Nitric oxide production by a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

Abstract

The aim of this study was to determine whether Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS-A. actinomycetemcomitans) could stimulate a murine macrophage cell line (RAW264.7 cells) to produce nitric oxide (NO). The cells were treated with LPS-A. actinomycetemcomitans or Escherichia coli LPS (LPS-Ec) for 24 h. The effects of N(G)-monomethyl-L-arginine (NMMA), polymyxin B and cytokines (IFN-gamma, TNF-alpha, IL-4 and IL-12) on the production of NO were also determined. The role of protein tyrosine kinase, protein kinase C and microtubulin organization on NO production were assessed by incubating RAW264.7 cells with genistein, bisindolylmaleide and colchicine prior to LPS-A. actinomycetemcomitans stimulation, respectively. NO levels from the culture supernatants were determined by the Griess reaction. The results showed that LPS-A. actinomycetemcomitans stimulated NO production by RAW264.7 cells in a dose-dependent manner, but was slightly less potent than LPS-Ec. NMMA and polymyxin B blocked the production of NO. IFN-gamma and IL-12 potentiated but IL-4 depressed NO production by LPS-A. actinomycetemcomitans-stimulated RAW264.7 cells. TNF-alpha had no effects on NO production. Genistein and bisindolylmalemaide, but not colchicine, reduced the production of NO in a dose-dependent mechanism. The results of the present study suggest that A. actinomycetemcomitans LPS, via the activation of protein tyrosine kinase and protein kinase C and the regulatory control of cytokines, stimulates NO production by murine macrophages.

Effect of Non-Surgical Therapy on Salivary Nitric Oxide and Lipid Peroxidation Levels in Type Ii Diabetic and Non Diabetic Patients With Periodontal Disease

“…These ROS are associated with the microvascular complications of diabetes. It is also known that severe periodontal disease can lead to endothelial dysfunction which is an early event in atherogenesis [15][16][17][18][19]. In this study, the compounding effect of coexisting diabetes and periodontitis on the levels of oxidative stress markers was assessed.…”

Effect of fermented Achyranthes japonica (Miq.) Nakai extract on osteoarthritis

“…NO is over-expressed when RAW264.7 cells, a macrophage cell line, are stimulated (16). We have treated RAW264.7 cells with LPS and FAJE at various concentrations to examine the effects of FAJE to suppress the NO formation.…”

The cytokine-inducing activities of surface components of the periodontopathogenic bacterium Porphyromonas gingivalis

“…NO는다른염증성질환에서와마찬가지로염증성치 주질환에 있어서도 중요한 역할을 하는 것으로 여겨 진다. 치주질환시NO의생성이증가하며 31) , 치주질 환병인균주의하나인A.actinomicetecomitrans의 LPS가대식세포에서NO의 생성을유발함이 보고된 바있다 32,33) . 또한, 치주질환병인균주인Prevotella intermedia와 Prevotella nigrescens의 세균내독 소는 대식세포에서NO 생성과iNOS의발현을유발 하였다 34,35) .…”