scholarly journals Proliferation of Interstitial Cells in the Cyclophosphamide-Induced Cystitis and the Preventive Effect of Imatinib

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Maria Sancho ◽  
Domingo Triguero ◽  
Aranzazu Lafuente-Sanchis ◽  
Angeles Garcia-Pascual
Keyword(s):  
Nitric Oxide ◽  
Receptor Tyrosine Kinase ◽  
Kinase Inhibitor ◽  
De Novo ◽  
Muscle Layer ◽  
Interstitial Cells ◽  
No Synthase ◽  
No Production ◽  
Preventive Effect ◽  
Enos Expression

Cyclophosphamide- (CYP-) induced cystitis in the rat is a well-known model of bladder inflammation that leads to an overactive bladder, a process that appears to involve enhanced nitric oxide (NO) production. We investigated the changes in the number and distribution of interstitial cells (ICs) and in the expression of endothelial NO synthase (eNOS) in the bladder and urethra of rats subjected to either intermediate or chronic CYP treatment. Pronounced hyperplasia and hypertrophy of ICs were evident within the lamina propria and in the muscle layer. IC immunolabeling with CD34, PDGFRα, and vimentin was enhanced, as reflected by higher colocalization indexes of the distinct pairs of markers. Moreover, de novo expression of eNOS was evident in vimentin and CD34 positive ICs. Pretreatment with the receptor tyrosine kinase inhibitor Imatinib prevented eNOS expression and ICs proliferation, as well as the increased voiding frequency and urinary tract weight provoked by CYP. As similar results were obtained in the urethra, urethritis may contribute to the uropathology of CYP-induced cystitis.

17β-Estradiol decreases hypoxic induction of erythropoietin gene expression

2002 ◽  
Vol 283 (2) ◽  
pp. R496-R504 ◽  
Author(s):  
Harshini Mukundan ◽  
Thomas C. Resta ◽  
Nancy L. Kanagy
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Oxygen Delivery ◽  
Chronic Hypoxia ◽  
No Synthase ◽  
No Production ◽  
Enos Expression ◽  
Hypoxic Induction ◽  
Endothelial No Synthase ◽  
17Β Estradiol

Exposure to chronic hypoxia induces erythropoietin (EPO) production to facilitate oxygen delivery to hypoxic tissues. Previous studies from our laboratory found that ovariectomy (OVX) exacerbates the polycythemic response to hypoxia and treatment with 17β-estradiol (E2-β) inhibits this effect. We hypothesized that E2-β decreases EPO gene expression during hypoxia. Because E2-β can induce nitric oxide (NO) production and NO can attenuate EPO synthesis, we further hypothesized that E2-β inhibition of EPO gene expression is mediated by NO. These hypotheses were tested in OVX catheterized rats treated with E2-β (20 μg/day) or vehicle for 14 days and exposed to 8 or 12 h of hypoxia (12% O2) or normoxia. We found that E2-β treatment significantly decreased EPO synthesis and gene expression during hypoxia. E2-β treatment did not induce endothelial NO synthase (eNOS) expression in the kidney but potentiated hypoxia-induced increases in plasma nitrates. We conclude that E2-β decreases hypoxic induction of EPO. However, this effect does not appear to be related to changes in renal eNOS expression.

scholarly journals Blunted flow-mediated responses and diminished nitric oxide synthase expression in lymphatic thoracic ducts of a rat model of metabolic syndrome

2016 ◽  
Vol 310 (3) ◽  
pp. H385-H393 ◽  
Author(s):  
Scott D. Zawieja ◽  
Olga Gasheva ◽  
David C. Zawieja ◽  
Mariappan Muthuchamy
Keyword(s):  
Nitric Oxide ◽  
Metabolic Syndrome ◽  
Rat Model ◽  
Ex Vivo ◽  
No Synthase ◽  
Frequency Regulation ◽  
No Production ◽  
Ros Scavenging ◽  
Enos Expression ◽  
Contraction Frequency

