Histamine induces Toll-like receptor 2 and 4 expression in endothelial cells and enhances sensitivity to Gram-positive and Gram-negative bacterial cell wall components
| Autor: | Jaya Talreja, Daniel J. Stechschulte, Michael B. Filla, Mohammad H. Kabir, Kottarappat N. Dileepan |
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| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Lipopolysaccharides
Immunology Lymphocyte Antigen 96 Receptors Cell Surface Histamine H1 receptor Peptidoglycan Biology chemistry.chemical_compound Histamine H2 receptor Cell Wall medicine Immunology and Allergy Humans Histamine H4 receptor RNA Messenger Receptors Immunologic Cells Cultured Adaptor Proteins Signal Transducing Membrane Glycoproteins Bacteria Interleukin-6 Toll-Like Receptors NF-kappa B Endothelial Cells Original Articles Mast cell Histamine H1 Antagonists Molecular biology Antigens Differentiation Toll-Like Receptor 2 Up-Regulation Endothelial stem cell Teichoic Acids Toll-Like Receptor 4 medicine.anatomical_structure chemistry Biochemistry Antigens Surface Myeloid Differentiation Factor 88 Lipoteichoic acid Histamine |
| Popis: | Histamine is a major inflammatory molecule released from the mast cell, and is known to activate endothelial cells. However, its ability to modulate endothelial responses to bacterial products has not been evaluated. In this study we determined the ability of histamine to modulate inflammatory responses of endothelial cells to Gram-negative and Gram-positive bacterial cell wall components and assessed the role of Toll-like receptors (TLR) 2 and 4 in the co-operation between histamine and bacterial pathogens. Human umbilical vein endothelial cells (HUVEC) were incubated with lipopolysaccharide (LPS), lipoteichoic acid (LTA), or peptidoglycan (PGN) in the presence or absence of histamine, and the expression and release of interleukin-6 (IL-6), and NF-kappaB translocation were determined. The effect of histamine on the expression of mRNA and proteins for TLR2 and TLR4 was also evaluated. Incubation of HUVEC with LPS, LTA and PGN resulted in marked enhancement of IL-6 mRNA expression and IL-6 secretion. Histamine alone markedly enhanced IL-6 mRNA expression in HUVEC, but it did not stimulate proportional IL-6 release. When HUVEC were incubated with LPS, LTA, or PGN in the presence of histamine marked amplification of both IL-6 production and mRNA expression was noted. HUVEC constitutively expressed TLR2 and TLR4 mRNA and proteins, and these were further enhanced by histamine. The expression of mRNAs encoding MD-2 and MyD88, the accessory molecules associated with TLR signalling, were unchanged by histamine treatment. These results demonstrate that histamine up-regulates the expression of TLR2 and TLR4 and amplifies endothelial cell inflammatory responses to Gram-negative and Gram-positive bacterial components. |
| Databáze: | OpenAIRE |
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