Effect of inhibition of inducible nitric oxide synthase (iNOS) on the murine splenic immune response induced by Aggregatibacter (Actinobacillus) actinomycetemcomitans lipopolysaccharide

Abstract

Animal studies suggest that inducible nitric oxide synthase (iNOS) may be associated with destructive periodontal disease. l-N(6)-(1-Iminoethyl)-lysine (L-NIL) has been shown to inhibit iNOS in a selective manner, and hence the aim of the present study was to test the hypothesis that treatment with l-NIL may induce a T-cell helper 1 (Th1)-like immune response by Aggregatibacter (Actinobacillus) actinomycetemcomitans lipopolysaccharide (LPS)-stimulated murine spleen cells in vitro. BALB/c mice were either sham-immunized or immunized with A. actinomycetemcomitans LPS. Spleen cells were stimulated with A. actinomycetemcomitans LPS in the presence or absence of L-NIL. Nitric oxide (NO), iNOS activity, specific IgG subclass antibodies, interferon-gamma (IFN-gamma), and interleukin-4 (IL-4) levels and cell proliferation were determined. The results showed that treatment with L-NIL suppressed both NO production and iNOS activity but enhanced specific IgG2a, IFN-gamma levels, and increased cell proliferation following stimulation with A. actinomycetemcomitans LPS-stimulated cells. The results of the present study suggest that inhibition of iNOS activity by L-NIL may skew the A. actinomycetemcomitans LPS-stimulated murine splenic immune response towards the Th1-like immune profile in vitro.

Arctigenin promotes degradation of inducible nitric oxide synthase through CHIP-associated proteasome pathway and suppresses its enzyme activity

“…The protein concentrations of the cell lysates were measured by using the Bradford protein assay kit (Bio-Rad). The iNOS activity was assessed as previously described [19]. Briefly, 50 μg cell lysate was incubated for 120 min at 37°C in 100 μl of 20 mM Tris-Cl (pH 7.9) containing 4 μM BH 4 , 4 μM FAD, 3 mM dithiothreitol, 2 mM NADPH, and 2 mM L-arginine.…”

Curcumin promotes degradation of inducible nitric oxide synthase and suppresses its enzyme activity in RAW 264.7 cells

“…The protein concentrations of the cell lysates were measured by using the Bradford protein assay kit (BioRad). The iNOS activity was assessed as previously described [18]. Briefly, 50 μg cell lysate was incubated for 120 min at 37°C in 100 μl of 20 mM Tris-HCl (pH 7.9) containing 4 μl MBH, 4 μl MFAD, 3 mM dithiothreitol, 2 mM NADPH, and 2 mM L-arginine.…”

Antimicrobial peptide hCAP‐18/LL‐37 protein and mRNA expressions in different periodontal diseases

“…It has been proposed that the association between a specific microbial environment and a modified host response could take place during the development of aggressive periodontitis (Meng et al 2007; Zheng et al , 2007). Researchers have stated that LL‐37 has killing effect on Aggregatibacter actinomycetemcomitans (Pütsep et al , 2002, de Haar et al , 2006, Tanaka et al , 2000) which is an important periodontopathogen for aggressive periodontitis (Gronert et al , 2004; Sosroseno et al , 2008). It has also been stated that functional defects in polymorphonuclear leukocytes and monocytes may increase host susceptibility to tissue destruction in aggressive periodontitis (Liu et al , 2001; Gronert et al , 2004).…”