Shear-dependent inhibition of lymphatic thoracic duct (TD) contractility is principally mediated by nitric oxide (NO). Endothelial dysfunction and poor NO bioavailability are hallmarks of vasculature dysfunction in states of insulin resistance and metabolic syndrome (MetSyn). We tested the hypothesis that flow-dependent regulation of lymphatic contractility is impaired under conditions of MetSyn. We utilized a 7-wk high-fructose-fed male Sprague-Dawley rat model of MetSyn and determined the stretch- and flow-dependent contractile responses in an isobaric ex vivo TD preparation. TD diameters were tracked and contractile parameters were determined in response to different transmural pressures, imposed flow, exogenous NO stimulation by S-nitro- N-acetylpenicillamine (SNAP), and inhibition of NO synthase (NOS) by l-nitro-arginine methyl ester (l-NAME) and the reactive oxygen species (ROS) scavenging molecule 4-hydroxy-tempo (tempol). Expression of endothelial NO synthase (eNOS) in TD was determined using Western blot. Approximately 25% of the normal flow-mediated inhibition of contraction frequency was lost in TDs isolated from MetSyn rats despite a comparable SNAP response. Inhibition of NOS with l-NAME abolished the differences in the shear-dependent contraction frequency regulation between control and MetSyn TDs, whereas tempol did not restore the flow responses in MetSyn TDs. We found a significant reduction in eNOS expression in MetSyn TDs suggesting that diminished NO production is partially responsible for impaired flow response. Thus our data provide the first evidence that MetSyn conditions diminish eNOS expression in TD endothelium, thereby affecting the flow-mediated changes in TD lymphatic function.

Decrease in ambient [Cl-] stimulates nitric oxide release from cultured rat mesangial cells

1994 ◽  
Vol 267 (1) ◽  
pp. F190-F195 ◽  
Author(s):  
H. Tsukahara ◽  
Y. Krivenko ◽  
L. C. Moore ◽  
M. S. Goligorsky
Keyword(s):  
Nitric Oxide ◽  
Mesangial Cells ◽  
Ionic Composition ◽  
Juxtaglomerular Apparatus ◽  
Cytosolic Calcium ◽  
No Synthase ◽  
Tubuloglomerular Feedback ◽  
No Production ◽  
Rapid Reduction ◽  
No Release

It has been hypothesized that fluctuations of the ionic composition in the interstitium of juxtaglomerular apparatus (JGA) modulate the function of extraglomerular mesangial cells (MC), thereby participating in tubuloglomerular feedback (TGF) signal transmission. We examined the effects of isosmotic reductions in ambient sodium concentration ([Na+]) and [Cl-] on cytosolic calcium concentration ([Ca2+]i) in cultured rat MC. Rapid reduction of [Na+] or [Cl-] in the bath induced a concentration-dependent rise in [Ca2+]i. MC are much more sensitive to decreases in ambient [Cl-] than to [Na+]; a decrease in [Cl-] as small as 14 mM was sufficient to elicit a detectable [Ca2]i response. These observations suggest that MC can be readily stimulated by modest perturbations of extracellular [Cl-]. Next, we examined whether activation of MC by lowered ambient [Cl-] influences cellular nitric oxide (NO) production. Using an amperometric NO sensor, we found that a 13 mM decrease in ambient [Cl-] caused a rapid, Ca2+/calmodulin-dependent rise in NO release from MC. This response was not inhibitable by dexamethasone, indicating the involvement of the constitutive rather than the inducible type of NO synthase in MC. In addition, the NO release was blunted by indomethacin pretreatment, suggesting that a metabolite(s) of cyclooxygenase regulates the activation of NO synthase in MC. Our findings that small perturbations in external [Cl-] stimulate MC to release NO, a highly diffusible and rapidly acting vasodilator, provide a possible mechanism to explain the transmission of the signal for the TGF response within the JGA.

