scholarly journals Molecular cloning and characterization of Ca2+-dependent inducible nitric oxide synthase from guinea-pig lung

1998 ◽  
Vol 333 (3) ◽  
pp. 795-799 ◽  
Author(s):  
Manabu SHIRATO ◽  
Tohru SAKAMOTO ◽  
Yoshiyuki UCHIDA ◽  
Akihiro NOMURA ◽  
Yukio ISHII ◽  
...  

We have isolated a full-length cDNA for an inducible nitric oxide synthase (iNOS) from guinea-pig lung. The cDNA has a 3447 bp open reading frame encoding 1149 amino acid residues. The deduced amino acid sequence is approx. 80% identical with iNOS of human epithelial cells and murine macrophages. Consensus recognition sites for cofactors are highly conserved. COS cell lysate transfected with the guinea-pig iNOS shows significant levels of nitric oxide synthase (NOS) activity, and this is inhibited by 79% by chelation of Ca2+ ions. The NOS activity is restored in a concentration-dependent manner by increasing the free Ca2+ level. The NOS activity is also inhibited by trifluoperazine, a calmodulin antagonist, which suggests that the Ca2+ dependence is due to Ca2+-dependent calmodulin binding to the enzyme. Northern blot analysis reveals that the cloned iNOS mRNA is expressed in the lung and the colon in normal guinea pigs. Stimulation in vivo by lipopolysaccharide induces the expression of iNOS in the kidney, the spleen and the colon, but in the lung the same stimulation decreases its expression. These results suggest that the cloned guinea-pig iNOS is distinct in characteristics and expression from previously described iNOS forms.

2000 ◽  
Vol 68 (12) ◽  
pp. 7087-7093 ◽  
Author(s):  
Y.-H. Li ◽  
Z.-Q. Yan ◽  
J. Skov Jensen ◽  
K. Tullus ◽  
A. Brauner

ABSTRACT Chronic lung disease (CLD) of prematurity is an inflammatory disease with a multifactorial etiology. The importance ofUreaplasma urealyticum in the development of CLD is debated, and steroids produce some improvement in neonates with this disease. In the present study, the capability of U. urealyticum to stimulate rat alveolar macrophages to produce nitric oxide (NO), express inducible nitric oxide synthase (iNOS), and activate nuclear factor κB (NF-κB) in vitro was characterized. The effect of NO on the growth of U. urealyticum was also investigated. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that U. urealyticum antigen (≥4 × 107 color-changing units/ml) stimulated alveolar macrophages to produce NO in a dose- and time-dependent manner (P < 0.05). This effect was further enhanced by gamma interferon (100 IU/ml; P < 0.05) but was attenuated by budesonide and dexamethasone (10−4 to 10−6 M) (P < 0.05). The mRNA and protein levels of iNOS were also induced in response to U. urealyticum and inhibited by steroids.U. urealyticum antigen triggered NF-κB activation, a possible mechanism for the induced iNOS expression, which also was inhibited by steroids. NO induced by U. urealyticum caused a sixfold reduction of its own growth after infection for 10 h. Our findings imply that U. urealyticum may be an important factor in the development of CLD. The host defense response againstU. urealyticum infection may also be influenced by NO. The down-regulatory effect of steroids on NF-κB activation, iNOS expression, and NO production might partly explain the beneficial effect of steroids in neonates with CLD.


2013 ◽  
Vol 16 (3) ◽  
pp. 443-451 ◽  
Author(s):  
W. Barański ◽  
J. Kaleczyc ◽  
S. Zduńczyk ◽  
W. Podlasz ◽  
E. Długołęcka-Malinowska ◽  
...  

Abstract The expression of CD14+ macrophages, CD4+, CD8+ lymphocytes and mRNA of inducible nitric oxide synthase (iNOS) was investigated in the endometrium of repeat breeders with subclinical endometritis [experimental group (EXP), n = 10] and healthy [control group (CTRL), n = 10] cows. The cows were selected on the basis of repeat breeding (3 unsuccessful inseminations), clinical and cytological examinations (> 10% polymorphonuclear neutrophils in uterine smears obtained by cytobrush). From all the cows endometrial biopsies were collected and the presence of CD14+, CD4+ and CD8+ cells in the endometrium was evaluated immunohistochemically using semi quantitative counting method. The mRNA expression of iNOS was determined using reverse transcription-PCR. In general, there were no significant differences between EXP and CTRL groups in the expression of CD4+ and CD8 + lymphocytes in all endometrial structures. In contrast, we observed a higher number of CD14+ macrophages in repeat breeding group compared to the control cows, however, this difference was slightly pronounced. CD14+ cells were detectable only in the stratum compactum and stratum spongiosum. The statistically significant (p ≤ 0.05) higher expression of iNOS mRNA was measured in the cows with subclinical endometritis compared to the healthy animals. Our results suggest that the increased expression of CD14+ macrophages and iNOS mRNA may be associated with embryonal mortality in repeat breeding cows with subclinical endometritis.


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