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E Noiri

Publications and source records attributed to E Noiri.

At least 37 records · Page 2Linked to original sources
PubMed1999

Nitric oxide modulation of focal adhesions in endothelial cells.

A permissive role of nitric oxide (NO) in endothelial cell migration and angiogenesis promoted by vascular endothelial growth factor (VEGF), endothelin, and substance P has previously been established. The present studies were designed to examine the mechanism(s) involved in the NO effect on focal adhesions. Time-lapse videomicroscopy of human umbilical vein endothelial cells (HUVECs) plated on the silicone rubber substrate revealed that unstimulated cells were constantly remodeling the wrinkling pattern, indicative of changing tractional forces. Application of NO donors reversibly decreased the degree of wrinkling, consistent with the release of tractional forces exerted by focal adhesions and stress fibers. Morphometric and immunocytochemical analyses showed that NO inhibited adhesion and spreading of HUVECs and attenuated recruitment of paxillin to focal adhesions. NO also had a profound dose-dependent effect on the formation of stress fibers by HUVECs. De novo formation of focal adhesions in HUVECs was significantly diminished in the presence of NO donors. Migration of HUVECs showed an absolute requirement for the functional NO synthase. NO donors did not interfere with focal adhesion kinase recruitment to focal adhesions but affected the state of its tyrosine phosphorylation, as judged from the results of immunoprecipitation and immunoblotting experiments. Videomicroscopy of HUVECs presented with VEGF in a micropipette showed that the rate of cell migration was slowed down by NO synthase inhibition as well as by inhibition of tyrosine phosphorylation. Collectively, these data indicate that NO reversibly releases tractional forces exerted by spreading endothelial cells via interference with the de novo formation of focal adhesions, tyrosine phosphorylation of components of focal adhesion complexes, and assembly of stress fibers.

Cell Adhesion↗
PubMed1999

Duality of nitric oxide in acute renal injury.

This brief overview focuses on the complexity of the distribution of nitric oxide (NO) synthases in the kidney and their regulation following acute renal injury. The authors attempt to provide clearcut distinctions between various targets of NO, describe its cytotoxic and renoprotective effects, and emphasize the role of combined oxidative and nitrozative stress in mediating renal injury. Furthermore, some strategies to pharmacologically manipulate the expression of NO synthases are described. This treatment of the subject is based on the authors' hypothesis that imbalance between the expression and activity of the inducible and constitutive endothelial isoforms of the enzyme is an important contributor to the pathophysiology of acute renal failure.

Acute Kidney Injury↗
PubMed1998

Podokinesis in endothelial cell migration: role of nitric oxide.

Previously, we demonstrated the role of nitric oxide (NO) in transforming epithelial cells from a stationary to locomoting phenotype [E. Noiri, T. Peresleni, N. Srivastava, P. Weber, W.F. Bahou, N. Peunova, and M. S. Goligorsky. Am. J. Physiol. 270 (Cell Physiol. 39): C794-C802, 1996] and its permissive function in endothelin-1-stimulated endothelial cell migration (E. Noiri, Y. Hu, W. F. Bahou; C. Keese, I. Giaever, and M. S. Goligorsky, J. Biol: Chem. 272: 1747-1753, 1997). In the present study, the role of functional NO synthase in executing the vascular endothelial growth factor (VEGF)-guided program of endothelial cell migration and angiogenesis was studied in two independent experimental settings. First, VEGF, shown to stimulate NO release from simian virus 40-immortalized microvascular endothelial cells, induced endothelial cell transwell migration, whereas NG-nitro-L-arginine methyl ester (L-NAME) or antisense oligonucleotides to endothelial NO synthase suppressed this effect of VEGF. Second, in a series of experiments on endothelial cell wound healing, the rate of VEGF-stimulated cell migration was significantly blunted by the inhibition of NO synthesis. To gain insight into the possible mode of NO action, we next addressed the possibility that NO modulates cell matrix adhesion by performing impedance analysis of endothelial cell monolayers subjected to NO. The data showed the presence of spontaneous fluctuations of the resistance in ostensibly stationary endothelial cells. Spontaneous oscillations were induced by NO, which also inhibited cell matrix adhesion. This process we propose to term "podokinesis" to emphasize a scalar from of micromotion that, in the presence of guidance cues, e.g., VEGF, is transformed to a vectorial movement. In conclusion, execution of the program for directional endothelial cell migration requires two coexisting messages: NO-induced podokinesis (scalar motion) and guidance cues, e.g., VEGF, which imparts a vectorial component to the movement. Such a requirement for the dual signaling may explain a mismatch in the demand and supply with newly formed vessels in different pathological states accompanied by the inhibition of NO synthase.

