scholarly journals Chronic NOS inhibition actuates endothelial-mesenchymal transformation

2007 ◽  
Vol 292 (1) ◽  
pp. H285-H294 ◽  
Author(s):  
Edmond O’Riordan ◽  
Natalia Mendelev ◽  
Susann Patschan ◽  
Daniel Patschan ◽  
Jonathan Eskander ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Asymmetric Dimethylarginine ◽  
Transforming Growth Factor ◽  
Fluorescent Protein ◽  
Transforming Growth Factor Β ◽  
Tissue Growth ◽  
Collagen Xviii ◽  
Green Fluorescent

Chronic kidney diseases are accompanied by the accumulation of substances like asymmetric dimethylarginine, phenylacetic acid, homocysteine, and advanced glycation end products, known to either inhibit endothelial nitric oxide synthase (eNOS) or uncouple it, consequently limiting the amount of available nitric oxide (NO). Reduced bioavailability of NO induces endothelial dysfunction. An early loss of peritubular capillaries in tubulointerstitial fibrotic areas and injury to endothelial cells have been linked to progressive renal disease. Screening endothelial genes in cells treated with NOS inhibitors showed upregulation of collagen XVIII, a precursor of a potent antiangiogenic substance, endostatin. This finding was confirmed at the level of mRNA and protein expression. Tie-2 promoter-driven green fluorescent protein mice treated with nonhypertensinogenic doses of a NOS inhibitor exhibited upregulation of collagen XVIII/endostatin and rarefaction of capillary profiles. This was accompanied by the increased expression of transforming growth factor-β and connective tissue growth factor in the kidney. Occasional endothelial cells expressed both the marker of endothelial lineage (green fluorescent protein) and mesenchymal marker (α-smooth muscle actin or calponin). In vitro studies of endothelial cells treated with asymmetric dimethylarginine showed decreased expression of eNOS and Flk-1 and enhanced expression of calponin and fibronectin, additional markers of smooth muscle and mesenchymal cells. These cells overexpressed transforming growth factor-β and connective tissue growth factor, as well as endostatin. In conclusion, data presented here 1) ascribe to NO deficiency in endothelial cells the function of a profibrotic stimulus associated with the expression of an antiangiogenic fragment of collagen XVIII (endostatin) and 2) provide evidence of endothelial-mesenchymal transdifferentiation in the course of inhibition of NOS by a pathophysiologically important antagonist, asymmetric dimethylarginine. Both mechanisms may account for microvascular rarefaction.

scholarly journals Kinetic Analysis of Smad Nucleocytoplasmic Shuttling Reveals a Mechanism for Transforming Growth Factor β-Dependent Nuclear Accumulation of Smads

2005 ◽  
Vol 25 (22) ◽  
pp. 9845-9858 ◽  
Author(s):  
Bernhard Schmierer ◽  
Caroline S. Hill
Keyword(s):  
Green Fluorescent Protein ◽  
Growth Factor ◽  
Nuclear Export ◽  
Transforming Growth Factor ◽  
Fluorescent Protein ◽  
Transforming Growth Factor Β ◽  
Nuclear Accumulation ◽  
Nucleocytoplasmic Shuttling ◽  
Green Fluorescent

ABSTRACT Upon transforming growth factor β (TGF-β) stimulation, Smads accumulate in the nucleus, where they regulate gene expression. Using fluorescence perturbation experiments on Smad2 and Smad4 fused to either enhanced green fluorescent protein or photoactivatable green fluorescent protein, we have studied the kinetics of Smad nucleocytoplasmic shuttling in a quantitative manner in vivo. We have obtained rate constants for import and export of Smad2 and show that the cytoplasmic localization of Smad2 in uninduced cells reflects its nuclear export being more rapid than import. We find that TGF-β-induced nuclear accumulation of Smad2 is caused by a pronounced drop in the export rate of Smad2 from the nucleus, which is associated with a strong decrease in nuclear mobility of Smad2 and Smad4. TGF-β-induced nuclear accumulation involves neither a release from cytoplasmic retention nor an increase in Smad2 import rate. Hence, TGF-β-dependent nuclear accumulation of Smad2 is caused exclusively by selective nuclear trapping of phosphorylated, complexed Smad2. The proposed mechanism reconciles signal-dependent nuclear accumulation of Smad2 with its continuous nucleocytoplasmic cycling properties.

scholarly journals Nitric Oxide Regulates Transforming Growth Factor-β Signaling in Endothelial Cells

2005 ◽  
Vol 97 (11) ◽  
pp. 1115-1123 ◽  
Author(s):  
Marta Saura ◽  
Carlos Zaragoza ◽  
Beatrice Herranz ◽  
Mercedes Griera ◽  
Luisa Diez-Marqués ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β

Intracisternal administration of transforming growth factor-β evokes fever through the induction of cyclooxygenase-2 in brain endothelial cells

2008 ◽  
Vol 294 (1) ◽  
pp. R266-R275 ◽  
Author(s):  
Shigenobu Matsumura ◽  
Tetsuro Shibakusa ◽  
Teppei Fujikawa ◽  
Hiroyuki Yamada ◽  
Kiyoshi Matsumura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cyclooxygenase 2 ◽  
Dependent Manner ◽  
Cox 2 ◽  
Β Receptor

Transforming growth factor-β (TGF-β), a pleiotropic cytokine, regulates cell proliferation, differentiation, and apoptosis, and plays a key role in development and tissue homeostasis. TGF-β functions as an anti-inflammatory cytokine because it suppresses microglia and B-lymphocyte functions, as well as the production of proinflammatory cytokines. However, we previously demonstrated that the intracisternal administration of TGF-β induces fever like that produced by proinflammatory cytokines. In this study, we investigated the mechanism of TGF-β-induced fever. The intracisternal administration of TGF-β increased body temperature in a dose-dependent manner. Pretreatment with cyclooxygenase-2 (COX-2)-selective inhibitor significantly suppressed TGF-β-induced fever. COX-2 is known as one of the rate-limiting enzymes of the PGE2 synthesis pathway, suggesting that fever induced by TGF-β is COX-2 and PGE2 dependent. TGF-β increased PGE2 levels in cerebrospinal fluid and increased the expression of COX-2 in the brain. Double immunostaining of COX-2 and von Willebrand factor (vWF, an endothelial cell marker) revealed that COX-2-expressing cells were mainly endothelial cells. Although not all COX-2-immunoreactive cells express TGF-β receptor, some COX-2-immunoreactive cells express activin receptor-like kinase-1 (ALK-1, an endothelial cell-specific TGF-β receptor), suggesting that TGF-β directly or indirectly acts on endothelial cells to induce COX-2 expression. These findings suggest a novel function of TGF-β as a proinflammatory cytokine in the central nervous system.

Transforming Growth Factor-β: Role in Mediating Serum-Induced Endothelin Production by Vascular Endothelial Cells*

Endocrinology ◽  
1991 ◽  
Vol 129 (5) ◽  
pp. 2355-2360 ◽  
Author(s):  
MARVIN R. BROWN ◽  
JOAN VAUGHAN ◽  
LETICIA L. JIMENEZ ◽  
WYLIE VALE ◽  
ANDREW BAIRD
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Vascular Endothelial Cells ◽  
Transforming Growth Factor Β ◽  
Vascular Endothelial
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