Project description:Streptococcus (S.) pneumoniae is the most frequently isolated causative pathogen community-acquired pneumonia, a leading cause of mortality worldwide. We investigated the role of the inflammasome sensor NLRP3 and the inflammasome adapter ASC during S. pneumoniae pneumonia. Detailed analysis of the early inflammatory response in the lung by whole genome transcriptional profiling, we identified several mediators that were differentially expressed between Nlrp3-/- and Asc-/ - mice. WT, Nlrp3- and Asc-deficient mice were intranasally inocculated with Streptococcus pneumoniae D39 and ATCC6303 both at high and low dose. Lung homogenates were harvested and gene expression profiling was performed.
Project description:Streptococcus (S.) pneumoniae is the most frequently isolated causative pathogen community-acquired pneumonia, a leading cause of mortality worldwide. We investigated the role of the inflammasome sensor NLRP3 and the inflammasome adapter ASC during S. pneumoniae pneumonia. Detailed analysis of the early inflammatory response in the lung by whole genome transcriptional profiling, we identified several mediators that were differentially expressed between Nlrp3-/- and Asc-/ - mice.
Project description:Aging is the major risk factor for cardiovascular and many other chronic diseases. During this natural process, many alterations occur in the organism which are associated with progressive impairment of several metabolic pathways related to body composition, insulin resistance, mitochondrial and autophagy dysfunction and inflammation. Recently, the role of NLRP3 inflammasome has been studied in cardiovascular diseases showing its implication in the pathological progression of atherosclerosis, heart failure, and hypertension. However, the role of the NLRP3 inflammasome in cardiac aging has been less well studied. Herein, we investigate the molecular mechanisms by which NLRP3 inhibition may attenuate cardiac aging. Ablation of NLRP3 inflammasome increased lifespan and protected mice from age-related increased insulin sensitivity, reduced IGF-1 and leptin/adiponectin ratio levels, and reduced cardiac damage with protection of the prolongation of age–dependent PR interval, which is associated with atrial fibrillation by cardiovascular aging. Furthermore, old NLRP3 KO mice showed an inhibition of PI3K/AKT/mTOR pathway and autophagy improvement compared with old wild type mice and preserved Nampt-mediated NAD+ levels with increased SIRT1 protein expression. These findings suggest that suppression of NLRP3 prevented many age-associated changes in the heart and preserved cardiac function of aged mice.
Project description:Inflammasome activation in macrophages induces the release of EVs, however, the effect of these inflammasome-induced EVs on recipient cells is poorly characterized. To characterize the effect EVs released upon LPS + nigericin stimulation, we performed 3' sequencing on the recipient cells (NLRP3 KO THP-1 macrophages and NLRP3 KO THP-1 macrophages that have been reconstituted with NLRP3 to resemble the WT). As controls, RNA isolated from EVs themselves or LPS- or nigericin-treated cells were subjected to 3' sequencing.
Project description:Immune response genes are disproportionately polymorphic in humans and mice, with heterogeneity amongst loci driving strain specific host defense responses. The inadvertent retention of polymorphic loci can confound results, lead to false conclusions, and delay scientific progress. By combining RNAseq and variant calling analyses, we identify a substantial region of 129S genome, including the highly polymorphic Nlrp1 locus proximal to Nlrp3, in one of the most commonly used mouse models of NLRP3 deficiency. We show that 129S NLRP1 can be tolerated at higher expression levels at steady-state, however this sensitizes Nlrp3-/- mice to NLRP1 inflammasome activation. Furthermore, the presence of 129S genome leads to altered gene and protein regulation across multiple cell-types, including of the key tissue-resident macrophage marker, TIM4. In order to resolve NLRP3 dependent phenotypes we validate a conditional Nlrp3 allele enabling temporal and cell-type specific control of NLRP3 deletion. Our study provides an accessible strategy to identify functionally relevant SNPs and assess genomic contamination in transgenic mice, to allow for unambiguous attribution of phenotypes to the target gene.
Project description:We report that the NLRP3 protein is able to interact with chromatin during Th2 differentiation Examination of the interaction of NLRP3 and transcription factors during early stages of Th2 CD4+ T cell differentiation
