Vascular Cell Adhesion Molecule-1 Production Research Articles

IL-17 Facilitates VCAM-1 Production and Monocyte Adhesion in Osteoarthritis Synovial Fibroblasts by Suppressing miR-5701 Synthesis.

Osteoarthritis (OA) is characterized by the infiltration and adhesion of monocytes into the inflamed joint synovium. Interleukin (IL)-17 is a critical inflammatory mediator that participates in the progression of OA, although the mechanisms linking IL-17 and monocyte infiltration are not well understood. Our analysis of synovial tissue samples retrieved from the Gene Expression Omnibus (GEO) dataset exhibited higher monocyte marker (CD11b) and vascular cell adhesion molecule 1 (VCAM-1) levels in OA samples than in normal, healthy samples. The stimulation of human OA synovial fibroblasts (OASFs) with IL-17 increased VCAM-1 production and subsequently enhanced monocyte adhesion. IL-17 affected VCAM-1-dependent monocyte adhesion by reducing miR-5701 expression through the protein kinase C (PKC)-α and c-Jun N-terminal kinase (JNK) signaling cascades. Our findings improve our understanding about the effect of IL-17 on OA progression and, in particular, VCAM-1 production and monocyte adhesion, which may help with the design of more effective OA treatments.

Cordycerebroside A suppresses VCAM-dependent monocyte adhesion in osteoarthritis synovial fibroblasts by inhibiting MEK/ERK/AP-1 signaling

• VCAM1 and CD11b higher levels express in OA compared with healthy controls. • Cordycerebroside A suppressed VCAM-1 mediated-monocyte adhesion in human OASF. • The MEK/ERK/AP-1 signaling regulated cordycerebroside A effects. Osteoarthritis (OA) is characterized by the infiltration and adhesion of monocyte into the joint synovium. Vascular cell adhesion molecule 1 (VCAM-1) is a critical cell adhesion molecule that controls monocyte motility during OA progression. Cordycerebroside A, a cerebroside compound isolated from Cordyceps militaris , inhibits the production of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in synovial macrophages, but has not yet been investigated in OA. Gene Expression Omnibus (GEO) dataset analysis revealed higher levels of VCAM-1 and CD11b (a monocyte marker) in OA synovial tissue compared with normal healthy tissue. The same results were observed in anterior cruciate ligament transaction (ACLT)-induced OA in rats compared with normal healthy controls. Cordycerebroside A markedly suppressed VCAM-1 expression and monocyte adhesion in human OA synovial fibroblasts. The MEK, ERK and AP-1 signaling cascades regulated cordycerebroside A-induced inhibition of VCAM-1 production. Thus, cordycerebroside A is a promising agent for the treatment of OA.

CXCL13/CXCR5 Interaction Facilitates VCAM-1-Dependent Migration in Human Osteosarcoma.

Osteosarcoma is the most common primary tumor of the skeletal system and is well-known to have an aggressive clinical outcome and high metastatic potential. The chemokine (C-X-C motif) ligand 13 (CXCL13) plays a vital role in the development of several cancers. However, the effect of CXCL13 in the motility of osteosarcoma cells remains uncertain. Here, we found that CXCL13 increases the migration and invasion potential of three osteosarcoma cell lines. In addition, CXCL13 expression was upregulated in migration-prone MG-63 cells. Vascular cell adhesion molecule 1 (VCAM-1) siRNA and antibody demonstrated that CXCL13 promotes migration via increasing VCAM-1 production. We also show that CXCR5 receptor controls CXCL13-mediated VCAM-1 expression and cell migration. Our study identified that CXCL13/CXCR5 axis facilitate VCAM-1 production and cell migration in human osteosarcoma via the phospholipase C beta (PLCβ), protein kinase C α (PKCα), c-Src, and nuclear factor-κB (NF-κB) signaling pathways. CXCL13 and CXCR5 appear to be a novel therapeutic target in metastatic osteosarcoma.

