Comment[ArrayExpressAccession] E-MTAB-1770 MAGE-TAB Version 1.1 Investigation Title Repeated systemic challenge with lipopolysaccharides induces dopaminergic neurodegeneration in the brain by activation of the complement-phagosome pathway Comment[Submitted Name] Repeated systemic challenge with lipopolysaccharides induces dopaminergic neurodegeneration in the brain by activation of the complement-phagosome pathway Experiment Description Systemic inflammatory reactions mediated by chronic infections activate microglia in the central nervous system (CNS) and have been postulated to exacerbate neurodegenerative diseases. We now demonstrate in vivo that repeated systemic challenge of mice with bacterial lipopolysaccharides (LPS) maintains an elevated microglial inflammatory response and triggers neurodegeneration. Repeated chronic intraperitoneal application of LPS over four consecutive days induced loss of dopaminergic neurons in the substantia nigra, a process that was accompanied by decreased levels of dopamine in the striatum. In contrast, total cumulative LPS dose given intraperitoneally within a single acute application did not induce a decrease in dopamine levels nor neurodegeneration. Mice that received repeated systemic LPS application showed increased microglial activation, elevated production of proinflammatory cytokines and activation of the classical complement and its associated phagosome pathway in the brain. Loss of dopaminergic neurons induced by repeated systemic LPS application was rescued in complement C3 deficient mice, confirming an involvement of the complement system in neurodegeneration. Thus, our data demonstrate that repeated systemic exposure to bacterial LPS induces a microglial phagosomal inflammatory response, leading to complement-dependent damage of dopaminergic neurons. Experimental Design compound treatment design dose response design in_vivo_design replicate design co-expression_design Comment[AEExperimentType] transcription profiling by array Comment[AEExperimentDisplayName] Transcription profiling by array of brain samples isolated from mice treated with a cumulative lipopolysaccharides (LPS) dose or LPS over four consecutive days Experimental Factor Name dose compound treatment Experimental Factor Type dose compound treatment Quality Control Type biological replicate Quality Control Term Source REF EFO Public Release Date 2014-07-11 Person Last Name Muller Person First Name Arnaud Person Mid Initials Person Email arnaud.muller@crp-sante.lu Person Phone 35226970283 Person Address Luxembourg, Luxembourg Person Affiliation CRP-Sante Person Roles submitter PubMed ID 24948809 Publication DOI 10.1523/JNEUROSCI.5002-13.2014 Publication Author List Bodea LG, Wang Y, Linnartz-Gerlach B, Kopatz J, Sinkkonen L, Musgrove R, Kaoma T, Muller A, Vallar L, Di Monte DA, Balling R, Neumann H Publication Title Neurodegeneration by activation of the microglial complement-phagosome pathway Publication Status published Protocol Name P-MTAB-33780 P-MTAB-33781 P-MTAB-33782 P-MTAB-33783 Protocol Type growth protocol treatment protocol nucleic acid extraction protocol nucleic acid labeling protocol Protocol Description C57BL/6J mice were obtained from CharlesRiver (Germany) and housed in specific pathogen free environment, with water and food ad libitum. Three months old male mice were intraperitoneally injected with 100 uL 1x PBS (LifeTechnologies) containing lipopolysaccharide (LPS, Enzo LifeSciences) or with 100 uL PBS vehicle as control. For the single treatment, animals were injected once with 4 ug LPS per gram body weight or vehicle and sacrificed in the 5th or 19th day since the start of the treatment. For the repeated treatment, 4 injections in consecutive days, with 1 ug LPS per gram body weight or vehicle were performed and the mice were sacrificed in the 5th or 19th day since the start of the treatment. Brain tissue was collected and homogenized. Total RNA was extracted using the phenol-clorophorm chloroform method (Chomczynski, P. & Sacchi, N. (1987). Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal. Biochem. 162: 156-159). Total RNA integrity and purity were assessed using the Agilent 2100 Bioanalyzer (Paolo Alto, USA) and RNA 6000 Nano LabChip kits. Only good quality RNA with no sign of contamination and degradation (RIN > 9) were used further processed. cDNA was fragmented, labeled and hybridized onto Affymetrix GeneChip Mouse Gene 1.0 ST Arrays according to the Ambion WT Expression kit for Affymetrix GeneChip Whole Transcript (WT) Expression Array Protocol (P/N 4425209 Rev.B 05/2009) and GeneChip WT Terminal Labeling and Hybridization User Manual for use with the Ambion WT Expression kit (P/N 702808 Rev.6) (Santa Clara, USA). Protocol Term Source REF EFO EFO EFO EFO Term Source Name EFO ArrayExpress Term Source File http://www.ebi.ac.uk/efo http://www.ebi.ac.uk/arrayexpress SDRF File E-MTAB-1770.sdrf.txt