Animals↗
PubMed1997

Permissive role of nitric oxide in endothelin-induced migration of endothelial cells.

Endothelin (ET) synthesis is enhanced at sites of ischemia or in injured vessels. The purpose of this study was to explore the possibility of autocrine stimulation of endothelial cell migration by members of the endothelin family. Experiments with microvascular endothelial cell transmigration in a Boyden chemotactic apparatus showed that endothelins 1 and 3, as well as a selective agonist of ETB receptor IRL-1620, equipotently stimulated migration. Endothelial cell migration was unaffected by the blockade of ETA receptor, but it was inhibited by ETB receptor antagonism. Based on our previous demonstration of signaling from the occupied ETB receptor to constitutive nitric oxide (NO) synthase (Tsukahara, H., Ende, H., Magazine, H. I., Bahou, W. F., and Goligorsky, M. S. (1994) J. Biol. Chem. 269, 21778-21785), we next examined the contribution of ET-stimulated NO production to endothelial cell migration. In three independent cellular systems, 1) migration and wound healing by microvascular endothelial cells, 2) wound healing by Chinese hamster ovary cells stably expressing ETB receptor with or without endothelial NO synthase, and 3) application of antisense oligodeoxynucleotides targeting endothelial NO synthase in human umbilical vein endothelial cells, an absolute requirement for the functional NO synthase in cell migration has been demonstrated. These findings establish the permissive role of NO synthesis in endothelin-stimulated migration of endothelial cells.

Animals↗
PubMed1997

Two novel probes reveal tubular and vascular Arg-Gly-Asp (RGD) binding sites in the ischemic rat kidney.

We have previously demonstrated that RGD peptides prevent tubular obstruction in ischemic acute renal failure (ARF) suggested that exposed unoccupied integrin receptors represent the target for such therapy. The present study investigated the topography of RGD binding sites and integrin receptors in ischemic rat kidneys. Two RGD peptides were synthesized: a cyclic biotinylated (Bt) RGD peptide and a linear RGD peptide (GRGDSP) labeled with rhodamine green (RhoG). Rats were subjected to 45 minutes of renal artery occlusion kidneys were harvested at different times post-ischemia, and stained with RGD peptides and a panel of antibodies to integrins. In control, Bt-RGD staining was undetectable in alkaline phosphatase histochemistry, whereas immunofluorescence detection with Rho-streptavidin conjugate as well as RhoG-GRGDSP staining faintly decorated the basolateral aspect of the proximal tubular cells in a punctate fashion. In contrast, ischemic kidneys showed binding to the basolateral and apical aspects of proximal tubules, peritubular capillaries, and desquamated cells within tubular lumen. The most conspicuous staining of ischemic kidneys was obtained with antibodies to the beta 1 (labeling of the apical aspect of proximal and distal tubules, as well as desquamated cells obstructing tubular lumen) and the alpha V (glomeruli, tubular epithelia, intima of blood vessels stained faintly, while the obstructing cellular conglomerates showed intense staining) subunits. Double staining with Bt-RGD and antibodies against the beta 1 and alpha V beta 3 integrins showed co-localization of staining within the tubules and vasculature, respectively. In vitro attachment of HL-60 leukocytes to the endothelial cells was inhibited by the cyclic RGD peptide. In conclusion, expression of RGD binding sites and beta 1 integrin subunits along the apical aspect of tubular epithelia and on the surface of desquamated cells is in concert with the hypothesis on the pathogenetic role of RGD-recognizing integrins in tubular obstruction. The expression of RGD binding sites along the intimal surface of blood vessels in ischemic kidneys suggests an additional target for RGD peptides in vascular endothelial cells.