Inhibitory Effects of Tranilast on Cytokine, Chemokine, Adhesion Molecule, and Matrix Metalloproteinase Expression in Human Corneal Fibroblasts Exposed to Poly(I:C)

ABSTRACTPurpose/Aim: Viral infection of the cornea can result in inflammation and scarring and eventually cause blindness. Polyinosinic–polycytidylic acid [poly(I:C)], an analog of viral double-stranded RNA, induces the synthesis of various cytokines, chemokines, adhesion molecules, and matrix metalloproteinases (MMPs) in corneal fibroblasts. The effects of tranilast on the expression of these molecules in human corneal fibroblasts were examined.Materials and methods: Human corneal fibroblasts were cultured with or without poly(I:C) or tranilast. The release of the proinflammatory cytokine interleukin (IL)-6 and of the chemokines IL-8 and monocyte chemotactic protein-1 (MCP-1) was measured with enzyme-linked immunosorbent assays. The expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), MMP-1, and MMP-3 was evaluated by immunoblot or immunofluorescence analysis. The phosphorylation of mitogen-activated protein kinases (MAPKs), c-Jun (a component of the transcription factor AP-1), and IκB-α (an endogenous inhibitor of the transcription factor NF-κB) was examined by immunoblot analysis.Results: Tranilast inhibited in a concentration- and time-dependent manner the production of IL-6, IL-8, MCP-1, ICAM-1, VCAM-1, MMP-1, and MMP-3 by corneal fibroblasts exposed to poly(I:C). It also inhibited the poly(I:C)-induced phosphorylation of c-Jun and the MAPK JNK without affecting that of IκB-α or the MAPKs ERK and p38.Conclusions: Tranilast inhibited proinflammatory cytokine, chemokine, adhesion molecule, and MMP expression in human corneal fibroblasts exposed to poly(I:C), with these effects likely being mediated by attenuation of JNK-AP-1 signaling. Tranilast might therefore be expected to limit immune cell infiltration and stromal degradation associated with viral infection of the cornea.

Simvastatin inhibits the expression of inflammatory cytokines and cell adhesion molecules induced by LPS in human dental pulp cells.

To investigate the effect of simvastatin on lipopolysaccharide (LPS)-stimulated inflammatory cytokines, cell adhesion molecules and nuclear factor-κB (NF-κB) transcription factors in human dental pulp cells (HDPCs). The effect of LPS and simvastatin on human dental pulp cell (HDPCs) viability was measured using a 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) assay. The expression of inflammatory cytokines and cell adhesion molecules was evaluated by reverse-transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. NF-κB transcription factors were evaluated by Western blot analysis. Statistical analysis was performed with analysis of variance (anova). The viability of cells exposed to different concentrations of E.coli LPS, P.gingivalis LPS and simvastatin was not significantly different compared with that of control cells (P>0.05). LPS significantly increased interleukin (IL)-1β (P<0.05) and IL-6 mRNA expression (P<0.05) and vascular cell adhesion molecule-1 (VCAM-1) (P<0.05) and intercellular adhesion molecule-1 (ICAM-1) protein expression (P<0.05) in HDPCs. Treatment with simvastatin significantly attenuated LPS-stimulated production of IL-1β, IL-6, VCAM-1 and ICAM-1 (P<0.05). Treatment with simvastatin decreased LPS-induced expression of p65 and phosphorylation of IκB and also significantly decreased the phosphorylation of p65 and IκB in the cytoplasm and the level of p65 in the nucleus (P<0.05). Simvastatin has a suppressing effect on LPS-induced inflammatory cytokine, cell adhesion molecules and NF-κB transcription factors in HDPCs. Therefore, simvastatin might be a useful candidate as a pulp-capping agent in vital pulp therapy.

EOLA1 Inhibits Lipopolysaccharide-Induced Vascular Cell Adhesion Molecule-1 Expression by Association with MT2A in ECV304 Cells.

