• Applied Microscopy
• /
• 제44권3호
• /
• pp.88-95
• /
• 2014

This study examined the effects of quercetin on corneal opacity caused by corneal edema by suppressing the damage on corneal endothelial cell, which was induced by mitomycin-C (MMC). In the MMC-treated group, the number of keratocytes was noticeably fewer compared to that of other groups. Although this group showed normal amount of fiber in the corneal stroma, the thickness was shown to be very thick and the alignment of the corneal endothelial cells that worked as the barrier against aqueous humor was irregular. According to such results, it was known that corneal opacity induced by MMC is not caused by proliferation of keratocytes, but by corneal edema triggered by the infiltration of aqueous humor. In the MMC+quercetin and quercetin+MMC-treated groups, the number of keratocytes was higher and polymorphonuclear leukocytes infilteration was lower significantly compared to that of the MMC-treated group. Although the amounts of fiber and endothelioid cell arrangement were normal, there was more space observed in the corneal stroma. Nonetheless, these groups showed significantly lower stromal thickness compared to that of the MMC group. In conclusion, quercetin has the effect on the reduction of corneal opacity caused by corneal edema that work MMC-induced damage to the corneal endothelial cells.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.274.2-274.2
• /
• 2013

We described a simple and efficient fabrication method for generating microfluidic channels with a circular-cross sectional geometry by exploiting the reflow phenomenon of a thick positive photoresist. Initial rectangular shaped positive photoresist micropatterns on a silicon wafer, which were fabricated by a conventional photolithography process, were converted into a half-circular shape by tuning the temperature to around $105^{\circ}C$. Through optimization of the reflow conditions, we could obtain a perfect circular micropattern of the positive photoresist, and control the diameter in a range from 100 to 400 ${\mu}m$. The resultant convex half-circular photoresist was used as a template for fabricating a concave polydimethylsiloxane (PDMS) through a replica molding process, and a circular PDMS microchannel was produced by bonding two half-circular PDMS layers. A variety of channel dimensions and patterns can be easily prepared, including straight, S-curve, X-, Y-, and T-shapes to mimic an in vivo vascular network. To inform an endothelial cell layer, we cultured primary human umbilical vein endothelial cells (HUVECs) inside circular PDMS microchannels, and demonstrated successful cell adhesion, proliferation, and alignment along the channel.

• Journal of Korean Neurosurgical Society
• /
• 제30권6호
• /
• pp.683-687
• /
• 2001

Objective : Angiogenesis, the proliferation of capillary endothelial cells, is a vital component in the development, progression, and metastasis of many human tumors. Vascular endothelial growth factor(VEGF) is an endothelial cell-specific mitogen and induces angiogenesis and vascular permeability. The features of glioblastoma, distinct from low grade astrocytomas, are the presence of necroses and vascular endothelial proliferation. In this study, we investigated VEGF expression in the different grades of astrocytomas and determined whether VEGF expression correlates with development of glioblastoma and progression of astrocytomas. Patients and Methods : Forty seven patients with astrocytic tumors(24 males and 23 females), aged 3 to 65 years, were evaluated. Immunohistochemical staining was carried out using labelled streptavidin biotin method and primary antibody was a antirabbit polyclonal Ab against N-terminus region of VEGF165(Oncogene research product, MA, USA). Immunoreactivity(IR) was classified into no IR(absent or a trace of stain), moderate IR and intense IR by level of staining amount and intensity. Results : Six pilocytic astrocytomas showed 3 no IR and 3 moderate IR, 10 astrocytomas showed 2 no IR, 6 moderate IR and 2 intense IR, 12 anaplastic astrocytomas showed I no IR, 7 moderate IR and 4 intense IR and 19 glioblastomas showed 1 no IR, 11 moderate IR and 7 intense IR. Immunoreactivity was significantly different between low and high grade of tumors but there was no significant difference between anaplastic astrocytomas and glioblastomas. Gemistocytic tumor cells represented the predominent VEGF-immunoreactive cell types, as compared with compactly-arranged small tumor cells. In glioblastomas VEGF IR was observed in both perinecrotic and vital tumor areas. Conclusion : VEGF seems to be a important angiogenic factor in anaplastic astrocytomas and glioblastomas and VEGF expression may contribute to neovascularization of human astrocytomas.

