Lipopolysaccharide directly stimulates the intrapituitary interleukin-6 production by folliculostellate cells via specific receptors and the p38α mitogen-activated protein kinase/n...

• Autores: Lohrer, P.; Gloddek, J.; Carbia Nagashima, A.; Korali, Z.; Hopfner, U.; Paez Pereda, M.; Arzt, E.; Stalla, G.K.; Renner, U.
• Año de publicación: 2000
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Endocrinology 2000;141(12):4457-4465
• Materia: 4 (4 fluorophenyl) 2 (4 methylsulfinylphenyl) 5 (4 pyridyl)imidazole; antibody; CD14 antigen; cycloheximide; dexamethasone; immunoglobulin enhancer binding protein; interleukin 6; lipopolysaccharide; lipopolysaccharide binding protein; mitogen activated protein kinase; toll like receptor 4; animal cell; antigen expression; article; cell line; cell stimulation; complex formation; controlled study; cytokine production; cytokine release; hypophysis cell; male; mouse; nonhuman; priority journal; protein metabolism; protein phosphorylation; signal transduction
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

Bacterial lipopolysaccharide (LPS) activates the immune system and induces increases in peripheral cytokines, which, in turn, affect the endocrine system. In particular, LPS-induced cytokines stimulate the hypothalamic-pituitary-adrenal axis to increase levels of antiinflammatory-acting glucocorticoids. In the present work, we show that LPS directly stimulates interleukin (IL)-6 release by mouse pituitary folliculostellate (FS) TtT/GF tumor cells and FS cells of mouse pituitary cell cultures. The stimulatory effect of LPS was strongly enhanced in the presence of serum, suggesting that LPS is only fully active as a complex with LPS-binding protein (LBP). Both TtT/GF cells and mouse pituitaries expressed CD14, which binds the LPS/LBP complex, and Toll-like receptor type 4, which induces LPS signals. LPS increased phospoinositol turnover in TtT/GF cells and induced phosphorylation of p38α mitogen-activated protein kinase and the inhibitor (IκB) of nuclear factor-κ B. Nuclear factor-κ B was activated by LPS in TtT/GF cells. Functional studies demonstrated that My4 (an antibody blocking the interaction between LPS/LBP and CD14), SB203580, (a specific inhibitor of p38α mitogen-activated protein kinase phosphorylation), dexamethasone, and the messenger RNA translation inhibitor cycloheximide all inhibited LPS-induced IL-6 production by TtT/GF cells and mouse pituitary FS cells. LPS-induced intrapituitary IL-6 may modulate the function of anterior pituitary cells during bacterial infection/inflammation.
Fil:Carbia Nagashima, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Paez Pereda, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.