Regulated expression of endothelin 1 in glomerular capillary endothelial cells

1991 ◽  
Vol 261 (1) ◽  
pp. F117-F125 ◽  
Author(s):  
P. A. Marsden ◽  
D. M. Dorfman ◽  
T. Collins ◽  
B. M. Brenner ◽  
S. H. Orkin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Endothelial Cell ◽  
Mrna Expression ◽  
Phospholipase C ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Glomerular Endothelial Cell ◽  
Glomerular Capillary ◽  
Capillary Endothelial Cells

Endothelin (ET)-1 is a powerful vasoconstrictor known to be produced and secreted by endothelial cells lining large vessels. Because ET-1 stimulates glomerular mesangial cell contraction, glomerular capillary endothelial cells (GEN), normally situated in close apposition to mesangial cells, were examined for potential ET expression and secretion. Cultured bovine GEN released ET in a time-dependent fashion. ET secretion was significantly stimulated by bradykinin, an agonist known to activate phospholipase C in these cells. Preproendothelin 1 (preproET-1) mRNA levels in GEN rose in a biphasic manner on stimulation with bradykinin. The early increments (at 30 min) were not dependent on new protein synthesis, whereas the late rise (6 h after addition of bradykinin) appeared to be protein synthesis dependent. Neither early or late bradykinin-stimulated preproET-1 mRNA expression in glomerular endothelial cells was due to inhibition of mRNA breakdown. Both phases of preproET-1 mRNA expression were observed with other glomerular endothelial cell calcium-mobilizing agonists, namely thrombin, and were mimicked by the calcium ionophore ionomycin. By contrast, the protein kinase C activator phorbol myristate acetate only enhanced preproET-1 mRNA expression at 30 min and suppressed expression thereafter. It is concluded that GEN have the potential to express and secrete ET-1 in a phospholipase C-regulated fashion. Furthermore, because glomerular mesangial cells respond to this peptide, the findings raise the possibility of paracrine regulation of mesangial cell tone by glomerular endothelial cell-derived ET-1.

scholarly journals Morphological Insights into the Origin of Glomerular Endothelial and Mesangial Cells and Their Precursors

2003 ◽  
Vol 51 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Jill M. Ricono ◽  
Yi-Chun Xu ◽  
Mazen Arar ◽  
Dong-chan Jin ◽  
Jeffrey L. Barnes ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Kidney Development ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Rat Kidney ◽  
Temporal Distribution ◽  
Metanephric Mesenchyme ◽  
Early Stages ◽  
Glomerular Capillary ◽  
In Cells

Glomerular endothelial and mesangial cells may originate from the metanephric mesenchyme. We used the MAb Thy1.1, a mesangial cell marker in the adult rat kidney, and rat endothelial cell markers MAb RECA-1, MAb PECAM-1 (CD31), and MAb Flk-1 as potential markers to characterize the spatial and temporal distribution of mesangial and endothelial cell precursors during nephrogenesis in the rat. At early stages of glomerulogenesis, RECA-1- and Thy1.1-positive cells were detected in the metanephric blastema at 14 days post conception (dpc) embryos and 15 dpc, respectively, with Thy1.1 expression in cells surrounding the ureteric bud. At 17 and 18 dpc, both RECA-1- and Thy1.1-positive cells were found in the cleft of the S-shaped bodies and in the capillary loops of maturing glomeruli. Double staining for BrdU, a marker of proliferation, and for RECA-1 or BrdU and Thy1.1 also localize in the cleft of S-shaped bodies and in glomerular capillary loops at later stages of development. PDGFRβ co-localizes in cells expressing endothelial or mesangial markers. The data suggest that endothelial and mesangial cell precursors share common markers during the course of glomerulogenesis and that full differentiation of these cells occurs at late stages of glomerular maturation. Thy1.1- and RECA-1-positive cells may be derived from the metanephric blastemal cells at early stages of kidney development. A sub-population of these Thy1.1- or RECA-1-positive cells may be precursors that can migrate into the cleft of comma and S-shaped bodies and proliferate in situ to form glomerular capillary tufts.

