Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By extrapolation from the responses of cultured human umbilical vein endothelial cells (EC) and bovine aortic EC to short-term cytokine stimulation, EC activation is postulated as a likely component of the host response in acute allograft rejection and cardiac transplant-associated accelerated arteriosclerosis. To investigate the extent to which EC activation occurs in vivo in humans and to identify potential targets for therapeutic interventions, we compared the phenotypic characteristics of vascular EC as seen during clinicopathologically significant vs non-significant acute cardiac allograft rejection. We used monoclonal and monospecific polyclonal antibodies to coagulation molecules [tissue factor, thrombomodulin (TM), antithrombin III (AT-III), fibrinogen/fibrin, cross-linked fibrin and von Willebrand factor (vWF)], adhesion molecules (P-selectin, ICAM-1) and major histocompatibility complex (MHC) class I and II molecules. In addition we sought evidence of local cytokine production (IL-1, IL-2R, IL-4, IL-6, IL-7, IL-8, TNF-alpha, PDGF-AA, PDGF-BB), which might mediate alterations in expression of these proteins. We found that in clinically significant grades of cardiac allograft rejection requiring increased immunosuppression, in contrast to lesser grades of rejection not requiring clinical intervention, there was increased microvascular EC activation and differential expression of cytokines. EC changes associated with more extensive cardiac allograft rejection requiring treatment included: (i) disruption of the normal anticoagulant state with downregulation of TM and AT-III, upregulation of tissue factor and vWF expression, and associated extensive fibrin deposition; (ii) upregulation of MHC class I antigens, which are potential targets for host cytotoxic T lymphocytes; (iii) increased expression of the leucocyte adhesion molecules P-selectin and ICAM-1; (iv) expression of the pro-inflammatory cytokines IL-1 beta and TNF-alpha; and (v) increased expression of PDGF-AA and BB, which are known to promote migration and proliferation of intimal cells, and hence may contribute to development of transplant-associated atherosclerosis. Collectively these findings suggest that immune events resulting in EC surface changes and/or production of key cytokines play a role in the pathogenesis of acute transplant rejection and may contribute to the long-term complication of accelerated arteriosclerosis in allograft coronary arteries.
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PMID:Endothelial activation and cytokine expression in human acute cardiac allograft rejection. 953 4

1. Extracellular adenosine triphosphate (ATP) is mitogenic for vascular smooth muscle cells (VSMC) and stimulates several events that are important for cell proliferation: DNA synthesis, protein synthesis, increase of cell number, immediate early genes, cell-cycle progression, and tyrosine phosphorylation. 2. Receptor characterization indicates mitogenic effects of both P2U and P2Y receptors. The P2X receptor is lost in cultured VSMC and is not involved. Several related biological substances such as UTP, ITP, GTP, AP4A, ADP, and UDP are also mitogenic. 3. Signal transduction is mediated via Gq-proteins, phospholipase C beta, phospholipase D, diacyl glycerol, protein kinase C alpha, delta, Raf-1, MEK, and MAPK. 4. ATP acts synergistically with polypeptide growth factors (PDGF, bFGF, IGF-1, EGF, insulin) and growth factors acting via G-protein-coupled receptors (noradrenaline, neuropeptide Y, 5-hydroxytryptamine, angiotensin II, endothelin-1). 5. The mitogenic effects have been demonstrated in rat, porcine, and bovine VSMC and cells from human coronary arteries, aorta, and subcutaneous arteries and veins. 6. The trophic effects on VSMC and the abundant sources for extracellular ATP in the vessel wall make a pathophysiological role probable in the development of atherosclerosis, neointima-formation after angioplasty, and possibly hypertension.
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PMID:Extracellular ATP: a growth factor for vascular smooth muscle cells. 959 70

