scholarly journals The expression of renin and the formation of angiotensin II in bovine aortic endothelial cells

2000 ◽  
Vol 164 (2) ◽  
pp. 207-214 ◽  
Author(s):  
F Xiao ◽  
GP Vinson ◽  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
In Situ Hybridization ◽  
Ang Ii ◽  
Rt Pcr ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Human Renin ◽  
Aortic Endothelial

One controversy in the field of vascular angiotensin generation has surrounded the nature and particularly the source of vascular renin. This study investigated the expression of renin protein and its mRNA in aortic endothelial cells using immunocytochemistry, Western blotting, in situ hybridization and reverse transcription PCR (RT-PCR). Using a monoclonal antibody against human renin, immunocytochemical analysis revealed positive immunoreactivity in the cytoplasm of cultured bovine aortic endothelial cells. Immunoblotting of solubilized proteins separated by SDS-PAGE from cultured aortic endothelial cells identified two immunoreactive species with molecular masses of approximately 37-40 kDa. In situ hybridization showed that renin mRNA was localized in the cytoplasm of these cells. Using RT-PCR of RNA extracted from bovine aortic endothelial cells with primers specific for human renin, a clear single band was detected, which had the predicted size of 142 bp for (pro)renin. Angiotensin II (Ang II) was assayed in conditioned medium (CM) from cultured bovine aortic endothelial cells, and in addition, the effects of Ang II and CM on the proliferation of aorta smooth muscle cells (ASMC) were also studied. The results showed that CM contained Ang II equivalent to 15.05+/-4.67 pg/10(6) cells. Assay of smooth muscle cell proliferation by cell number, and by tritiated thymidine uptake, showed that proliferative responses in the presence of Ang II at a concentration of 10(-6)M were evident within 1 day of subculture, and cell numbers were nearly twice those of controls after 2 days. Thymidine incorporation into ASMC was also increased by Ang II in a dose-dependent manner and by endothelial cell CM. In both cases, stimulated proliferation was inhibited by the Ang II type 1 (AT1) receptor selective antagonist, losartan. These findings suggest that these vascular endothelial cells are a source of locally synthesized renin that may thus be involved in vascular Ang II generation. They also suggest that Ang II produced by the endothelial cells may be secreted and stimulate ASMC proliferation via the AT1 receptor.

Horizontal Transfer of DNA by the Uptake of Apoptotic Bodies

Blood ◽  
1999 ◽  
Vol 93 (11) ◽  
pp. 3956-3963 ◽  
Author(s):  
Lars Holmgren ◽  
Anna Szeles ◽  
Eva Rajnavölgyi ◽  
Judah Folkman ◽  
Georg Klein ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
In Situ Hybridization ◽  
Expression Pattern ◽  
Cell Lines ◽  
Immunofluorescent Staining ◽  
Apoptotic Bodies ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

In this study we have raised the question of whether DNA can be transferred from one cell to another by phagocytosis of apoptotic bodies. We have used integrated copies of the Epstein-Barr virus (EBV) as a marker to follow the fate and expression pattern of apoptotic DNA in the phagocytotic host. Apoptosis was induced in EBV-carrying cell lines by irradiation before cultivation with either human fibroblasts, macrophages, or bovine aortic endothelial cells. Analysis of the expression pattern of EBV-encoded genes was performed by immunofluorescent staining as well as in situ hybridization. Cocultivation of apoptotic bodies from lymphoid cell lines containing integrated but not episomal copies of EBV resulted in expression of the EBV-encoded genes EBER and EBNA1 in the recipient cells at a high frequency. Fluorescence in situ hybridization analysis showed uptake of human chromatin as well as integrated EBV-DNA into the nuclei of bovine aortic endothelial cells. These data show that DNA may be rescued and reused from apoptotic bodies by somatic cells. In addition, our findings suggest that apoptotic bodies derived from EBV-carrying B lymphocytes may serve as the source of viral transfer to cells that lack receptors for the EBV virus in vivo.

Horizontal Transfer of DNA by the Uptake of Apoptotic Bodies

Blood ◽  
1999 ◽  
Vol 93 (11) ◽  
pp. 3956-3963 ◽  
Author(s):  
Lars Holmgren ◽  
Anna Szeles ◽  
Eva Rajnavölgyi ◽  
Judah Folkman ◽  
Georg Klein ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
In Situ Hybridization ◽  
Expression Pattern ◽  
Cell Lines ◽  
Immunofluorescent Staining ◽  
Apoptotic Bodies ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

Abstract In this study we have raised the question of whether DNA can be transferred from one cell to another by phagocytosis of apoptotic bodies. We have used integrated copies of the Epstein-Barr virus (EBV) as a marker to follow the fate and expression pattern of apoptotic DNA in the phagocytotic host. Apoptosis was induced in EBV-carrying cell lines by irradiation before cultivation with either human fibroblasts, macrophages, or bovine aortic endothelial cells. Analysis of the expression pattern of EBV-encoded genes was performed by immunofluorescent staining as well as in situ hybridization. Cocultivation of apoptotic bodies from lymphoid cell lines containing integrated but not episomal copies of EBV resulted in expression of the EBV-encoded genes EBER and EBNA1 in the recipient cells at a high frequency. Fluorescence in situ hybridization analysis showed uptake of human chromatin as well as integrated EBV-DNA into the nuclei of bovine aortic endothelial cells. These data show that DNA may be rescued and reused from apoptotic bodies by somatic cells. In addition, our findings suggest that apoptotic bodies derived from EBV-carrying B lymphocytes may serve as the source of viral transfer to cells that lack receptors for the EBV virus in vivo.

