Res. Chem. Intermed.
, Vol. 32, No. 9, pp. 847–856 (2006)
Also available online - www.brill.nl/rci
Disruption of lipid rafts impairs the production of nitric
oxide in lipopolysaccharide-stimulated murine RAW264.7
, JUEFEI ZHOU
and TAOTAO WEI
Department of Laboratory Medicine, Huaihua Medical College, Huaihua 418000, China
Center for Structural and Molecular Biology, Institute of Biophysics, Chinese Academy of Sciences,
15 Datun Road, Chaoyang District, Beijing 100101, China
Graduate School of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China
Received 18 August 2005; accepted 5 July 2006
Abstract—Upon stimulation with lipopolysaccharide, murine RAW264.7 macrophages generated
a high amount of nitric oxide. Pretreatment of macrophages with methyl-β-cyclodextrin, which
disrupted the lipid raft microdomains of the plasma membrane, inhibited the generation of nitric
oxide by down-regulating the expression of inducible nitric oxide synthase. Methyl-β-cyclodextrin
exposure signiﬁcantly inhibited the degradation of IκB-α, blocked the translocation of p65/RelA into
the nuclei and prevented the activation of the NF-κB signaling pathway. The results suggest that the
expression of inducible nitric oxide synthase and the consequent production of nitric oxide depend on
the integrity of the lipid rafts.
Keywords: RAW 264.7 macrophage; nitric oxide; lipopolysaccharide; iNOS; NF-κB; lipid raft;
Nitric oxide (NO) is a poisonous, unstable free radical gas that has been known
for years to be a constituent of air pollutants and is supposed to be involved in the
depletion of the ozone layer. On the other hand, NO plays diverse biological roles
including vascular regulation , host defense  and neuronal communication .
NO is synthesized from
-arginine by nitric oxide synthase (NOS) . In acti-
vated macrophages, the transcriptionally expressed inducible nitric oxide synthase
(iNOS) is responsible for the prolonged and profound production of NO . The
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