• Applied Microscopy
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• 제34권4호
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• pp.231-239
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• 2004

뇌에서 혈액뇌장벽을 형성하는 내피세포는 치밀이음부를 통해 뇌의 항상성을 유지하고 있다. 치밀이음부의 단백질 중의 하나인 occludin은 뇌혈관장벽(BBB)의 기능을 유지하는 중요한 단백질로 인식되고 있다. 본 실험에서는 소의 뇌에서 배양된 BBB 내피세포에서 활성산소종의 하나인 $H_2O_2$에 의해 일어나는 occludin 단백질의 변화를 관찰하였다. $H_2O_2$에 의해 TEER가 감소하는 것은 occludin의 재분포에 의한 것이었다. 세포독성은 4시간내에서는 1mM $H_2O_2$ 이하에서는 나타나지 않았다. Confocal laser microscope으로 관찰한 결과, $H_2O_2$에 의해 occludin은 치밀이음부에서 중간중간이 사라져 감소해 있었고, 이러한 양상은 $H_2O_2$의 용량과 노출시간에 비례하였다. 그러나 Western blot 결과, occludin의 총량은 증가하였다. 투과전자현미경 관찰을 통해 $H_2O_2$가 세포사이의 결합의 구조에 뚜렷한 변화를 미치지 않는 것을 알 수 있었다. 이를 통해 $H_2O_2$에 의한 BBB 기능소실은 occludin이 치밀이음부에서 부분적으로 사라지는 것에 의하지만, 세포는 기능손상을 복구하기위한 방편으로 이 단백질의 생산을 더욱 증가시키는 것으로 생각된다.

• Journal of Ginseng Research
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• 제46권5호
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• pp.700-709
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• 2022

Background: Ginsenoside Rd is a natural compound with promising neuroprotective effects. However, the underlying mechanisms are still not well-understood. In this study, we explored whether ginsenoside Rd exerts protective effects on cerebral endothelial cells after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment and its potential docking proteins related to the underlying regulations. Method: Commercially available primary human brain microvessel endothelial cells (HBMECs) were used for in vitro OGD/R studies. Cell viability, pyroptosis-associated protein expression and tight junction protein degradation were evaluated. Molecular docking proteins were predicted. Subsequent surface plasmon resonance (SPR) technology was utilized for validation. Flow cytometry was performed to quantify caspase-1 positive and PI positive (caspase-1+/PI+) pyroptotic cells. Results: Ginsenoside Rd treatment attenuated OGD/R-induced damage of blood-brain barrier (BBB) integrity in vitro. It suppressed NLRP3 inflammasome activation (increased expression of NLRP3, cleaved caspase-1, IL-1β and GSDMD-N terminal (NT)) and subsequent cellular pyroptosis (caspase-1+/PI + cells). Ginsenoside Rd interacted with SLC5A1 with a high affinity and reduced OGD/R-induced sodium influx and potassium efflux in HBMECs. Inhibiting SLC5A1 using phlorizin suppressed OGD/R-activated NLRP3 inflammasome and pyroptosis in HBMECs. Conclusion: Ginsenoside Rd protects HBMECs from OGD/R-induced injury partially via binding to SLC5A1, reducing OGD/R-induced sodium influx and potassium efflux, thereby alleviating NLRP3 inflammasome activation and pyroptosis.

• Applied Microscopy
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• 제29권1호
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• pp.83-94
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• 1999

미세혈관 수술의 발달로 수지동맥의 재접합술이 성행함에 따라 혈관벽의 구조에 관한 연구들이 활발하지만 수지의 미세동맥과 모세혈관에 관한 연구는 드물다. 이에 저자는 흰쥐 수지의 충양근 안에 있는 미세동맥과 모세혈관의 구조를 전자현미경으로 관찰하여 보고하고자 한다. 1. 흰쥐 충양근 내의 미세동맥 (small arterioles)은 그 직경이 $12\sim20{\mu}m$로 중막이 한 층의 평활근세포로 구성된 종말소동맥 (terminal arteriole) 형태였는데 인체의 종말소동맥$(30\sim35{\mu}m)$에 비해 직경이 작았으며, 모세혈관은 직경이 $5\sim8{\mu}m$로 비슷하였다. 2. 모든 미세동맥 및 모세혈관의 내막을 구성하는 내피세포는 연속형 (continuous type)이었고, 따라서 전체 세포질내에 포음소포(pinocytic vesicles)가 많이 관찰되었다. 3. 모세혈관 주위에서 자주 혈관주위세포(pericytes)가 관찰되었는데 철관주위세포의 긴 들기가 내피세포의 일부를 싸는 경우도 많았으며 이들은 기저판에 의해 둘러싸여 있었다. 4. 내피세포들 사이에는 여러 가지 형태의 접촉이 있었으나 특히 폐쇄띠 (tight junction)를 가장 많이 관찰할 수 있었다. 미세동맥의 내피하층은 기저판 아래에서 매우 불규칙한 양상으로 나타났는데 곳곳에 내피세포와 중막을 구성하는 평활근세포의 막이 꽉 붙어 관찰되었다. 5. 미세동맥의 중막을 구성하는 한 층의 평활근세포의 세포질은 많은 filaments가 있어 균질성으로 보이는 균질성 영역 (homogeneous area)과 mitochondria, 조면내형질망, 골지복합체, polyribosome 등이 관찰되는 핵 주위의 비균질성 영역 (non-homogeneous area)으로 구분되었다. 6. 미세동맥의 외막은 섬유모세포의 아주 가느다란 돌기들로 형성되어 있었으며 군데군데 교원섬유들이 관찰되었다.