Animals↗
PubMed1997

Long-term effects of LTB4 antagonist on lipid induced renal injury.

Glomerular infiltration of macrophages is a characteristic alteration of renal histopathology in hyperlipidemic renal injury. Each macrophage has two key enzymes to synthesize LTB4:5-lipoxygenase and LTA4 hydrolase. In this study we examined the long-term effects of LTB4 antagonist on real function and histopathology of spontaneously hypercholesterolemic (SHC) rat, which is model of hyperlipidemic renal injury, to see if the LTB4 antagonist could reduce the progression of renal damage. Spontaneously hypercholesterolemic rats fed a normal diet (C) developed end-stage renal failure in 26 weeks, while those fed a diet supplemented with LTB4 antagonist (E) showed normal renal function, and mild histopathological alterations (SCr: C, 1.4 +/- 0.3; E, 0.6 +/- 0.1 mg/dl, P < 0.03) without statistical differences in serum total cholesterol, body weight and blood pressure between two groups. These results suggest that LTB4 plays an important role in progression of hyperlipidemic renal injury.

Animals↗
PubMed1996

In vivo targeting of inducible NO synthase with oligodeoxynucleotides protects rat kidney against ischemia.

Gene products of all three distinct nitric oxide synthases are present in the mammalian kidney. This mosaic topography of nitric oxide synthase (NOS) isoforms probably reflects distinct functional role played by each enzyme. While nitric oxide (NO) is cytotoxic to isolated renal tubules, inhibition of NO production in vivo invariably results in the aggravation of renal dysfunction in various models of acute renal failure. We reasoned that the existing ambiguity on the role of nitric oxide in acute renal failure is in part due to the lack of selective NOS inhibitors. Phosphorothioated derivatives of antisense oligodeoxynucleotides targeting a conserved sequence within the open reading frame of the cDNA encoding the inducible NOS (iNOS) were designed to produce a selective knock-down of this enzyme. In vivo use of these antisense constructs attenuated acute renal failure in rats subjected to renal ischemia. This effect was due, at least in part, to the rescue of tubular epithelium from lethal injury. Application of antisense constructs did not affect endothelial NOS, as evidenced by a spared NO release after the infusion of bradykinin during in vivo monitoring with an NO-selective microelectrode. In conclusion, the data provide direct evidence for the cytotoxic effects of NO produced via iNOS in the course of ischemic acute renal failure, and offer a novel method to selectively prevent the induction of this enzyme.

Animals↗
PubMed1996

Nitric oxide is necessary for a switch from stationary to locomoting phenotype in epithelial cells.

The restitution of epithelial integrity is accomplished in part by cell migration. Studying this process, we have found that nitric oxide (NO) release migrating epithelial BSC-1 cells displayed a biphasic response to the inflicted wounds; an initial transient release of NO is followed by a delayed sustained elevation. Whereas the constitutive endothelial NO synthase (NOS) did not show any spatial or temporal changes associated with wounding, the inducible NOS became expressed 3 h after wounding and showed higher abundance at the edges of epithelial wounds. L-Arginine (L-Arg) or NO donor, S-nitroso-N-acetyl-DL-penicillamine, exerted motogenic effect in epithelial and endothelial cells. Inhibition of NOS with NG-nitro-L-arginine methyl ester (L-NAME) or a selective knockout of inducible NOS with antisense oligodeoxynucleotides reduced the rate of spontaneous or epidermal growth factor (EGF)-induced BSC-1 cell migration. Migrating cells showed the polarized expression of NOS, suggesting a head-to-rear NO gradient. Several growth factors (EGF, insulin-like growth factor I, hepatocyte growth factor, and fibroblast growth factor) were motogenic for BSC-1 cells, but this effect was abrogated by pretreatment with L-NAME. We conclude that endogenous NO production is a prerequisite for BSC-1 cell migration. A vectorial NO release may be essential for the spatially and temporally coordinated reciprocal phenomena that occur at the leading and trailing edge of locomoting epithelial cells. Although the exact mode of NO action remains uncertain, it is conceivable that the production of NO serves as a cellular switch from the stationary to the locomoting epithelial phenotype.

