• Title/Summary/Keyword: cellular adhesion

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Improved cell adhesion to ion beam-irradiated biodegradable membranes (이온빔조사에 의한 생분해성 차폐막의 세포부착력 증진에 관한 연구)

  • Lee, Yong-Moo;Park, Yoon-Jeong;Lee, Seung-Jin;Ku, Young;Rhyu, In-Chul;Han, Soo-Boo;Choi, Sang-Mook;Chung, Chong-Pyoung
    • Journal of Periodontal and Implant Science
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    • v.28 no.4
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    • pp.601-611
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    • 1998
  • Ion irradiation is a very promising tool to modify the chemical structure and physical properities of polymers. This study was aimed to evaluate the cellular adhesion to ion beam-irradiated surface of biodegradable poly-l-lactide(PLLA) membrane. The PLLA membrane samples were irradiated by using 35 KeV $Ar^+$ to fluence of $5{\times}10^{13}$, $5{\times}10^{14}$ and $5{\times}10^{15}\;ion/cm^2$. Water contact angles to control and each dose of ion beam-irradiated PLLA membranes were measured. Cultured fetal rat calvarial osteoblasts were seeded onto control and each dose of ion beam-irradiated PLLA membranes and cultured. After 24 hours, each PLLA membranes onto which osteoblasts attached were examined by scanning electron microscopy(SEM). Osteoblasts were removed from each PLLA membrane and then, the vitality and the number of cells were calibrated. Alkaline phosphatase of detached cells from each PLLA membranes were measured. Ion beam-irradiated PLLA membranes showed no significantly morphological change from control PLLA membranes. In the measurement of water contact angle to each membrane, the dose range of ion beam employed in this study reduced significantly contact angles. Among them, $5{\times}10^{14}\;ion/cm^2$ showed the least contact angle. The vitalities of osteoblastes detached from each membranes were confirmed by flow cytometer and well attached cells with their own morphology onto each membranes were observed by SEM. A very strong improvement of the cell adhesion and proliferation was observed for ion beam-irradiated surfaces of PLLA membranes. $5{\times}10^{15}\;ion/cm^2$ exhibited the most strong effect also in cellular adherence. ALPase activities also tended to increase in ion beam-irradiated membranes but statistical differences were not found. These results suggested that ion beam irradiation is an effective tool to improve the adhesion and spreading behaviour of the cells onto the biodegradable PLLA membranes for the promotion of membrane-tissue integration.

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Genipin Selectively Inhibits TNF-${\alpha}$-activated VCAM-1 But Not ICAM-1 Expression by Upregulation of PPAR-${\gamma}$ in Human Endothelial Cells

  • Jung, Seok-Hwa;Mun, Lidiya;Kim, Hye-Jung;Seo, Han-Geuk;Lee, Jae-Heun;Kwak, Jong-Hwan;Lee, Dong-Ung;Chang, Ki-Churl
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.3
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    • pp.157-162
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    • 2011
  • Vascular inflammation process has been suggested to be an important risk factor in the development of atherosclerosis. Recently we reported that induction of peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$) selectively inhibits vascular cell adhesion molecule-1 (VCAM-1) but not intercellular cell adhesion molecule-1 (ICAM-1) in tumor necrosis factor (TNF)-${\alpha}$-activated human umbilical vein endothelial cells (HUVEC). In this study, we investigated whether genipin inhibits expression of cellular adhesion molecules, which is relevant to inflammation. Pretreatment with genipin reduced reactive oxygen species (ROS) production and expression of VCAM-1, but not ICAM-1 in TNF-${\alpha}$-activated HUVEC. Genipin dose- and time-dependently increased PPAR-${\gamma}$ expression and inhibited TNF-${\alpha}$-induced phosphorylation of Akt and PKC with different degrees. Finally, genipin prevented TNF-${\alpha}$-induced adhesion of U937 monocytic cells to HUVEC. Taken together, these results indicate that upregualtion of PPAR-${\gamma}$ by genipin selectively inhibits TNF-${\alpha}$-induced expression of VCAM-1, in which regulation of Akt and/or PKC play a key role. We concluded that genipin can be used for the treatment of cardiovascular disorders such as atherosclerosis.

