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

An inhibitor of urokinase, human urinary plasminogen activator, was found in the media of human arteries using a histochemical method (fibrin slide sandwich technique). Arteriosclerotic lesions, especially atherosclerosis, apparently contained the urokinase inhibitor. The inhibitor did not alter plasmin activity. This inhibitor of urokinase may be involved in regulation of fibrinolysis in arterial wall and thus a significant role in atherogenesis.
 ...
PMID:Inhibitor of plasminogen activator in human arterial wall. I. Histochemical study. 623 46

Fibrin contains a factor which promotes growth of the mesenchymal cells and such may be related tissue repair. Effects of fibrin and fibrinogen degradation products (FDP) on the growth of smooth muscle cells (SMC) of rabbit aortas in culture were investigated, in relation to atherogenesis. Fibrin, free from plasminogen enhanced the proliferation of SMC during the experimental period of 48 h. Fibrin, rich in plasminogen also stimulated the proliferation of SMC within 24 h, but inhibited it after 48 h. FDP (fragments D and E) inhibited the proliferation of SMC. SMC of rabbit aortas demonstrated plasminogen activator activity. Thrombin and urokinase exhibited no promoting effects on the growth of SMC. These results support the hypothesis that the proliferation of SMC is stimulated by fibrin and later inhibited by FDP, as produced by the fibrinolytic activity of SMC. It is proposed that the metabolism of fibrin in the arterial wall may be of importance in the regulation of SMC proliferation and that the coagulation-fibrinolysis system may play a significant role in atherogenesis.
Atherosclerosis 1982 Aug
PMID:Effects of fibrin and fibrinogen-degradation products on the growth of rabbit aortic smooth muscle cells in culture. 713 18

The accumulation of excessive cholesterol-rich lipoproteins within vascular cells, the proliferation of vascular cells, and fibrin deposition are hallmark features of atherosclerosis. Evidence accumulated over the past few years supports the hypothesis that one member of the LDL receptor family, the low density lipoprotein receptor-related protein (LRP), affects the dynamics of each of these processes. LRP is expressed in several vascular cell types, including smooth muscle cells, and in macrophages, and is also expressed in these cells in atherosclerotic lesions. This receptor is a large endocytotic receptor that mediates the catabolism of a number of molecules known to be important in vascular biology, including apolipoprotein E- and lipoprotein lipase-enriched lipoproteins, thrombospondin, and plasminogen activators. The capacity of LRP to mediate lipoprotein catabolism may be a factor in the development of the lesion by contributing to the formation of foam cells. LRP has recently been shown to mediate the catabolism of thrombospondin, a molecule that has potent biological effects on cells of the vasculature. The regulation of its extracellular accumulation by LRP might modulate the dynamic processes of tissue remodeling associated with the response to vascular injury. In addition, LRP regulates the expression of plasmin activity by directly binding and mediating the cellular internalization of urokinase- and tissue-type plasminogen activators. The cellular removal of these two enzymes decreases the local profibrinolytic potential, possibly leading to a thrombotic state at lesion sites.
 ...
PMID:LDL receptor-related protein: a multiligand receptor for lipoprotein and proteinase catabolism. 761 59

The plasminogen/plasmin or fibrinolytic system with its physiological triggers, tissue-type plasminogen activator, and urokinase-type plasminogen activator has been presumed to participate in normal and pathological processes of the vessel wall such as blood clot dissolution (thrombolysis), hemostasis, aneurysm formation, neovascularization, restenosis, and atherosclerosis. The implied role of the fibrinolytic system in vivo is, however, deduced from correlations between fibrinolytic activity and (patho)physiological phenomena, which does not allow establishing a cause/consequence relationship. Gene targeting and gene transfer technologies allow establishment of the in vivo role of gene products more conclusively. This article reviews briefly the findings of such studies on thrombolysis/thrombosis, hemostasis, neointima formation, atherosclerosis, and associated effects on survival.
 ...
PMID:Gene targeting and gene transfer studies of the plasminogen/plasmin system: implications in thrombosis, hemostasis, neointima formation, and atherosclerosis. 761 62