• 생명과학회지
• /
• 제26권12호
• /
• pp.1367-1375
• /
• 2016

Cilostazol은 phosphodiesterase III의 선택적 저해제로 알려져 있으며, 뇌졸중 치료에 일반적으로 사용되고 있다. Cilostazol을 처리한 경우, 국소 뇌허혈이 발생한 후에 혈관신생을 통해서 혈관형성이 향상된다는 것을 본 연구자들이 발표하였다. 혈관신생은 조직의 허혈상태를 극복하기 위해서 혈관재생을 촉진하는 중요한 과정으로써, 혈관내피세포의 증식, 이동, 모세관구조 형성의 다단계 과정으로 구성되어 있다. 이에 본 연구에서는 인간 뇌혈관내피세포를 이용하여 cilostazol이 혈관신생의 각 단계들에 어떤 영향을 미치는지 조사하였다. Cilostazol은 농도의존적으로 뇌혈관내피세포의 이동성을 촉진하였으나, 뇌혈관내피세포의 증식과 모세관구조 형성에는 영향을 미치지 않았다. Cilostazol이 세포이동을 조절하는 기전을 분석하기 위해서 cDNA microarray를 수행하였고, 세포이동에 관련성이 있는 5종의 후보 유전자들을 선택하여 real-time PCR을 통해 해당 유전자의 발현을 검증하였다. Cilostazol에 의해서 발현양이 조절되는 유전자들로써, phosphoserine aminotransferase 1 (PSAT1)와 CCAAT/enhancer binding protein ${\beta}$ ($C/EBP{\beta}$)은 발현이 증가하였고, tissue factor pathway inhibitor 2 (TFPI2), retinoic acid receptor responder 1 (RARRES1), RARRES3는 발현이 감소하였다. 이상의 결과를 통해서 cilostazol이 혈관내피세포의 이동을 촉진하여 혈관신생을 향상시킬 수 있음을 제안할 수 있으며, 뇌혈관내피세포에 대한 cilostazol의 조절기전에 대해서 더욱 상세히 규명을 한다면 혈관형성을 통하여 허혈성 질환을 치료할 수 있는 유용한 정보가 될 것으로 기대한다.

• 대한임상검사과학회지
• /
• 제49권4호
• /
• pp.323-328
• /
• 2017

신생혈관생성은 여러 신생혈관 생성 인자들이 포함되는 중요한 과정이며, 특히 이 과정에서는 섬유아세포증식인자(FGF-2)는 세포의 증식률과 미세관 형성을 촉진하기 때문에 중요한 신생혈관 생성인자로 여겨진다. 최근 연구에 따르면 해조류에서 추출되는 후코이단 다당류 물질이 섬유아세포 증식인자2에 의한 혈관내피세포의 미세관형성을 더욱 촉진한다고 보고하였다. 그러나 섬유아세포 증식인자와 후코이단 복합처리에 따른 신생혈관생성 활성에 대한 분자적 메카니즘은 아직 연구가 부족하다. 따라서 본 연구에서는 신생혈관생성 활성을 알아보기 위하여 섬유아세포 증식인자와 후코이단 물질의 복합처리에 따른 세포의 증식과 미세관형성률 그리고 세포의 이동율을 측정하였다. 또한 이들의 신생혈관 생성 활성에 관련된 인자를 탐색하기 위하여 VEGF-A, ICAM-1, MMP9, 그리고 ICAM-1 유전자를 연전사 중합연쇄반응으로 평가하였다. 본 연구의 결과에서는 후코이단과 섬유아세포 증식인자 복합처리는 혈관내피세포의 성장률, 미세관 형성률 그리고 세포의 이동률을 촉진하고, 이 과정에서 신생혈관생성 기능과 관련된 STAT3, VEGF-A, MMP9 그리고 ICAM-1의 유전자 발현을 촉진함으로 신생혈관 생성활성이 나타나는 것으로 보여진다. 그러나 이러한 유전자 발현이 fucoidan/FGF2에 의한 angiogenic 활성 촉진에 직접적인 영향을 미치는 지에 대한 추가적인 연구가 이루어져야 할 것으로 생각된다.

• 환경생물
• /
• 제28권1호
• /
• pp.8-13
• /
• 2010

본 연구는 BRECs에서 AGEs로 유도된 세포의 이동 및 침윤에 있어서 AuNP의 역할에 관한 연구이다. 소 망막으로부터 내피세포를 분리하고, 세포 생존율은 MTT assay로 확인하였다. Wound migration assay는 BRECs의 이동력을 확인하기 위해 수행하였다. Tube formation은 on-gel system을 통해 확인하였다. AuNP의 apoptosis 유도는 caspase-3 assay를 통해 확인하였다. AGE-BSA은 세포증식 및 이동에 있어서 증가함을 보여주었다. 또한 AuNP는 AGE-BSA 존재 유무에 상관없이 세포의 증식, 이동, 신생혈관 형성을 억제하였고, caspase-3을 통해 apoptosis를 유도하였다. 이러한 결과, AuNP는 AGE로 유도된 신생혈관 형성 및 세포의 이동성을 억제하는 약재제로서, 당뇨성 합병증에 있어서 잠재적으로 중요한 분자가 될 것이다.