Animals↗
PubMed1996

Antisense oligodeoxynucleotides to inducible NO synthase rescue epithelial cells from oxidative stress injury.

Until recently, the lack of specific inhibitors of various forms of nitric oxide synthase (NOS) hampered a stringent evaluation of the role played by inducible NOS (iNOS) in cell damage. Phosphorothioate derivatives of iNOS antisense and control sense or scrambled oligodeoxynucleotides (S-ODNs) were synthesized, and their effect on epithelial cell viability was examined under oxidant stress. Exposure of BSC-1 kidney tubular epithelial cells to H2O2 resulted in elevation of NO release, accompanied by a significant decrease in the population of viable cells (from 97.4 +/- 1.7% to 72.4 +/- 2.4% population). Nitrite production by BSC-1 cells exposed to H2O2 increased almost 10-fold compared with control. Pretreatment of the cells with 10 microM antisense ODNs significantly blunted this response, whereas sense or scrambled ODNs did not modify it. Pretreatment of BSC-1 cells with 10 microM antisense ODNs virtually prevented lethal cell damage in response to H2O2, whereas sense ODNs were ineffective. Lipopolysaccharide induction of iNOS, also preventable by the antisense construct, resulted in a lesser compromise to cell viability. Immunocytochemistry of iNOS in cells pretreated with antisense ODNs showed minimal cytoplasmic staining, as opposed to the untreated or sense ODN-treated positively stained cells. Staining with antibodies to nitrotyrosine was conspicuous in stressed cells but undetectable in antisense ODN-treated cells. In conclusion, oxidant stress is accompanied by the induction of iNOS, increased production of NO, and impaired cell viability; selective inhibition of iNOS using the designed antisense ODNs dramatically improved BSC-1 cell viability after oxidant stress.

Animals↗
PubMed1996

Biodistribution and clearance of 99mTc-labeled Arg-Gly-Asp (RGD) peptide in rats with ischemic acute renal failure.

Based on the previous demonstration of a renoprotective effect of arginine-glycine-aspartic acid (RGD) peptides in acute renal failure, experiments were designed to test the distribution and renal accumulation of the peptide. To accomplish this goal, in this study, RGD peptide was radiolabeled and its biodistribution and renal accumulation was determined in rats with ischemic acute renal failure (ARF). 99mTc-RGD with or without 111In-DTPA were injected intravenously in control and ARF rats. Various organs were dissected at different times after injection and subjected to gamma-scintillation counting and autoradiography (ARG). Blood clearance of 99mTc-RGD was rapid, with t1/2 < 10 min, and unchanged in ARF compared with control rats. Kidneys retained the largest portion of the injected dose in both control and ARF rats, as detected using scintillation counting and whole-body ARG (10.56 +/- 1.05% and 10.12 +/- 3.16% injected dose/g wet weight, respectively). Renal ARG revealed a significant increase in binding to the cortex in ARF kidneys, compared with that of control kidneys. Given the differences in renal blood flow and GFR in control and postischemic kidneys, the next series of experiments was performed with two radiopharmaceuticals, 99mTc-RGD and 111In-DTPA. The ratio of 99mTc-RGD:111In-DTPA was increased more than three-fold in ARF kidneys compared with control kidneys (2.7 +/- 0.15 versus 0.8 +/- 0.19, respectively). The results indicate that (1) RGD peptide undergoes a rapid clearance predominantly via the renal route; (2) despite a significant reduction in the renal perfusion, 99mTc-RGD peptide accumulates in the postischemic kidney; (3) this is consistent with the hypothesis on the involvement of RGD-recognizing integrins in the development of tubular obstruction in renal ischemia.

