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α-Synuclein was originally identified as the precursor of non-amyloid β component of Alzheimer''s disease amyloid (NAC). NAC is detected in cerebral amyloid angiopathy; and we studied whether cerebral vascular cells express α-synuclein. Immunohistochemical studies of normal human cerebral tissues revealed the expression of α-synuclein in vascular endothelial and smooth muscle cells. Also cultures of human umbilical vein endothelial cells and umbilical artery smooth muscle cells were found, by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis, to constitutively express α-synuclein mRNA. Western blot analysis disclosed the presence of α-synuclein protein in lysates of these cells. We conclude that vascular cells express α-synuclein, and it may play some role in the physiology of the vascular wall. [Copyright &y& Elsevier]

Background: Galectin-9 is involved in chemotaxis and adhesion of eosinophils, and is induced in vascular endothelial cells by interferon-γ (IFN-γ). 15-Deoxy-Δ[sup 12,14] -prostaglandin J[sub 2] (15d-PGJ[sub 2] ) is a ligand for peroxisome proliferator-activated receptor-γ (PPAR-γ), and known to modulate the expression of various genes. Methods: We have studied the effect of 15d-PGJ[sub 2] on the IFN-γ-induced galectin-9 expression in human umbilical vein endothelial cells (HUVEC) in culture. Results: 15d-PGJ[sub 2] inhibited the IFN-γ-induced galectin-9 expression in a PPAR-γ-independent manner, and also inhibited the adhesion of EoL-1 cells to an HUVEC monolayer treated with IFN-γ. 15d-PGJ[sub 2] partially inhibited IFN-γ-induced phosphorylation of STAT-1 in HUVEC. Conclusions: 15d-PGJ[sub 2] may regulate inflammatory reactions through the inhibition of galectin-9 expression.Copyright © 2003 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Summary Peroxisome proliferator-activated receptor-γ (PPAR-γ)is a member of nuclear hormone receptor superfamily, and is knownto play a role in various biological processes including inflammatoryresponses and adipocyte differentiation. CX3CL1/fractalkineis a potent agonist for chemotaxis and adhesion of monocytes and lymphocytes.Endothelial cells produce fractalkine when stimulated with cytokinessuch as interleukin-1 (IL-1), tumour necrosis factor-α andinterferon-γ (IFN-γ). We herein report that 15-deoxy-n12,14 -prostaglandinJ2 (15d-PGJ2 ), a PPAR-γ agonist,inhibits the expression of fractalkine induced by IFN-γ orIL-1β in human endothelial cells. Agonist for PPAR-α (WY14643)or PPAR-γ (ciglitazone) did not inhibit the cytokine-inducedfractalkine expression, and the effect of 15d-PGJ2 maybe independent of PPAR. 15-Deoxy- D12,14 prostaglandinJ2 also inhibited the adhesion of blood mononuclear cellsto endothelial monolayers treated with IFN-γ or IL-1β.The data suggest that 15d-PGJ2 regulates inflammatoryreactions, at least in part, through the inhibition of fractalkineexpression and leucocyte traffic through the endothelium. [ABSTRACT FROM AUTHOR]

The non-amyloid β component of Alzheimer''s disease amyloid (NAC) is detected in cerebral amyloid angiopathy; and the precursor of NAC is now known to be identical to α-synuclein (α-S), a major component of Lewy bodies in Parkinson''s disease. We studied if cerebral vascular cells express α-S. Immunohistochemical studies of human cerebral tissues from control and cerebral amyloid angiopathy patients revealed the expression of α-S in vascular endothelial and smooth muscle cells. Then we studied the expression of α-S in vitro using cultures of vascular cells. Cultures of human umbilical vein endothelial cells and umbilical artery smooth muscle cells were found to constitutively express α-S messenger RNA and protein. α-S is normally expressed in vascular cells and may play some physiological role in the vascular wall. [Copyright &y& Elsevier]

Growth related oncogene protein-alpha (GRO-alpha) is a member of C-X-C chemokine and plays an important role in inflammatory responses. Expression of GRO gene family is regulated by a number of factors at both transcriptional and posttranscriptional levels. In the present study, we have addressed the possible regulation of GRO-alpha expression by ubiquitin-proteasome system. Cultures of human umbilical vein endothelial cells were treated with a proteasome inhibitor, MG132, and the levels of GRO-alpha mRNA were analyzed by reverse transcription-polymerase chain reaction or northern blotting. Levels of GRO-alpha protein in the cell-conditioned medium were determined by enzyme-linked immunosorbent assay. MG132 alone increased the levels of GRO-alpha mRNA and protein; however, it did not affect the GRO-alpha mRNA induced by lipopolysaccharide (LPS) and inhibited the LPS-induced decrease in IkappaB levels. Other proteasome inhibitors, MG115 and lactacystin, also induced the expression of GRO-alpha mRNA. MG132 induced the phosphorylation of p38 MAPK, MEK and JNK. Pretreatment of the cells with SB203580, an inhibitor of p38 MAPK, suppressed the MG132-induced GRO-alpha expression, but pretreatment of the cells with U0126, PD98059 or SP600125, inhibitors of MEK1/2 or JNK, did not influence the effect of MG132. We conclude that MG132 upregulates GRO-alpha expression in vascular endothelial cells, at least in part, through the activation of p38 MAPK.