Arginase inhibition increases nitric oxide production in bovine pulmonary arterial endothelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L60-L68 ◽  
Author(s):  
Louis G. Chicoine ◽  
Michael L. Paffett ◽  
Tamara L. Young ◽  
Leif D. Nelin
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
No Synthase ◽  
No Production ◽  
Urea Production ◽  
Pulmonary Arterial ◽  
Factor Α ◽  
Arterial Endothelial Cells ◽  
Regular Medium ◽  
Necrosis Factor

Nitric oxide (NO) is produced by NO synthase (NOS) from l-arginine (l-Arg). Alternatively, l-Arg can be metabolized by arginase to produce l-ornithine and urea. Arginase (AR) exists in two isoforms, ARI and ARII. We hypothesized that inhibiting AR with l-valine (l-Val) would increase NO production in bovine pulmonary arterial endothelial cells (bPAEC). bPAEC were grown to confluence in either regular medium (EGM; control) or EGM with lipopolysaccharide and tumor necrosis factor-α (L/T) added. Treatment of bPAEC with L/T resulted in greater ARI protein expression and ARII mRNA expression than in control bPAEC. Addition of l-Val to the medium led to a concentration-dependent decrease in urea production and a concentration-dependent increase in NO production in both control and L/T-treated bPAEC. In a second set of experiments, control and L/T bPAEC were grown in EGM, EGM with 30 mM l-Val, EGM with 10 mM l-Arg, or EGM with both 10 mM l-Arg and 30 mM l-Val. In both control and L/T bPAEC, treatment with l-Val decreased urea production and increased NO production. Treatment with l-Arg increased both urea and NO production. The addition of the combination l-Arg and l-Val decreased urea production compared with the addition of l-Arg alone and increased NO production compared with l-Val alone. These data suggest that competition for intracellular l-Arg by AR may be involved in the regulation of NOS activity in control bPAEC and in response to L/T treatment.

scholarly journals Induction and stability of human Th17 cells require endogenous NOS2 and cGMP-dependent NO signaling

2013 ◽  
Vol 210 (7) ◽  
pp. 1433-1445 ◽  
Author(s):  
Nataša Obermajer ◽  
Jeffrey L. Wong ◽  
Robert P. Edwards ◽  
Kong Chen ◽  
Melanie Scott ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
T Cells ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
De Novo ◽  
Inflammatory Diseases ◽  
Suppressor Cells ◽  
Guanosine Monophosphate ◽  
No Production ◽  
No Signaling

Nitric oxide (NO) is a ubiquitous mediator of inflammation and immunity, involved in the pathogenesis and control of infectious diseases, autoimmunity, and cancer. We observed that the expression of nitric oxide synthase-2 (NOS2/iNOS) positively correlates with Th17 responses in patients with ovarian cancer (OvCa). Although high concentrations of exogenous NO indiscriminately suppress the proliferation and differentiation of Th1, Th2, and Th17 cells, the physiological NO concentrations produced by patients’ myeloid-derived suppressor cells (MDSCs) support the development of RORγt(Rorc)+IL-23R+IL-17+ Th17 cells. Moreover, the development of Th17 cells from naive-, memory-, or tumor-infiltrating CD4+ T cells, driven by IL-1β/IL-6/IL-23/NO-producing MDSCs or by recombinant cytokines (IL-1β/IL-6/IL-23), is associated with the induction of endogenous NOS2 and NO production, and critically depends on NOS2 activity and the canonical cyclic guanosine monophosphate (cGMP)–cGMP-dependent protein kinase (cGK) pathway of NO signaling within CD4+ T cells. Inhibition of NOS2 or cGMP–cGK signaling abolishes the de novo induction of Th17 cells and selectively suppresses IL-17 production by established Th17 cells isolated from OvCa patients. Our data indicate that, apart from its previously recognized role as an effector mediator of Th17-associated inflammation, NO is also critically required for the induction and stability of human Th17 responses, providing new targets to manipulate Th17 responses in cancer, autoimmunity, and inflammatory diseases.

scholarly journals Protein kinase Cδ regulates endothelial nitric oxide synthase expression via Akt activation and nitric oxide generation

2008 ◽  
Vol 294 (3) ◽  
pp. L582-L591 ◽  
Author(s):  
Neetu Sud ◽  
Stephen Wedgwood ◽  
Stephen M. Black
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Promoter Activity ◽  
Dominant Negative ◽  
No Production ◽  
Enos Expression ◽  
Akt Activation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