Antioxidant and Anti-inflammatory Activities of Ethanol Extract from Leaves of Cirsium japonicum

  • Lee, Je-Hyuk;Choi, Soo-Im;Lee, Yong-Soo;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.17 no.1
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    • pp.38-45
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    • 2008
  • Antioxidant and anti-rheumatoid activities of Cirsium japonicum leaf extract (CJLE) were investigated in this study. CJLE had similar DPPH radical scavenging activity and reducing power to ascorbic acid and several flavonoids. Rheumatoid arthritis (RA) is a chronic inflammatory tissue-destructive disease, partly related with functions of hyaluronidases (HAases) and collgenases. CJLE ($1,000\;{\mu}g/mL$) had approximately 60.7 and 31.9% inhibition of HAase and collagenase activity, respectively. Also, CJLE inhibited lipopolysaccharide (LPS)-induced nitrite production in a dose-dependent manner, and CJLE ($1,000\;{\mu}g/mL$) suppressed approximately 70% of LPS-induced nitrite production effectively in RAW 264.7 macrophage cells. CJLE had inhibitory effects on the adherence of monocytic THP-1 to human umbilical vein endothelial cell (HUVEC) monolayers to the basal level. Inhibitory effect of CJLE on the adhesion was caused by suppression of tumor necrosis factor-a-upregulated expression of vascular cellular adhesion molecule-1 (VCAM-1) and E-selectin. We expect that CJLE may alleviate the inflammatory process in rheumatoid synovium, and these findings will raise the possibility of the usage of C. japonicum as a traditional pharmaceutical of anti-rheumatoid arthritis.

Suppression of Human Fibrosarcoma Cell Metastasis by Phyllanthus emblica Extract in Vitro

  • Yahayo, Waraporn;Supabphol, Athikom;Supabphol, Roongtawan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6863-6867
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    • 2013
  • Phyllanthus emblica (PE) is known to exhibit various pharmacological properties. This study aimed to evaluate the antimetastatic potential of a PE aqueous extract. Cytotoxicity to human fibrosarcoma cells, HT1080, was determined by viability assay using the 3-(4,5-dimethylthiazol,2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent. Cell migration and invasion were investigated using chemotaxis chambers containing membranes precoated with collagen IV and Matrigel, respectively. Cell attachment onto normal surfaces of cell culture plates was tested to determine the cell-adhesion capability. The molecular mechanism of antimetastatic activity was assessed by measuring the gene expression of matrix metalloproteinases, MMP2, and MMP9, using reverse transcription-polymerase chain reaction (RT-PCR) assay. The mRNA levels of both genes were significantly down-regulated after pretreatment with PE extract for 5 days. Our findings show the antimetastatic function of PE extract in reducing cell proliferation, migration, invasion, and adhesion in both dose- and time-dependent manners, especially growth arrest with low $IC_{50}$ value. A decrease in the expression of both MMP2 and MMP9 seems to be the cellular mechanism for antimetastasis in this case. There is a high potential to use PE extracts clinically as an optional adjuvant therapeutic drug for therapeutic intervention strategies in cancer therapy or chemoprevention.

P-Selectin-mediated Acute Inflammation Can Be Blocked by Chemically Modified Heparin, RO-Heparin

  • Gao, Yanguang;Li, Na;Fei, Rui;Chen, Zhihong;Zheng, Sheng;Zeng, Xianlu
    • Molecules and Cells
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    • v.19 no.3
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    • pp.350-355
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    • 2005
  • Selectins are carbohydrate-binding cell adhesion molecules that play a major role in the initiation of inflammatory responses. Heparin can bind to P-selectin, and its anti-inflammatory property is mainly due to inhibition of P-selectin. However, the strong anticoagulant activity of heparin limits its clinical use. We prepared periodate-oxidized, borohydride-reduced heparin (RO-heparin) by chemical modification and tested its anticoagulant and anti-inflammatory activities. Activated partial thromboplastin time (aPTT) assays showed that, compared with heparin, RO-heparin had greatly reduced anticoagulant activity. Intravenous administration of this compound led to reduction in the peritoneal infiltration of neutrophils in a mouse acute inflammation model. In vitro cell adhesion experiments demonstrated that the effect of RO-heparin on inflammatory responses was mainly due to inhibiting the interaction of P-selectin with its ligands. These results indicate that RO-heparin may be a safer treatment for inflammation than heparin, especially when selectin is targeted.

Src Redox Regulation: There Is More Than Meets the Eye

  • Chiarugi, Paola
    • Molecules and Cells
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    • v.26 no.4
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    • pp.329-337
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    • 2008
  • Src-family kinases are critically involved in the control of cytoskeleton organization and in the generation of integrin-dependent signaling responses, inducing tyrosine phosphorylation of many signaling and cytoskeletal proteins. Activity of the Src family of tyrosine kinases is tightly controlled by inhibitory phosphorylation of a carboxy-terminal tyrosine residue, inducing an inactive conformation through binding with its SH2 domain. Dephosphorylation of C-ter tyrosine, as well as its deletion of substitution with phenylalanine in oncogenic Src kinases, leads to autophosphorylation at a tyrosine in the activation loop, thereby leading to enhanced Src activity. Beside this phophorylation/dephosphorylation circuitry, cysteine oxidation has been recently reported as a further mechanism of enzyme activation. Mounting evidence describes Src activation via its redox regulation as a key outcome in several circumstances, including growth factor and cytokines signaling, integrin-mediated cell adhesion and motility, membrane receptor cross-talk as well in cell transformation and tumor progression. Among the plethora of data involving Src kinase in physiological and pathophysiological processes, this review will give emphasis to the redox component of the regulation of this master kinase.

