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: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: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: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:While the role of prostaglandin E2 (PGE2) in promoting malignant progression is well-established, how to optimally block the activity of PGE2 signaling remains to be demonstrated. Clinical trials with prostaglandin pathway targeted agents have shown activity but without sufficient significance or dose-limiting toxicities that have prevented approval. PGE2 signals through four receptors (EP1-4) to modulate tumor progression. EP2 and EP4 signaling exacerbates tumor pathology and is immunosuppressive through potentiating cAMP production. EP1 and EP3 signaling has the opposite effect through increasing IP3 and decreasing cAMP. Using available small molecule antagonists of single EP receptors, the COX-2 inhibitor celecoxib, or a novel dual EP2/EP4 antagonist generated in this investigation, we tested which approach to block PGE2 signaling optimally restored immunologic activity in mouse and human immune cells and antitumor activity in syngeneic, spontaneous and xenograft tumor models. We found that dual antagonism of EP2 and EP4 together significantly enhanced the activation of PGE2-suppressed mouse and human monocytes and CD8+ T cells in vitro as compared to single EP antagonists. CD8+ T cell activation was dampened by single EP1 and EP3 antagonists. Dual EP2/EP4 PGE2 receptor antagonists increased TME lymphocyte infiltration and significantly reduced disease burden in multiple tumor models, including in the adenomatous polyposis coli (APC)min+/- spontaneous colorectal tumor model, compared to celecoxib. These results support a hypothesis that redundancy of EP2 and EP4 receptor signaling necessitates a therapeutic strategy of dual blockade of EP2 and EP4. Here we describe TPST-1495, a first-in-class orally available small molecule dual EP2/EP4 antagonist.