Project description:Inflammasome-activated cells undergo an inflammatory cell death associated with the release of potent pro-inflammatory cytokines and poorly characterized extracellular vesicles (EVs). Since inflammasome-induced EVs could signal inflammasome pathway activation in patients with chronic inflammation and modulate bystander cell activation, we performed a systems analysis of the RNA content and function of two EV classes. Therefore, PMA-differentiated THP-1 macrophages were either stimulated with inflammasome activators or TLR ligands and subsequently differently sized EVs (10K and SEC EVs) were isolated from the tissue culture supernatant. The RNA contained within EV preparations was extracted and subjected to the Clariom D microarray. Web link to Clariom D chip: https://www.thermofisher.com/order/catalog/product/902925?de&en#/902925?de&en
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:Inflammasome, activated by pathogen-derived and host-derived danger signals, constitutes a multimolecular signaling complex that serves as a platform for caspase-1 (CASP1) activation and interleukin-1beta (IL1B) maturation. The activation of NLRP3 inflammasome requires two-step signals. The first “priming” signal (Signal 1) enhances gene expression of inflammasome components. The second “activation” signal (Signal 2) promotes the assembly of inflammasome components. Deregulated activation of NLRP3 inflammasome contributes to the pathological processes of Alzheimer’s disease (AD) and multiple sclerosis (MS). However, at present, the precise mechanism regulating NLRP3 inflammasome activation and deactivation remains largely unknown. By genome-wide gene expression profiling, we studied the molecular network of NLRP3 inflammasome activation-responsive genes in a human monocyte cell line THP-1 sequentially given two-step signals. We identified the set of 83 NLRP3 inflammasome activation-responsive genes. Among them, we found the NR4A nuclear receptor family NR4A1, NR4A2, and NR4A3, the EGR family EGR1, EGR2, and EGR3, the IkappaB family NFKBIZ, NFKBID, and NFKBIA as a key group of the genes that possibly constitute a negative feedback loop for shutting down inflammation following NLRP3 inflammasome activation. By molecular network analysis, we identified a complex network of NLRP3 inflammasome activation-responsive genes involved in cellular development and death, and immune and inflammatory responses, where transcription factors AP-1, NR4A, and EGR serve as a hub. Thus, NLRP3 inflammasome activation-responsive genes constitute the molecular network composed of a set of negative feedback regulators for prompt resolution of inflammation. To load the Signal 1 (S1), THP-1 cells were incubated for 3 hours in the culture medium with or without inclusion of 0.2 microgram/ml lipopolysaccharide (LPS). To load the Signal 2 (S2), they were incubated further for 2 hours in the culture medium with inclusion of 10 microM nigericin sodium salt dissolved in ethanol or the equal v/v% concentration of ethanol (vehicle), followed by processing for microarray analysis on Human Gene 1.0 ST Array (Affymetrix).
Project description:Inflammasome, activated by pathogen-derived and host-derived danger signals, constitutes a multimolecular signaling complex that serves as a platform for caspase-1 (CASP1) activation and interleukin-1beta (IL1B) maturation. The activation of NLRP3 inflammasome requires two-step signals. The first “priming” signal (Signal 1) enhances gene expression of inflammasome components. The second “activation” signal (Signal 2) promotes the assembly of inflammasome components. Deregulated activation of NLRP3 inflammasome contributes to the pathological processes of Alzheimer’s disease (AD) and multiple sclerosis (MS). However, at present, the precise mechanism regulating NLRP3 inflammasome activation and deactivation remains largely unknown. By genome-wide gene expression profiling, we studied the molecular network of NLRP3 inflammasome activation-responsive genes in a human monocyte cell line THP-1 sequentially given two-step signals. We identified the set of 83 NLRP3 inflammasome activation-responsive genes. Among them, we found the NR4A nuclear receptor family NR4A1, NR4A2, and NR4A3, the EGR family EGR1, EGR2, and EGR3, the IkappaB family NFKBIZ, NFKBID, and NFKBIA as a key group of the genes that possibly constitute a negative feedback loop for shutting down inflammation following NLRP3 inflammasome activation. By molecular network analysis, we identified a complex network of NLRP3 inflammasome activation-responsive genes involved in cellular development and death, and immune and inflammatory responses, where transcription factors AP-1, NR4A, and EGR serve as a hub. Thus, NLRP3 inflammasome activation-responsive genes constitute the molecular network composed of a set of negative feedback regulators for prompt resolution of inflammation.
Project description:Vascular calcification often occurs with osteoporosis, a contradictory association called “calcification paradox”. We find that extracellular vesicles (EVs) released from aged bone matrix (AB-EVs) during bone resorption favor adipogenesis rather than osteogenesis of BMSCs and augment calcification of vascular smooth muscle cells (VSMCs). Intravenous or intramedullary injection of AB-EVs promotes bone-fat imbalance and exacerbates Vitamin D3 (VD3)-induced vascular calcification in young or old mice. To explore the involvement of miRNAs in the AB-EVs-induced promotion of adipocyte formation and vascular calcification, the Agilent miRNA array was conducted to compare the miRNA expression profiles in AB-EVs and YB-EVs from mouse bone specimens. Our study uncovers the role of AB-EVs as a messenger for calcification paradox by transferring functional miRNAs.
Project description:Extracellular vesicles (EVs) are lipid-membrane bound vesicles that can be beneficial or detrimental depending on the content they carry. As epithelial cells are the first line of defense against harmful particles, this work explored the role of COPD bronchial epithelial cell-derived EVs (CepEVs) in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). RNA sequencing of macrophages stimulated with CepEVs revealed the upregulation of various inflammasome-related genes, alongside significant IL-1b and IL-18 release, which could be attenuated with caspase-1 or NLRP3 inhibition. The proteome of CepEVs was also assessed, which highlighted a significant reduction in antibacterial proteins compared to healthy EVs (HepEVs). When functionally assessed in NTHi infection of THP-1 cells, pre-incubation with HepEVs stimulated NTHi clearance and reduced pro-inflammatory cytokine release by macrophages, which was reduced in CepEV-stimulated cells. This study shows for the first time that CepEVs are able to both prime and activate the inflammasome in healthy macrophages, and highlights EV-induced inflammasome inhibition as a potential therapeutic target for the dysregulated inflammation seen in COPD. Alongside the inflammasome, we were also able to show that CepEVs are deficient for multiple antibacterial proteins, and that one or more of these proteins are essential in mounting an immune response against NTHi in macrophages. This finding contributes to a potential therapeutic pipeline through the supplementation of the depleted antibacterial proteins in CepEVs, allowing for efficient bacterial clearance and reduced consequential inflammatory burden. CepEV co-incubation resulted in a persistent state of inflammation and infection. Both sets of findings contribute to the overall knowledge of COPD pathogenesis, and highlight epithelial EVs as key players in the propagation of inflammation and susceptibility to infection.
Project description:To identify specific miRNAs carried by hUCMSC-EVs, and explore their crucial roles in hUCMSC-EV-based improvement of inflammatory diseases.