The role of matrix metalloproteinase activity in the maturation of human capillary endothelial cells in vitro

1999 ◽  
Vol 112 (10) ◽  
pp. 1599-1609 ◽  
Author(s):  
B.M. Kraling ◽  
D.G. Wiederschain ◽  
T. Boehm ◽  
M. Rehn ◽  
J.B. Mulliken ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Cell Proliferation ◽  
Protein Levels ◽  
Matrix Deposition ◽  
Capillary Endothelial Cells ◽  
Vessel Maturation

Vessel maturation during angiogenesis (the formation of new blood vessels) is characterized by the deposition of new basement membrane and the downregulation of endothelial cell proliferation in the new vessels. Matrix remodeling plays a crucial, but still poorly understood role, in angiogenesis regulation. We present here a novel assay system with which to study the maturation of human capillary endothelial cells in vitro. When human dermal microvascular endothelial cells (HDMEC) were cultured in the presence of dibutyryl cAMP (Bt2) and hydrocortisone (HC), the deposition of a fibrous lattice of matrix molecules consisting of collagens type IV, type XVIII, laminin and thrombospondin was induced. In basal medium (without Bt2 and HC), HDMEC released active matrix metalloproteinases (MMPs) into the culture medium. However, MMP protein levels were significantly reduced by treatment with Bt2 and HC, while protein levels and activity of endogenous tissue inhibitor of MMPs (TIMP) increased. This shift in the proteolytic balance and matrix deposition was inhibited by the specific protein kinase A inhibitors RpcAMP and KT5720 or by substituting analogues without reported glucocorticoid activity for HC. The addition of MMP inhibitors human recombinant TIMP-1 or 1,10-phenanthroline to cultures under basal conditions induced matrix deposition in a dose-dependent manner, which was not observed with the serine protease inhibitor epsilon-amino-n-caproic acid (ACA). The deposited basement membrane-type of matrix reproducibly suppressed HDMEC proliferation and increased HDMEC adhesion to the substratum. These processes of matrix deposition and downregulation of endothelial cell proliferation, hallmarks of differentiating new capillaries in the end of angiogenesis, were recapitulated in our cell culture system by decreasing the matrix-degrading activity. These data suggest that our cell culture assay provides a simple and feasible model system for the study of capillary endothelial cell differentiation and vessel maturation in vitro.

Enhancement of tumor necrosis factor-induced endothelial cell injury by cycloheximide

1990 ◽  
Vol 259 (2) ◽  
pp. L123-L129
Author(s):  
K. B. Nolop ◽  
U. S. Ryan
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Morphological Evidence ◽  
Human Aorta ◽  
Dependent Manner ◽  
Inhibitor Of Protein Synthesis ◽  
Necrosis Factor

Tumor necrosis factor (TNF), a potent polypeptide mediator released by activated monocytes and macrophages, has a number of proinflammatory effects on endothelial cells. TNF is cytotoxic to tumor cells in vivo and in vitro, but TNF-induced toxicity to endothelial cells is less well established. We now report that cycloheximide (CHX), an inhibitor of protein synthesis, renders endothelial cells highly susceptible to TNF-induced lysis. TNF alone did not change the overall rate of protein synthesis by endothelial cells, whereas the addition of CHX completely abolished protein synthesis. Endothelial cells incubated in TNF alone in high concentrations (up to 1,000 U/ml) showed minimal rounding up and release of 51Cr. Likewise, CHX alone (5 micrograms/ml) had no significant effect on endothelial cell morphology and release of 51Cr. However, incubation of endothelial cells in both CHX and TNF caused injury in a dose-dependent manner. Morphological evidence of cell retraction, rounding, and detachment began within 2 h, but specific 51Cr release did not begin to rise until after 4 h. These changes were not observed when endothelial cells were incubated with TNF/CHX at 4 degrees C. The combination of TNF/CHX was lethal to all endothelial cells tested (bovine pulmonary artery, human umbilical vein, and human aorta), with human aortic cells showing the most pronounced changes. We conclude that healthy endothelial cells are resistant to TNF-induced lysis, but inhibition of their ability to make protein renders them highly susceptible.