In this study, we explore the roles of the delta isoform of PKC (PKCδ) in the regulation of endothelial nitric oxide synthase (eNOS) activity in pulmonary arterial endothelial cells isolated from fetal lambs (FPAECs). Pharmacological inhibition of PKCδ with either rottlerin or with the peptide, δV1-1, acutely attenuated NO production, and this was associated with a decrease in phosphorylation of eNOS at Ser1177 (S1177). The chronic effects of PKCδ inhibition using either rottlerin or the overexpression of a dominant negative PKCδ mutant included the downregulation of eNOS gene expression that was manifested by a decrease in both eNOS promoter activity and protein expression after 24 h of treatment. We also found that PKCδ inhibition blunted Akt activation as observed by a reduction in phosphorylated Akt at position Ser473. Thus, we conclude that PKCδ is actively involved in the activation of Akt. To determine the effect of Akt on eNOS signaling, we overexpressed a dominant negative mutant of Akt and determined its effect of NO generation, eNOS expression, and phosphorylation of eNOS at S1177. Our results demonstrated that Akt inhibition was associated with decreased NO production that correlated with reduced phosphorylation of eNOS at S1177, and decreased eNOS promoter activity. We next evaluated the effect of endogenously produced NO on eNOS expression by incubating FPAECs with the eNOS inhibitor 2-ethyl-2-thiopseudourea (ETU). ETU significantly inhibited NO production, eNOS promoter activity, and eNOS protein levels. Together, our data indicate involvement of PKCδ-mediated Akt activation and NO generation in maintaining eNOS expression.

scholarly journals Induction of nitric oxide synthesis in J774 cells lowers intracellular glutathione: effect of modulated glutathione redox status on nitric oxide synthase induction

1997 ◽  
Vol 322 (2) ◽  
pp. 477-481 ◽  
Author(s):  
John S. HOTHERSALL ◽  
Fernando Q. CUNHA ◽  
Guy H. NEILD ◽  
Alberto A. NOROHNA-DUTRA
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
De Novo ◽  
Redox Status ◽  
No Production ◽  
Duration Of Treatment ◽  
Intracellular Glutathione ◽  
J774 Cells ◽  
Oxide Synthase ◽  
Glutathione Redox

Under pathological conditions, the induction of nitric oxide synthase (NOS) in macrophages is responsible for NO production to a cytotoxic concentration. We have investigated changes to, and the role of, intracellular glutathione in NO production by the activated murine macrophage cell line J774. Total glutathione concentrations (reduced, GSH, plus the disulphide, GSSG) were decreased to 45% of the control 48 h after cells were activated with bacterial lipopolysaccharide plus interferon γ. This was accompanied by a decrease in the GSH/GSSG ratio from 12:1 to 2:1. The intracellular decrease was not accounted for by either GSH or GSSG efflux; on the contrary, rapid export of glutathione in control cells was abrogated during activation. The loss of intra- and extracellular glutathione indicates either a decrease in synthesis de novo, or an increase in utilization, rather than competition for available NADPH. All changes in activated cells were prevented by pretreatment with the NOS inhibitor l-N-(1-iminoethyl)ornithine. Basal glutathione levels in J774 cells were manipulated by pretreatment with (1) buthionine sulphoximine (glutathione synthase inhibitor), (2) acivicin (γ-glutamyltranspeptidase inhibitor), (3) bromo-octane (glutathione S-transferase substrate) and (4) diamide/zinc (thiol oxidant and glutathione reductase inhibitor). All treatments significantly decreased the output of NO following activation. The degree of inhibition was dependent on (i) duration of treatment prior to activation, (ii) rate of depletion or subsequent recovery and (iii) thiol end product. The level of GSH did not significantly affect the production of NO, after induction of NOS. Thus, glutathione redox status appears to plays an important role in NOS induction during macrophage activation.

