• Journal of Chest Surgery
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• v.44 no.6
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• pp.406-412
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• 2011

Background: Development of thoracic aortic aneurysms and aortic dissections (TAAD) is attributed to unbearable wall tension superimposed on defective aortic wall integrity and impaired aortic repair mechanisms. Central to this repair mechanisms are well-balanced and adequately functional cellular components of the aortic wall, including endothelial cells, smooth muscle cells (SMCs), inflammatory cells, and adventitial fibroblasts. Adventitial fibroblasts naturally produce aortic extracellular matrix (ECM), and, when aortic wall is injured, they can be transformed into SMCs, which in turn are involved in aortic remodeling. We postulated the hypothesis that adventitial fibroblasts in patients with TAAD may have defects in ECM production and SMC transformation. Materials and Methods: Adventitial fibroblasts were procured from the adventitial layer of fresh aortic tissues of patients with TAAD (Group I) and of multi-organ donors (Group II), and 4-passage cell culture was performed prior to the experiment. To assess ECM production, cells were treated with TNF-${\alpha}$ (50 pM) and the expression of MMP-2/MMP-3 was analyzed using western blot technique. To assess SMC transformation capacity, cells were treated with TGF-${\beta}1$ and expression of SM ${\alpha}$-actin, SM-MHC, Ki-67 and SM calponin was evaluated using western blot technique. Fibroblasts were then treated with TGF-${\beta}1$ (10 pM) for up to 10 days with TGF-${\beta}1$ supplementation every 2 days, and the proportion of transformed SMC in the cell line was measured using immunofluorescence assay for fibroblast surface antigen every 2 days. Results: MMP-3 expression was significantly lower in group I than in group II. TGF-${\beta}1$-stimulated adventitial fibroblasts in group I expressed less SM ${\alpha}$-actin, SM-MHC, and Ki-67 than in group II. SM-calponin expression was not different between the two groups. Presence of fibroblast was observed on immunofluorescence assay after more than 6 days of TGF-${\beta}1$ treatment in group I, while most fibroblasts were transformed to SMC within 4 days in group II. Conclusion: ECM production and SMC transformation are compromised in adventitial fibroblasts from patients with TAAD. This result suggests that functional restoration of adventitial fibroblasts could well be a novel approach for the prevention and treatment of TAAD.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1375-1383
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• 2015

Background: Objective Myocardin-related transcription factor (MRTF)-A is a Rho signaling-responsive co-activator of serum response factor (SRF). The purpose of this study is to investigate the role of MRTF-A and AQP1 (aquaporin 1) in pathological vascular remodeling. Materials and Methods: MRTF-A, AQP1 and neointima expression was detected both in the wire injured femoral arteries of wild-type mice and the atherosclerotic aortic tissues of $ApoE^{-/-}$ mice. Expression of ICAM-1, matrix metallopeptidase 9 (MMP-9) and integrin ${\beta}1$ were also assayed. The intercourse relationship between the molecules were investigated by interfering RNA and inhibitor assay. Results: MRTF-A and AQP1 expression were significantly higher in the wire injured femoral arteries of wild-type mice and in the atherosclerotic aortic tissues of $ApoE^{-/-}$ mice than in healthy control tissues. Both in wire-injured femoral arteries in MRTF-A knockout ($Mkl1^{-/-}$) mice and atherosclerotic lesions in $Mkl1^{-/-}$; $ApoE^{-/-}$ mice, neointima formation were significantly attenuated and the expression of AQP1 were significantly decreased. Expression of ICAM-1, matrix metallopeptidase 9 (MMP-9) and integrin ${\beta}1$, three SRF targets and key regulators of cell migration, and AQP1 in injured arteries was significantly weaker in $Mkl1^{-/-}$ mice than in wild-type mice. In cultured vascular smooth muscle cells (VSMCs), knocking down MRTF-A reduced expression of these genes and significantly impaired cell migration. Underlying the increased MRTF-A expression in dedifferentiated VSMCs were the down-regulation of microRNA-300. Moreover, the MRTF-A inhibitor CCG1423 significantly reduced neointima formation following wire injury in mice. Conclusions: MRTF-A could be a novel therapeutic target for the treatment of vascular diseases.

• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.507-515
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• 2005

Melatonin, the principal hormone of the vertebral pineal gland, participates in the regulation of cardiovascular system in vitro and in vivo. However, the effects of melatonin on vascular tissues are still vague. The aim of this study was to assess the relationship between phospholipase C (PLC) and nitric oxide synthase (NOS)/cyclic guanosine 3',5'-monophosphate (cGMP) signaling cascade in the relaxatory action of melatonin in isolated rat aorta. Melatonin induced a concentration-dependent relaxation in phenylephrine (PE)- and KCl-precontracted endothelium intact (+E) aortic rings. In KCl-precontracted +E aortic rings, the melatonin-induced vasorelaxation was not inhibited by endothelium removal or by pretreatment with NOS inhibitors, L-$N^G$-nitor-arginine (L-NNA) and L-$N^G$-nitor-arginine methyl ester (L-NAME), guanylate cyclase (GC) inhibitors, methylene blue (MB) and 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (ODQ). In PE-precontracted +E aortic rings, the melatonin-induced vasorelaxation was inhibited by endothelium removal or by pretreatment with L-NNA, L-NAME, MB, ODQ and 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC). Moreover, in without endothelium (-E) aortic rings and in the presence of L-NNA, L-NAME, MB and ODQ in +E aortic rings, the melatonin-induced residual relaxations and residual contractile responses to PE were not affected by NCDC, a PLC inhibitor. It is concluded that melatonin can evoke vasorelaxation due to inhibition of PLC pathway through the protein kinase G activation of endothelial NOS/cGMP signaling cascade.

• IMMUNE NETWORK
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• v.9 no.3
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• pp.106-113
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• 2009

Background: We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. Methods: Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 ($AT_1$) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [$^3H$]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. Results: Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the $AT_1$ receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an $AT_1$ receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. Conclusion: These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.841-845
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• 2003

In order for engineered tissues to find clinical utility, the engineered tissues must function appropriately. However, smooth muscle (SM) tissues engineered in vitro with a conventional tissue engineering technique may not exhibit contractile functions, because smooth muscle cells (SMCs) cultured in vitro typically revert from a contractile, differentiated phenotype to a synthetic, nondifferentiated phenotype and lose their ability to contract. SMCs in vivo typically reside in mechanically dynamic environments. We hypothesized that cyclic mechanical stretch induces the features of SMCs in in vitro engineered tissues to be similar to those of SMCs in native tissues. To test the hypothesis, aortic SMCs were seeded onto elastic, three-dimensional scaffolds and cultured in vitro under a cyclic mechanical stretching condition for 4 weeks. A significant cell alignment in a direction parallel to the cyclic stretching direction was found in the SM tissues exposed to cyclic stretching. The cellular alignment and alignment direction were consistent with those of native vascular SM tissues, in which SMCs in vivo align in the radial direction (parallel to stretching direction). In control tissues (SM tissues engineered without stretching), cells randomly aligned. The expression of SM ${\alpha}-actin$ and SM myosin heavy chain, phenotypic markers of SMCs in a contractile state, was upregulated in the stretched tissues by 2.5- and 2.0-fold, respectively, compared to SMCs in the control tissues. The cellular features of alignment and contractile phenotype of SMCs in the SM tissues engineered under a mechanically dynamic environment could allow the engineered SM tissues to exhibit contractile functions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.148-154
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• 2008

The butanol extract of Euonymus alatus (BEA) induced dose-dependent relaxation of phenylephrine-precontracted aorta, which was abolished by removal of functional endothelium. Pre-treatment of the endothelium-intact aortic tissues with $N^G-nitro-L-arginine methylester$ (L-NAME), and 1 H-[1,2,4]-oxadiazole- [$4,3-{\alpha}$]-quinoxalin-1-one (ODQ) inhibited the relaxation induced by BEA, respectively. BEA-induced vascular relaxation was not blocked by glibenclamide, tetraethylammonium (TEA), indomethacin, atropine, propranolol, verapamil, and diltiazem, respectively. Moreover, BEA inhibits phenylephrine-induced vascular constriction in a dose-dependent manner. These results suggest that BEA relaxes vascular smooth muscle via endothelium-dependent nitric oxide/cGMP signaling.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.102-107
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• 2009

Fish oil and shortening have been suggested to have opposite effects on cardiovascular disease (CVD). This study investigated the effect of shortening and fish oil on CVD risk factors and aorta histopathology, and the association between risk factors and aorta histopathology. Male Wister rats (n=30) were fed an AIN-93G diet containing 20% fat in the form of fish oil, shortening, or soybean oil for 4 weeks. Total cholesterol (TC), triacylglyceride (TG), and C-reactive protein levels were significantly (P<0.001) lower in the fish oil than in soybean oil and shortening groups. HDL-cholesterol concentrations were significantly different (P<0.001) between groups. In addition, LDL-cholesterol levels were significantly (P<0.001) lower in the fish oil and shortening groups than in the soybean oil group. Insulin and glucose concentrations did not differ among groups. Effect of dietary fat on tissue fatty acid composition significantly differed in abdominal fat and brain compared with RBC, heart, kidney and liver. The aortic wall was significantly (P=0.02) thinner in the fish oil group than in the soybean oil and shortening groups. The aortic wall thickness was positively correlated with TG and TC, but negatively with EPA + DHA levels of all tissues. These results suggested that fish oil had protective effects on aorta histopathology by hypolipidemic action in this rat model.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.49-59
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• 1977

