Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Karyotypic and phenotypic changes were found in human adult endothelial cells (EC) during aging in vitro. A trisomy of chromosome 11 was found in 11 out of 12 EC cultures examined, derived from 9 cell lines from 8 donors. The incidence of this trisomy in some cell lines increased over time from 0% to as much as 100% near the end of their in vitro life span. A number of oncogenes and other important genes are on chromosome 11. These genes might play a role in the changes observed. An increase in the percentage of polyploid cells was also found near the end of the in vitro life span in 6 lines. The cellular levels of two gene products characteristic of the EC, von Willebrand factor (vWF) or Factor VIII, and angiotensin converting enzyme (ACE) were also monitored. vWf was studied in 2 lines and was decreased in both with serial passage. ACE decreased in three out of the four lines examined. These chromosomal and phenotypic changes which occur with increasing age in vitro make the endothelial cell a suitable model to study in vitro culture-related changes, senescence, cardiovascular disease, and tumorigenesis.
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PMID:Karyotypic and phenotypic changes during in vitro aging of human endothelial cells. 130 25

Two endothelial cell lines were derived from grafts of the central nervous system using retrovirus mediated gene transfer to introduce the polyoma middle-T oncogene into fetal rat brain endothelial cells and transplantation of these cells into adult rat brain. In this report, we further characterize these cells and the effect of dexamethasone on the expression of specific enzymatic markers. These cells take up acetylated low density lipoprotein, leucine, and glucose, and express Factor VIII-related antigen, angiotensin converting enzyme, alkaline phosphatase, gamma-glutamyltranspeptidase, and as yet undescribed aminopeptidase A and B-like enzymes. When grown on semi-permeable membranes, these transformed cells do not spontaneously retain small hydrophilic molecules. In culture, one of the lines (EC 193) forms a confluent monolayer of spindle-shaped cells homogenously expressing gamma-glutamyltranspeptidase at a level comparable to primary cells. The other cell line (EC 219) grows as clusters of elongated cells, and gamma-glutamyltranspeptidase activity is expressed mainly in cells forming the clusters. This clustered pattern changes to a confluent one after culture on type-I collagen. Dexamethasone increases angiotensin-converting enzyme activity, and decreases the expression of gamma-glutamyltranspeptidase and aminopeptidase A, whereas the aminopeptidase B activity is little modified. Inhibition of aminopeptidase A activity by amastatin, potentiates angiotensin II effects on DNA synthesis. These results indicate that retrovirally transformed brain endothelial cells are a useful model for studying the blood-brain barrier in vitro and that dexamethasone, an agent with the potential to reduce brain edema, directly affects some blood-brain barrier properties in these endothelial cell lines.
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PMID:Dexamethasone selectively regulates the activity of enzymatic markers of cerebral endothelial cell lines. 135 67

A reliable technique to produce consistently pure cultures of endothelial cells prepared from isolated rat brain capillaries has been established. The cells express many of the morphological and antigenic characteristics of endothelium in vivo, including the formation of tight junctions and possession of Factor VIII/von Willebrand Factor antigen (FVIII/vWF) and angiotensin converting enzyme (ACE). Using indirect immunofluorescence, surface IgG Fc receptors (FcR) could not be demonstrated, either when the cells were incubated in aggregated IgG, or in adult rat serum. Rat peritoneal macrophages served as a positive control. However, permeabilization of the endothelial cells with glacial acetic acid/ethanol prior to incubation with IgG allowed the demonstration of internal binding sites. The lack of surface receptors in the normal state does not rule out the possibility of their induction during pathological conditions.
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PMID:Brain capillary endothelial cells in vitro lack surface IgG Fc receptors. 294 4

Endothelial cells can be harvested from segments of adult human saphenous vein in a varicose condition removed from patients having single or bilateral vein ligation and stripping. The cells are harvested by scraping with a scalpel, seeded on to gelatin coated or Primaria flasks and are passaged by removal with a rubber policeman. The cells cultured in this manner are maintained in a growth medium that is not supplemented with growth factors. The cells grow with a cobblestone monolayer morphology, possess angiotensin converting enzyme activity and react with antibodies to Factor VIII antigen. The cells fluoresce brightly after reaction with monoclonal antibodies specific for human endothelial cells. Thus, stripped varicose vein segments provide a readily available source of endothelial cells.
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PMID:Varicose veins as a source of adult human endothelial cells. 299 69

Factor VIII-related antigen (F8) and Ulex europaeus lectin (UEL) are accepted markers for human blood vessel endothelium. However, disagreement exists as to whether lymphatic vessels stain for F8, and accordingly this study was undertaken to address this issue. Moreover, another vascular endothelial marker, angiotensin converting enzyme (ACE) was also examined in lymphatics. Segments of human thoracic duct and portions of small bowel containing lacteals with post-mortem intervals of less than 15 hours, were removed at autopsy and fixed in B5 or formalin. The specimens were processed routinely and sections examined by indirect immunohistochemical techniques for F8 (Dako Corp.), ACE and for UEL (EY Lab). F8, UEL, and ACE positivity was uniformly found in thoracic ducts and lacteals; however, the staining intensity was less in lymphatic vessels with F8 and UEL than with comparable arteries or veins. ACE staining intensity, on the other hand, was similar in blood vessels and lymphatics. Both formalin and B5 fixation preserved antigenicity; however, background staining was greater with B5 fixation whereas tissue staining was slightly more intense with formalin fixation.
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PMID:Vascular endothelial markers of the human thoracic duct and lacteal. 303 2