Our research group firstly discovered endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1, GenBank number AY074889) as a lipopolysaccharide (LPS) responsive gene in ECV304 cells. The previous studies have further demonstrated the association of EOLA1 with metallothionein 2A (MT2A), while the role of EOLA1 during LPS-induced inflammatory response in ECV304 cells is unknown. In this report, we determined the subcellular localization of EOLA1 and the regulatory capacity of EOLA1 on vascular cell adhesion molecule-1 (VCAM-1) in response to LPS in ECV304 cells. Our results show that EOLA1 is broadly diffuse in the cells, and EOLA1 expression is dramatically induced by LPS. EOLA1 knockdown results in significant enhancement of LPS-induced VCAM-1 production. Consistent with this, overexpression of EOLA1 leads to the reduction of LPS-induced VCAM-1 production. Furthermore, MT2A knockdown reduces LPS-induced VCAM-1 production. Collectively, our results demonstrate a negative regulatory role of EOLA1 on LPS-induced VCAM-1 expression involving its association with MT2A in ECV304 cells.

The 18-kDa Translocator Protein Inhibits Vascular Cell Adhesion Molecule-1 Expression via Inhibition of Mitochondrial Reactive Oxygen Species.

Translocator protein 18 kDa (TSPO) is a mitochondrial outer membrane protein and is abundantly expressed in a variety of organ and tissues. To date, the functional role of TSPO on vascular endothelial cell activation has yet to be fully elucidated. In the present study, the phorbol 12-myristate 13-acetate (PMA, 250 nM), an activator of protein kinase C (PKC), was used to induce vascular endothelial activation. Adenoviral TSPO overexpression (10–100 MOI) inhibited PMA-induced vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) expression in a dose dependent manner. PMA-induced VCAM-1 expressions were inhibited by Mito-TEMPO (0.1–0.5 μM), a specific mitochondrial antioxidants, and cyclosporin A (1–5 μM), a mitochondrial permeability transition pore inhibitor, implying on an important role of mitochondrial reactive oxygen species (ROS) on the endothelial activation. Moreover, adenoviral TSPO overexpression inhibited mitochondrial ROS production and manganese superoxide dismutase expression. On contrasts, gene silencing of TSPO with siRNA increased PMA-induced VCAM-1 expression and mitochondrial ROS production. Midazolam (1–50 μM), TSPO ligands, inhibited PMA-induced VCAM-1 and mitochondrial ROS production in endothelial cells. These results suggest that mitochondrial TSPO can inhibit PMA-induced endothelial inflammation via suppression of VCAM-1 and mitochondrial ROS production in endothelial cells.

Inhibitory effect of Malvidin on TNF-α-induced inflammatory response in endothelial cells

Vascular inflammatory responses are key mediators of endothelial dysfunction that leads to various pathologies in many diseases including atherosclerosis and cancer. The purpose of the study was to investigate the effects and molecular mechanisms of Malvidin, a natural pigment with strong antioxidant activity, on regulating inflammatory response in endothelial cells. Our results showed that tumor necrosis factor-alpha (TNF-α) significantly increased the protein or mRNA levels of monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1), whereas pretreatment with Malvidin inhibited TNF-α-induced increases of MCP-1, ICAM-1, and VCAM-1 production in a concentration-dependent manner. In addition, Malvidin could inhibit degradation of IκBα and the nuclear translocation of p65, which suggesting the anti-inflammation mechanism of Malvidin by the nuclear factor kappa B (NF-κB) pathway. These results indicate the potential role of Malvidin in preventing chronic inflammation in many diseases.

Chlorella 11-Peptide Inhibits the Production of Macrophage-Induced Adhesion Molecules and Reduces Endothelin-1 Expression and Endothelial Permeability

