Project description:The EP4 receptor is known to mediate the protective effect of prostaglandin (PG) E2 in the gastrointestinal tract; however, the exact role of epithelial EP4 in intestinal pathophysiology remains unknown. We investigated the role of epithelial EP4 in maintaining colonic homeostasis by characterizing the intestinal epithelial cell-specific EP4 knockout (EP4 cKO) mice. We found a significant enrichment of genes involved in apoptosis-related pathways in the EP4 cKO colons. Moreover, inflammation-associated pathways were highly enriched and revealed more than half of the top 20 pathways related to immune response.
Project description:To examine the effects of prostaglandin E2/EP4 signaling on bovine CD4+ T cells, CD4+ T cells were isolated from bovine peripheral blood mononuclear cells. Isolated CD4+ T cells were cultured with anti-bovine CD3 and anti-bovine CD28 monoclonal antibodies. Following 18 hours of incubation, the cultures were incubated with EP4 agonist or DMSO, a vehicle control for 4 hours. After incubation, the cells were collected and microarray analysis was performed.
Project description:Changes of genome-wide mRNA transcription levels of human ciliary smooth muscle (hCSM) cells were determined by treating hCSM cells in culture with 200 nM of either an prostaglandin E2 receptor subtype EP2 or subtype EP4 selective agonist for 6 hours in comparison to untreated controls. This was followed by competitive hybridization of fluorescent Cy3 or Cy5 labeled cRNA probes derived from the treated versus untreated control total RNA samples onto an Agilent Human Whole Genome Expression oligonucleotide microarray. Log 2 (LN) of the intra-slide ratios (RATIO, PRE_VALUE) of treated versus untreated samples was reported as VALUE in the sample files. Keywords: prostaglandin E2 receptor agonists, subtype EP2, subtype EP4, hCSM
Project description:A persistent and non-resolving inflammatory response to accumulating Aβ peptide species is a cardinal feature in the development of Alzheimer's disease (AD). In response to accumulating Aβ peptide species, microglia, the innate immune cells of the brain, generate a toxic inflammatory response that accelerates synaptic and neuronal injury. Many pro-inflammatory signaling pathways are linked to progression of neurodegeneration. However, endogenous anti-inflammatory pathways capable of suppressing Aβ-induced inflammation represent a relatively unexplored area. Here we hypothesized that signaling through the prostaglandin-E2 (PGE2) EP4 receptor potently suppresses microglial inflammatory responses to Aβ42 peptides. In cultured microglial cells, EP4 stimulation attenuated levels of Aβ42-induced inflammatory factors and potentiated phagocytosis of Aβ42. Microarray analysis was performed and demonstrated that EP4 stimulation broadly opposed Aβ42-driven gene expression changes in microglia, with enrichment for targets of IRF1, IRF7, and NF-κB transcription factors.
Project description:Paracrine signals play pivotal roles in organ homeostasis. Mesenchymal stromal cells (MSCs) play a key role in regulating epithelium homeostasis in the intestine while their paracrine effects are poorly characterized. Here, we identified prostaglandin E2 (PGE2) secreted by cyclooxygenase (COX)-expressing MSCs as a vital factor to maintain the intestinal mucosal barrier. We found that MSCs-induced organoid swelling through paracrine effect in vitro, a process due to enhanced water adsorption and is mediated by the COX-PGE2-EP4 axis. To further explore the regulatory effect of this axis on the intestinal epithelial barrier in vivo, we established the conditional knockout mouse model to specifically delete COX in MSCs and found that PGE2 reduction downregulated the gene Muc2 and induced a gastric metaplasia-like phenotype. Moreover, PGE2 defects increased the susceptibility of intestinal epithelium to colitis. Our study uncovers the paracrine signaling of COX-expressing MSCs in intestinal mucosal barrier maintenance, providing a basis for understanding the role of mesenchymal cells in the psychophysiology function of the intestine.