Upregulation of the Low Density Lipoprotein Receptor at the Blood-Brain Barrier: Intercommunications between Brain Capillary Endothelial Cells and Astrocytes

1987 ◽  
Vol 84 (1) ◽  
pp. 465-473
Author(s):  
Bénédicte Dehouck ◽  
Marie-Pierre Dehouck ◽  
Jean-Charles Fruchart ◽  
Roméo Cecchelli
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Ldl Receptor ◽  
Receptor Expression ◽  
Brain Barrier ◽  
Brain Capillary ◽  
Ldl Receptors ◽  
Brain Capillary Endothelial Cells ◽  
Capillary Endothelial Cells

In contrast to the endothelial cells in large vessels where LDL receptors are downregulated, brain capillary endothelial cells in vivo express an LDL receptor. Using a cell culture model of the blood-brain barrier consisting of a coculture of brain capillary endothelial cells and astrocytes, we observed that the capacity of endothelial cells to bind LDL is enhanced threefold when cocultured with astrocytes. We next investigated the ability of astrocytes to modulate endothelial cell LDL receptor expression. We have shown that the lipid requirement of astrocytes increases the expression of endothelial cell LDL receptors. Experiments with dialysis membranes of different pore size showed that this effect is mediated by a soluble factor(s) with relative molecular mass somewhere between 3,500 and 14,000. Substituting astrocytes with smooth muscle cells or brain endothelium with endothelium from the aorta or the adrenal cortex did not enhance the luminal LDL receptor expression on endothelial cells, demonstrating the specificity of the interactions. This factor(s) is exclusively secreted by astrocytes cocultured with brain capillary endothelial cells, but it also upregulates the LDL receptor on other cell types. This study confirms the notion that the final fine tuning of cell differentiation is under local control.

scholarly journals Mast cell heparin stimulates migration of capillary endothelial cells in vitro.

1980 ◽  
Vol 152 (4) ◽  
pp. 931-944 ◽  
Author(s):  
R G Azizkhan ◽  
J C Azizkhan ◽  
B R Zetter ◽  
J Folkman
Keyword(s):  
Endothelial Cells ◽  
Mast Cell ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Mast Cells ◽  
Endothelial Cell Migration ◽  
Capillary Endothelial Cell ◽  
Migration Activity ◽  
Capillary Endothelial Cells

Migration of capillary endothelial cells is an important component of angiogenesis in vivo. Increased numbers of mast cells have been associated with several types of angiogenesis. We have used a quantitative assay in vitro to demonstrate that mast cells release a factor that significantly increases bovine capillary endothelial cell migration. The factor is present in medium conditioned by mast cells as well as lysates of mast cells. The stimulatory effect of mast cells on migration is specific for capillary endothelial cells. Furthermore, mast cells have no mitogenic activity for capillary endothelial cells. Of all the secretory products of mast cells tested, only heparin stimulated capillary endothelial cell migration in vitro. Heparin preparations from a variety of sources stimulated capillary endothelial cell migration to the same degree but did not stimulate migration of several other cell types. The migration activity of heparin and mast cell conditioned medium was blocked by specific antagonists of heparin (protamine and heparinase), but not by chondroitinase ABC. The migration activity of mast cell conditioned medium was resistant to heat (100 degrees C) and incubation with proteolytic enzymes. These results suggest that the role of mast cells in angiogenesis may be to enhance migration of the endothelial cells of growing capillaries.

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