• Title, Summary, Keyword: iNOS

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Effects of Nitric Oxide on the Induction of Experimental Allergic Orchitis in Guinea Pig

  • An, Jeong Hwan;Kim, In Keun;Kim, Taek Sang;Kwak, Hyun Jeong;Rhew, Hyun Yul;Chung, Hun-Taeg
    • IMMUNE NETWORK
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    • v.4 no.2
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    • pp.108-115
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    • 2004
  • Background: Production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathology of autoimmune disease. It is unknown whether iNOS expression is increased within testes and whether iNOS and NO have essential roles in the pathogenesis of EAO. Methods: EAO was induced in guinea pig testes at 17 days after secondary immunization by administration of crude extract (CE) and purified glycoprotein 1 (GP1) from normal guinea pig testes. iNOS gene expression was assessed by RT-PCR and Northern blot analysis in testes. Localization of iNOS and Mac-1 and the indicator of NO-mediated tissue injury, nitrotyrosine, were detected in the testicular lesion by immunohistochemistry. Results: In control testes, inflammation and iNOS gene expression were not detected, whereas, in CE- and GP1-injected testes, inflammation and marked iNOS gene expression were evident at day 17 after secondary immunization. Immunohistochemistry of Mac-1 showed the colocalization with iNOS protein and nitrotyrosyl proteins in intertubules, suggesting that NO produced by infiltrated macrophages may be involved in inflammatory lesions of intertubules. Intraperitoneal administration of aminoguanidine significantly prevented EAO with reduction of inflammation, iNOS expression and nitrotyrosine formation. Conclusion: These results suggest that NO production by macrophages may be important in the pathogenesis of CE- and GP1-induced EAO. Furthermore, this study demonstrated the therapeutic potential of iNOS inhibitor in the treatment of inflammatory and autoimmune mediated-diseases.

Establishment of In vitro Detection System for iNOS Expression and the Verification of Suppressive Effect by Pine Needle Extract (iNOS 발현 검출을 위한 in vitro 시스템의 확립 및 적송잎 추출물에 의한 저해효과 검증)

  • Kim, Nam-Young;Jang, Hye-Ji;Lee, Dong-Geun;Jang, Min-Kyung;Lee, Seung-Woo;Jeon, Myong-Je;Kim, Mi-Hyang;Kim, Sung-Gu;Lee, Sang-Hyeon
    • KSBB Journal
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    • v.26 no.2
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    • pp.172-176
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    • 2011
  • This study was aimed to verify suppressive effect of pine-needle extract on lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression. In order to evaluate suppressive effect on iNOS expression, RAW 264.7 cells were stably transfected using an iNOS promoterluciferase reporter plasmid yielding RAW 264.7/pGL2-NeomiNOS_ pro11 cells. Established in vitro detection system revealed to diminish LPS-induced iNOS expression by 0.1~500 ${\mu}g/mL$ of saponin at the concentration-dependant manner. Pine needle extract also diminished LPS-induced iNOS expression to 92 and 88% at 500 and 50 ${\mu}g/mL$, respectively. These results suggest that the in vitro detection system developed here could be useful for the verification of suppressive materials on iNOS expression and pine needle extract could be used for the development of functional foods.

Expression and localization of endothelial and inducible nitric oxide synthase in bovine uterus (소 자궁에서 endothelial nitric oxide synthase(NOS) 및 inducible NOS의 발현)

  • Lee, Yongduk;Kim, Seungjoon;Moon, Changjong;Shin, Taekyun
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.551-554
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    • 2003
  • Nitric oxide synthase (NOS) has been reported in uterus. We examined the expression of the NOS isoforms, constitutive endothelial (eNOS) and inducible NOS (iNOS), in bovine uterus by immunohistochemistry. eNOS immunoreactivity was localized predominantly to the endothelial cells that line uterine microvessels and to endometrial glandular epithelial cells, but was barely detectable in endometrial stromal cells. iNOS immunostaining was detected in glandular epithelial and stromal cells in the endometrium and in the endothelial cells of myometrial blood vessels. These findings suggest that both eNOS and iNOS may play important roles in the physiology of the uterus, possibly by generating NO.