Vascular smooth muscle cells (VSMC), under conditions of induced proliferation, similar to those involved in atherosclerosis, secrete an acidic glycan, 82% of which exhibits structural homology with hyaluronic acid (HA), has a molecular mass of 340 kDa (HA-340) and inhibits VSMC proliferation in vitro. In this study, the expression of glycans was investigated in human atheromatic aortas and evidence is presented that a HA molecule, similar to HA-340, is distinctly expressed in all aortic layers. The isolation of the glycans from human aortas was performed after homogenization of the individual aortic layers (atheromatic plaque, tunica intima, tunica media and tunica adventitia), by lipid extraction and extensive digestion with pronase and DNase. The total glycans were purified from the digestion products by gel filtration on Sephadex G-25 and fractionated on a Superose 6 column. Enzymatic treatment of the ensuing glycan fractions with all known glycosaminoglycan-degrading enzymes, followed by electrophoresis on polyacrylamide gradient gels and cellulose acetate membranes, revealed that, in addition to HA, the tunica intima and the atheromatic plaque also contained dermatan sulfate, while the tunica media and the tunica adventitia also contained chondroitin sulfates and heparan sulfate. The highest concentration of the human aorta HA was found in the tunica media, exhibiting a negative concentration gradient from the tunica media to the atheromatic plaque. Investigation of the biological function of the human aorta HA revealed that this molecule acts as a negative regulator on the PDGF-induced VSMC proliferation and as a positive regulator on the PDGF-induced VSMC migration. The differential expression of HA within the aortic layers correlates with the biological function attributed to this acidic glycan and associates it with key events in the progression of atherogenesis.
Atherosclerosis 1998 May
PMID:The differential distribution of hyaluronic acid in the layers of human atheromatic aortas is associated with vascular smooth muscle cell proliferation and migration. 967 73

Long-term treatment with n-3 eicosapentaenoic acid (EPA) has been shown to exert hypotensive effects and have beneficial effects on atherosclerosis. To elucidate one of the underlying mechanisms of these effects, intracellular calcium concentration [Ca2+]i, and resting membrane potential were measured in rat vascular smooth muscle cells (A7r5 cell) treated with EPA, using Ca2+-sensitive dye fura-2 AM and the patch clamp technique. The alterations in fatty acid compositions of phospholipids and cell migration after treatment with EPA (30 microM) for 6 h-7 days were also examined. After treating cells with EPA, the EPA and DPA (docosapentaenoic acid) content of the phospholipid fraction (mol.%) increased in a time-dependent manner. Alternatively, arachidonic acid (AA) decreased, and then the ratio of EPA and AA (EPA/AA) increased significantly. The resting [Ca2+]i decreased from 170 +/- 46 nM (n = 16) in control cells to 123 +/- 29 nM (n = 16) in cells treated with EPA (30 microM) for 7 days. Vasopressin (100 nM), endothelin-1 (100 nM) and platelet-derived growth factor (PDGF 5 ng/ml) evoked an initial peak of [Ca2+]i, followed by a smaller sustained rise of [Ca2+]i in the presence of extracellular Ca2+. In EPA-treated cells, both the peak and the sustained rise of [Ca2+]i induced by these agonists decreased in comparison to the control cells. EPA treatment also decreased the transient [Ca2+]i rise evoked by these agonists in the absence of extracellular Ca2+. Under the current clamp condition, resting membrane potential was significantly higher in EPA-treated cells (-49.8 +/- 10.4 mV, n = 41) than in control cells (-44.6 +/- 7.4 mV, n = 41, P < 0.05), and the input resistance of the cell was lower in EPA-treated cells, while cell size and capacitance were not statistically different. In addition, long-term treatment with EPA for 7 days significantly inhibited PDGF-induced cell migration. These results suggest that cellular incorporation of n-3 eicosapentaenoic acid attenuates intracellular mechanisms related to changes of [Ca2+]i and affects membrane potential, thereby inhibiting migration of vascular smooth muscle cells. These actions of EPA may contribute to its vasorelaxant and antiatherosclerotic effects.
Atherosclerosis 1998 May
PMID:Influence of cellular incorporation of n-3 eicosapentaenoic acid on intracellular Ca2+ concentration and membrane potential in vascular smooth muscle cells. 967 77

Phosphorylated tyrosine residues of growth factor receptors that associate with intracellular proteins containing src-homology 2 (SH2) domains are integral components in several signal transduction pathways related to proliferative diseases such as cancer, atherosclerosis, and restenosis. In particular, a phosphorylated pentapeptide [pTyr751-Val-Pro-Met754-Leu (pTyr = phosphotyrosine)] derived from the primary sequence of platelet-derived growth factor-beta (PDGF-beta) receptor blocks the association of the C-terminal SH2 domain of the p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) to PDGF-beta receptor with an IC50 of 0.445 +/- 0.047 microM. Further evaluation of the structure-activity relationships for pTyr751-Val-Pro-Met-Leu resulted in the design of smaller peptidomimetics with enhanced affinity including Ac-pTyr-Val-Ala-N(C6H13)2 (IC50 = 0.076 +/- 0.010 microM). In addition, the phosphotyrosine residue was replaced with a difluorophosphonate derivative [4-phosphono(difluoromethyl)phenylalanine (CF2Pmp)] which has been shown to be stable to cellular phosphatases. The extracellular administration of either CF2Pmp-Val-Pro-Met-Leu or Ac-CF2Pmp-Val-Pro-Met-NH2 in a whole cell assay resulted in specific inhibition of the PDGF-stimulated association from the C-terminal SH2 domain of the p85 subunit of PI 3-kinase to the PDGF-beta receptor in a dose-dependent manner. These compounds were also effective in inhibiting GLUT4 translocation, c-fos expression, and cell membrane ruffling in single-cell microinjection assay.
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PMID:Design of peptidomimetics that inhibit the association of phosphatidylinositol 3-kinase with platelet-derived growth factor-beta receptor and possess cellular activity. 978 8

