increased by ABEE. Therefore, these results demonstrate that ABEE could promote blood circulation via above actions, suggesting that may be helpful for health of blood vessel.

• Journal of Life Science
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• v.18 no.12
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• pp.1651-1656
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• 2008

Redox factor-1 (Ref-1) is essential for repair of oxidatively damaged DNA and also govern the reductive activation of many transcription factors. In this study, we examined the effect of overexpressed Ref-1 on AKT activation for nitric oxide (NO) production in mouse aortic endothelial (MAE) cells. Adenoviral-mediated overexpression of Ref-1 enhanced NO production in unstimulated- as well as bradykinin-stimulated MAE cells. Importantly, forced overexpression of Ref-1 induced direct phosphorylation of AKT in cells. And, a PI3K inhibitor wortmannin completely abolished the increase in AKT phosphorylation by stimulation of bradykinin and/or overexpressed Ref-1. In addition, inhibition of AKT activity with HA-tagged activation-deficient AKT suppressed Ref-1-induced endothelial NO synthase (eNOS) phosphorylation and resulted in a corresponding inhibition of unstimulated- and bradykinin-stimulated NO production. These results suggest that Ref-1 stimulates direct phosphorylation of AKT for eNOS enzyme activity in murine endothelial cells.

• 한국체육학회지인문사회과학편
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• v.51 no.3
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• pp.363-372
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• 2012

One of the major ocular complications of diabetes mellitus(DM) is retinopathy, which is characterized by increased neovascularization and neural degeneration in the retina. In the present study, we investigated the effects of treadmill exercise on retinopathy in the rats with DM. Thirty-two male Sprague-Dawley rats were divided into four groups(n = 8 in each group): control group, exercise group, DM-induction group, and DM-induction and exercise group. DM was induced by intraperitoneal injection of streptozotocin. The rats in the exercise groups were made to run on the treadmill for 30 min five times per a week, during 12 weeks. The expressions of phosphoinositide 3-kinase(PI3K), phospho-protein kinase B(pAkt), hypoxia inducible factor-1α(HIF-1α), and vascular endothelial growth factor(VEGF) in the retina were determined using western blot analysis and immunohistochemistry. In the present results, the expressions of PI3K, pAkt, HIF-1α, and VEGF in the retina of the diabetic rats were increased. Treadmill exercise suppressed HIF-1α and VEGF expressions through inhibition of PI3K/pAkt pathway in the diabetic rats. These results suggest that treadmill exercise may ameliorate the progression of diabetes-induced retinopathy by inhibiting neovascularization in the retina.