scholarly journals BIM deficiency differentially impacts the function of kidney endothelial and epithelial cells through modulation of their local microenvironment

2012 ◽  
Vol 302 (7) ◽  
pp. F809-F819 ◽  
Author(s):  
Nader Sheibani ◽  
Margaret E. Morrison ◽  
Zafer Gurel ◽  
SunYoung Park ◽  
Christine M. Sorenson
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Cell Types ◽  
Proper Function ◽  
Causative Role ◽  
Structural Support ◽  
Cell Adhesion And Migration ◽  
And Migration ◽  
Endothelial Nitric Oxide

The extracellular matrix (ECM) acts as a scaffold for kidney cellular organization. Local secretion of the ECM allows kidney cells to readily adapt to changes occurring within the kidney. In addition to providing structural support for cells, the ECM also modulates cell survival, migration, proliferation, and differentiation. Although aberrant regulation of ECM proteins can play a causative role in many diseases, it is not known whether ECM production, cell adhesion, and migration are regulated in a similar manner in kidney epithelial and endothelial cells. Here, we demonstrate that lack of BIM expression differentially impacts kidney endothelial and epithelial cell ECM production, migration, and adhesion, further emphasizing the specialized role of these cell types in kidney function . Bim −/− kidney epithelial cells demonstrated decreased migration, increased adhesion, and sustained expression of osteopontin and thrombospondin-1 (TSP1). In contrast, bim −/− kidney endothelial cells demonstrated increased cell migration, and decreased expression of osteopontin and TSP1. We also observed a fivefold increase in VEGF expression in bim −/− kidney endothelial cells consistent with their increased migration and capillary morphogenesis. These cells also had decreased endothelial nitric oxide synthase activity and nitric oxide bioavailability. Thus kidney endothelial and epithelial cells make unique contributions to the regulation of their ECM composition, with specific impact on adhesive and migratory properties that are essential for their proper function.

Dissociation of endothelial nitric oxide synthase phosphorylation and activity in uterine artery endothelial cells

2006 ◽  
Vol 290 (4) ◽  
pp. H1433-H1445 ◽  
Author(s):  
Jacqueline M. Cale ◽  
Ian M. Bird
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Uterine Artery ◽  
Cell Types ◽  
Enos Activity ◽  
Key Residues ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Pregnancy enhanced nitric oxide production by uterine artery endothelial cells (UAEC) is the result of reprogramming of both Ca2+ and kinase signaling pathways. Using UAEC derived from pregnant ewes (P-UAEC), as well as COS-7 cells transiently expressing ovine endothelial nitric oxide synthase (eNOS), we investigated the role of phosphorylation of five known amino acids following treatment with physiological calcium-mobilizing agent ATP and compared with the effects of PMA (also known as TPA) alone or in combination with ATP. In P-UAEC, ATP stimulated eNOS activity and phosphorylation of eNOS S617, S635, and S1179. PMA promoted eNOS phosphorylation but without activation. PMA and ATP cotreatment attenuated ATP-stimulated activity despite no increase in phospho (p)-T497 and potentiation of p-S1179. In COS-7 cells, PMA inhibition of ATP-stimulated eNOS activity was associated with p-T497 phosphorylation. Although T497D eNOS activity was reduced to 19% of wild-type eNOS with ATP and 44% with A23187, we nonetheless observed more p-S1179 with ATP than with A23187 (3.4-fold and 1.8-fold of control, respectively). Furthermore, the S1179A eNOS mutation partly attenuated ATP- but not A23187-stimulated activity, but when combined with T497D, no further reduction of eNOS activity was observed. In conclusion, although phosphorylation of eNOS is associated with activation in P-UAEC, no single or combination of phosphorylation events predict activity changes. In COS-7 cells, phosphorylation of T497 can attenuate activity but also influences S1179 phosphorylation. We conclude that in both cell types, observed changes in phosphorylation of key residues may influence eNOS activation but are not sufficient alone to describe eNOS activation.

scholarly journals Rho GTPase/Rho Kinase Negatively Regulates Endothelial Nitric Oxide Synthase Phosphorylation through the Inhibition of Protein Kinase B/Akt in Human Endothelial Cells

2002 ◽  
Vol 22 (24) ◽  
pp. 8467-8477 ◽  
Author(s):  
Xiu-Fen Ming ◽  
Hema Viswambharan ◽  
Christine Barandier ◽  
Jean Ruffieux ◽  
Kozo Kaibuchi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Rho Gtpase ◽  
Protein Kinase B ◽  
Rho Kinase ◽  
Enos Expression ◽  
Enos Phosphorylation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