The inflammation process in large vessels involves the up-regulation of vascular adhesion molecules such as endothelial cell selectin (E-selectin), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) which are also known as the markers of atherosclerosis. We have reported that Chlorella 11-peptide exhibited effective anti-inflammatory effects. This peptide with an amino sequence Val-Glu-Cys-Tyr-Gly-Pro-Asn-Arg-Pro-Gln-Phe was further examined for its potential in preventing atherosclerosis in this study. In particular, the roles of Chlorella 11-peptide in lowering the production of vascular adhesion molecules, monocyte chemoattractant protein (MCP-1) and expression of endothelin-1 (ET-1) from endothelia (SVEC4-10 cells) were studied. The production of E-selectin, ICAM-1, VCAM-1 and MCP-1 in SVEC4-10 cells was measured with ELISA. The mRNA expression of ET-1 was analyzed by RT-PCR and agarose gel. Results showed that Chlorella 11-peptide significantly suppressed the levels of E-selectin, ICAM, VCAM, MCP-1 as well as ET-1 gene expression. The inhibition of ICAM-1 and VCAM-1 production by Chlorella 11-peptide was reversed in the presence of protein kinase A inhibitor (H89) which suggests that the cAMP pathway was involved in the inhibitory cause of the peptide. In addition, this peptide was shown to reduce the extent of increased intercellular permeability induced by combination of 50% of lipopolysaccharide (LPS)-activated RAW 264.7 cells medium and 50% normal SEVC cell culture medium (referred to as 50% RAW-conditioned medium). These data demonstrate that Chlorella 11-peptide is a promising biomolecule in preventing chronic inflammatory-related vascular diseases.

Role of JNK and NF-κB pathways in Porphyromonas gingivalis LPS-induced vascular cell adhesion molecule-1 expression in human aortic endothelial cells

An increasing number of studies have shown a correlation between Porphyromonas gingivalis (P. gingivalis) infection and atherosclerosis. A recent study demonstrated that the expression of vascular cell adhesion molecule-1 (VCAM-1) was induced by P. gingivalis lipopolysaccharide (LPS) in human aortic endothelial cells (HAECs). The activation of p38 mitogen-activated protein kinase (p38 MAPK) was at least partially involved in this process. Those results suggested the potential involvement of P. gingivalis LPS in the pathogenesis of atherosclerosis. However, the mechanism involved in P. gingivalis LPS-induced VCAM-1 production has not yet been elucidated. The present study examined the role of the c-Jun N-terminal kinase (JNK) and nuclear factor‑κB (NF‑κB) cell signaling pathways in P. gingivalis LPS-induced VCAM-1 expression in HAECs. Western blotting was used to investigate the activation of JNK and NF‑κB pathways in HAECs exposed to P. gingivalis LPS. Following this, specific pharmacological inhibitors were introduced and the protein production of VCAM-1 was studied. The results showed that the JNK and NF‑κB pathways in HAECs were capable of being activated by P. gingivalis LPS. The inhibition of NF-κB by SN50 significantly attenuated P. gingivalis LPS-induced VCAM-1 expression, while the inhibition of JNK by SP600125 enhanced VCAM-1 expression in P. gingivalis LPS-treated HAECs. Therefore, the results indicated that NF‑κB was essential for the P. gingivalis LPS-induced VCAM-1 expression in HAECs and that JNK may be a suppressor of VCAM-1 expression in HAECs.

Role of p38 Mitogen‐Activated Protein Kinase Pathway in Porphyromonas gingivalis Lipopolysaccharide–Induced VCAM‐1 Expression in Human Aortic Endothelial Cells

Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) has been reported to induce the expression of vascular cell adhesion molecule-1 (VCAM-1) in vascular endothelial cells. This finding suggests the potential roles for Pg in the pathogenesis of atherosclerosis. However, the mechanism involved in Pg LPS-induced VCAM-1 production in endothelial cells remains unclear. Quantitative real-time polymerase chain reaction and Western blotting were used, respectively, to investigate the mRNA expression and protein production of VCAM-1 in human aortic endothelial cells (HAECs) induced by Pg LPS. The involvement of the p38 mitogen-activated protein kinase (p38 MAPK) cell signaling pathway in VCAM-1 expression was investigated by assays with specific inhibitors. Pg LPS-induced expression in HAECs of VCAM-1 occurred in a dose- and time-dependent manner. In addition, the p38 MAPK inhibitor (SB 203580) significantly attenuated Pg LPS-induced VCAM-1 expression. Activation of p38 MAPK is at least partially involved in Pg LPS-induced VCAM-1 expression in HAECs, which may contribute to the acceleration of atherosclerosis.