To provide an in vitro system for studies of brain capillary function we developed a method for culture of brain capillary endothelial cells. Capillaries were isolated from rat brain and enzymatically treated to remove the basement membrane and contaminating pericytes. Subsequent Percoll gradient centrifugation resulted in a homogeneous population of capillary endothelial cells that attached to a collagen substrate and incorporated [3H]thymidine. Evidence for the endothelial nature of these cells was provided by the presence of Factor VIII antigen and angiotensin converting enzyme activity and by the failure of platelets to adhere to the cell surface. In addition, the cells were joined together by tight junctions. Thus, primary cultures of these cells retained both endothelial and blood-brain barrier features.
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PMID:Primary culture of capillary endothelium from rat brain. 626 91

Angiotensin I-converting enzyme is responsible for the activation of angiotensin I and the inactivation of bradykinin. It has been localized by immunofluorescence on the endothelium of a variety of tissues and has been considered to be a specific marker for endothelial cells in culture. The present paper demonstrates, by immunofluorescence, the presence of angiotensin I-converting enzyme in monolayer cultures of fibroblasts derived from adult rat lung, bovine calf pulmonary artery, and human foreskin (CF-3 cells). Fluorescent localization of angiotensin I-converting enzyme was observed over the cytoplasm of adult rat lung and bovine calf pulmonary artery fibroblasts and as distinct areas overlying the nuclei of human foreskin fibroblasts. Determination of angiotensin I-converting enzyme activity by fluorimetric assay in parallel studies confirmed the presence of angiotensin I-converting enzyme activity in cultured fibroblasts. Immunofluorescent studies with antibody to Factor VIII demonstrated the presence of Factor VIII on cultured endothelial cells but not on fibroblasts. These results indicate that angiotensin I-converting enzyme is not confined to endothelial cells, and thus may not serve as a specific marker for endothelial cells in culture. Factor VIII may be a more specific marker for these cells.
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PMID:Angiotensin I-converting enzyme localization on cultured fibroblasts by immunofluorescence. 628 49

Endothelial cells were cultured from the carotid artery with thickened intima comprised of two to five layers of smooth muscle cells, isolated from a 19-yr-old female, who died from an accident. The cells were grown and subcultured in Medium 199 supplemented with 20% heat inactivated fetal bovine serum. The cells are still viable at present, the 22nd passage. The cultured cells were found to have the following characteristics: existence of Factor VIII-related surface antigen and prostacyclin synthesis slightly less than that for typical endothelial cells. The most outstanding feature was the formation by an individual cell of a single ring, and a composite ring formed by two to five cells. Neither the synthesis of an angiotensin converting enzyme nor that of a Weibel-Palade body could be detected by electron microscopy. The cultured cells possessed only a few characteristics specific for typical endothelial cells and were designated as variant endothelial cells.
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PMID:Variant endothelial cells from human carotid artery in culture. 642 99

Endothelial cells were cultured from various different human vessels, including aortas, pulmonary, ovarian, and umbilical arteries, and pulmonary, ovarian, and umbilical veins. The cultured cells were identified as endothelial cells by the presence of Factor VIII antigen and antiotensin I converting enzyme (kininase II). They retained these markers for at least five passages in culture, and some cells had them for seven passages or more. Endothelial cells from the various vessels were compared with respect to their ability to metabolize angiotensins I and II and bradykinin. Cells from arteries had three to five times the angiotensin I converting enzyme activity as cells from veins. The activity of angiotensinase A (aspartyl aminopeptidase) had a similar distribution, and cells from arteries were consistently more active than cells from veins. Cultures of endothelial cells from pulmonary and umbilical vessels formed prostacyclin in response to mechanical stimulation. Media from cell monolayers that were subjected to a change of medium and gentle agitation inhibited aggregation of human platelets. This inhibitory activity was generated within 2-5 min, and it was not formed by cells that were treated with indomethacin or tranylcypromine. Addition of prostaglandin (PG)H(2) to indomethacin-treated cells restored the ability to form the inhibitor, but cells treated with tranylcypromine were not responsive to PGH(2). In experiments where [(14)C]arachidonic acid was added to the cells before stimulation, the major metabolite identified by thin-layer chromatography was 6-keto PGF(1alpha). Thus, it appears that pulmonary endothelial cells, as well as umbilical cord cells, can form prostacyclin. In experiments comparing the ability of arterial and venous cells to form prostacyclin, arterial cells were more active than venous cells. These studies of cells from various human vessels suggest that the vascular origin of cultured endothelial cells determines how they metabolize vasoactive peptides and form prostacyclin.
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PMID:Human pulmonary endothelial cells in culture. Activities of cells from arteries and cells from veins. 698 68

To provide an in vitro system for studying retinal capillary function we have developed methods for isolation and culture of microvascular endothelial cells from retina. Retinal microvessels were isolated by homogenization of the retina and collection of the microvessels onto nylon mesh. Treatment of the isolated microvessels with collagenase and dispase followed by Percoll gradient centrifugation yielded endothelial cells that were largely free of pericytes. A homogeneous population of endothelial cells that were capable of at least six population doublings was obtained by plating onto a fibronectin coated substrate in plasma derived serum. The endothelial origin of these cells was confirmed by the presence of Factor VIII antigen, angiotensin converting enzyme activity, numerous tight junctions, and a cell surface that did not bind platelets. A second cell type, which did not exhibit these cell markers and which is presumably the intramural pericyte, was obtained when the isolated microvessels were plated on tissue culture grade plastic in fetal bovine serum.
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PMID:Primary culture of microvascular endothelial cells from bovine retina: selective growth using fibronectin coated substrate and plasma derived serum. 714 46


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