The plasminogen activator (PA) system may participate in the pathogenesis of atherosclerosis by modulating the turnover of intimal fibrin and extracellular matrix deposits and by contributing to intimal cell migration. We present an analysis of tissue-type PA (tPA) and urokinase-type PA (uPA) expression at three levels: mRNA by in situ hybridization, antigen by immunohistochemistry, and enzymatic activity by histoenzymology and zymography. For PA colocalization with cellular or matrix components, we used double immunofluorescence labeling in conjunction with confocal microscopy. In normal arteries, tPA antigen and mRNA were detected in endothelial cells and smooth muscle cells (SMCs). In atherosclerotic arteries, tPA antigen and mRNA were increased in intimal SMCs and in macrophage-derived foam cells of fibro-fatty lesions. Part of the tPA was detected in the extracellular space and colocalized with fibrin deposits. uPA antigen and mRNA were detected in association with the intimal macrophages and SMCs. A particularly high uPA expression was noted on macrophages localized on the rims of the necrotic core. Moreover, using a novel histoenzymological assay as well as classic zymography, we revealed uPA-dependent lytic activity in the advanced lesions, whereas in normal arteries, only tPA-dependent activity was detected, mainly over the vasa vasorum. Also, strong tPA and uPA staining was detected in neomicrovessels of the plaques, suggesting that PAs may play a role in plaque angiogenesis. Our results suggest a local dynamic process of PA-dependent proteolysis in lesion areas that is associated with macrophages and SMCs. A better comprehension of these proteolytic mechanisms in advanced atherosclerotic plaques may provide the basis for therapeutic approaches for plaque stabilization.
 ...
PMID:Plasminogen activator expression in human atherosclerotic lesions. 767 Sep 60

To determine whether thrombin directly modifies mobility of vascular smooth muscle cells (SMC), in Transwell systems (modified Boyden chambers), we exposed SMC to alpha-thrombin. In concentrations as low as 1 NIH U/ml, thrombin induced migration as well as proliferation of SMC. Inhibition of protein synthesis by cycloheximide (2 micrograms/ml) obviated thrombin's chemotactic effect. Neither gamma-thrombin nor D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (PPACK)-inactivated alpha-thrombin (both used as controls) exerted a chemotactic effect. Concomitant hirudin or antithrombin III plus heparin inhibited chemotaxis by thrombin when added up to 2 h after addition of thrombin. alpha-Thrombin increased SMC synthesis of urokinase receptor (uPAR) and its cell surface expression as shown by metabolic labeling and immunoprecipitation as well as by flow cytometry. Thus alpha-thrombin, in concentrations thought to be present in vivo at sites of vascular injury, can stimulate not only proliferation but also migration of vascular SMC though a mechanism(s) possibly involving synthesis of uPAR, which is known to influence migration in diverse types of cells. Accordingly, both proliferation and migration dependent on thrombin may accelerate atherosclerosis, restenosis, or both after interventions such as angioplasty.
 ...
PMID:Vascular smooth muscle cell migration mediated by thrombin and urokinase receptor. 776 12

The localization of proteases to cell surfaces via receptors may facilitate cell migration, invasion, and matrix degradation. Since vascular smooth muscle cell (SMC) migration may be an important event in atherosclerosis and in intimal thickening after vascular injury, we studied the cell surface expression of a receptor for urokinase-type plasminogen activator (u-PAR) in cultured human vascular SMC. Using immunofluorescence microscopy, we demonstrated several staining patterns of SMC u-PAR: at the periphery of the cell membrane, at the leading edge, and at cell-cell contact sites. When migration experiments were performed using a wound assay, one-third of the SMC at the wound edge demonstrated polarization of cell surface u-PAR toward the leading edge of the cell membrane (32 +/- 2%, +/- SEM, n = 7). A similar pattern was seen with an antibody to caveolin, a transmembrane protein found in caveolae, but not with an antibody to 5'-nucleotidase, another cell surface glycophosphatidylinositol-anchored protein, which was homogeneously expressed on the cell surface. Low-density lipoprotein receptor-related protein, which mediates internalization of u-PAR bound ligands, was distributed in a diffuse punctate pattern, not polarized to the leading edge. Double immunofluorescent studies demonstrated codistribution of SMC u-PAR with vinculin and caveolin in migrating SMC at the leading edge in a wound assay. Polarization of cell surface u-PAR was not observed in either nonwounded or subconfluent cultures, despite random migratory behavior. These studies suggest that in response to wounding, human vascular SMC polarize and concentrate cell surface u-PAR to their leading edge, perhaps facilitating directional migration.
 ...
PMID:Migrating vascular smooth muscle cells polarize cell surface urokinase receptors after injury in vitro. 786 16