Nuclear-localized focal adhesion kinase regulates inflammatory VCAM-1 expression

Vascular cell adhesion molecule-1 (VCAM-1) plays important roles in development and inflammation. Tumor necrosis factor-α (TNF-α) and focal adhesion kinase (FAK) are key regulators of inflammatory and integrin-matrix signaling, respectively. Integrin costimulatory signals modulate inflammatory gene expression, but the important control points between these pathways remain unresolved. We report that pharmacological FAK inhibition prevented TNF-α-induced VCAM-1 expression within heart vessel-associated endothelial cells in vivo, and genetic or pharmacological FAK inhibition blocked VCAM-1 expression during development. FAK signaling facilitated TNF-α-induced, mitogen-activated protein kinase activation, and, surprisingly, FAK inhibition resulted in the loss of the GATA4 transcription factor required for TNF-α-induced VCAM-1 production. FAK inhibition also triggered FAK nuclear localization. In the nucleus, the FAK-FERM (band 4.1, ezrin, radixin, moesin homology) domain bound directly to GATA4 and enhanced its CHIP (C terminus of Hsp70-interacting protein) E3 ligase-dependent polyubiquitination and degradation. These studies reveal new developmental and anti-inflammatory roles for kinase-inhibited FAK in limiting VCAM-1 production via nuclear localization and promotion of GATA4 turnover.

Involvement of mitogen-activated protein kinases and peroxisome proliferator-activated receptor γ in monosodium urate crystal-induced vascular cell adhesion molecule 1 expression in human rheumatoid arthritis synovial fibroblasts

To investigate whether monosodium urate (MSU) crystals could induce the production of VCAM-1 (vascular cell adhesion molecule1) in human synovial cells and its possible signaling pathways, human synovial cells isolated from synovial tissue explants were stimulated with various doses of MSU crystals for different time intervals. Expression of VCAM-1 was evaluated with Western blotting. To explore the underlying mechanisms, VCAM-1 protein expression was also evaluated after activation of several signaling molecules including mitogen-activated protein kinases (MAPKs) and peroxisome proliferator-activated receptorγ (PPARγ) were blocked. Exposure of synovial cells to MSU crystals induced VCAM-1 expression in culture medium in a dose- and time-dependent manner, reaching a plateau at 1000µM and 24h. Inhibition of the activation of MAPKs and PPARγ could block this increase. The present results demonstrated that MSU crystals could induce VCAM-1 expression. MAPKs and PPARγ signaling pathways regulated the induced VCAM-1 expression.

Serum Amyloid A Directly Accelerates the Progression of Atherosclerosis in Apolipoprotein E-Deficient Mice

Although serum amyloid A (SAA) is an excellent marker for coronary artery disease, its direct effect on atherogenesis in vivo is obscure. In this study we investigated the direct effect of SAA on promoting the formation of atherosclerosis in apolipoprotein E-deficient (ApoE⁻/⁻) mice. Murine SAA lentivirus was constructed and injected into ApoE⁻/⁻ mice intravenously. Then, experimental mice were fed a chow diet (5% fat and no added cholesterol) for 14 wks. The aortic atherosclerotic lesion area was larger with than without SAA treatment. With increased SAA levels, the plasma levels of interleukin-6 and tumor necrosis factor-α were significantly increased. Macrophage infiltration in atherosclerotic regions was enhanced with SAA treatment. A migration assay revealed prominent dose-dependent chemotaxis of SAA to macrophages. Furthermore, the expression of monocyte chemotactic protein-1 and vascular cell adhesion molecule-1 (VCAM-1) was upregulated significantly with SAA treatment. SAA-induced VCAM-1 production was detected in human aortic endothelial cells in vitro. Thus, an increase in plasma SAA directly accelerates the progression of atherosclerosis in ApoE⁻/⁻ mice. SAA is not only a risk marker for atherosclerosis but also an active participant in atherogenesis.