• Biomolecules & Therapeutics
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• 제27권5호
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• pp.474-483
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• 2019

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, ${\beta}$-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.

• Toxicological Research
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• 제29권3호
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• pp.157-164
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• 2013

Although stroke is one of the leading causes of death and disability worldwide, preventive or therapeutic options are still limited. Therefore, a better understanding of the pathophysiological characteristics of this life-threatening disease is urgently needed. The incidence and prevalence of ischemic stroke are increased by exposure to certain types of xenobiotics, including heavy metals, suggesting the possible toxicological contribution of these compounds to the onset or aggravation of stroke. Among the potential targets, we have focused on alterations to cerebral endothelial cells (CECs), which play important roles in maintaining the functional integrity of brain tissue.

• Journal of Gastric Cancer
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• 제23권2호
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• pp.289-302
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• 2023

Purpose: Liver metastasis (LM) is reported in approximately 40% of patients with advanced/metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM-) LM at baseline. Materials and Methods: Patients (n=665) were randomly assigned on a 1:1 basis to receive either RAM+PAC (LM+: 150, LM-: 180) or placebo and paclitaxel (PL+PAC) (LM+: 138, LM-: 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan-Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM- subgroups was analyzed using the Cox regression model with reported interaction P-values. Results: The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM- (OS HR, 0.71 [LM+] vs. 0.88 [LM-]; PFS HR, 0.47 [LM+] vs. 0.76 [LM-]). Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05). Conclusions: RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM.

• Journal of Chest Surgery
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• 제43권4호
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• pp.356-363
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• 2010

배경: 승모판막의 석회화는 죽상경화와 밀접한 연관관계가 있는 것으로 알려져 있다. 그러나, 승모판막 질환에서 혈관 죽상경화에 중요한 역할을 하는 것으로 알려진 Connexin43 매개에 의한 Gap junction의 신호전달의 변화는 잘 알려져 있지 않다. 따라서, 저자들은 승모판막의 퇴행성 변화과정이 Gap junction을 통한 세포간 신호전달의 변화와 연관이 있을 것이라고 가정하였다. 대상 및 방법: 뉴질랜드산 토끼 20마리를 2군으로 나눈후, 1군(10마리)에서는 정상식이를 시행하였고, 2군(10마리)에서는 1% 콜레스테롤식이를 12주간 시행하였다. 각군의 토끼들의 혈장에서 총 콜레스테롤, 중성지방, 저밀도 콜레스테롤, 고밀도 콜레스테롤 수치를 측정하였으며, 승모판막을 절제하여 Connexin43, 근육섬유모세포 그리고 대식세포에 대한 면역조직화학염색을 시행하였으며, Connexin43에 대한 정량적 검사를 위하여 Real-time Reverse Transcriptase polymerase chain reaction (real time RT-PCR)을 시행하였다. 결과: 면역조직화학염색에서 근육섬유모세포와 대식세포의 발현은 콜레스테롤 식이를 시행한 군의 승모판막에서 증가되었으며, Connexin43의 발현도 콜레스테롤 식이군에서 증가되어 있었다. RT-PCR을 이용한 정량적 검사에서 Connexin43의 발현은 콜레스테롤 식이군에서 의미있게 증가되어 있었다(p<0.01). 결론: 고콜레스테롤혈증이 유발된 토끼의 승모판막의 변화는 초기 죽상경화와 유사한 과정을 보이며, Connex43의 발현이 증가되었다. 따라서 고콜레스테롤혈증에서의 승모판막질환은 증가된 Connexin43매개 Gap junction을 통한 세포간 신호전달의 변화가 중요한 역할을 한다고 생각된다.

• Journal of Ginseng Research
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• 제45권3호
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• pp.433-441
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• 2021

Background: Multiple sclerosis (MS) and its animal model, the experimental autoimmune encephalomyelitis (EAE), are primarily characterized as dysfunction of the blood-brain barrier (BBB). Ginsenoside-Rg3-enriched Korean Red Ginseng extract (Rg3-KRGE) is known to exert neuroprotective, anti-inflammatory, and anti-oxidative effects on neurological disorders. However, effects of Rg3-KRGE in EAE remain unclear. Methods: Here, we investigated whether Rg3-KRGE may improve the symptoms and pathological features of myelin oligodendroglial glycoprotein (MOG)_35-55 peptide - induced chronic EAE mice through improving the integrity of the BBB. Results: Rg3-KRGE decreased EAE score and spinal demyelination. Rg3-KRGE inhibited Evan's blue dye leakage in spinal cord, suppressed increases of adhesion molecule platelet endothelial cell adhesion molecule-1, extracellular matrix proteins fibronection, and matrix metallopeptidase-9, and prevented decreases of tight junction proteins zonula occludens-1, claudin-3, and claudin-5 in spinal cord following EAE induction. Rg3-KRGE repressed increases of proinflammatory transcripts cyclooxygenase-2, inducible nitric oxide synthase, interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha, but enhanced expression levels of anti-inflammatory transcripts arginase-1 and IL-10 in the spinal cord following EAE induction. Rg3-KRGE inhibited the expression of oxidative stress markers (MitoSOX and 4-hydroxynonenal), the enhancement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) and NOX4, and NADPH activity in the spinal cord of chronic EAE mice. Furthermore, apocynin, a NOX inhibitor, mimicked beneficial effects of Rg3-KRGE in chronic EAE mice. Conclusion: Our findings suggest that Rg3-KRGE might alleviate behavioral symptoms and pathological features of MS by improving BBB integrity through modulation of NOX2/4 expression.