CX3CL1/fractalkine is a chemokine with a unique CX3C motif. Hypoxia mediates the expression of various genes, such as vascular endothelial growth factor (VEGF), cyclooxygenase-2, and plasminogen-activator inhibitor-1, in vascular endothelial cells. We studied the effect of hypoxia on the expression of fractalkine induced by interferon-gamma (IFN-gamma) in endothelial cells. Human umbilical vein endothelial cells were cultured, and the stimulation of the cells with IFN-gamma was found to induce the expression of fractalkine. Hypoxia inhibited the expression of fractalkine mRNA and protein by IFN-gamma, and this effect was observed with concomitant increase in VEGF expression. Desferrioxamine, an iron chelator that mimics hypoxia in vitro, also inhibited the fractalkine production induced by IFN-gamma. Hypoxia did not affect the degradation of fractalkine mRNA. The inhibition of fractalkine expression by hypoxia was reversed on returning the cultures to reoxygenation condition. Inhibition of IFN-induced fractalkine expression by hypoxia was not affected by the presence of a radical scavenger, N-acetyl-L-cysteine, and the involvement of reactive oxygen species may be excluded. Inhibition of fractalkine expression by hypoxia may be involved in the pathophysiology of ischemic diseases.

Background: Cyclin E and p27 play pivotal roles in cancer development and progression. We investigated whether the prognosis in cases of non-small cell lung cancer without lymph node metastases that underwent complete resection could be associated with tissue expression of cyclin E, p27, and Ki-67., Methods: Tumors from 62 patients at least 5 years after surgery were assessed by immunohistochemistry for expression of cyclin E, p27, and Ki-67. Disease-free survival (DFS) after surgery was used to evaluate disease prognosis. We also investigated the relationship between expression of these factors and postoperative recurrence., Results: In non-small cell lung cancer, p27-negative expression and pT factor were significantly unfavorable prognostic factors in multivariate analysis. The DFS rate in cyclin E-positive expression was significantly lower than in cyclin E-negative expression. Similarly, p27-negative expression and high Ki-67 expression correlated with a shortened DFS rate. In combinations of expression of cyclin E and p27, the cyclin E-negative/p27-positive group had a significantly higher DFS rate than did the other groups. According to histological type, there were correlations between the risk of postoperative recurrence and expression of these three biological factors, especially in adenocarcinoma., Conclusion: By analyzing the expression of cyclin E, p27, and Ki-67 of tumor cells, it was possible to extract the patient group for whom closer follow-up and postoperative treatment is necessary to improve survival rate.

Galectin-9 is a member of the galectin family and has been identified as an eosinophil chemoattractant produced by activated T lymphocytes. Vascular endothelial cells play an important role in the initial step of eosinophil recruitment and activation in immune and inflammatory responses. We have addressed the stimulation of galectin-9 expression in endothelial cells. Galectin-9 was detected in membrane and cytosolic fractions of human umbilical vein endothelial cells stimulated with interferon-gamma (IFN-gamma). IFN-gamma also enhanced the adhesion of human eosinophilic leukemia-1 cells to endothelial monolayers, and it was inhibited by the presence of lactose. Interleukin-4, which induces eotaxin expression, did not affect the expression of galectin-9. The in situ endothelium from patients with inflammatory diseases was found to express galectin-9. IFN-gamma-induced production of galectin-9 by endothelial cells may play an important role in immune responses by regulating interactions between the vascular wall and eosinophils.

Plasminogen activator inhibitor-1 (PAI-1) is one of the target genes of hypoxia inducible factor-1alpha (HIF-1alpha). Besides being an important physiological regulator of the fibrinolytic system PAI-1 is also involved in cancer invasiveness. HIF-1alpha is expressed in various types of pulmonary cells, but the relation of PAI-1 to HIF-1alpha under hypoxic condition in these cells are not fully elucidated. We, therefore, studied the effect of hypoxia on the expression of PAI-1 in a lung cancer cell line EBC-1. The expression of HIF-1alpha protein in EBC-1 cells was enhanced by hypoxia, and this was associated with increased secretion of PAI-1. Hypoxia did not affect the levels of HIF-1alpha mRNA but enhanced the PAI-1 mRNA. Pretreatment of the cells with MG132, which inhibits the proteasomal degradation of HIF-1alpha, increased the production of PAI-1 under both normoxia and hypoxia. We conclude that hypoxia induces PAI-1 expression, in EBC-1 cells, through the stabilization of HIF-1 complex and this may be related to cancer metastasis.