Genipin Selectively Inhibits TNF-α-activated VCAM-1 But Not ICAM-1 Expression by Upregulation of PPAR-γ in Human Endothelial Cells

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-γ (PPAR-γ) selectively inhibits vascular cell adhesion molecule-1 (VCAM-1) but not intercellular cell adhesion molecule-1 (ICAM-1) in tumor necrosis factor (TNF)-α-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-α-activated HUVEC. Genipin dose- and time-dependently increased PPAR-γ expression and inhibited TNF-α-induced phosphorylation of Akt and PKC with different degrees. Finally, genipin prevented TNF-α-induced adhesion of U937 monocytic cells to HUVEC. Taken together, these results indicate that upregualtion of PPAR-γ by genipin selectively inhibits TNF-α-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.

Egg-Derived Peptide IRW Inhibits TNF-α-Induced Inflammatory Response and Oxidative Stress in Endothelial Cells

Oxidative stress and vascular inflammatory response are key mediators of endothelial dysfunction that leads to cardiovascular diseases. A novel peptide, IRW, was previously characterized from egg protein with angiotensin converting enzyme inhibitory activity. The purpose of the study was to investigate the effects and molecular mechanisms of IRW on regulating inflammatory response in endothelial cells. The results showed that tumor necrosis factor-α (TNF-α) significantly increased the protein levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1), whereas pretreatment with IRW inhibited TNF-α-induced increases of ICAM-1, VCAM-1, and MCP-1 production in a concentration-dependent manner. IRW also reduced the levels of superoxide ions in the presence and absence of TNF-α. These results indicate the potential role of IRW in preventing cardiovascular disease as a functional food ingredient or nutraceutical.

Hemoglobin induced oxidative stress is associated with both endogenous peroxidase activity and H2O2 generation from polyunsaturated fatty acids

Patients with increased hemolytic hemoglobin (Hb) have 10–20 times greater incidence of cardiovascular mortality than the general population. In the presence of an exogenous source of H2O2, Hb is essential and responsible for the oxidation of low‐density lipoproteins (LDL). However, the role of Hb peroxidase activity in LDL oxidation remains elusive. Our study indicated that Hb could induce the formation of H2O2 by reacting with LDL, linoleic acid, and cell membrane lipid extracts. In the presence of NaN3 (a peroxidase inhibitor), endogenous peroxidase activity and subsequent Hb‐induced LDL oxidation was significantly inhibited and H2O2 concentrations accumulated. Furthermore, Hb was shown to dramatically stimulate the expression of intercellular adhesion molecule‐1 (ICAM‐1) and vascular cell adhesion molecule‐1 (VCAM‐1) in both a concentration‐ and time‐ dependent manner. Nevertheless, this stimulation was completely inhibited by a potent antioxidant, probucol. We found that 2, 2′azo‐bis‐(2‐amindinopropane) hydrochloride (AAPH) could also induce LDL oxidation and stimulate the expression of ICAM‐1 and VCAM‐1, but was not inhibited by NaN3. In conclusion, the present study suggests that the oxidative effect of Hb to produce atherogenic oxidized LDL and to induce the production of ICAM‐1 and VCAM‐1 are due to H2O2 formation as well as its endogenous peroxidase activity toward polyunsaturated fatty acids. The biochemical and physiologic significance of this study are discussed.

Expression and secretion of the vascular cell adhesion molecule-1 in human placenta and its decrease in fetal growth restriction.

The vascular cell adhesion molecule-1 (VCAM-1) is a member of the immunoglobulin gene superfamily and is expressed principally on endothelial cells. The present study was undertaken to compare the expression and secretion of VCAM-1 from normal pregnancies and those complicated by fetal growth restriction (FGR). Placentas from first-trimester (FT) (n = 17), normal term (n = 19), and FGR (n = 16) patients were collected immediately after elective cesarean delivery. VCAM-1 mRNA expression profiles by reverse transcriptase polymerase chain reaction, protein levels by enzyme-linked immunosorbent assay using explant culture in vitro, and its cellular localization by confocal microscopy were compared between FGR and normal placentas. Functionally active placental explants were used to detect immunoreactive VCAM-1 in conditioned media of all the samples from the three groups. The mean levels of VCAM-1 produced by FT villi were found to be 1.9-, 1.7-, and 1.5-fold higher (P <.02) than term villi at 24, 48, and 72 hours of culture, respectively. Conversely, the respective mean levels of VCAM-1 produced by FGR placental villi were 2.3-, 2.5-, and 2.0-fold lower than levels of the normal term placental villi (P <.05). The secretion profiles of VCAM-1 from FT, term, and FGR villi correlated well with the mRNA levels; the amount secreted in FT villi was twice that of term villi. Moreover, mRNA transcripts from FGR pregnancies showed significantly decreased expression, in conformity with explant results. The presence of VCAM-1 in placental villi and down-regulation of its production at term indicate that VCAM-1 production is specific to developmental stage. The decreased VCAM-1 expression in FGR pregnancy could be attributed to the uteroplacental deficiency that is characteristic of this condition.