Acute Kidney Injury↗
PubMed1994

Cyclic RGD peptides ameliorate ischemic acute renal failure in rats.

Renal tubular obstruction is an important contributor to the pathophysiology of acute renal failure. Based on the previous findings of the role played by arginine-glycine-aspartic acid (RGD) recognizing integrins in tubular obstruction, this study examined the effect of RGD peptides on the course of ischemic acute renal failure in rats. For in vivo studies, animals were subjected to 45 minutes of unilateral renal ischemia with contralateral nephrectomy, and cyclic RGD peptides or a linear biotinylated RGD peptide were injected systemically after the release of renal artery clamp. In vitro studies compared the potency of the peptides in inhibiting BS-C-1 cell-matrix and cell-cell adhesion. Two novel cyclic RGD peptides utilized in these studies showed different inhibitory potency in preventing cell-matrix adhesion: cyclic RGDDFV was a highly potent in vitro inhibitor of BS-C-1 cell-matrix adhesion, whereas cyclic RGDDFLG was less potent. In cell-cell adhesion assays, however, both peptides were equipotent. Despite the differences in inhibiting cell-matrix adhesion, a single systemic administration of either peptide improved creatinine clearance postoperatively and accelerated recovery of renal function with a rank order: cyclic RGDDFV > or = RGDDFLG >> RDADFV (inactive control). These findings represent the first in vivo demonstration of the effectiveness of cyclic RGD peptides in ameliorating ischemic acute renal failure, and suggest that in this setting RGD peptides predominantly inhibit cell-cell adhesion, whereas inhibition of cell-matrix adhesion is of lesser significance.

Acute Kidney Injury↗
PubMed1994

Therapeutic strategy of nephrotic syndrome in patients over eighty.

In the present paper, we report four very elderly patients (80 years of age or older) with primary nephrotic syndrome. In all patients, oral prednisolone (PSL) alternative day therapy was attempted and three patients responded very well (complete remission 2, partial remission 1). However, one patient exhibited no effect of PSL and died from acute oliguric renal failure in spite of aggressive measures including hemodialysis. Fracture of the femoral neck occurred in one patient during PSL therapy, although the relationship between the fracture and PSL therapy was uncertain. In addition to our reported cases, 5 cases of nephrotic syndrome in similar patients reported elsewhere are analyzed together with our cohort. PSL was commonly effective in inducing remission in very elderly patients (7 of 9 patients; 78%). Very elderly patients with nephrotic syndrome frequently suffer from oliguric renal failure, which has a potentially high mortality. Based on these data, we conclude that PSL therapy can ameliorate primary nephrotic syndrome in patients over the age of eighty years. However, the complications both of the disease and its treatment, (e.g., acute oliguric renal failure, hip fracture) must be carefully monitored.

Acute Kidney Injury↗
PubMed1994

Tumor necrosis factor-alpha mRNA expression in lipopolysaccharide-stimulated rat kidney. Chronological analysis of localization.

To study the time course of lipopolysaccharide-induced production of tumor necrosis factor-alpha (TNF-alpha) in the kidney, we utilized a highly sensitive non-radioisotopic in situ hybridization with 1-nm gold-conjugated anti-digoxigenin for localization of TNF-alpha mRNA expression after lipopolysaccharide administration. TNF-alpha mRNA expression localized by in situ hybridization showed a peak increment in proximal tubular epithelial cells and glomeruli at 2 hours and returned to almost normal levels at 6 hours. The intensity of the signal was much stronger in proximal tubules than in glomeruli. These findings were confirmed by the demonstration of similar kinetics in the increase of TNF-alpha message, measured by using amplification of the third and fourth exons of TNF-alpha gene by reverse transcription-polymerase chain reaction of microdissected proximal tubular segments and isolated glomeruli. Reverse transcription-polymerase chain reaction of cultured rat mesangial and glomerular epithelial cells demonstrated that mesangial cells, not glomerular epithelial cells, were responsible for the observed glomerular signals.

Animals↗