20S-dihydroprotopanaxatriol modulates functional activation of monocytes and macrophages

  • Kim, Mi-Yeon;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.37 no.3
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    • pp.300-307
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    • 2013
  • 20S-dihydroprotopanaxatriol (2H-PPT) is a derivative of protopanaxatrol from ginseng. Unlike other components from Panax ginseng, the pharmacological activity of this compound has not been fully elucidated. In this study, we investigated the modulatory activity of 2H-PPT on the cellular responses of monocytes and macrophages to understand its immunoregulatory actions. 2H-PPT strongly upregulated the release of radicals in sodium nitroprusside-treated RAW264.7 cells and the surface levels of costimulatory molecule CD86. More importantly, this compound remarkably suppressed nitric oxide production, morphological changes, phagocytic uptake, cell-cell aggregation, and cell-matrix adhesion in RAW264.7 and U937 cells in the presence or absence of lipopolysaccharide, anti-CD43 antibody, fibronectin, and phorbal 12-myristate 13-acetate. Therefore, our results suggest that 2H-PPT can be applied as a novel functional immunoregulator of macrophages and monocytes.

Fusobacterium nucleatum GroEL signaling via Toll-like receptor 4 in human microvascular endothelial cells

  • Lee, Hae-Ri;Choi, Bong-Kyu
    • International Journal of Oral Biology
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    • v.37 no.3
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    • pp.130-136
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    • 2012
  • The GroEL heat-shock protein from Fusobacterium nucleatum, a periodontopathogen, activates risk factors for atherosclerosis in human microvascular endothelial cells (HMEC-1) and ApoE-/- mice. In this study, we analyzed the signaling pathways by which F. nucleatum GroEL induces the proinflammatory factors in HMEC-1 cells known to be risk factors associated with the development of atherosclerosis and identified the cellular receptor used by GroEL. The MAPK and NF-${\kappa}B$ signaling pathways were found to be activated by GroEL to induce the expression of interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and tissue factor (TF). These effects were inhibited by a TLR4 knockdown. Our results thus indicate that TLR4 is a key receptor that mediates the interaction of F. nucleatum GroEL with HMEC-1 cells and subsequently induces an inflammatory response via the MAPK and NF-${\kappa}B$ pathways.

Antioxidant and Anti-inflammatory Activities of Allium victorialis subsp. platyphyllum Extracts

  • Lee, Je-Hyuk;Choi, Soo-Im;Lee, Yong-Soo;Kim, Gun-Hee
    • Food Science and Biotechnology
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    • v.16 no.5
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    • pp.796-801
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    • 2007
  • This study was conducted to investigate antioxidant activity and anti-immunological inflammatory effect of Allium victorialis subsp. platyphyllum extracts (AVPEs). Antioxidant activities of AVPEs were determined by free radical scavenging assay and reducing power test. Leaf-part extract had comparatively better antioxidant activity than other-part extracts. Antioxidant activity of extracts had protective effect for human umbilical vein endothelial cells (HUVECs) against superoxide anions secreted from activated neutrophils. Also, we observed AVPEs had inhibitory effects on the adherence of monocytic THP-1 to HUVEC monolayer to the basal level. Inhibitory effect on cell adhesion was caused by suppression of tumor necrosis factor-${\alpha}\;(TNF-{\alpha})-upregulated$ expression of vascular cellular adhesion molecule-1 (VCAM-1) and E-selectin in HUVECs. From these results, we expect to support the evidence of anti-immunological inflammatory effects of Allium victorialis subsp. platyphyllum (AVP) as a Korean traditional pharmaceutical.

The Role of Biomechanics in Tissue Engineering (조직공학에서 생체역학의 역할)

  • Park, Kwi-Deok
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1458-1460
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    • 2008
  • Tissue engineering is an interdisciplinary field that utilizes the principles of engineering and life sciences toward the creation of biological substitutes. Traditionally, major components of tissue engineering are cells, scaffolds, growth factors and recently biomechanical aspects have been given much attention. A large number of studies have reported that mechanical signals are of particular interest in either encouraging or inhibiting cellular responses. In tissue engineering, cell adhesion is a very important step, because quality of adhesion may determine a cell fate in the future. Elasticity of cell-adhesive substrate is found critical in regulating stem cell differentiation. Cells exert different contractile forces for cell migration, depending on substrate mechanics. Though tissue engineering is very interactive with diverse expertise, for a breakthrough, principles of biomechanics in tissue and cell level needs to be fully understood.

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