Differential influences of bFGF and VEGF on the expression of vascular cell adhesion molecule-1 on human umbilical vein endothelial cells

A fundamental feature of inflammation includes angiogenesis, adhesion of leukocytes to vascular endothelium, and entry of leukocytes into inflamed tissues. Recent studies have suggested that angiogenesis and cellular adhesion may be mutually linked processes. Both basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have been shown to facilitate angiogenesis. However, their roles in the expression of adhesion molecules on the endothelial cells have not been clarified. The current studies therefore examined the effect of bFGF and VEGF on the expression of vascular cell adhesion molecule-1 (VCAM-1) on human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor alpha (TNF-alpha). HUVEC (1 x 10(4)/well) were incubated in a 96 well microtiter plate with culture medium containing endothelial cell growth supplement (ECGS) for 24 h. After the incubation, culture medium was replaced by ECGS free culture medium with or without TNF-alpha (10 ng/ml), bFGF (10 ng/ml) and VEGF (10 ng/ml), and the culture was further carried out for additional 24 h. The expression of VCAM-1, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) was measured by cell ELISA and the proliferation of HUVEC was measured by MTT colorimetric assay. Soluble VCAM-1 (sVCAM-1) in the supernatants were assessed by ELISA. Although, both bFGF and VEGF supported the proliferation of HUVEC, bFGF, but not VEGF, selectively suppressed the expression of VCAM-1 on HUVEC stimulated with TNF-alpha. The expression of ICAM-1 and E-selectin induced by TNF-alpha was not inhibited by either bFGF or VEGF. In addition, bFGF also decreased the levels of sVCAM-1 in the supernatants of TNF-alpha stimulated HUVEC. The data indicate that bFGF, but not VEGF, suppresses the production of VCAM-1 by HUVEC under stimulation with TNF-alpha. These results therefore suggest that angiogenic cytokines bFGF and VEGF play different roles in the regulation of the expression of adhesion molecules on endothelial cells under inflammation.

Relationship between circulating vascular cell adhesion molecule-1 and microvascular complications in type 2 diabetes mellitus.

The soluble form of the vascular cell adhesion molecule-1 (VCAM-1) is detectable in human sera and is elevated in diabetic patients, with unknown clinical significance. In the present study, the relationship between serum soluble VCAM-1 and diabetic microvascular complications (retinopathy, nephropathy, and neuropathy) was evaluated in 95 Japanese patients with Type 2 diabetes mellitus (DM). Serum soluble VCAM-1 concentration was higher in patients with more advanced stages of retinopathy as well as nephropathy. There was a significant correlation between soluble VCAM-1 and log10 (urinary albumin excretion) in 69 patients with normal serum creatinine levels (r = 0.51, p < 0.0001) and a significant correlation between soluble VCAM-1 and log10 (serum creatinine) in all the patients (r = 0.83, p < 0.0001). Soluble VCAM-1 concentration was also elevated in patients with neuropathy. There was a significant correlation between soluble VCAM-1 concentration and the number of microvascular complications (r = 0.59, p < 0.0001). However, multivariate regression analysis revealed that only diabetic nephropathy, was associated with the soluble VCAM-1 concentration. The elevation of circulating VCAM-1 level in diabetic nephropathy may result from underlying systemic endothelial dysfunction, increased VCAM-1 production in damaged renal tubular or glomerular epithelial cells and/or decreased renal clearance of this molecule, depending on the stage of nephropathy.