Inhibition of p65 Nuclear Translocation by Baicalein

  • Seo, Min-Bum;Lee, Seog-Ki;Jeon, Young-Jin;Im, Jin-Su
    • Toxicological Research
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    • v.27 no.2
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    • pp.71-76
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    • 2011
  • We demonstrate that baicalein, a bioactive flavonoid originally isolated from Scutellaria baicalensis, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Treatment of peritoneal macrophages and RAW 264.7 cells with baicalein inhibited LPS-stimulated nitric oxide production in a dose-related manner. Immunohistochemical staining of iNOS and RT-PCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunostaining of p65, EMSA, and reporter gene assay showed that baicalein inhibited NF-${\kappa}$B nuclear translocation, DNA binding, and transcriptional activation, respectively. Collectively, these series of experiments indicate that baicalein inhibits iNOS gene expression by blocking NF-${\kappa}$B nuclear translocation. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of baicalein on iNOS suggest that baicalein may represent a useful anti-inflammatory agent.

Effects of Astaxanthin on the Production of NO and the Expression of COX-2 and iNOS in LPS-Stimulated BV2 Microglial Cells

  • Choi, Seok-Keun;Park, Young-Sam;Choi, Dong-Kug;Chang, Hyo-Ihl
    • Journal of Microbiology and Biotechnology
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    • v.18 no.12
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    • pp.1990-1996
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    • 2008
  • Astaxanthin has shown antioxidant, antitumor, and anti-inflammatory activities; however, its molecular action and mechanism in the nervous system have yet to be elucidated. We examined the in vitro effects of astaxanthin on the production of nitric oxide (NO), as well as the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Astaxanthin inhibited the expression or formation of nitric oxide (NO), iNOS and COX-2 in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Astaxanthin also suppressed the protein levels of iNOS and COX-2 in LPS-stimulated BV2 microglial cells. These results suggest that astaxanthin, probably due to its antioxidant activity, inhibits the production of inflammatory mediators by blocking iNOS and COX-2 activation or by the suppression of iNOS and COX-2 degradation.

Inhibition of p65 Nuclear Translocation by Radicicol, Heat Shock Protein Inhibitor

  • Kim, Sang-Gyu;Jeon, Young-Jin;Lee, Seog-Ki
    • Toxicological Research
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    • v.21 no.4
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    • pp.285-290
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    • 2005
  • We demonstrate that radicicol, a macrocyclic antifungal antibiotic originally isolated from Monosporium bonorden, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Treatment of peritoneal macrophages and RAW 264.7 cells with radicicol inhibited LPS-stimulated nitric oxide production in a dose-related manner. Immunohistochemical staining of iNOS and RTPCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunostaining of p65, EMSA, and reporter gene assay showed that radicicol inhibited $NF-\kappa/Rel$ nuclear translocation. DNA binding, and transcriptional activation, respectively. Collectively, these series of experiments indicate that radicicol inhibits iNOS gene expression by blocking $NF-\kappa/Rel$ nuclear translocation. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of radicicol on iNOS suggest that radicicol may represent a useful anti-inflammatory agent.

Effects of Sandalwood Essential Oil on the iNOS Expression and Proinflammatory Cytokine Production (Sandalwood Essential Oil의 iNOS 발현과 염증성사이토카인의 생성에 미치는 영향)

  • Park, Jeoung-Suk;Jung, Sook-Heui
    • YAKHAK HOEJI
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    • v.57 no.1
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    • pp.70-75
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    • 2013
  • The present study was designed to determine the effect of the Sandalwood Essential Oil (Santalum album) on pro-inflammatory factors such as NO, iNOS expression and IL-$1{\beta}$, IL-6, TNF-${\alpha}$ in lipopolysaccharide (LPS) - stimulated RAW264.7 macrophages cells. The cell toxicity was determined by MTS assay. To evaluate of anti-inflammatory effect of Sandalwood Essential Oil, amount of NO was measured using the NO detection kit and the iNOS expression was measured by western blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). And proinflammatory cytokines were measured by ELISA kit. As a result, Sandalwood Essential Oil reduced NO, iNOS expression and IL-$1{\beta}$, IL-6, TNF-${\alpha}$ production without cytotoxicity. Our results suggest that the Sandalwood Essential Oil may have an anti-inflammatory property through suppressing inflammatory mediator productions and appears to be useful as an anti-inflammatory oil.

Altered Vascular Expression of Nitric Oxide Synthase Isozymes in Hypertension (고혈압에서 혈관 산화질소 합성 동위 효소 발현 변화)