ABSTRACT Endothelial nitric oxide synthase (eNOS) is an important regulator of cardiovascular homeostasis by production of nitric oxide (NO) from vascular endothelial cells. It can be activated by protein kinase B (PKB)/Akt via phosphorylation at Ser-1177. We are interested in the role of Rho GTPase/Rho kinase (ROCK) pathway in regulation of eNOS expression and activation. Using adenovirus-mediated gene transfer in human umbilical vein endothelial cells (HUVECs), we show here that both active RhoA and ROCK not only downregulate eNOS gene expression as reported previously but also inhibit eNOS phosphorylation at Ser-1177 and cellular NO production with concomitant suppression of PKB activation. Moreover, coexpression of a constitutive active form of PKB restores the phosphorylation but not gene expression of eNOS in the presence of active RhoA. Furthermore, we show that thrombin inhibits eNOS phosphorylation, as well as expression via Rho/ROCK pathway. Expression of the active PKB reverses eNOS phosphorylation but has no effect on downregulation of eNOS expression induced by thrombin. Taken together, these data demonstrate that Rho/ROCK pathway negatively regulates eNOS phosphorylation through inhibition of PKB, whereas it downregulates eNOS expression independent of PKB.

Effects of homocysteine on endothelial nitric oxide production

2000 ◽  
Vol 279 (4) ◽  
pp. F671-F678 ◽  
Author(s):  
Xiaohui Zhang ◽  
Hong Li ◽  
Haoli Jin ◽  
Zachary Ebin ◽  
Sergey Brodsky ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Redox State ◽  
Calcium Ionophore ◽  
No Production ◽  
Cellular Redox ◽  
A Cell ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Peroxynitrite Scavengers

Hyperhomocysteinemia (HHCy) is an independent and graded cardiovascular risk factor. HHCy is prevalent in patients with chronic renal failure, contributing to the increased mortality rate. Controversy exists as to the effects of HHCy on nitric oxide (NO) production: it has been shown that HHCy both increases and suppresses it. We addressed this problem by using amperometric electrochemical NO detection with a porphyrinic microelectrode to study responses of endothelial cells incubated with homocysteine (Hcy) to the stimulation with bradykinin, calcium ionophore, or l-arginine. Twenty-four-hour preincubation with Hcy (10, 20, and 50 μM) resulted in a gradual decline in responsiveness of endothelial cells to the above stimuli. Hcy did not affect the expression of endothelial nitric oxide synthase (eNOS), but it stimulated formation of superoxide anions, as judged by fluorescence of dichlorofluorescein, and peroxynitrite, as detected by using immunoprecipitation and immunoblotting of proteins modified by tyrosine nitration. Hcy did not directly affect the ability of recombinant eNOS to generate NO, but oxidation of sulfhydryl groups in eNOS reduced its NO-generating activity. Addition of 5-methyltetrahydrofolate restored NO responses to all agonists tested but affected neither the expression of the enzyme nor formation of nitrotyrosine-modified proteins. In addition, a scavenger of peroxynitrite or a cell-permeant superoxide dismutase mimetic reversed the Hcy-induced suppression of NO production by endothelial cells. In conclusion, electrochemical detection of NO release from cultured endothelial cells demonstrated that concentrations of Hcy >20 μM produce a significant indirect suppression of eNOS activity without any discernible effects on its expression. Folates, superoxide ions, and peroxynitrite scavengers restore the NO-generating activity to eNOS, collectively suggesting that cellular redox state plays an important role in HCy-suppressed NO-generating function of this enzyme.

scholarly journals Cilostazol Induces eNOS and TM Expression via Activation with Sirtuin 1/Krüppel-like Factor 2 Pathway in Endothelial Cells

2021 ◽  
Vol 22 (19) ◽  
pp. 10287
Author(s):  
Chih-Hsien Wu ◽  
Yi-Lin Chiu ◽  
Chung-Yueh Hsieh ◽  
Guo-Shiang Tsung ◽  
Lian-Shan Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Umbilical Vein ◽  
Sirtuin 1 ◽  
No Production ◽  
Beneficial Effects ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Cilostazol was suggested to be beneficial to retard in-stent atherosclerosis and prevent stent thrombosis. However, the mechanisms responsible for the beneficial effects of cilostazol are not fully understood. In this study, we attempted to verify the mechanism of the antithrombotic effect of cilostazol. Human umbilical vein endothelial cells (HUVECs) were cultured with various concentrations of cilostazol to verify its impact on endothelial cells. KLF2, silent information regulator transcript-1 (SIRT1), endothelial nitric oxide synthase (eNOS), and endothelial thrombomodulin (TM) expression levels were examined. We found cilostazol significantly activated KLF2 expression and KLF2-related endothelial function, including eNOS activation, Nitric oxide (NO) production, and TM secretion. The activation was regulated by SIRT1, which was also stimulated by cilostazol. These findings suggest that cilostazol may be capable of an antithrombotic and vasculoprotective effect in endothelial cells.

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