Interaction of lysophosphatidylcholine with aortic endothelial cells

1992 ◽  
Vol 262 (6) ◽  
pp. H1853-H1860 ◽  
Author(s):  
L. L. Stoll ◽  
H. J. Oskarsson ◽  
A. A. Spector
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Arterial Wall ◽  
Endothelial Monolayer ◽  
Aortic Endothelial Cells ◽  
Cell Monolayers ◽  
Bovine Aortic Endothelial Cells ◽  
Ldl Uptake ◽  
High Concentrations ◽  
Aortic Endothelial

To better understand the vascular actions of lysophosphatidylcholine (lysoPC), we studied the interaction of [1-14C]palmitate-labeled lysoPC with bovine aortic endothelial cells. These cells took up lysoPC from media containing albumin, low-density lipoproteins (LDL), or acetyl-LDL. Uptake occurred faster than conversion to phosphatidylcholine (PC), leading to some lysoPC accumulation in endothelial lipids. Endothelial cell monolayers grown on micropore filters took up lysoPC from both apical and basolateral surfaces, preventing substantial amounts from passage across the endothelial monolayer. However, lysoPC present in the interstitial medium of an endothelial-smooth muscle coculture was incorporated primarily by the smooth muscle cells. Endothelial cells grown on filters released lysoPC into both the apical and basolateral medium in the presence of albumin or lipoproteins. Exposure to 50 microM lysoPC produced no evidence of endothelial cytotoxicity, but prostaglandin (PG)I2 production was reduced. These studies suggest that the endothelium can participate in the processing of circulating lysoPC and, through basolateral uptake, can facilitate the removal of lysoPC formed within the arterial wall. By decreasing PGI2 output, however, exposure to high concentrations of lysoPC may reduce the antithrombotic and vasodilator capacity of the endothelium.

scholarly journals Thrombospondin: synthesis and secretion by cells in culture.

1982 ◽  
Vol 95 (1) ◽  
pp. 351-354 ◽  
Author(s):  
G J Raugi ◽  
S M Mumby ◽  
D Abbott-Brown ◽  
P Bornstein
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Human Platelets ◽  
Enzyme Linked Immunosorbent Assay ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Human Foreskin Fibroblasts ◽  
Aortic Endothelial

Thrombospondin, a high molecular weight glycoprotein secreted by platelets in response to activation by thrombin, has been identified by immunofluorescence in bovine aortic endothelial cells, human foreskin fibroblasts, and human aortic smooth muscle cells. Immunofluorescence patterns were found to be similar using antisera raised to thrombospondins purified either from bovine aortic endothelial cells or from human platelets. Radioimmune precipitation of pulse-labeled cellular proteins confirmed the presence of thrombospondin in positively stained cells. A sensitive quantitative enzyme-linked immunosorbent assay (ELISA) was developed and used to determine that the accumulation of secreted thrombospondin was similar for endothelial cells and fibroblasts but was higher for smooth muscle cells. The presence of thrombospondin in a variety of cells suggests that its function may not be limited to an involvement in platelet interactions.

Effects of Dipyrone on Prostaglandin Production by Human Platelets and Cultured Bovine Aortic Endothelial Cells

1983 ◽  
Vol 49 (02) ◽  
pp. 132-137 ◽  
Author(s):  
A Eldor ◽  
G Polliack ◽  
I Vlodavsky ◽  
M Levy
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

SummaryDipyrone and its metabolites 4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoan- tipyrine inhibited the formation of thromboxane A2 (TXA2) during in vitro platelet aggregation induced by ADP, epinephrine, collagen, ionophore A23187 and arachidonic acid. Inhibition occurred after a short incubation (30–40 sec) and depended on the concentration of the drug or its metabolites and the aggregating agents. The minimal inhibitory concentration of dipyrone needed to completely block aggregation varied between individual donors, and related directly to the inherent capacity of their platelets to synthesize TXA2.Incubation of dipyrone with cultured bovine aortic endothelial cells resulted in a time and dose dependent inhibition of the release of prostacyclin (PGI2) into the culture medium. However, inhibition was abolished when the drug was removed from the culture, or when the cells were stimulated to produce PGI2 with either arachidonic acid or ionophore A23187.These results indicate that dipyrone exerts its inhibitory effect on prostaglandins synthesis by platelets or endothelial cells through a competitive inhibition of the cyclooxygenase system.

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