  • 김인광;강대길;이종은;오봉석
    • The Korean Journal of Thoracic and Cardiovascular Surgery
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    • v.32 no.2
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    • pp.138-143
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    • 1999
  • Background: The endothelium-dependent vasorelaxation has been largely accounted for by the release of nitric oxide (NO). Three distinct isoforms of NO synthases (NOS) have been characterized, i.e., brain(bNOS), inducible (iNOS), and endothelial constitutive (ecNOS). Although hypertension hasbeen associated with a vascular endothelial dysfunction, changes in the vascular expression of NOS isoforms have not been established. The present study was aimed at exploring the vascular expression of NOS isozymes in hypertension. Material and Method: Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were induced in rats. The expression of different NOS isozymes in the thoracic aorta was determined by Western blot analysis. The vascular tissue contents of nitrites were measured by colorimetric assay. Result: Arterial blood pressure was significantly higher in experimental groups of 2K1C and DOCA-salt rats compared with their corresponding control rats. The vascular expression of bNOS as well as that of ecNOS was decreased in both models of hypertension. iNOS was not changed in DOCA-salt hypertension, but was also decreased in 2K1C hypertension. The vascular contents of nitrites were significantly decreased in DOCA-salt as well as in 2K1C hypertension. Conclusion: These results suggest that 2K1C and DOCA-salt hypertension are associated with decreases in the vascular expression of NOS isozymes and nitrite contents.

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Effect of Chitosan on Nitric Oxide Content and Inducible Nitric Oxide Synthase Activity in Serum and Expression of Inducible Nitric Oxide Synthase mRNA in Small Intestine of Broiler Chickens

  • Li, H.Y.;Yan, S.M.;Shi, B.L.;Guo, X.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.1048-1053
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    • 2009
  • The present study was conducted to determine the effects of chitosan on nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in serum, and relative expression of iNOS mRNA in the duodenum, jejunum, and ileum of broiler chickens. A total of 240 one-day-old Arbor Acre mixed-sex broiler chickens were randomly allotted to six dietary treatments with five replicates in each treatment and eight chickens in each replicate. The broiler chickens in the six treatments were fed the basal diet supplemented with 0 (control), 0.05, 0.2, 0.5, 1.0 or 2.0 g/kg chitosan. The trial lasted for 42 days. The results showed that dietary chitosan enhanced NO content and iNOS activity in serum as well as iNOS mRNA expression in the duodenum and ileum of broiler chickens in a quadratic dose-dependent manner (p<0.05), and improved jejunum iNOS mRNA expression in a quadratic dose-dependent manner (p<0.10) with increasing addition of chitosan. Chicks fed a diet containing 0.5-1.0 g/kg chitosan had higher NO content and iNOS activity in serum as well as small-intestinal iNOS mRNA expression compared with birds given the control diet, but positive effects of chitosan tended to be suppressed when addition of chitosan in the diet was increased to 2.0 g/kg. These results implied that there was a threshold level of chitosan inclusion beyond which progressive reductions in serum NO content and small intestinal iNOS expression occured, and the regulation of chitosan on immune functions in chickens is probably associated with activated expression of iNOS and NO secretion.

Role of $NF-_{{\kappa}B}$ Binding Sites in the Regulation of Inducible Nitric Oxide Synthase by Tyrosine Kinase

  • Ryu, Young-Sue;Hong, Jang-Hee;Lim, Jong-Ho;Bae, So-Hyun;Ahn, Ihn-Sub;Seok, Jeong-Ho;Lee, Jae-Heun;Hur, Gang-Min
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.55-63
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    • 2001
  • In macrophages, lipopolysaccharide (LPS) alone or in combination with $interferon-{\gamma}\;(IFN-{\gamma})$ has been shown to release a nitric oxide (NO) through the increase of the transcription of the inducible nitric oxide synthase (iNOS) gene. To investigate the exact intracellular signaling pathway of the regulation of iNOS gene transcription by LPS plus $IFN-{\gamma},$ the effects of protein tyrosine kinase (PTK) inhibitor and protein kinase C (PKC) inhibitors on NO production, iNOS mRNA expression, nuclear $factor-_{\kappa}B\;(NF-_{\kappa}B)$ binding activity and the promoter activity of iNOS gene containing two $NF-_{\kappa}B$ sites have been examined in a mouse macrophage RAW 264.7 cells. LPS or $IFN-{\gamma}$ stimulated NO production, and their effect was enhanced synergistically by mixture of LPS and $IFN-{\gamma}.$ The PTK inhibitor such as tyrphostin reduced LPS plus $IFN-{\gamma}-induced$ NO production, iNOS mRNA expression and $NF-_{\kappa}B$ binding activity. In contrast, PKC inhibitors such as H-7, Ro-318220 and staurosporine did not show any effect on them. In addition, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that tyrphostin inhibited the iNOS promoter activity through the $NF-_{\kappa}B$ binding site, whereas PKC inhibitors did not. Taken together, these suggest that PTK, but not PKC pathway, is involved in the regulation of the iNOS gene transcription through the $NF-_{\kappa}B$ sites of iNOS promoter in RAW 264.7 macrophages by LPS plus $IFN-{\gamma}$.

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