Glycoprotein 330 (gp330) is a member of a family of receptors with structural similarities to the low-density lipoprotein receptor. Gp330 is expressed by a number of specialized epithelia, including renal proximal tubules, where it can mediate endocytosis of ligands such as complexes of urokinase and the serpin, plasminogen activator inhibitor-1. Gp330 has also been shown to bind in vitro to lipoprotein lipase and apolipoprotein E-enriched beta VLDL, suggesting a role for this receptor in lipoprotein metabolism. The 39-kDa protein, referred to as receptor associated protein (RAP), binds to and copurifies with gp330 and antagonizes the ligand binding activity of gp330. In this paper, we report the use of homology-PCR cloning to isolate cDNAs encoding human gp330. Using gp330 cDNA and previously isolated human RAP cDNA probes, we performed fluorescence in situ hybridization to map the human chromosomal location of the genes for these proteins. The gene for gp330 was mapped at a single site on the long arm of human chromosome 2 on the border of bands 2q24-q31. The gene for RAP was mapped to the short arm of human chromosome 4 at position 4p16.3, which is in the region of the chromosomal deletion causing Wolf-Hirschhorn syndrome. The assignment of chromosomal map positions for gp330 and RAP genes will aid in the evaluation of their potential roles in human diseases such as Wolf-Hirschhorn syndrome and disorders of lipoprotein metabolism, such as atherosclerosis.
 ...
PMID:Chromosomal localization of human genes for the LDL receptor family member glycoprotein 330 (LRP2) and its associated protein RAP (LRPAP1). 795 95

Due to the incidence of symptomatic atherosclerosis in uremic patients, hemostasis-derived cardiovascular risk factors, basal plasma concentrations of some endothelial-derived glycoproteins and desmopressin-induced variations of endothelial-derived proteins were studied in 22 uremic patients on prolonged maintenance hemodialysis with no cardiovascular antecedent. Compared to control subjects, patients had increased predialysis hemostasis-related cardiovascular risk factors: high fibrinogen, proconvertin, and type 1 plasminogen activator inhibitor plasma concentrations; low albumin values; generally low antithrombin III values but sometimes high. They had high predialysis plasma concentrations of endothelium-derived glycoproteins: von Willebrand factor, tissue-type plasminogen activator and urokinase-type plasminogen activator, which are secreted by endothelial cells, but also soluble thrombomodulin, a marker of endothelial cell injury. The desmopressin-induced release of tissue-type plasminogen activator and of von Willebrand factor were lower than in controls. High fibrinogen, type 1 plasminogen activator inhibitor and low albumin plasma concentrations may be linked to repeated acute phase reactions associated with hemodialysis. Data concerning endothelium-related proteins are concordant with the co-existence of a chronic in vivo endothelial activation and endothelial injury in uremia. This could be linked to the initiation and progression of atherosclerosis.
 ...
PMID:Increased cardiovascular risk factors and features of endothelial activation and dysfunction in dialyzed uremic patients. 799 2

Angiographic demonstration of luminal narrowing during pulse-spray pharmacomechanical thrombolysis (PSPMT) may reflect residual lysable clot, organized thrombus, platelet-rich clot, atherosclerosis, neointimal hyperplasia, or functional narrowing. The authors evaluated the efficacy and safety of lytic stagnation (initial rapid lysis followed by insubstantial further lysis with additional treatment) as an end point for PSPMT. Lytic stagnation was evaluated with serial angiography in 16 arterial and five bypass graft occlusions. Substantial lysis occurred after administration of mean doses of 512,000 units +/- 182,000 of urokinase or 5.3 mg +/- 2.0 of tissue-type plasminogen activator. Additional treatment with either of those agents produced minimal or no further change in the appearance of residual disease. Recanalization was successful in all patients after angioplasty. Distal emboli were noted in four cases, in three of which angioplasty of large intraluminal filling defects had been performed. The authors conclude that lytic stagnation is a reliable and safe end point for PSPMT in the absence of large intraluminal filling defects.
 ...
PMID:Occluded peripheral arteries and bypass grafts: lytic stagnation as an end point for pulse-spray pharmacomechanical thrombolysis. 832 83


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>