Project description:Objectives How HLA-B27 contributes towards arthritis susceptibility is still unclear, but effects on the response to bacteria unrelated to the classical antigen presenting role of B27 have been suggested. This study investigated whether HLA-B27 modulates the innate response to LPS, a component shared between all Gram –ve bacteria that can trigger reactive arthritis. Methods Pools of U937 transfectants expressing either HLA-B27, HLA-A2, or the expression plasmid alone were differentiated with PMA and stimulated with LPS. Supernatants were analysed for TNF-alpha secretion and the gene expression profiles of unstimulated and LPS stimulated cells were determined by microarray analysis. Changes in gene expression that are indicative of an unfolded protein response were also analysed by quantitative PCR. Results TNF-alpha secretion, a biological marker of the inflammatory response to LPS, was not significantly different between U937-B27 and U937-control. No differences in gene expression between unstimulated U937- B27 and U937-control lines were detected. Both U937-control and U937-B27 exhibited a stereotypic response to LPS. Only 1 gene, OAS2, was differentially expressed by these cell lines, and this was confirmed by quantitative PCR. Analysis of XBP-1 splicing suggested that a small increase in the unfolded protein response is induced following LPS stimulation, but this increase was seen in all transfectants. Conclusions The expression of B27 does not profoundly alter gene expression following LPS stimulation. Therefore, additional signals, such as those provided by cytokines or intracellular infection, may be required to reveal any influence of B27 expression on the inflammatory response. Keywords: antigen response
Project description:HLA-B27-associated inflammatory diseases remains one of the strongest HLA-disease known to date. HLA-B27-associated acute anterior uveitis has wide-ranging medical significance due to its ocular, systemic, immunologic, and genetic features. To investigate the genes and signalling pathways located upstream of the inflammatory processes in HLA-B27-associated acute anterior uveitis will help to know the mechanism of this disease. HLA-B27-positive and -negative monocytes isolated from human peripheral blood were stimulated with Vibrio cholera lipopolysaccharide (LPS). Gene expression microarrays were used to identify the differentially expressed genes, and they were analysed by a series of bioinformatics-based techniques. Gene expression microarray analysis revealed marked differences between B27-positive monocytes in the genes that are upregulated in response to LPS stimulation. Gene Ontology enrichment (GO) and pathway analysis indicated that genes participating in protein transport and folding were essential to the inflammatory process. The LPS receptor, TLR4, induced the Toll-like receptor signalling pathway and pathways related to Vibrio cholerae infection, which are located upstream of the network and contribute to the overall response. Among the DE genes, PIK3CA, PIK3CB, AKT3, and MAPK1 may play critical roles in inflammation.Equivalent LPS stimulation induces a different response in HLA-B27-positive monocytes compared to monocytes lacking this HLA protein, suggesting that the TLR pathway is involved in the pathogenesis of HLA-B27-associated AAU. Blocking this pathway and other pathways by siRNA interference of candidate genes may contribute to the development of a treatment for this type of AAU.
Project description:HLA-B27-associated inflammatory diseases remains one of the strongest HLA-disease known to date. HLA-B27-associated acute anterior uveitis has wide-ranging medical significance due to its ocular, systemic, immunologic, and genetic features. To investigate the genes and signalling pathways located upstream of the inflammatory processes in HLA-B27-associated acute anterior uveitis will help to know the mechanism of this disease. HLA-B27-positive and -negative monocytes isolated from human peripheral blood were stimulated with Vibrio cholera lipopolysaccharide (LPS). Gene expression microarrays were used to identify the differentially expressed genes, and they were analysed by a series of bioinformatics-based techniques. Gene expression microarray analysis revealed marked differences between B27-positive monocytes in the genes that are upregulated in response to LPS stimulation. Gene Ontology enrichment (GO) and pathway analysis indicated that genes participating in protein transport and folding were essential to the inflammatory process. The LPS receptor, TLR4, induced the Toll-like receptor signalling pathway and pathways related to Vibrio cholerae infection, which are located upstream of the network and contribute to the overall response. Among the DE genes, PIK3CA, PIK3CB, AKT3, and MAPK1 may play critical roles in inflammation.Equivalent LPS stimulation induces a different response in HLA-B27-positive monocytes compared to monocytes lacking this HLA protein, suggesting that the TLR pathway is involved in the pathogenesis of HLA-B27-associated AAU. Blocking this pathway and other pathways by siRNA interference of candidate genes may contribute to the development of a treatment for this type of AAU. HLA-B27-positive monocytes isolated from human peripheral blood were stimulated with Vibrio cholera lipopolysaccharide (LPS) for 12 hours.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Beta-hydroxybutyrate (BHB) is a ketone body synthesized during fasting or strenuous exercise. Our previous study demonstrated that a cyclic ketogenic diet (KD), which induces BHB levels similar to fasting every other week, reduces midlife mortality and improves memory in aging mice. BHB actively regulates gene expression and inflammatory activation through non-energetic signaling pathways. Neither of these activities has been well-characterized in the brain and they may represent mechanisms by which BHB affects brain function during aging. First, we analyzed hepatic gene expression in an aging KD-treated mouse cohort using bulk RNA-seq. In addition to the downregulation of TOR pathway activity, cyclic KD reduces inflammatory gene expression in the liver. We observed via flow cytometry that KD also modulates age-related systemic T cell functions. Next, we investigated whether BHB affects brain cells transcriptionallyin vitro. Gene expression analysis in primary human brain cells (microglia, astrocytes, neurons) using RNA-seq shows that BHB causes a mild level of inflammation in all three cell types. However, BHB inhibits the more pronounced LPS-induced inflammatory gene activation in microglia. Furthermore, we confirmed that BHB similarly reduces LPS-induced inflammation in primary mouse microglia and bone marrow-derived macrophages (BMDMs). BHB is recognized as an inhibitor of histone deacetylase (HDAC), an inhibitor of NLRP3 inflammasome, and an agonist of the GPCR Hcar2. Nevertheless, in microglia, BHB's anti-inflammatory effects are independent of these known mechanisms. Finally, we examined the brain gene expression of 12-month-old male mice fed with one-week and one-year cyclic KD. While a one-week KD increases inflammatory signaling, a one-year cyclic KD reduces neuroinflammation induced by aging. In summary, our findings demonstrate that BHB mitigates the microglial response to inflammatory stimuli, like LPS, possibly leading to decreased chronic inflammation in the brain after long-term KD treatment in aging mice.
Project description:Asthma is a chronic inflammatory airway disease characterized by airway inflammation and remodeling. The role of 15-oxo-5Z,8Z,11Z,13E-eicosatetraenoic acid (15-oxoETE), a 15-HETE metabolite catalyzed by 15-prostaglandin dehydrogenase (15-PGDH), has been relatively unexplored in asthma. In this study, we used RNA-seq to explore the effect of 15-KETE on the transcriptome of airway epithelial cells, aiming to identify its potential downstream targets and mechanisms of action.