Role of cell-surface nucleolin in lipopolysaccharide-stimulated expression and secretion of TNF-alpha and IL-1beta.
- Author:
Li FANG
1
;
Kang-kai WANG
;
Lei JIANG
;
Bi-mei JIANG
;
Xing WEI
;
Lan SONG
;
Gong-hua DENG
;
Xian-zhong XIAO
Author Information
1. Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, and Department of Cardiology, Xiangya Hospital, Changsha 410008, China.
- Publication Type:Journal Article
- MeSH:
Cell Line;
Cell Membrane;
metabolism;
Humans;
Interleukin-1beta;
biosynthesis;
metabolism;
Lipopolysaccharides;
pharmacology;
Monocytes;
cytology;
metabolism;
Phosphoproteins;
metabolism;
physiology;
RNA-Binding Proteins;
metabolism;
physiology;
Tumor Necrosis Factor-alpha;
biosynthesis;
metabolism
- From:
Journal of Central South University(Medical Sciences)
2008;33(11):999-1004
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To explore the role of cell-surface nucleolin in lipopolysaccharide (LPS)-stimulated expression and secretion of TNF-alpha and IL-1beta in human THP-1 monocytes.
METHODS:Immuno-fluorescence assay and Western blot were used to identify the expression of nucleolin on the surface of THP-1 monocytes. Inactivation of nucleolin was induced by anti-nucleolin monoclonal antibody blockage, and the expression and secretion of TNF-alpha and IL-1beta were observed by using reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immuno-sorbent assay (ELISA)respectively in LPS-mediated human THP-1 monocyte inflammatory model.
RESULTS:Immuno-fluorescence showed that nucleolin was localized on the cell surface of THP-1 monocytes as indicated by dotted red fluorescence. Western blot assay indicated that nucleolin existed in the cell membrane fractions. RT-PCR assay showed that the expressions of TNF-alpha and IL-1beta mRNA significantly increased at 2 h and 3 h after the treatment with 1000 microg/L LPS. After 1 h pretreatment with anti-nucleolin antibody, the levels of TNF-alpha and IL-1beta mRNA decreased compared with an anti-nucleolin antibody untreated group and an irrelevant IgG+LPS group (P<0.05). ELISA assay showed that the pretreatment with anti-nucleolin antibody inhibited significantly the secretion of LPS-induced levels of TNF-alpha and IL-1beta after 4, 12 and 24 h treatment with 1000 microg/L LPS.
CONCLUSION:Nucleolin expresses on the cell surface of THP-1 monocytes and involves in the LPS-mediated expression and secretion of TNF-alpha and IL-1beta.