Adrenergic receptors are now classified into alpha type and beta type These adrenergic receptors are distributed in various tissue in different patterns. Therefore, the adrenergic response of a certain tissue may be different from those of the other tissues, and such differences may exist among various species of animals. In this paper, the authors attempt to reevaluate the effect of epinephrine on the isolated atria, aortic strips, and vas deferenses of rabbits preincubated with alpha receptor blockades (ergotamine and dibenamine) and beta receptor blockades (propranolol and dichloroisoproterenol) in Locke-Ringer bathing medium. The results obtained were summarized as follows; 1) The dose dependent responses of isolated atria to epinephrine were significantly inhibited by propranolol and dichloroisoproterenol, and slightly inhibited by dibenamine, but not affected by ergotamine. 2) The dose dependent responses of excised aortic strips to epinephrine were significantly inhibited by ergotamine and dibenamine, but the responses were slightly potentiated by propranolol, and significantly by dichloroisoproterenol. 3) The dose dependent responses of isolated vas deferenses to epinephrine were significantly inhibited by ergotamine and dibenamine, but slightly potentiated by propranolol and dichloroisoproterenol.

• YAKHAK HOEJI
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• v.37 no.2
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• pp.163-171
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• 1993

In order to study the functions of vascular endothelial nitric oxide(NO) generating system, we examined the effects of monomethylarginine(MMA) and dimethylarginine(DMA)(asym., sym.), arginine analogues, on modulation of vascular tone. Also, the concentrations of endogenous arginie and MMA were measured by HPLC in rat aortic tissues. The results were as follows. 1. The maximum relaxation induced by Ach (1.5$\times$10$^{-6}$M) was 80% of the contractility of rings of rat aorta induced by phenylephrine and L-Arg causes endothelium-dependent relaxation of the aorta precontracted with phenylephrine and these relaxation were concentration-dependent. 2. Endothelium-dependent contractility of rings of rat aorta induced by MMA (100 $\mu{M}$), DMA (asym., 100 $\mu{M}$) and DMA (sym., 100 $\mu{M}$) were 25.5%, 27.5% and 16.5% of that induced by phenylephrine respectively. 3. The relaxation of rat aortic ring induced by L-Arg was inhibited by MMA, DMA(asym.) and DMA(sym.). The degrees of inhibition induced by MMA, DMA(asym.) and DMA(sym.) were 45.7%, 37.1% and 18.3%, respectively. 4. The endogenous arginine and monomethylarginine contents in rat aorta were 83 pmoles/mg wet tissue, and 34.9 pmoles/mg wet tissue. After stimulation with Ach, the concentrations of L-Arg and MMA were significantly decreased. These results suggest that there are the strong relationships between the endogenous L-Arg and methylated arginines and NO-generating system.

• IMMUNE NETWORK
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• v.23 no.4
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• pp.28.1-28.20
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• 2023

Lipid accumulation in macrophages is a prominent phenomenon observed in atherosclerosis. Previously, intimal foamy macrophages (FM) showed decreased inflammatory gene expression compared to intimal non-foamy macrophages (NFM). Since reprogramming of lipid metabolism in macrophages affects immunological functions, lipid profiling of intimal macrophages appears to be important for understanding the phenotypic changes of macrophages in atherosclerotic lesions. While lipidomic analysis has been performed in atherosclerotic aortic tissues and cultured macrophages, direct lipid profiling has not been performed in primary aortic macrophages from atherosclerotic aortas. We utilized nanoflow ultrahigh-performance liquid chromatography-tandem mass spectrometry to provide comprehensive lipid profiles of intimal non-foamy and foamy macrophages and adventitial macrophages from Ldlr^-/- mouse aortas. We also analyzed the gene expression of each macrophage type related to lipid metabolism. FM showed increased levels of fatty acids, cholesterol esters, phosphatidylcholine, lysophosphatidylcholine, phosphatidylinositol, and sphingomyelin. However, phosphatidylethanolamine, phosphatidic acid, and ceramide levels were decreased in FM compared to those in NFM. Interestingly, FM showed decreased triacylglycerol (TG) levels. Expressions of lipolysis-related genes including Pnpla2 and Lpl were markedly increased but expressions of Lpin2 and Dgat1 related to TG synthesis were decreased in FM. Analysis of transcriptome and lipidome data revealed differences in the regulation of each lipid metabolic pathway in aortic macrophages. These comprehensive lipidomic data could clarify the phenotypes of macrophages in the atherosclerotic aorta.