Endothelin stimulates endothelial nitric oxide synthase expression in the thick ascending limb

2004 ◽  
Vol 287 (2) ◽  
pp. F231-F235 ◽  
Author(s):  
Marcela Herrera ◽  
Jeffrey L. Garvin
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Receptor Antagonist ◽  
Endothelial Nitric Oxide Synthase ◽  
No Production ◽  
Thick Ascending Limb ◽  
Enos Expression ◽  
No Release ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Endothelin-1 (ET-1) acutely inhibits NaCl reabsorption by the thick ascending limb (THAL) by activating the ETB receptor, stimulating endothelial nitric oxide synthase (eNOS), and releasing nitric oxide (NO). In nonrenal tissue, chronic exposure to ET-1 stimulates eNOS expression via the ETB receptor and activation of phosphatidylinositol 3-kinase (PI3K). We hypothesized that ET-1 increases eNOS expression in the THAL by binding to ETB receptors and stimulating PI3K. In primary cultures of medullary THALs treated for 24 h, eNOS expression increased by 36 ± 18% with 0.01 nM ET-1, 123 ± 30% with 0.1 nM ( P < 0.05; n = 5), and 71 ± 30% with 1 nM, whereas 10 nM had no effect. BQ-788, a selective ETB receptor antagonist, completely blocked stimulation of eNOS expression caused by 0.1 nM ET-1 (12 ± 25 vs. 120 ± 40% for ET-1 alone; P < 0.05; n = 5). BQ-123, a selective ETA receptor antagonist, did not affect the increase in eNOS caused by 0.1 nM ET-1. Sarafotoxin c (S6c; 0.1 μM), a selective ETB receptor agonist, increased eNOS expression by 77 ± 30% ( P < 0.05; n = 6). Wortmannin (0.01 μM), a PI3K inhibitor, completely blocked the stimulatory effect of 0.1 μM S6c (77 ± 30 vs. −28 ± 9%; P < 0.05; n = 6). To test whether the increase in eNOS expression heightens activity, we measured NO release in response to simultaneous treatment with l-arginine, ionomycin, and clonidine using a NO-sensitive electrode. NO release by control cells was 337 ± 61 and 690 ± 126 pA in ET-1-treated cells ( P < 0.05; n = 5). Taken together, these data suggest that ET-1 stimulates THAL eNOS, activating ETB receptors and PI3K and thereby increasing NO production.

Functional difference between SP and NKA: relaxation of gastric muscle by SP is mediated by VIP and NO

1993 ◽  
Vol 264 (4) ◽  
pp. G678-G685
Author(s):  
J. G. Jin ◽  
S. Misra ◽  
J. R. Grider ◽  
G. M. Makhlouf
Keyword(s):  
Nitric Oxide ◽  
Circular Muscle ◽  
No Synthase ◽  
No Production ◽  
Neurokinin A ◽  
Functional Difference ◽  
Receptor Agonists ◽  
Gastric Muscle ◽  
Guinea Pig Stomach ◽  
Synthase Inhibitor

The mechanism of action of endogenous tachykinins [substance P (SP) and neurokinin A and B (NKA and NKB)] and of receptor-specific tachykinin analogues (SP methyl ester (SPME), [beta-Ala8]NKA-(4-10), and senktide) was examined in circular muscle of guinea pig stomach. Cross-desensitization studies confirmed that SPME and SP interacted with NK-1 receptors, [beta-Ala8]NKA-(4-10) and NKA with NK-2 receptors, and senktide and NKB with NK-3 receptors. NK-1 and NK-3-receptor agonists induced relaxation and stimulated vasoactive intestinal peptide (VIP) release and nitric oxide (NO) production: tetrodotoxin abolished VIP release, NO production, and relaxation, converting the response to NK-1-receptor agonists to contraction; the NO synthase inhibitor NG-nitro-L-arginine (L-NNA) abolished NO production, partly inhibited VIP release (56-64%, P < 0.01), and abolished relaxation; the VIP antagonist VIP-(10-28) partly inhibited NO production (73-74%, P < 0.001) and relaxation (56-58%, P < 0.01); and atropine augmented relaxation by 28-35% (P < 0.01). The pattern of inhibition implied that: 1) relaxation was mediated by VIP and NO; 2) VIP release was partly dependent on NO production, since it was strongly inhibited by L-NNA; and 3) NO was largely produced by the action of VIP on muscle cells, since it was strongly inhibited by VIP-(10-28). NK-2-receptor agonists elicited only contraction that was not affected by tetrodotoxin; these agonists also inhibited VIP release, NO production, and relaxation induced by NK-1- and NK-3-receptor agonists.(ABSTRACT TRUNCATED AT 250 WORDS)

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