• Plant Resources
• /
• 제8권3호
• /
• pp.209-216
• /
• 2005

Persicaria thunbergii has been utilized for the treatment of cancer as a folk medicine. We examined the effect of isorhamnetin, a flavonoid isolated from Persicaria thunbergii, on angiogenesis in vitro and in vivo. Basic fibroblast growth factor (bFGF) is a potent angiogenic factor found in various tumors. In this study, we found that the isorhamnetin decreased bFGF-induced human umbilical vein endothelial cells (HUVECs) proliferation and migration in a concentration-dependent manner (5, 10 and $20\;{\mu}M$) whereas, it did not inhibit bFGF-induced capillary-like formation of HUVECs. The chicken chorioallantoic membrane assay revealed that addition of isorhamnetin (10, 20 and $40\;{\mu}M$) displayed an antiangiogenic effect in vivo. These results suggest that the isorhamnetin inhibits the proliferation and migration of endothelial cells induced by bFGF, which may explain its anti-angiogenic properties.

• Restorative Dentistry and Endodontics
• /
• 제48권2호
• /
• pp.20.1-20.13
• /
• 2023

This mini-review was conducted to present an overview of the use of exosomes in regenerating the dentin-pulp complex (DPC). The PubMed and Scopus databases were searched for relevant articles published between January 1, 2013 and January 1, 2023. The findings of basic in vitro studies indicated that exosomes enhance the proliferation and migration of mesenchymal cells, as human dental pulp stem cells, via mitogen-activated protein kinases and Wingless-Int signaling pathways. In addition, they possess proangiogenic potential and contribute to neovascularization and capillary tube formation by promoting endothelial cell proliferation and migration of human umbilical vein endothelial cells. Likewise, they regulate the migration and differentiation of Schwann cells, facilitate the conversion of M1 pro-inflammatory macrophages to M2 anti-inflammatory phenotypes, and mediate immune suppression as they promote regulatory T cell conversion. Basic in vivo studies have indicated that exosomes triggered the regeneration of dentin-pulp-like tissue, and exosomes isolated under odontogenic circumstances are particularly strong inducers of tissue regeneration and stem cell differentiation. Exosomes are a promising regenerative tool for DPC in cases of small pulp exposure or for whole-pulp tissue regeneration.

• Animal cells and systems
• /
• 제8권1호
• /
• pp.27-32
• /
• 2004

Endothellial cells are subjected to hemodynamic shear stress, the dragging force generated by blood flow. Shear stress regulates endothelial cell shape, structure, and function, including gene expression. Since endothelial cells must be anchored to their extracellular matrices(ECM) for their survival and growth, we hypothesized that ECMs are crucial for shear-dependent activation of extracellular signalactivated regulated kinase(ERK) that is important for cell proliferation. Shear stress-dependent activation of ERK was observed in cells plated on two different matrices, fibronectin and vitronectin(the two most physiologically relevant ECM in endothelial cells). We then treated bovine aortic endothelial cells(BAECs) with Arg-Gly-Asp(RGD) peptides that block the functional activation of integrin binding to fibronectin and vitronectin, and a nonfunctional peptide as a control. Treatment of cells with the RGD peptides, but not the control peptide, significantly inhibited ERK activity in a concentration-dependent manner. This supports the idea that integrin adhesion to the ligands, fibronectin and vitronectin, mediates shear stress-dependent activation of ERK. Subsequently, whereas antagonists of vitronectin(LM 609, an antibody for integrin ${\alpha}_{\gamma}$/${\beta}_3$ and XT 199, an antagonist specific for integrin ${\alpha}_{\gamma}$/${\beta}_3$) did not have any effect on shear-dependent activation of ERK, antagonists of fibronectin(a neutralizing antibody for integrin ${\alpha}_5$/${\beta}_1$or ${\alpha}_4$${\beta}_1$ and SM256) had an inhibitory effect. These results clearly demonstrate that mechanoactivation of ERK requires anchoring of endothelial cells to fibronectin through integrins.

• BMB Reports
• /
• 제50권7호
• /
• pp.384-389
• /
• 2017

The Nogo-B receptor (NgBR) is necessary for not only Nogo-B-mediated angiogenesis but also vascular endothelial growth factor (VEGF) -induced angiogenesis. However, the molecular mechanisms underlying the regulatory role of the VEGF-NgBR axis in angiogenesis are not fully understood. Here, we report that miR-26a serves as a critical regulator of VEGF-mediated angiogenesis through directly targeting NgBR in endothelial cells (ECs). Stimulation of ECs by VEGF increased the expression of NgBR and decreased the expression of miR-26a. In addition, miR-26a decreased the VEGF-induced migration and proliferation of ECs. Moreover, miR-26a overexpression in ECs decreased the VEGF-induced phosphorylation of the endothelial nitric oxide synthase (eNOS) and the production of nitric oxide, which is important for angiogenesis. Overall, these data suggest that miR-26a plays a key role in VEGF-mediated angiogenesis through the modulation of eNOS activity, which is mediated by its ability to regulate NgBR expression by directly targeting the NgBR 3'-UTR.