tailieunhanh - báo cáo hóa học: " Lipopolysaccharide modulates astrocytic S100B secretion: a study in cerebrospinal fluid and astrocyte cultures from rats"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Lipopolysaccharide modulates astrocytic S100B secretion: a study in cerebrospinal fluid and astrocyte cultures from rats | Guerra et al. Journal of Neuroinflammation 2011 8 128 http content 8 1 128 JJOURNAL1 OF. NEUROINFLAMMATION RESEARCH Open Access Lipopolysaccharide modulates astrocytic S100B secretion a study in cerebrospinal fluid and astrocyte cultures from rats Maria Cristina Guerrat Lucas S Tortorelli Fabiana Galland Carollina Da Ré Elisa Negri Douglas S Engelke Leticia Rodrigues Marina C Leite and Carlos-Alberto Gongalves Abstract Background Inflammatory responses in brain are primarily mediated by microglia but growing evidence suggests a crucial importance of astrocytes. S100B a calcium-binding protein secreted by astrocytes has properties of a neurotrophic or an inflammatory cytokine. However it is not known whether primary signals occurring during induction of an inflammatory response . lipopolysaccharide LPS directly modulate S100B. Methods In this work we evaluated whether S100B levels in cerebrospinal fluid CSF and serum of Wistar rats are affected by LPS administered by intraperitoneal IP or intracerebroventricular ICV injection as well as whether primary astrocyte cultures respond directly to lipopolysaccharide. Results Our data suggest that S100B secretion in brain tissue is stimulated rapidly and persistently for at least 24 h by ICV LPS administration. This increase in CSF S100B was transient when LPS was IP administered. In contrast to these S100B results we observed an increase in in TNFa levels in serum but not in CSF after IP administration of LPS. In isolated astrocytes and in acute hippocampal slices we observed a direct stimulation of S100B secretion by LPS at a concentration of 10 pg mL. An involvement of TLR4 was confirmed by use of specific inhibitors. However lower levels of LPS in astrocyte cultures were able to induce a decrease in S100B secretion after 24 h without significant change in intracellular content of S100B. In addition after 24 h exposure to LPS we observed a decrease in astrocytic glutathione and an increase .