Dietary omega-3 fatty acids retard coronary atherosclerosis. Previously, we demonstrated that dietary omega-3 fatty acids reduce platelet-derived growth factor (PDGF)-A and PDGF-B mRNA levels in unstimulated, human mononuclear cells (MNCs). In a randomized, investigator-blinded intervention trial, we have now compared the effect of ingestion of 7 g/d omega-3, omega-6, or omega-9 fatty acids for 4 weeks versus no dietary intervention on PDGF-A, PDGF-B, heparin-bound epidermal growth factor (HB-EGF), monocyte chemoattractant protein-1 (MCP-1), and interleukin-10 gene expression in unstimulated MNCs and in monocytes that were adherence-activated ex vivo in a total of 28 volunteers. In unstimulated MNCs, mRNA steady-state levels of PDGF-A, PDGF-B, and MCP-1 were reduced by 25+/-10%, 31+/-13%, and 40+/-14%, respectively, after omega-3 fatty acid ingestion, as assessed by quantitative polymerase chain reaction (all P<0.05). In monocytes that were adherence-activated ex vivo for 4 and 20 hours, mRNA steady-state levels of PDGF-A, PDGF-B, and MCP-1 were reduced by 25+/-13%, 20+/-15%, and 30+/-8%, respectively (all P<0.05). Interleukin-10 and HB-EGF mRNA steady-state levels were not influenced by omega-3 fatty acid ingestion. Expression of all respective mRNAs in control volunteers or in those ingesting omega-6 or omega-9 fatty acids were not altered. We conclude that human gene expression for PDGF-A, PDGF-B, and MCP-1, factors thought relevant to atherosclerosis, is constitutive, is constant, and can be reduced only by dietary omega-3 fatty acids in unstimulated and adherence-activated monocytes.
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PMID:Dietary omega-3, omega-6, and omega-9 unsaturated fatty acids and growth factor and cytokine gene expression in unstimulated and stimulated monocytes. A randomized volunteer study. 988 67

Evidence suggests that human cytomegalovirus (HCMV) infection contributes to the development of atherosclerosis and restenosis. Because smooth muscle cell (SMC) proliferation and migration are crucial events of both processes, and because PDGF beta-receptor modulates SMC migration, we determined whether HCMV infection affects SMC proliferation, migration, and PDGF beta-receptor expression. We employed a SMC model in which HCMV infection leads to expression of only the immediate early (IE) HCMV gene products-HCMV infection of rat SMCs. We found that HCMV infection significantly (i) increased SMC proliferation (from 0.9 x 10(6) +/- 0.024 x 10(6) to 1.4 x 10(6) +/- 0.051 x 10(6) cells/well, p < 0.001); (ii) augmented SMC migration toward PDGF (from 64 +/- 37 to 116 +/- 51 cells/high power field; p < 0.01); and (iii) enhanced PDGF beta-receptor expression in a time-dependent fashion. We conclude that HCMV infection of rat SMCs increases SMC proliferation, migration, and PDGF beta-receptor expression. These findings identify further mechanisms by which CMV may contribute to the development of atherosclerosis and restenosis.
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PMID:The immediate early gene products of human cytomegalovirus increase vascular smooth muscle cell migration, proliferation, and expression of PDGF beta-receptor. 1008 Sep 46

