PARP1 and Salmonella. Mus musculus

BACKGROUND & AIMS: The immune system comprises an innate and an adaptive immune response to combat pathogenic agents. The human enteropathogen Salmonella enterica serovar Typhimurium invades the intestinal mucosa and triggers an early innate pro-inflammatory host gene response, which results in diarrheal disease. Several host factors are involved in the acute early response to Salmonella infection. Transcription factors and transcription co-regulators have an especially important function, because they are required for the expression and synthesis of pro-inflammatory cytokines, chemokines and adhesion molecules. A central transcription factor involved in inflammation is NF-κB, which requires the nuclear protein PARP1 as co-factor for the expression of some of its target genes. Here, we investigated the role of PARP1 during Salmonella infection using a mouse model for Salmonella-induced colitis. METHODS: To study enterocolitis by Salmonella Typhimurium, an established mouse model system, which relies on streptomycin-pretreatment prior to Salmonella infection, was employed. Histopathologic signs of inflammation and cecum colonization at various time-points after infection of wild type and PARP1 knockout mice were analyzed. PARP1 expression in the gut mucosa was studied by quantitative RT-PCR, Western blot and immunofluorescence. Gene expression profiles of infected and control infected mice in the wild type or PARP1 knockout background were obtained by whole mouse genome arrays and confirmed by quantitative RT-PCR. Overall design: 2 genotypes (wildtype, PARP1 knockout), 2 treatments (Salmonella SB300 infection, Salmonella SB161 control infection), 2 time-points (6h, 10h). 2-3 replicates/condition.