Evidence of expression of endotoxin receptors CD14, toll-like receptors TLR4 and TLR2 and associated molecule MD-2 and of sensitivity to endotoxin (LPS) in islet beta cells
| Autor: | Marta Vives-Pi, Mario O. Labéta, F Vargas, Aurora Alba, P Caro, J Fernández-Alvarez, Nuria Somoza, Ricardo Pujol-Borrell, Roger R. Gomis |
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| Jazyk: | angličtina |
| Rok vydání: | 2003 |
| Předmět: |
Adult
Lipopolysaccharides Male Adolescent CD14 Immunology Lipopolysaccharide Receptors Lymphocyte Antigen 96 Receptors Cell Surface Biology Islets of Langerhans Basic Immunology Species Specificity Insulin Secretion medicine Tumor Cells Cultured Immunology and Allergy Humans Insulin Receptor Cells Cultured geography Toll-like receptor geography.geographical_feature_category Membrane Glycoproteins Dose-Response Relationship Drug Reverse Transcriptase Polymerase Chain Reaction Pancreatic islets Toll-Like Receptors Middle Aged medicine.disease Islet Toll-Like Receptor 2 Toll-Like Receptor 4 TLR2 medicine.anatomical_structure Glucose Antigens Surface Tumor necrosis factor alpha Female Insulitis |
| Zdroj: | Universitat Autònoma de Barcelona |
| Popis: | SUMMARY CD14, a GPI-linked membrane protein, is a component of the lipopolysaccharide (LPS) receptor complex, one of the pattern-recognizing receptors (PRR) expressed by myeloid lineage cells. Here we report that CD14, the functionally linked toll-like receptor molecules, TLR2 and TLR4, and the associated molecule MD-2 are expressed in endocrine cells of the human pancreatic islets. CD14 expression in human pancreatic islets was determined by immunofluorescence staining of tissue sections and primary cultures, and confirmed by flow cytometry of dispersed normal islets and SV40-transformed islet cells (HP62). The latter cells synthesized and secreted CD14 in response to lipopolysaccharide (LPS) in a time- and dose-dependent manner. Reverse transcription polymerase chain reaction (RT-PCR)-Southern was positive for CD14, TLR2, TLR4 and MD-2 in human pancreas, purified islets and HP62 cells. In vitro experiments using rat islets (also positive for CD14 by RT-PCR) and HP62 cells showed that LPS regulates glucose-dependent insulin secretion and induces inflammatory cytokines [interleukin (IL)-1α, IL-6 and tumour necrosis factor (TNF)-α]. The functional expression of CD14 and associated molecules in islet β cells adds a new pathway that islet cells may follow to adjust their function to endotoxaemia situations and become vulnerable to the inflammatory events that occur during diabetogenic insulitis. |
| Databáze: | OpenAIRE |
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