Enhanced activity of receptor tyrosine kinases such as the PDGF beta-receptor and EGF receptor has been implicated as a contributing factor in the development of malignant and nonmalignant proliferative diseases such as cancer and atherosclerosis. Several epidemiological studies suggest that green tea may prevent the development of cancer and atherosclerosis. One of the major constituents of green tea is the polyphenol epigallocathechin-3 gallate (EGCG). In an attempt to offer a possible explanation for the anti-cancer and anti-atherosclerotic activity of EGCG, we examined the effect of EGCG on the PDGF-BB-, EGF-, angiotensin II-, and FCS-induced activation of the 44 kDa and 42 kDa mitogen-activated protein (MAP) kinase isoforms (p44(mapk)/p42(mapk)) in cultured vascular smooth muscle cells (VSMCs) from rat aorta. VSMCs were treated with EGCG (1-100 microM) for 24 h and stimulated with the above mentioned agonists for different time periods. Stimulation of the p44(mapk)/p42(mapk) was detected by the enhanced Western blotting method using phospho-specific MAP kinase antibodies that recognized the Tyr204-phosphorylated (active) isoforms. Treatment of VSMCs with 10 and 50 microM EGCG resulted in an 80% and a complete inhibition of the PDGF-BB-induced activation of MAP kinase isoforms, respectively. In striking contrast, EGCG (1-100 microM) did not influence MAP kinase activation by EGF, angiotensin II, and FCS. Similarly, the maximal effect of PDGF-BB on the c-fos and egr-1 mRNA expression as well as on intracellular free Ca2+ concentration was completely inhibited in EGCG-treated VSMCs, whereas the effect of EGF was not affected. Quantification of the immunoprecipitated tyrosine-phosphorylated PDGF-Rbeta, phosphatidylinositol 3'-kinase, and phospholipase C-gamma1 by the enhanced Western blotting method revealed that EGCG treatment effectively inhibits tyrosine phosphorylation of these kinases in VSMCs. Furthermore, we show that spheroid formation of human glioblastoma cells (A172) and colony formation of sis-transfected NIH 3T3 cells in semisolid agar are completely inhibited by 20-50 microM EGCG. Our findings demonstrate that EGCG is a selective inhibitor of the tyrosine phosphorylation of PDGF-Rbeta and its downstream signaling pathway. The present findings may partly explain the anti-cancer and anti-atherosclerotic activity of green tea.
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PMID:Epigallocathechin-3 gallate selectively inhibits the PDGF-BB-induced intracellular signaling transduction pathway in vascular smooth muscle cells and inhibits transformation of sis-transfected NIH 3T3 fibroblasts and human glioblastoma cells (A172). 1019 59

In the diabetic vascular complication, biochemical and mechanical injuries to endothelial cells are involved not only in the process of microangiopathy, but also in diabetic atherosclerosis (or arteriosclerosis) which is so-called macroangiopathy. In the presence of diabetes or persistent hyperglycemia, many cytokines including growth factors such as PDGF, HB-EGF, IL-1 beta and TNF alpha are upregulated in intimal cells of the arterial or aortic wall. These changes alter the cytokine network in the common mechanism of atherosclerosis, "Response-to-injury hypothesis", and further accelerate the formation of atherosclerotic lesion. In addition, diabetes causes abnormal responsibility to HB-EGF, PDGF and TGF-beta in medial smooth muscle cells leading to the elevated activity to their proliferation and migration into the intima. Thus, all cell types consisting arterial or aortic wall are involved in the process of diabetic atherosclerosis.
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PMID:[Mechanism of atherosclerosis in diabetes: altered cytokine network in the vascular wall]. 1019 40

Hydroxymethylglutaryl-Coenzyme A (HMG-CoA) reductase inhibitors were shown to be effective in primary and secondary prevention of coronary heart disease. The beneficial effect of statins is generally attributed to their cholesterol lowering activity. However recent work points to additional cholesterol independent effects of these drugs on cellular signal transduction. In this study it was investigated whether HMG-CoA reductase inhibition could affect induction of the transcription factors c-Jun and c-Fos in smooth muscle cells, which play an important role in atherogenesis. SMC were preincubated for 12 h with or without lovastatin (5 microM) and subsequently stimulated with platelet derived growth factor (PDGF, 10 ng/ml) or angiotensin II (0.1 microM) for 1, 2, 4 and 12 h or with phorbol myristate acetate (100 pM) for 2 h. Stimulation in the absence of the HMG-CoA reductase inhibitor led to a significant induction of c-Jun and c-Fos. Lovastatin inhibited, PDGF-, angiotensin II- and PMA-mediated induction. Concomitant addition of mevalonate, farnesylpyrophosphate and geranylgeranylpyrophosphate prevented the effects of HMG-CoA reductase inhibition resulting in rescued expression of c-Jun and c-Fos. The suppression of these transcription factors was associated with a complete growth arrest. Viability was not affected by pretreatment with the HMG-CoA reductase inhibitor. The data demonstrate that lovastatin can suppress PDGF- and angiotensin II-mediated induction of c-Jun and c-Fos protein in human SMC. This inhibitory effect may prevent activation of numerous growth factor- and cell cycle- genes. Whether these findings contribute to the effects of statins in atherosclerosis remains to be further investigated.
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PMID:Effects of HMG-CoA reductase inhibition on PDGF- and angiotensin II- mediated signal transduction: suppression of c-Jun and c-Fos in human smooth muscle cells in vitro. 1020 88


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